Making bows from boards is fun and effective, but what's even cooler is making a bow from a stave (an unrefined piece of wood split from a log). After I got into bow building last year I knew I had to try making bows from staves, so I went looking for a tree to cut down. Not just any tree will make a good bow. The tree needs to be hardwood, and it needs to be nice and straight. I didn't have access to any of the common bow wood trees (osage, yew, locust, ash, hard maple, oak, etc.) so I had to make do. The available trees were various conifers (spruce, pine, etc.), soft maple, and yellow birch. Coniferous trees and soft maple are really not good bow woods, so yellow birch was the only option. It's not commonly used for bows, but I read that it should work okay, so I went ahead and took down a nice straight tree about 5" in diameter.

Note: I just figured out a few days ago that I do have access to hard maple; oh well, next time.

I got two good 7' sections, and then split them in half and debarked them. I must say that splitting a log in half using axes and sledgehammers feels extremely manly and I thoroughly enjoyed it.

Note: I really should be using a splitting maul not a falling axe, but this was all I had at the time.

It's really amazing how straight a log will split.

The best way to split is to alternate between a few wedges as you move down the log.

After splitting the logs I set them aside and forgot about them (you need to let wood dry for quite a while before you can work on it). Fast forward 8 months and I've got free time, motivation, and some fairly dry staves to work on. I acquired a draw knife, which is really the ultimate tool for roughing out bows from staves, and got to work. The drawknife I bought was a cheap TimberTuff brand model, which has a poorly sharpened and strange shaped blade. However, it still works impressively well, and if I put in the time and effort with a file I could definitely even out the blade and make it a lot better. After roughing out the shape of the bow I gave it another week or two to dry, since 8 months isn't quite long enough. The bow was quite thin at this point so it dried quickly and seemed totally fine after this extra week of drying.

For this bow I wanted to play it safe, so I went for a 66" flatbow with a 6" stiff handle. It's 2" from the fades to mid limb, and tapers to 1/2" at the tips. I cut simple side nocks and just used the original thickness of the stave for the stiff handle. No tip overlays, no backing, and no handle lamination for this bow. I also decided not to do any heat bending, since the tips were lined up alright with the handle, albeit in a slightly crooked and propeller twisted manner.

I did all the rough tillering with the draw knife and then finished up with a card scraper. This was a great combination; I'm really starting to prefer bladed tools over sanding.

The tillering went really smoothly and I didn't run into any major issues.

The bow came out to about 40# at 28" and shoots pretty fast and hard. I finished it with some Danish oil and that was that. I don't think I'll wrap the handle since it's fairly comfortable as is and the darker heartwood at the top of the handle looks nice.

The back of the bow still has a little bit of cambium on it, which gives it a cool natural look.

Now for something new; a video of the bow in action! Try to ignore the funny faces I make when I'm trying to aim.

Builing this bow was a ton of fun, and the result was very satisfying. There's something special about creating something completely from scratch. It's cool to look back on the process, from carrying logs out of the forest to putting the finishing touches on a functional bow. Now that I've seen success and proved to myself that yellow birch is an acceptable bow wood, I'll certainly be trying some more interesting bow designs, so look forward to that!

Ever since my brother was a wee boy he wanted a CNC machine. While I was climbing trees, playing tag, and goofing around, he was tinkering with electronics and salvaging parts from old scanners. In fact, he wrote an instructable on how to build a stepper controller from recycled parts 7 years ago when he was just a kid (side note, that thing got over 300 000 hits!). Needless to say, a CNC machine was his childhood dream.

Over the years he made a few attempts, which were impressive given the materials he used and the fact that he was just a kid working on it by himself. However, they weren't exactly functional. Fast forward 5 or 6 years and I decide that this CNC stuff might actually be pretty cool. So we teamed up and built a CNC machine out of MDF. This machine moved and made a few cuts in foam, but it was admittedly pretty mediocre.

At this point we said "forget it" and did what anyone else would do; we built a 3D printer instead. And... The 3D printer (a Reprap Rostock) actually worked really well!

Jump to the next year and we've gotten a lot better at building things, I know how to use 3D modelling software, and we're ready to give this CNC thing another go.

This time we opted to use metal and plastic (no MDF except for the bed). The main frame is constructed from aluminum angle, and all of the motor mounts and rod guides are 3D printed with PLA. The linear rail system consists of 3D printed PLA bushings sliding on 1/2" drill rod. This is super cheap and works great in this setting.

These older photos give a clear view of the frame design. The spindle you see in the photos is just a dc motor with a collet attachment. These spindles are useless for anything other than light engraving. A rotary tool is a much better choice.

