# Frame Jig Questions



## seanmurphy265 (Mar 24, 2011)

Been riding mt bikes a few years. Been welding / fabrication most of my life, so I am not worried about my fabricating skills. Where can you find a simple jig or fixture to build bikes, I am looking for some simple plans, pictures, ideas. Buying a jig is out of the question, I am doing this as a hobby for me.

I am going to get a cheap set of tubes to practice my first build, and get a good set after I feel that I know what I am doing.


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## pyranha (Aug 7, 2007)

Believe it or not, you can go a long ways with nothing more than a known flat piece of plate, some V blocks, and a couple of C clamps. That being said, this topic has been covered a lot around here in the past. The 80/20 extrusion stuff seems to be popular among the hobbyist set. My first jig was a thrown together copy of a Bringhelli I made with 1/2" Mic-6 plate. The following link discusses this topic.....
http://forums.mtbr.com/showthread.php?t=541584


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## Walt (Jan 23, 2004)

*Do a search...*

For "Dr. Welby" and "jig". I believe it's on instructables as well?

Just FYI, you should be aware that even as a hobby, framebuilding is an incredible time/money sink. If what you want is an awesome bike, you will be much happier (and have more money in your pocket) just buying something. If, on the other hand, you just love building things, then damn the torpedoes - get some tubes and build something.

-Walt



seanmurphy265 said:


> Been riding mt bikes a few years. Been welding / fabrication most of my life, so I am not worried about my fabricating skills. Where can you find a simple jig or fixture to build bikes, I am looking for some simple plans, pictures, ideas. Buying a jig is out of the question, I am doing this as a hobby for me.
> 
> I am going to get a cheap set of tubes to practice my first build, and get a good set after I feel that I know what I am doing.


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## seanmurphy265 (Mar 24, 2011)

It's something I want to try! I already have the majority tools needed, it's the jig part that concerns me the most.



Walt said:


> For "Dr. Welby" and "jig". I believe it's on instructables as well?
> 
> Just FYI, you should be aware that even as a hobby, framebuilding is an incredible time/money sink. If what you want is an awesome bike, you will be much happier (and have more money in your pocket) just buying something. If, on the other hand, you just love building things, then damn the torpedoes - get some tubes and build something.
> 
> -Walt


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## dr.welby (Jan 6, 2004)

There should be a sticky with links to all the great homebrew jigs discussed here, but here are my two efforts, as Walt posted:

http://www.instructables.com/id/The-simplest-bicycle-framebuilding-jig-I-could-com/

http://www.instructables.com/id/Almost-jigless-bicycle-frame-building/

In addition to be a time/money sink, also expect some serious soul-searching when you get 80% done with your frame and you realize the rear wheel isn't lining up straight...


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## pyranha (Aug 7, 2007)

dr.welby said:


> In addition to be a time/money sink, also expect some serious soul-searching when you get 80% done with your frame and you realize the rear wheel isn't lining up straight...


+1

Don't be discouraged, but stay humble. Best of luck!


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## Hooder (Jul 21, 2009)

My first frame I did completely jigless following the sub-assembly method outlined in the Paterik manual. On the second frame I used Dr. Welby's "Almost Jigless" method (thanks Dr. W). It worked great. I highly recommend it. I also have a large drafting table that I can lay the frame over a full scale drawing which is very helpful. 

I think when starting out less might be better because it helps you gain an understanding of what is critical (what has to be square to what and so on) and how things move when you start joining tubes (not that a fancy jig will change that). You probably already have a good understanding of this because of your fabrication experience. I was amazed how wacky things can get when you join a joint with a so-so miter. 

Yes, it is a lot of time and when you get done with number 1 and you add up the time and money you will seriously wonder why you did it and then you will start number 2 the next week. Good luck.


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## Jehoshaphat (Mar 18, 2011)

Economies of scale don't justify a jig for a while. 

I've got four frames planned for my upcoming jig with more frames sure to follow. 

