A little over a year ago I took a bicycle frame building class through the United Bicycle Institute. I attended the chromoly brazing class at their Portland campus. Since then I have wanted to build more bike frames. I am interested in making money doing it, and perhaps someday, making it my sole source of income. On the path to becoming a bicycle frame builder one of my biggest obstacles is acquiring a frame building jig. They are expensive, arguably the most expensive single tool you need to accurately build quality bicycle frames. So I, like many bicycle frame hobbyists, decided to build by own. My personal goal for my frame jig however, was to build a professional quality frame jig. I wanted something I could potentially start a business with.
In Portland I learned to build using an Arctos jig. The simplistic, functional and approachable design seemed like an obvious choice for me. I scoured the internet for photos of bicycle frame jigs, in particular Arctos jigs. A handful of people have posted photos of Arctos style jigs that they have built. Alex Wettmore built a very close replica he called the “Arctos Clone Frame Fixture”. His photos and descriptions were helpful and inspiring.
With the Arctos model at the core of my design I started out to make changes to suit my specific needs. Some of the changes I wanted to implement included the option of simple attachments to make a tandem frame as well as room for extra long chain stays (for cargo bikes). The room for long chain stays was easy. I simply left the main spine of the jig as long as possible. I will discuss the the tandem attachment I came up with later in this instructable.
I designed specific parts of my jig as I built them. I prototyped as I constructed so you wouldn’t have to. I did not draw the entire jig in CAD. I used a variety of specific drawings and views to produce everything. I have attached all my CAD files both as original technical drawings and dimensioned labeled PDFs. This instructable will be broken down in to one step for each sub assembly of the Jig.
Some Acronyms I might be using:
HT - Head Tube
ST - Seat Tube
TT - Top Tube
DT - Down Tube
BB - Bottom Bracket
CS - Chain Stay
SS - Seat Stay