In the final assembly corner joint reinforcements are installed:

We are running large Nema 17 steppers on the X and Y axes with a 3.75:1 belt reduction.

The Z axis has a smaller Nema 17 stepper with a multi-start 8mm pitch lead screw. The X and Y axes are belt driven with 6mm GT2 belt. I'm quite happy with this design. The 3D printed parts provide accurate alignment and ease of construction, while the aluminum angle and drill rod provide rigidity and strength. Hannah Montana isn't the only one getting the best of both worlds.

The machine has a roughly 10"x10"x2" cutting area (x,y,z). A 2" Z axis doesn't seem like much, but when you're using a spindle with a 1/8" collet (a dremel in our case), you aren't going to find many bits that can cut much deeper than this anyway.

Traditional DIY CNC skeptics would probably suggest that unsupported rods, printed bushings, and printed brackets and fittings would lead to a uselessly flimsy CNC machine, but in fact the machine is more than sturdy enough. When it comes down to it, a machine is only as good as its weakest component. In our case the dremel or the steppers will stall out long before the rigidity of the frame becomes an issue. This machine won't be cutting metal or hogging through 1/2" of wood with a large cutter, but it wasn't designed for that. It works perfectly fine for milling circuit boards and cutting wood with a reasonable depth of cut.

The enclosure is constructed from pine and plywood with a sliding plexiglass door on the front and plexiglass windows on the sides. The enclosure works great and I can't imagine using the machine without it (sawdust everywhere!). We have a small shop vac hooked up to the head of the machine to keep the dust at bay while the machine is cutting.

Every CNC machine needs a big red stop button.

As for the electronics, we are using an Arduino mega with a ramps board. It is running a version of GRBL. We are currently controlling the machine with BCNC on the computer.

Now what you've all been waiting for... A video of the machine working!

As you can see, the cuts are very clean and precise.

I'm sure we'll make some more improvements over time (first up is a proper vacuum attachment), but I think it's safe to call this machine a success. We've named it the Rift because it fiercely (and very slowly), tears great divides into wood!

*Update: The files for the 3D printed parts are now available for download.

Click to Download

Here comes another longbow (can you tell I'm addicted?).
Given that I'm still a novice bowyer, I'm sticking to fairly simple designs. At the same time, I like to do something different with each bow, so I made this bow 6" shorter than my first two bows, and made the tips and handle fancier.

Now that I've done a few bows the process is becoming much more refined. This time I used a jig to cut the tapers, which turned out perfect.

I also got a card scraper, which has quickly become one of my favourite tools. It only cost $6 and it is awesome! It removes wood faster than sanding while leaving a nicer finish. It's perfect for fine tillering. My strategy now is to use a rasp until I'm getting close to being done tillering, then I switch to the scraper. By the time I'm done tillering with the scraper, all of the rasp marks are removed and there's hardly any finish work to be done.

For the handle I used a spindle sander, which allowed me to get better results than my previous bows and took about 1/10th of the time. Another amazing tool.

Other than those changes the process was similar to my previous bows, so I'll get right to stats and pictures.

The bow is 66" long, with a 6" stiff handle (including fades). It pulls about 45# at 28". It is 1.5" wide to mid limb, tapering to 1/2" nocks, which I later thinned to around 1/4". The bow is red oak with a random dark hardwood used as an accent on the tips and handle. The top layer of the tip overlays is bone, which I got from a dog toy. Bone is really hard, which makes it a great tip overlay, but it smells terrible when you cut or sand it. The bow is backed with paper as I've done in the past, but this time I used a decorative wrapping paper to give the bow some character.

Here are some shots of the handle being constructed:

And a shot of the bone overlay before shaping:

Most importantly, here's the finished bow:

And finally here's a full draw picture:

This picture is not quite straight so it throws things off a bit, but the tiller on this bow is decent. I think it's still too stiff near the handle, but not as bad as on my last bow. I'll try to improve that next time. As always, I had a ton of fun building this bow, and can't wait to build another!

Shortly after finishing my first bow (before I even test shot it), I began working on my second bow. For my second bow I decided to keep things simply and use the same layout as the first bow, but do some fancy stuff with the handle and tip overlays. The bow is 72" tip to tip, parallel to a bit less than mid-limb, and has an 8" stiff handle (including fades). It took about an inch and a half of set.