Since building without a jig doesn't cost anything and my time is "free", there really is no break even point for me. I would just rather build with a jig and can spend the money. 

If I continue to account $0 for my time, I can save money by frame building because I'm one of those physiological oddities that no one builds a production frame for, but it will take several frames to amortize the jig and other tooling. 

If you are building one frame and lugs are available to suit your geometry, jigless is the cheapest way to DIY but it might be better to look at your budget to see how much jig you can afford and then choose your build method.


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## bighit (Feb 13, 2004)

I was going to ask the same question. In my case I am not building high end frames yet, but modifying old cruisers. Even though they are rat they still have to line up to weld up.


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## MDEnvEngr (Mar 11, 2004)

*There should be a sticky on the low-tech, homemade jigs, eh?*

I use a set of "fixtures" I made and a surface plate as a "jig". See this thread:

http://forums.mtbr.com/showthread.php?t=670483&highlight=fixture

No need for a fancy jig...I'm thinking ever, but that is just me.

B


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## Walt (Jan 23, 2004)

*Can someone help me out...*

...and make a quick list of links to good jig threads? I'll put it in the FAQ.

-Walt


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## nato_the_greato (Jan 27, 2008)

Could the Alex Meade method (tubing blocks over drawings) work with say, blocks made for 31.8+ tubing, but with shims like for front derailers to use smaller diameter tubing? 

That seems like a cheap way to get a "universal" non-jig, instead of buying each block individually for different tube diameters.


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## Blaster1200 (Feb 20, 2004)

Nato, you could also use matching V-blocks sitting on their end. Then use clamps to hold each tube in the V-block. Since all of the centerlines are on the same plane, there is no need to be concerned with spacers/shims. V-blocks are also relatively inexpensive.


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## Jehoshaphat (Mar 18, 2011)

Tube blocks can be made with pretty good precision using common tooling and wood. That's one of the cheaper DIY options. 

Unless you plan on doing lots of frames with the blocks over paper method, make the blocks yourself. If you can't make the blocks, you might want to re-think making a frame. If you are set up to make blocks, there is no reason to fool with shims, just make the blocks in the sizes you need.


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## nato_the_greato (Jan 27, 2008)

Jeho - I forgot about wood. That seems really obvious and simple. Some simple geometry should get me the required dimensions. 

Anything special to keep in mind when designing the blocks? Can you use wood for the BB/HT holders to tack, or would the heat mess up the wood? I assume the blocks on the main tubes would be far enough from the torch.


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## Jehoshaphat (Mar 18, 2011)

If it's one frame, wood stand-offs for the BB and dropouts should be fine. 

For the blocks, the one critical dimension is centerline height and they should match block to block. I would start with some round spacers in the diameters of the tubes you are using. You could turn them in a lathe or on a mandrel chucked in a drill press if you have no lathe. Then get a chop saw and bolt a mandrel to the bed, slide on a spacer and a block and chop it off. Since the mandrel is fixed relative to the blade, your centerline height will match as long as the blade and mandrel are perpendicular to the bed and the spacers are turned concentrically. 

After they are cut to length you can cut off the tops to make them clamps. 

That method can produce good results if you're a little handy and it should be pretty easy to verify by eye that things are lined up close enough.


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## JaquesN (Sep 14, 2009)

I've only built four bikes, and a bunch of racks and forks, so take this with a grain of salt, as advice from one novice to another:

They will tell you you don't need a jig. They are right.

Think of it this way: every join you're doing is going to be a separate step, especially at first. You're not going to perfectly miter the tubes, throw them in a jig, and produce a bike. You're going to miter your dt and mate it to your ht, miter your st and join it to your bb, etc.

Each time, you just need a way to hold the *TWO individual pieces* in the proper plane and at the proper angle.

You can do this with some clamps and a relatively flat welding table, or a million other ways.

Regards,
Jim


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## Blaster1200 (Feb 20, 2004)

JaquesN said:


> I've only built four bikes, and a bunch of racks and forks, so take this with a grain of salt, as advice from one novice to another:
> 
> They will tell you you don't need a jig. They are right.
> 
> ...


