im thinking about resurecting the cheap frame jig project

[Jim N]

My perspective as a guy who builds 3-5 frames a year and has been doing so for about 5 years:

I built frames 1-14 without a jig. I built them one joint at a time, so all I really need is something to hold the two pieces I'm doing at any given moment.

The only part of the process that's at all complex or prone to error, for me, is getting the chainstays right so that the wheel is in plane with the front triangle.

I then got a jig, but not a very expensive one. I found that, because this jig was not so easy to set up, and not super accurate, especially in the rear triangle, it was not an improvement over my old methods.

It's also very large. I suspect that's a factor for a lot of hobbyists.

Just for me, if you can make something that holds two pipes in place, and that helps with the chainstays (wheel in plane, BB drop correct), that's all you need.

I would not buy another inexpensive jig, as it's not helpful. Many have said something to the effect of, even if it takes a while to set up they'd still be interested in a cheap jig. I disagree. That's not an improvement over what I had, which is basically some tube blocks, shims, clamps, and square tubing.

Just my 2 cents.

[duanedr]

interesting point of view. And I think I experienced this myself but didn't really put it into perspective until you said it.

My first fork was made without a jig and it's just dandy. My second, finished last weekend, was made with a jig made of extrusions and other parts along the design of others seen here and the steerer tube ended up crooked in the crown by a degree or so. As I built the jig, I was super careful to make sure the jig is set up straight and accurate as best as I can measure and the 4 other forks I have confirm that it's as straight as current carbon and custom steel forks are.

Maybe for the hobbyist a jig just provides something to rely on other than care and caution and if it's not foolproof, the results are less satisfactory, not more. It also showed the value of pinning crowns and lugs.

Thanks for adding this perspective.

[Michael Gordon]

In terms cheap jigs, I don't know that anything is cheaper than what I came up with... I say "what I came up" with loosely... While I did not learn this method from anyone else, others who have seen this picture before have told me that that they have seen it in the past. This would not surprise me at all.

1. Get a piece of MDF Board, and cut it to the angle you are brazing.
2. In the edges of the MDF Board that you will be laying against the tubes, cut a groove so that the MDF board will sit securely on the tube.
3. Cut a notch out of the MDF board where you will be brazing your joint.
4. Drill holes through which to pass hose clamps which will hold the tubes against the grooves in the MDF board and keep them securely at the desired angle.
5. Braze!

IMG_0813.jpg

[jclay]

Low cost materials, much of the fabrication is within the hobbyist's or small welding shop's capability, only a few precision machined parts required. If I were to do it again this is probably how I'd go.

FB_maintriangle.JPG

[Rusty Mac]

Hi Mike,

I'm in the UK (but even further North than bencooper) and am going to be looking to build my own frames in the future as a hobby so would be interested in this if you pursue it. I have some drawings I got from Kris Henry at 44 Bikes for the jig he built and was going to use them as the basis for my jig however as you have pointed out the extrusion can be difficult to source over here.

As you will see by this being one of if not my first posts on this site I am in the very early stages of looking into all this stuff and still have my garage to fit out as a workshop before I start on anything so if you need anyone to look at it from an idiots eye point of you please don't hesitate to get in touch.

[Rusty Mac]

First post, first mistake - oops. This one should hopefully contain my name, I can't seem to find a way to edit the above post to show my signature.

[Mike Mcdermid]

Hi Mike,

I'm in the UK (but even further North than bencooper) and am going to be looking to build my own frames in the future as a hobby so would be interested in this if you pursue it. I have some drawings I got from Kris Henry at 44 Bikes for the jig he built and was going to use them as the basis for my jig however as you have pointed out the extrusion can be difficult to source over here.

As you will see by this being one of if not my first posts on this site I am in the very early stages of looking into all this stuff and still have my garage to fit out as a workshop before I start on anything so if you need anyone to look at it from an idiots eye point of you please don't hesitate to get in touch.

Rusty mac

Im going to try an keep this short as its become evident as this has gone on its more of a commercial prospect than it was and I'm not wanting to flout the forum rules or upset the mods on here

I'm actually sending Ben cooper one the minute i get them done

It turns out the woman who supplies our Aerospace aluminium and tooling plates also supplies both BOSCH Rexroth and ITEM and another company that imports a system called valuframe, collectively over 150 tons per month, with their extrusions

the main problem is in Europe of course is we are metric led and the 8020 Generic system over in the US doesnt quite tie in directly so in effect I designed a system now to be a lot more things to all men and in kit form to boot, when you look at what the hobby guy needs half the time its just a case of not thinking what i use in production

but

borrowing the usefull bits of design and toning them down ,machining them up for a price that doesnt break the bank, i know from experience half the battle is getting something machined up and people sometimes just wanna meccano set of quality parts if they cant make them,so we designed it to work with lots of the extrusion systems all the holes are in already.... as we are now becoming more of a custom machine shop too this is the route we have decided to go down , and we will now not be manufacturing jigs for other people and offering these direct as in effect we dont need to subcontract our manufacturing to the cheapest supplier and we are buying enough stuff to make it viable economically

there's going to be a website going up next week with it all on but pricing isn't break the bank money and it gets the guys in europe a resource for fiddling about without the need to machine stuff

once again if you feel the need to lock it up now mods please do there's a sense of using the forum to get PR now creeping in

[bencooper]

I'd be happy to send my old jig further north ;-)

[savine]

Low cost materials, much of the fabrication is within the hobbyist's or small welding shop's capability, only a few precision machined parts required. If I were to do it again this is probably how I'd go.

FB_maintriangle.JPG

I learnt on this jig on one of Dave´s courses and this is a great jig.......said he´d make me one but the price was silly for what this is.

[Andrew R Stewart]

I've said it before that if I were starting over I'd strongly consider Doug Fattic's jig, which is a really nicely detailed out version of the classic window frame jig. But then I'd have to get a larger surface plate to lay the jig on. Andy.