I start my board bows out by cutting the limb width tapers with a table saw and then using a power planer to do the thickness profile. With this bow the width tapers came out pretty messy (freehand table saw cutting is difficult, I've since made a jig that allows me to get perfect tapers). This forced me to plane the sides of the bow, which resulted in much more narrow limbs than originally intended. Right from the start, this bow bent a lot in the tips because they were so narrow and thin, which meant that I spent the whole tillering process working on the inner and mid limbs only. By the end of the process I managed to get a fairly even bend, if a little stiff in the inner portion of the limbs.

The funny thing about all of this is that my mistake forced me to make a better bow. The tips are around 1/4" wide, which is very narrow by most standards. I wouldn't have risked narrow tips on my second bow ever, but it turned out to be a good thing. This bow shoots quite fast with no hand shock thanks to the low mass of the outer limbs.

*Finger for Scale

The bow is about 40# at 28", and has a paper backing just like my first bow. The handle has three layers, and the tip overlays have 2 layers.

The alternating layers of different wood give a really nice contrast. I'm not sure what species the darker wood is, but it looks amazing. It has a really nice shine to it when oiled. The handle is bulb shaped, which turned out to be pretty comfortable.

No handle wrap because I don't want to cover up the nice looking wood. The arrow rest is 3D printed and bent to fit the bow using heat. The idea behind the design is the allow the use of arrows with vanes (shooting vanes off a shelf can cause inaccuracy because the vanes aren't flexible enough).

I'm not sure if the vane actually passes through the slot when the arrow is fired, but it seems to shoot fairly accurately.

This bow is paper backed like my first bow for some extra security and to add some more contrast. If you want to paper back a bow, I have a handy tutorial.

All in all I am very happy with this bow and feel that it is a significant improvement on my first, albeit not entirely intentional.

The tiller on this bow is quite good I think. If anything it might be a little bit whip tillered, mostly on the top limb.

Mainly I'm just happy that I've made it through two bows without breaking any! This bow has at least 500 shots through it at this point and looks as good as ever.

I've always wanted to learn more about internet connected systems (also known as “the internet of things”). My goal was to create a basic sensor network that could be expanded to a full home automation system. I chose to start with a simple temperature sensor and display. The sensor sits outside, and sends its temperature reading to an internet server over Wi-Fi. The display module connects to this server and displays the temperature. Since our display is internet connected, we can expand it to include other features, including getting a weather forecast for the next 3 days.

Both the display and the sensor are based off the ESP8266 microcontroller. This microcontroller is unique because in addition to its 32-bit processor, it includes a full wifi chipset. All of this comes at a cost of approximately three dollars, making it ideal for our sensor network. One of the interesting things about the ESP8266 is that it allows you to choose between several programming languages. In an effort to learn as much as I could about this microcontroller, I chose to use a different language for the sensor and the display module.

The sensor module uses a DS18b20 digital temperature sensor. This sensor communicates with the microcontroller over the “One Wire” protocol. The microcontroller on the sensor module runs an embedded operating system called NodeMCU. This operating system allows you to write programs in a language called LUA. Our program has 2 main steps. When the module first powers on, it connects to a pre coded wifi network. Once the connection has been established, the microcontroller reads the temperature from the sensor. It then sends this value to the server using an HTTP GET request. The server stores this data, where it can be sent to other modules in the network.

The server is a simple program written in NodeJS, and running on a VPS from DigitalOcean. It listens for requests from the sensor, and logs the data for later use.

The display module uses an small graphic OLED display to show information. For this module, I chose to use a more traditional language, based on the Arduino version of C. The program for the display module is based on the work of GitHub user ENTER GITHUB NAME HERE. Their code provided an excellent base, allowing the display to access weather forecast information provided by Weather Underground. This code was extended to also connect to the server and download real time temperature data from the sensor module.

Both modules are housed in attractive 3d printed cases, designed by my brother.

The case was originally designed as one piece, but it was very difficult to fit the electronics into the case securely, so we decided to switch to a two piece design. The circuit board is mounted into a frame which holds it securely. This skeleton frame is then mounted into the box with two screws. This makes everything much easier to work with, and more solid. This is especially important for the USB port on the back, which has a fair amount of force exerted on it when you plug a cord into it. A piece of acrylic is used as the front panel of the enclosure to give it a nice sleek look. The acrylic is much easier to mount because of the inner frame.

Here you see the electronics mounted in the inner frame with the acrylic attached to the front.
And here is how the inner frame and enclosure fit together.
Overall it's a pretty classy looking prototype!