Step 1: Supplies and Tools

Aluminum Extrusions:
I decided to build the majority of my jig using 80/20 brand extrusions. There are a variety of aluminum extrusions available, Arctos jigs use Item brand extrusions.
Because many bicycle dimensions are given in metric, and I think it is a better system, I went with Metric extrusions. I went with the 40 series metric extrusions.
A little information I learned about 80/20:
80/20 comes in a variety of metric and SAE sizes. Their naming system give the distance between channels on all extrusions in that series. For example metric 40 series is 40mm between channels and the 1.5 series (the approx. metric equivalent to the 40 series) is 1.5 inches between channels. The individual extrusion options are named for their dimensions. 40-40 (the skinniest option in the 40 series) is 40mm x 40mm. It has one channel in the center of each face (20mm from each side). The 80-40 series is 40mm x 80mm. The 80mm face has two channels and the 40mm face has one channel. Each extrusion series is designed to use a specific hardware. 40 series is made for M8 bolts. The channels take M8 bolts and the end holes are the right diameter to be tapped for M8 threading. Therefor I used almost exclusively M8 bolts for this project. Detailed CAD drawings of lots of the available 80/20 extrusions can be found on McMaster Carr. However, McMaster did not have all the specific extrusions that I wanted so I ordered all of my 80/20 on Amazon.
See the attached .pdf of all the specific extrusions I purchased (as well as what lengths I used).
Aluminum Stock:
The specific parts that I milled were almost entirely 6061 aluminum. It is fairly light, fairly cheap and I had access to lots of scrap. I used flat stock from 1/4” up to 1 1/2” and round stock with a diameter of 1.5”. I also used some 3”x3” angle aluminum (1/4" thick).
Handles and Hardware:
I bought all my hardware from McMaster Carr.
I bought dummy axles from the United Bicycle Institute. Note: My Jig is designed to work with the specific dimensions of these dummy axles, modify yours if you use different dummy axles.
Tools (at least some of the important ones):
Bridgeport 1 Series Manual Vertical Mill for milling parts
Sharp Manual Lathe for making cones and BB shell mount
Omax Waterjet for cutting parts from stock
Cold saw for cutting stock and 80/20
Horizonal and Vertical Band Saws for cutting stock
<p>I cant find the parts PDF. I want to start collecing the 80/20</p>
<p>thanks for the thread............lookjs like it should work great</p>
<p>Hey Tanner, great post. I've begun my build following your instructions. Is there a mistake in your extrusion materials diagram however? You mention using 160 x 80 in your description on page two. But in your materials list you have a length of 160 x 40...?? </p>
<p>160x80 seems correct :)</p>
<p>It can be hard to get the exact extrusions for this Jig, but you can get cut to length materials from item to make a custom jig. Check out www.itemNA.com </p>
<p>How can I open these dwg and dxf files?</p>
I use Autocad personally but I think there are other CAD programs that will open them.
<p>I know this is a little late to the party, but the same people that make SolidWorks (Dassault Systemes) offers a program called DraftSight for free and it is basically an AutoCad replica.</p>
Thanks for the instructable. I just finished mine today.
<p>Hi dukeduck. Great work! I wonder if you could send me your 3D file or make it available here? that would help a lot to reproduce the work...</p>
<p>Hi Tanner,</p><p>This is an invaluable post. I'm wondering if you kept track of the material cost and, if so, what was the final tally?</p>
<p>Awesome instructable! Loved it ! and a superbly finished jig!<br>I'm planning on building one based on this instructable. But I'm not able to find drawings for the dummy axle block. Did i miss something?! It would be great if you can upload that Thanks a tonne !</p>
<p>Also, I can't seem find any place that sells 8020 160x40 Extrusions. 8020 sells 120x40 or 160x80 though.</p>
<p>Do you think it possible to make this jig without access to my own machine shop?</p><p>Can a drill press substitute for a vertical mill for example?</p><p>I'll probably have to find a machine shop to machine some of the parts.</p>
<p>hi, i m going to build your amazing jig, and was wondering if there was any way you could sell me the dummy axle block?</p><p>seems impossible for me to build it.</p><p>thanks</p><p>martin</p>
Nice work! I've been interested in building frames for a while. I have a full machine &amp; welding shop. I need to make a jig like this. <br><br>One word of advice, buy some center drills. Drilling using a punch mark is bad technique. The drill will walk no matter what you do if you don't. Just trying to help you on your journey so don't take this as a bash!
<p>Very nice. Which T-slot nuts did you go with under the handles for the sliding elements?</p>
http://www.mcmaster.com/#5537t455/=w8z9mc<br><br>I used the standard zinc-plated steel End-Feed Fasteners for Aluminum T-Slotted Framing from McMaster. In my case, I used the ones for 40mm series aluminum extrusions...<br><br>
<p>Hello, nice work.</p><p>Do you have a drawing with demensioning from the drawing of the &quot;parts&quot;?</p><p>I can view the drawing only without dimensions?</p>
<p>can this jig be used to make bmx frames? </p>
I think the only thing different about building BMX frames is that they typically have bottom bracket rise rather than bottom bracket drop. To make your jig capable of building BMX frames all you need is a little longer axle mount piece so you can lower the rear axle further down.
<p>Wow man, this is great work. Thank you so much for putting this up.</p>
Any chance you could post your drawings in DXF format? My Turbocad 18 doesn't want to open the DWG files for some reason.
I uploaded .DXF files. Let me know if they don't work either.
<p>Great job, but i can't find your drawings/blueprints. Where are they? thanks.</p>
<p>They are on the first page of the instructable. At the bottom of the &quot;intro&quot; before step one. (at least that is where they show up when I open the instructable)</p>
<p>They don't show up for me!! I don't get it! :( could you please send them to me!! it would be great.</p>
<p>Does this work?</p>
<p>THANKS!! it works great!!</p>
Works perfectly. Thank you!
<p>Sold </p><p>Many thanks for all the interest.</p>
<p>Tanner, thank you for putting this out there! Great build and the pics are superb. I can't open any of the files though. Would you be able to email the files to me? Thanks! Todd </p>
<p>Incredible job man, congratulations. Is there any chance that you sell a package of this jig and ship it internationally? I would like to have one but I don't have the same materials available here. Any ideas of total cost? </p>
<p>Very cool jig, thanks for figuring this one out for us. I'm about to pull the trigger on a McMaster order and get this thing rolling, but wanted to touch on one thing first... I plan to do offset ST's to accommodate short CS's on 29's, w/o bends in the ST. I'm curious if you've come up with any mods, or have any ideas for a mod before I start construction? Again, very nice work. Thanks a bunch. </p><p>-MF</p>
I would change the BB shell mount. When I turned the BB shell attachment points on a lathe I didn't do a very good job. They should slip fit on to a 5/8&quot; steel rod but I used a 5/8&quot; bit to drill the aluminum stock. The hole is too big, they are a sloppy fit.<br>I am going to make new BB shell &quot;cones&quot; but this time I will use steel (as I mentioned in the instructable). I will drill a smaller than 5/8&quot; hole and use a boring bar on the lathe to get a perfect slip fit. <br>That is all I have planned for mods currently. I am hoping to build another frame next week. If I notice anything else worth changing I will message you.
<p>Thanks!</p><p>Yes, that should snug things up on the BB. I wonder if the ST cone mount (AL angle) would be too difficult to build so that it pivots? I'm looking for a way to have a snug connection (at the proper angle) at the top, so I can push the bottom of the ST forward of the center of the BB a bit, even overlapping on the DT slightly. I guess I can't decide if it needs to pivot in the center of the mount, or if it should be slotted?</p><p>Thanks again, nice work.</p>
<p>Or another BB shell mount with an offset...</p>
hello, I can not see or access the cad files ... as I can get them?<br><br>
Nicely done. Excellent idea to make it usable for tandems. Also great that you are considering Cargo bikes. Too many jigs are only useful for the sort of frame you can order from QBP. My motivation for frame building is that I need a 68 or 70 cm frame and I can either build them or pay someone else to, and few builders seem to &quot;get&quot; that you just can't scale up the ST and HT and have a decent handling frame. I best stop before I hit full rant mode!
I hear you gumby_kevbo. I got in touch with Rivendell for some of the specs from their 71cm <a href="http://www.rivbike.com/product-p/f-hilsen.htm" rel="nofollow">A. Homer Hilsen</a> while I was designing my jig. They got it right with the double top tube. With its 300mm HT the flex in the frame without a second TT would be crazy.
Great job, Very professional! <br>I'm wondering if this could this be adapted to making Motorcycle Frames?
I don't know much about motorcycle frames but I imagine you could modify the design to work with them.
Very professional work! Out of curiosity, what frame are you building in step 10? A transport bike with a top tube curved upwards near the head tube?
Thanks ElegantAndrogyne! Yeah, curved top tube cruiser, easiest to just share a picture of the finished frame. Built up with a 5 speed internally geared hub. It ended up being a really fun bike.<br> <br>
great job! bottle opener dropout? way to go! <br>
Yeah! Definitely put a bottle opener dropout on it! From Paragon Machine Works.
great job! bottle opener dropout? way to go!
This is a great Instructable to teach my GCSE RMT class about Jigs. Many Thanks
This is instructables, where did you put the rusty 6&quot; nail :)
Haha no 6&quot; nails... at least not yet.

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More by Tanner W:Build a Bicycle Frame Bicycle Frame Building Jig Wood Tubing Blocks 
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