Bringheli Jig Redesign

[ToddFarr]

I have some big plans for my Bringheli Jig. (Which is funny because I haven't even used it to build a full frame yet). My first frame's front triangle was built using jigless methods, and I acquired the Bringheli just in time to tack the rear triangle. Although it's a great jig for the money, there are some things that I can see being quite the headache. I've been doing a ton of research on how to setup up the jig, and what people are typically complaining about. I stumbled upon Dave Anderson's website, and he has developed a great way to setup up the jig. But he mentioned that he has to go back and forth checking the head tube dimensions because the angle and horizontal slide are all on one single bolt. So I am starting there. On the front end.



This is my original idea. The Head Tube Angle, Vertical and Horizontal Adjustments are all split into there own adjustment points, with the ease and quickness of adjustable clamping levers. All the levers will have accompanying t-nuts (instead of hex nuts). This will allow for only the need to loosen the handles. The bottom cone will be replaced with a flat cone surface. This will allow for location of the bottom of the HT regardless of the diameter (there will be changeable inserts).



To make finding this point easier I am adding a 3/8" shaft that I will mill into a pointer that is the exact same height as the Bottom HT support. That pointer will be pointing to a line I will engraving directly into the center of the Extruded piece. I will be able to use a method similar to Dave Anderson's, but eliminate the step of holding a square out to find the Bottom HT support position. I will just be able to use my X-Y dimensions (Dave's Method) to bisect this engraving, then simply adjust the Bottom HT support up until the pointer points to where the 2 lines cross.

Eventually I will probably rebuild the entire thing except for the Base, that is just the way I am. I will be adding prints, pictures and documenting every step of the process in this thread. This will give people a resource to attempt similar modifications. I will also give feedback on what I like/dislike about the modifications. I am hoping this thread will become a creative venture where everyone can input different ideas and things they have done to this solid foundation of a jig.

[ToddFarr]

Some material came in today, and since I am waiting on Vendors for my real job, I decided to bust out the HT Centering Cone. Here is the print:



And here is some of the machining pictures:





And the finished product (maybe, I might add fittings for backpurge. I don't do any tig right now but someday I might):



That's all today, probably some more tomorrow.

[WadePatton]

drives me batshit crazy (er) not having a tool or two to do work like that.

picture the jig as i do guns or trucks: where the makers (JB in this case, Ruger and Daimler/Chrysler in the former) sells you a "complete kit" for a reasonable price that satisfies many people. But I have to modify/tune/rework many parts and pieces to get the instrument i want (but that most folks wouldn't pay for-nor appreciate).

Great work, carry on , godspeed.

[ToddFarr]

Thank you, Yeah it's kinda nice being a Engineer/machine builder for an occupation, I already have all the tools, connections and relationships to get myself into some real trouble with this bicycle building thing. If you lived around here you would be more than welcome to come to my shop and use the tools.

I'm exactly like you. I bought the Bringheli for the base, and because I got a good deal on it, but I've always had the intention of stripping the thing down and rebuilding it from the ground up. I'll probably eventually get to the point where I just sell it off and completely build my own. This is after I've spent a bunch of time with the Bringheli though. I want to really get to know framebuilding and learn about all the weaknesses and strengths of the jig. I think understanding this type of thing comes with practice and time in front of it.

It's probably why the ANVIL is so nice. I don't think Don just up and one day thought of the jig, I'm sure it's countless hours of repetition honed by continued use. In order to build a jig for the framebuilding industry, you must first know the framebuilding industry.

[Jamie Medeiros]

Looks good. Have you thought about making the head tube angle pivot around the center-bottom of the head tube so the "x" and "y" wouldn't change with angle changes? Both my Sputnik and Anvil fixtures pivot there.

[ToddFarr]

Brownbird, I have thought about this, and the problem with the Bringheli is that it relies on movable cones to position the head tube height. Unlike the Anvil and Sputnik which have a completely separate axis adjustment for the "y" or head tube height. Back to the Bringheli, since the main support that holds this apparatus is fixed, the bottom HT support will have to be moved up and down to accommodate for the "y".

But thank you for bringing this up. I may go back and revisit to see if I can find another way.

[Todd Mosley]

Make the puck reversible so that it will hold 1 1/8 or 44mm head tube, while keeping bottom of head tube constant with either side.



image-1143675736.jpg

[Billy Bigfoot]

Did you ever end up making any of these to sell? I would be very interested. Still using a bringheli jig

[ToddFarr]

Billy,
Finished the back end and I have 3 sets left now.


Assembly by FARR Frameworks, on Flickr

Never finished the front though. Too busy with too many things. I'll gladly turn over STP files if you want to try to get them machined elsewhere.
Thanks,

[Dallas Tex]

Todd,

Send me the files. I'm going to get a couple made. I'll even get some made for others, on a prepaid basis.

Gt

[ToddFarr]

Glenn,
Sure then, I'll get them compiled Monday and sent over, PM me your email.