My father and I recently decided that we wanted a router table. Rather than buying a full unit which would be expensive and take up precious shop space, we decided to build an insert that would mount to a table saw. I won't go into the details of the table build (perhaps in another post), but want to share the vacuum mount I made for the table.
In order to accommodate the router, an extension had to be made for the table saw fence (the bit needs to be able to go into a slot in the fence). My father constructed the fence attachment out of plywood and ground down some bolts to go into the t-slot on the table saw fence. Above the slot for the router, an opening was made so that chips and sawdust could escape.
This stopped the bit from getting clogged, but made a big mess; obviously a vacuum attachment was needed! Yikes!

This seemed like a perfect 3D printing task, so I went ahead and designed a simple bracket that snaps into the slot on the fence and has a receiver for the vacuum hose. It is tapered and contoured on the inside to redirect the dust into the vacuum hose. All of the interfaces are simply friction fit, which proves to be easy and effective.
The inside is a little bit messy from support material, but it's only cosmetic.
As you can see, it looks quite nice mounted to the fence!

There's not much to it, but it sure works great. The suction is excellent and it completely removes all of the sawdust, making the router table much nicer to use.

Here are a few action shots. I promise the router was actually on for this (it's amazing how well a flash can freeze a fast moving object, eh?).
I'd post an after shot of the table but it looks exactly the same as before, no dust!

This is a great example of why it is handy to have a 3D printer, and shows that they can do more than make trinkets. I was able to make this attachment fit our vacuum and fence perfectly, and didn't have to buy any special adapters. A custom fitting for less than a dollar and an hour of work? That's a pretty great deal!

It's safe to say that 3D printing has moved past trinkets and toys and onto more interesting things. From large scale objects like cars to functional 3D printed motors, it seems that almost anything can be 3D printed. In order to build these huge or complicated items, one must work around the limitations of 3D printing and make careful design choices. A key shortcoming of 3D printing is the strength of the parts. With this in mind, I pose the question: is it possible to 3D print a powerful full sized crossbow?

Yes, in fact, it is.

Materials

This crossbow is made mainly out of 3D printed parts, but some hardware and other materials are also necessary. A few lengths of 1/2" and 3/4" aluminum tube were used to form the channel for the arrow (or bolt if you prefer). The prod (bow) is made of a piece of 3/4" PVC with two lengths of fiberglass driveway marker inside, and has a draw weight of 85 pounds at 20".
Various bolts and nuts were also used. Everything else is printed in PLA.

Design/Features

Obviously, there are very high levels of stress involved in a crossbow. Combine this with the fact that plastic, especially when 3D printed, is not especially durable, and you have a bit of a design challenge. To prevent the crossbow from breaking, the majority of the stress is placed on the aluminum tubes, which are plenty strong. Also, all of the printed parts are printed in such a way that the forces won't separate the layers.

The trigger mechanism is a three piece system inspired by this video.
Obviously the part that holds the string is taking the most force. By bolting this piece through the aluminum tube, all of the stress from the bow is placed on the tubes, and not the plastic trigger housing.
The other trigger pieces also need to be strong, but they are only under a direct compressive force, and don't place a shearing force on the housing. All connections between the aluminum and the plastic are bolted right through the tube for maximum strength.

The bow has a fairly simple shoulder stock that offers a bit of length adjustment.
There is also a Picatinny rail on the top of the handle and trigger housing to allow for a scope or other sighting device.

Testing

This issue was fixed by securing the bow more solidly to the stock and by adding a spacer which prevents the string from leaving the trigger mechanism without hitting the bolt (you can see this spacer taped on in the video). Once I made these fixes it worked! Mind you, the trigger is a bit hard to pull (this is due to poor leverage and less than ideal engagement angles), but overall it is a success. I consider this bow to be more of a test than a useful device, but as you can see in the test video, it definitely works! While the 85 pound draw weight is lower than most crossbows, the extra long 20" draw length gives it some extra power, and it hits pretty hard. After about 50-60 shots the trigger system has become less reliable, causing the bow to only cock about 50% of the time.

Stay tuned for my next crossbow, which also features a 3D printed trigger mechanism, but is much more reliable and has a far lighter trigger pull.

Note: The DIY Dudes do not condone any form of violence against people, animals or anything else. The crossbow built in this post is a proof of concept done in the name of science. We take no responsibility for any injuries or property damage resulting from attempts to recreate the subject of this post.

An Archer is only as good as his arrows, and making a good arrow is easier said than done. An important part of arrows is the fletching; it plays a key role in making the arrow fly straight. Installing the fletching can be tricky, which is why fletching jigs were invented. A fletching jig holds the feathers or vanes in the correct position as you attach them to the arrow shaft.
There are lots of commercial fletching jigs available, but they can be fairly pricey. They certainly don't cost $1 like my jig did!