Newbie here as well. I've built four fillet-brazed frames, including a tandem. 
Agreed with everything Jim said.


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## TgMN (Aug 22, 2006)

1st frame main triangle was built jigless. But I decided I wanted something to help me tack the rear triangle so MDF was pressed into service. Worked fine and was reasonably straight.... just be careful where you aim the torch! I've since moved on to an 80/20 jig like many others.


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## Blaster1200 (Feb 20, 2004)

TgMN said:


> ... so MDF was pressed into service.


Nice pun!


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## toddre (Mar 1, 2004)

Hey everyone... I'm back with a clean bill of health (for now) and working on getting my body back to where it needs to be...
I haven't picked up a torch in over a year but I think I'll be back behind a helmet practicing my TIGing soon...
Anyways, I can't believe no one has come up with an affordable jig for the hobbyist like alot of us here who might only do a few frames a year... Wouldn't there be some sort of market for it?


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## compositepro (Jun 21, 2007)

"Hey everyone... I'm back with a clean bill of health (for now) and working on getting my body back to where it needs to be...
I haven't picked up a torch in over a year but I think I'll be back behind a helmet practicing my TIGing soon...
Anyways, I can't believe no one has come up with an affordable jig for the hobbyist like alot of us here who might only do a few frames a year... Wouldn't there be some sort of market for it"

sssssh there is a jig for hobby builders on the way ...well it exists and is in production ...wasn't going to go public or say anything till the next batch was ready but I have been talking with peter at ceeway regarding these TO GET THEM OUT THERE

basically a 8020 jig in kit form (you just bolt it together) and a more advanced jig which uses stable castings (these are at the machinists/grinders right now) they arent made in china but in sheffield england the more advanced jig lets you do a lot of stuff on it

I was going to get in touch with walt to see if I need to place an ad before outing the info on these but if its wrong then im sure he will just delete the post


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## tybeede (Apr 2, 2011)

I did quite a bit of searching before figuring I would build an Arctos style jig from Misumi USA aluminum extrusions. I posted a survey of frame jigs with links to some of the common 8020 style ones on my blog site at the following link

http://mechanicalhacks.wordpress.com/2011/03/31/bike-frame-jig-survey/

For some reason I managed to leave out Henry James and Bringheli jigs under the commercially produced section. I kinda crossed those out of my mind early on for a jig I would buy off-the-shelf because they lack quick setup features like angle scribe lines. I figure if you're going to drop some bucks on a jig it needs to be quick to setup.

In my case I'm building 2-3 frames a year at most so a DIY is going to work well.


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## Smudgemo (Nov 30, 2005)

I'm with MDEnvEngr on this one.

There are some photos of the jig I built in another thread, but I must confess that I really haven't used it much. I hated doing drawings, so I popped for BikeCAD at one point and found making the sub assemblies really easy with nothing more than a BB post mounted to a 2'x3' surface plate and some vee blocks. 

BikeCAD gives every angle you can think of, so I simply draw the angle on the inside of a cereal box, cut the circle for the BB post and line up the tubes for tacking. Accuracy is really good, and it's easy to tweak things with the post if needed. 

My suggestion is start simple and learn the process. I think it's easier to spot where you went wrong when there isn't a bunch of equipment cluttering your view (so to speak.)


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## febikes (Jan 28, 2011)

tybeede said:


> For some reason I managed to leave out Henry James and Bringheli jigs under the commercially produced section. I kinda crossed those out of my mind early on for a jig I would buy off-the-shelf because they lack quick setup features like angle scribe lines. I figure if you're going to drop some bucks on a jig it needs to be quick to setup.
> 
> In my case I'm building 2-3 frames a year at most so a DIY is going to work well.


For building 2-3 frames a year the benefit of "quick" setup time is really not so much. From what I have seen the Bringheli, Henry James, and Brew jigs are really nice, all three are very simple designs. Angle scribe lines and other measurement features would be nice if I was building lots of bikes but for my planned volume of 2-3 frame this year spending a bit more time on setup is not really a problem.