The Design

I wanted this jig to be easy to print and easy to use, so I decided to build the folding arm variety of fletching jig. It's quite simple; the nock clips into the base and the arms fold up and hold the fletching in the correct position. For convenience, the arm that positions the cock feather is printed in a different colour. It took a few iterations to settle on a design I liked, but I'm fairly happy with the current design.
Here's the final jig next to some of the previous arm designs. As you can see it sometimes takes a few attempts to get things perfect. That's the beauty of rapid prototyping.
The first version was designed to be printed vertically, which lessened the quality of the print (tall skinny objects Wobble when printed). Also, it was hard to keep everything held down while all three vanes were being glued on.

The second version is designed to be printed laying flat, which improves print quality. This time, the arms are all different lengths so that an elastic band can be used to hold one arm in place without getting in the way of the other arms. The arms are also thicker, with reliefs so that the vane can be held into the jig as you tilt the arm into place. These improvements make the jig much more effective.
The jig has a 3 degree offset, but the design is easily modified for straight fletching, helical fletching, or other degrees of offset. This jig is designed specifically for 5/16" shafts, but given that the jig only costs $1 you could have a separate jig for every size of shaft at a fraction of the cost of any commercial jig. In addition, having it sized exactly for one shaft diameter makes it more accurate.

The Results

As I mentioned earlier the jig is very easy to use and the results are excellent, as can be seen in the pictures below.
If you have a 3D printer and would like to build your own jig, you can download the files below. The only other parts you'll need are three 12mm M3 bolts.

Click to Download

If you'd like the jig resized for a specific shaft size, let me know.

Last year I took a slight interest in archery and did some research on how to build a bow. I read a detailed build-along thread and decided it was definitely something I might like to do, but then summer ended and I forgot about it. This summer, however, I actually followed through and built myself a longbow. The two resources that helped me most were this forum thread (it's very detailed and even includes history!) and http://poorfolkbows.com/. Here are some details and photos of the process.

Starting Out

Given that this was my first bow, I wanted to keep things simple. I decided to make a 6' longbow from a 1x2x6 board. After looking through a bunch of boards at one store and then giving up and going to another store, I finally found a maple board with nice and straight grain.
Red oak was also an option, but the maple board was better so I went with it. As for the design of the bow, I did an 8" stiff handle, kept the bow full width until the last 12" of each limb and then tapered to 1/2" at the tips. The thickness was an even taper from full thickness at the handle to 3/8" at the tips. The width tapers were cut with a table saw (no jig just carefully fed through by hand), and the thickness tapers were done with an electric hand planer. Power tools generally aren't recommended for bow building, but in the roughing stages they are very useful, especially the planer. I had a very even and consistent starting point because of it.

After roughing out the profile I glued on a handle riser (I think that's the right term), and tip overlays. I used oak to provide some contrast.
I did some basic shaping and added grooves for the string, but left the majority of that for the end, since it doesn't affect tillering and there's no sense doing a bunch of work just to have the bow break later.
After this I added a backing. I used brown paper (it might actually be wrapping paper), which won't change the properties of the bow but should help prevent splinters from lifting. Check out my post on how to do a brown paper backing here: How to Paper Back a Bow

I also rounded the edges of the back to reduce the chance of breakage.

Making a String

Before I could go any further, I obviously needed a string! I made one out of B50 Dacron. I did an 8 strand string (2 bundles of 4) reverse twisted with a loop at one end and a bowyers knot on the other end. I made it extra long so I could use it for tillering and then adjust it to the right length to brace the bow. I followed the steps described on this forum (scroll down to find the post about strings).

I used a bunch of spring clamps to make things easier. I had a very strange method of working on the string which involved sticking a clamp holding the two bundles in my waistband while I twisted and reverse twisted the strands. I did this by a stairway and hung all of the excess over the end to keep it straight and untangled. It looked funny but it worked fairly well.
I didn't serve the string until I finished the bow, but I'll describe it here. I started by designing and 3D printing a serving tool. Then I used the method in this video to do the center serving and to reinforce the area where the strands end.

Here I have started the serving:
With the serving started, I used the serving tool to quickly and effectively serve the string.
Once the serving was the right length, I finished it using the method described in the video linked above.
Here I have added a serving overtop of the section of the string where the strands end, in order to hold down the loose ends.

Tillering

Next I took on the most important step: tillering. Tillering is the part of the process where you make the bow bend to the correct length and weight. I decided to go for 35# at 28". However, as I went I tillered for 40# because I figured I might need room to correct issues (this turned out to be a good idea). Here are a few photos of the early tillering stages:
As I built this bow I was continually doing research. If you want to build a bow you should read as much as you can online. Anyways, something I came across was the tillering gizmo, which allows you to mark flat spots on the limbs. I whipped up a design and 3d printed myself one:
This tool is awesome and made the process way easier. It removes a lot of guesswork and eyeballing. Eventually I had enough bend to brace the bow. At this point I needed a stringer, which I built. Check out the tutorial for that here:
How to Build a Bow Stringer I started by bracing the bow low and worked up from there. Note that I never used a longer string than necessary. Even when long string tillering, I used a string that just barely fit on the bow. An extra long string will just make your tillering less representative of what will happen when you brace the bow. From here I kept tillering and increased brace height until I got to about 6". Then it was just a slow steady and careful process until I reached my desired draw weight and length. One significant problem I ran into was limb twist. One limb began aggressively turning at some point. I blame this on the wood's natural tendencies, but perhaps I accidentally left one side slightly thicker as I tillered. This is when I made my biggest mistake, I read about how to fix twist online and then tried to fix it by aggressively removing extra wood from one side of the limb. This didn't help at all and probably made things worse.
Yikes! I decided to stop, but I'd already gone pretty far. I spent the rest of the tillering process trying to correct this and just bring the limb back to even thickness side to side. This seemed to improve the twist, and then I just ignored it. The other limb twisted slightly in the opposite direction, so the string still lined up on the handle. I did the final tillering and leveling with sandpaper so that I wouldn't lose draw weight trying to smooth things out.

Finishing

After I was satisfied with the draw weight, draw length, and the bend of the limbs, I shaped the handle and the bow tips. I narrowed the handle to 1" wide and shaped the fades to make them look nice.
For the tips i just rounded them in all directions.
I then finished with 180 and 320 grit sandpaper and applied many layers of danish oil. This brought out the colour of the paper and the oak and gave the bow a nice contrast.
Then I made a simple handle wrapvout of vinyl. I used a punch to make holes and laced it like a shoe. I will be using a floppy rest for the arrow shelf, but haven't installed it yet.

Conclusion

That's it, my first bow finished!
In the end the bow came out to about 35# at 28", which I think is a nice weight for a first bow. I didn't get a chance to shoot the bow until about a month after I finished building it, and by that point I'd actually built a second bow, so I tested the two of them at the same time. My second bow pulls about 40# at 28" and has much thinner tips. From my beginner archer's perspective, the second bow seemed nicer to shoot (less hand shock and a bit more power), but the first definitely wasn't bad. I probably put about 50 shots through each bow, and neither showed any sign of chrysals on the belly or any other issues; so far so good! Building bows has become a serious obsession for me and I find everything about it really fascinating. If you're looking for a fun new hobby, this is a good one!

A few years ago I bought some macro extension tubes so that I could experiment with macro photography. Unfortunately, the tubes didn't work very well; the lens wouldn't lock into the tubes, so using them was very risky. I put them aside and moved on; they were only $6 anyway.

Fast forward a year and we have built a 3D printer: time to fix these extension tubes!

The Problem

Looking inside the tubes I could see that the lever that holds the lens in place was too thin. It could easily slip past the slot in the lens, preventing it from locking.

The Solution

The obvious solution here is to modify or replace the locking lever. I decided to 3D print a new lever.
This new lever would be thicker and fit into the slot of the lens better. Designing it was a bit tricky, since the lever was a very random shape. I got out my calipers and did my best to recreate the lever. Then I printed it... And it didn't fit. Time to try again! I continued tweaking the design and reprinting until it fit and worked properly.

The Result

With the new lever installed the macro extension tubes work exactly as intended. This is one of the smallest parts I've ever printed and I'm very impressed with how well it turned out; 3D printing is awesome!
Instead of buying a new set of macro extension tubes and hoping they were better quality, I was able to fix the ones I have for a total cost of about 1¢. Add that to the list of everyday uses for 3D printing!

3D printers may seem like a piece of specialty equipment, but they have a lot of practical uses. We use ours all the time and don't know what we'd do without one!

Recently my father was installing sliding doors in a gazebo. The doors hang off of a set of rollers in a track. This means that the top of the door is held in place, but the bottom can swing in and out. This could be a problem in a wind storm, so some kind of guide is needed... Off to the 3D printer!