I am thinking of getting a Wixey angle gauge to use in conjunction with my simple jig.
http://www.wixey.com/anglegauge/index.html

Building without a jig is awesome and I love the idea plus if you ever make something other then a standard bike design it is good skill to have. If you enjoy making things, designing and building your own jig is the way to go because it saves you money and can be rewarding in its own way. The 80/20 jigs I have seen look great.

I bought a BREW jig and overall find it works well. It is a *very* basic design with absolutely no features but it is solid and gets the job done. The jig actually seems to have less features then most of the 80/20 designs I have seen. Mostly I just got the jig because I wanted to focus on building a frame rather then spend a lot of time working up a jig design of my own.


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## jgerhardt (Aug 31, 2009)

Once you actually start using the Bringheli jig it is actually quite easy to set up. Probably not as easy to set up as the Anvil or Sputnik jigs. Walt does a great job of explaining the pros and cons of a good jig here

There seems to be a lot of hate surrounding the Bringheli for some reason and from my experience it does a really good job. And as for the 80/20's, after pricing out everything needed the cost difference (especially after considering the hours spent building the darn thing) is not that much different than the Bringheli.


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## tybeede (Apr 2, 2011)

I wasn't meaning to put down the Bringheli or Henry James jigs. I'm sure they are easy enough to use once you get going with it. For the purpose of my summary I mentally divided the jigs into two classes, stuff for pros and joes. If you're knocking out 5-8 frames a week and charging top dollar I bet you'll like Anvil/Sputnik over the HJ/Bringheli. My buddy switched from a HJ to an Anvil and it is worlds better in quality and ease of setup. Hank is a great guy with a nice product line but the HJ jig in question had some QC issues with the tolerance stack ups.

For low volumes a drawing, v-blocks, squares, BB bost and a plate is enough. The pictures above tell the whole story. Grizzly has v-blocks in a wide range of sizes at very affordable prices. If you like to tinker, like myself, a DIY jig project is fun. Jigs are always a hot button issue... everybody has their own way of doing things that they strongly believe in. Just have fun and build something :thumbsup:


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## tybeede (Apr 2, 2011)

If you're looking for a digital angle finder you might like one of these from eBay.

http://cgi.ebay.com/Digital-Protractor-Angle-Finder-Inclinometer-V-Groove-/250795167730?pt=LH_DefaultDomain_0&hash=item3a648e8ff2

They are a lower cost alternative to the SPI version that features the v-groove in the bottom to help align the angle finder with the round tube. I've been thinking about buying one and if it comes close to the specifications they list it is plenty accurate. Heck, I've seen people use the iPhone level application quite successfully as a digital level for projects.


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## clarence (Mar 31, 2008)

For my first frame I am planning on copying a reliable old favorite. Through a friend who restores motorcycles I have access to tools, for the jig I was thinking about using that old frame. The plan is bolt bb shell to bb shell and using angle irons bolted at the top and bottom of the head tubes align them. Essentially building anew frame side by side to the old. At least for the main triangle. 

This is for learning and building skill so a new design isn't high on my list. 

Has anyone done anything like this? Is this an incredibly bad idea that I can't see the fault in? I am almost certain I won't weld the two frames together.


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## Jehoshaphat (Mar 18, 2011)

Assuming a frame is straight as a reference has the same danger as trusting the angle markings on a jig. 

If it's correct, everything works out fine, if not, get ready to bend or start over. 

For a DIY jig I think angle markings are a liability more than a benefit. No markings will force the builder to check as they go rather than be surprised by errors once it's almost finished. 

To me, it would be nicer to make it quick to remove and replace the frame than quick to set up. That would let you go from tacking to welding/brazing, to straightening and back in the jig. That's a feature I want to have in my jig. 

Getting back to your question, I'm sure using an existing frame as a jig could work. It's just not something I would do if I had a choice.


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