To accomplish the task, we designed two simple reinforced L brackets: one straight and one with an angled edge.
The guides are used in pairs, with one on either side of the door. The straight guides go in the middle, and the angled brackets go on the ends. The angle ensures that the door enters the guides without getting stuck.
With the guides installed, the door slides freely but can no longer swing out at the bottom.
Success! Another everyday use for 3D printers.

Backing a bow (adding a layer of another material to the back of a bow) is done with a variety of materials for a variety of reasons. Some backings change the properties of a bow (wood, rawhide, etc.) and some are just for looks and to add slight protection from splinters lifting on the back (snakeskin, paper, etc.). In this post I'll explain how I applied a paper backing to my bow. I'm by no means an expert, but my method seemed to work very well.

Preparation

I backed my bow after gluing on the handle and tip overlays, but before I did anything else. I figured if a splinter was going to lift it might happen during tillering, so it makes sense to back it ahead of time.

I'd recommend laying everything out on a clean work surface to make things go smoothly. Cut the paper roughly to size and lay it out beside the bow. You'll also need to water down some wood glue in order to make it easier to spread across the back of the bow.

Application

Start by putting a good coat of glue on the back of the bow using a brush. Then carefully place the paper over the bow, and work from one end to the other to smooth it out. It is good to have a helper for this, because lining up a 6' piece of paper by yourself is tough.
Using a rolling pin is very effective for smoothing out the backing and ensuring that it is tightly pressed against the back of the bow.
Right after applying the first piece of paper, repeat the process with a second piece of paper. Then let it dry. Once dry, use a file on the edges to remove the excess paper.
After this I rounded the corners of the bow, removing more of the paper backing in the process. This is okay because a splinter is unlikely to lift in the rounded section, so the paper isn't needed there. I think it also looks good to have the paper stop and not wrap around the edges. In addition, it leaves a very clean edge to the paper, and makes it difficult for the paper to peel off.

Around the tips I left lots of excess, and then sanded away the paper to about a 1/2" from the tip overlays.

With an oil finish the paper really darkens and stands out against a light coloured bow.
All in all I am very happy with how this turned out!

If you have a bow (or just finished making one, like me) then you should have a bow stringer. A bow stringer allows you to easily string your bow without putting potentially harmful stress on the limbs. Bow stringers can be purchased, but they're also really easy to make, and it just seems fitting to make your own bow stringer if you're making a bow.

Design

There are a few ways to make a bow stringer; mine will simply be a pouch and a vinyl strip on opposite ends of a nylon strip. The pouch goes on the bow tip that already has the string in the nock, the leather strip goes the other end. This design is easy to make, and places all stress on the rope and not on the pouch.

Layout

The dimensions of the pouch and strip can be seen in the pictures below. These dimensions are based on a longbow with a narrow tip; you should modify the dimensions to fit your specific bow.

Construction

Each half of the pouch is symmetrical in both directions, so in order to cut out the pattern, I fold the vinyl both ways and make one cut.
This method will give you perfect symmetry and you only have to make one cut! After doing this to both sides, you piece of material should look like this:
Now you need to fold and sew the pouch like this
Leave the top side open on the bottom so that the bow tip can slide in. The bottom can sewn fully shut. I also sewed an extra strip of fabric over the pouch to reinforce the area the bow tip will push on.
The strip used on the other end of the bow is simply to pieces of vinyl sewn back to back. Once you finish sewing both parts they should like this:
Now you can punch holes for the string. I used a regular paper hole punch. It worked fine on vinyl, but I leather might be too tough.
Now you just need to string it all together. One end is a large loop with the small leather strip. For the other end, feed the string through the holes as shown in the photo below, then tie a knot. The string needs to be significantly longer than your bow, and should allow you to hold the bow around waist height when stringing it. I cut the string extra long and then tested and moved the knot until I liked the length.

Using Your Bow Stringer

To use the bow stringer, slide the pouch over one tip of your bow (this tip should have the bow-string fully attached), and the loop on the end of the bow, far enough up the limb to avoid interfering with sliding the loop of the bow-string into the nock. Then step on the both stringer with both feet roughly shoulder width apart. Using both feet is important; if you use one foot the stringer loop will slide down the bow limb. Hold the bow by the handle and pull upwards to make the limbs flex. Now slide the loop of your bow-string up and into the nock. Gently release the tension on the stringer and remove it from the bow. To unstring follow the same process in reverse.
As you can see, the bow stringer makes stringing your bow a breeze!

Features

Over the years I've made my fair share of camera sliders, from very simple 2x4 sliders to more complicated wooden sliders. Most of them worked well enough since they were motorized, but they weren't great and without the motor it was difficult to move them steadily. Now that I have a 3D printer, I thought I'd have another go at making a slider. This time I opted for aluminum rails and printed bushings.
The tension of the bushings can be adjusted with an Allen key, which allows you to compensate for wear over time and adjust the friction of the slider. The rails are supported by printed end pieces with legs that can be adjusted using convenient knobs, and feature a locking mechanism to prevent any slippage.
The main carriage is a sturdy plate with a slot for a tripod bolt, and could easily have a tripod head mounted to it if you prefer. This slider is also extremely lightweight; it weighs almost nothing! It is best suited for smaller DSLRs, mirrorless cameras, and small camcorders. A heavier version could be made for a larger camera.

Check out the following video to see the camera slider in action!

Parts and Cost

To build this slider you will need:

• 2 pieces of 3/4" Aluminum tube
• 12 10mm M3 machine screws (for mounting bushings)
• 4 M3 set screws (for locking tubes into end pieces)
• 16 M3 nuts
• 4 30mm M5 hex head bolts (for tightening legs)
• 4 20mm M5 hex head bolts (for attaching feet)
• 4 16mm M5 allen bolts (for tightening bushings)
• 8 M5 nuts
• Printed parts

The aluminum cost about $10, the printed parts amount to roughly $5, and the hardware can be purchased for $5-$10. Once you have all of the parts, assembly is a breeze; no drilling or cutting, just bolt it all together. For roughly $20 and a little bit of work, you have a smooth slider with adjustable legs and adjustable friction.

All of the files can be downloaded for free right here.

Click to Download

Print your own and tell us about it in the comments! Stay tuned for a motorized version and future improvements.

The hot end is one of the most important parts of a 3D printer, and also one of the most troublesome. The thermal dynamics of a hot end are very critical, and if everything isn't perfect, they just won't work. I am by no means an expert on the subject, but I've had my fair share of issues, so hopefully my experiences can be of help to others. Here are some of the issues I've had and how I fixed them. This post deals specifically with J-Heads, but most of the tips apply to other hot ends as well.

Cooling

I'll start with something extremely important and also easy to fix. With hot ends like the J-Head, active cooling is a must. You need to have a fan blowing across the PEEK barrel of the hot end to prevent heat from travelling up from the heater block. Without this, jams will occur due to the fact that the plastic is melting too far above the heater block. If you do not have a fan and are having jams, simply add a 30mm or 40mm fan to your hot end. There are plenty of mounts available for download, or you can design your own. In addition, make sure that you insulate your heater block with kapton tape or another insulating material like fiberglass. This will help to keep the heat in the heater block and stop it from creeping up the barrel of your hot end.

Plug Formation

This is a big problem with cheap J-Head clones, and has been an issue with every J-Head I have bought off of eBay (if you buy a real J-Head I doubt you will have to worry about this). The problem here is that in knock-off J-Heads, the set screw or pneumatic fitting that screws into the top does not push down on the PTFE liner tube. When you try to use the hot end, the melted plastic expands and pushes the liner tube upwards, filling the space beneath it. This creates a plug which stops the filament from coming out of the nozzle. This problem is also easily remedied: simply add a spacer between the set screw and the liner tube. M3 nuts are the perfect size and work well. I place two on top of the liner tube and then screw in the pneumatic fitting, making sure that it pushes on the nuts and that the threads don't bottom out first.

Unidentifiable Blockages

Sometimes a hot end doesn't work and there is no obvious reason. There could be debris in the nozzle, or something else that you are not aware of. In these cases I've found it best to clean out the nozzle by using a very thin guitar string. Heat up the hot end and then thread the string through the nozzle, running it back and forth to clean out any debris. Even when there is no obvious blockage removed, this can help. I've had hot ends start working after doing this even though I never actually diagnosed the problem.

Temperatures

Try a few different temperatures if your hot end refuses to extrude. It's possible that you are running too hot or too cold, both of which can lead to jamming. You can't always trust recommended temperatures. Filament is not all the same, and neither are thermistors. For example, many manufacturers recommend printing PLA at 170 degrees and up, however we sometimes print at 165 degrees and can extrude at as low as 145 degrees. This is most likely because our thermistor is not completely accurate. This won't cause problems as long as it is consistent, but it means that you can't always go by what other people are doing, because not every machine is the same. So experiment and see if changing the temperature can make your hot end start working.

Conclusion

That basically sums up all of the advice I have for solving hot end jams, specifically with J-Heads. I'm sure that there are many other issues that I didn't cover, but hopefully this can help people who experience similar issues to what I faced. I have found that once a hot end is working properly it gives me very little trouble. Happy printing!