# Tube Miter Jig



## ggodwin (Apr 25, 2011)

Hey folks,
If you don't mind posting pictures of your tube miter methods I would like to see how you do it.

For me it is as simple as it gets. I use the JD Square tube notcher. But, I have come to the conclusion that I could make my frames much faster and more accurate if I created a jig. I'm think about creating a jig for the front triangle that reflects the frame specs. I would insert the tubes and miter all together. Example. I can fixture my Down Tube and Seat Tube in place and just make one cut. Same for the Down Tube and Top Tube. If I am able to do this I will be able to have the the tubes that have two miters pro But before I do that, I want to see how everyone else does this.

I'm making five frames in a time and need to get more efficient.


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## afwalker (Apr 26, 2012)

Mine is a copy of Carl's at Metal Guru's framebuilding class. Horizonal mill, 80-20, self-centering vise, horizontal rotary table, careful allignment of all 3 axis by using dead centers as pointers, dummy vertical and horizontal tubes the same height as the center line.







more pics on page 3 of my flickr
and on this thread
http://forums.mtbr.com/frame-building/through-cutting-bb-dt-943255.html
If bikecad says the c-c is 731.5mm I line it up and cut away, pretty accurate. Now you can buy the main tube mitering setup from Don at Anvil and save yourself a lot of time, but you'll need a rotary table, and a mill anyway, but this shows it can be done. I had to have Todd Farr fab me a custom adjustable dead center that fit into the M2 taper of the rotary table, so it was lots of work to acquire all the pieces needed, but I love using it every time!!!
cheers
andy walker
www.flickr.com/photos/afwalker50 page 3-4 has the jig, check the video Img_1411 showing how the dead centers stay in perfect alignment when I rotate the table.


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## BenCooper (Feb 25, 2013)

I use a modified Pro Tools notcher - I can use it for main frame tubes, seatstays and chainstays:


Mitring setup - main frame tubes. by Ben Cooper, on Flickr


Mitring setup in seatstay mode. by Ben Cooper, on Flickr


Chainstay mitring - test setup. by Ben Cooper, on Flickr


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## ggodwin (Apr 25, 2011)

How do you guys assure that tubes with two mitre's are properly aligned. 90 degrees or concentric to each other?


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## afwalker (Apr 26, 2012)

Center to center, so if the head tube is 44mm, my dummy tube is 44mm in a jig that holds it on center to the measuring tape so it's center is on the c-c. If it's not the same axis as the dt-ht but the ht-st I use the swiveling jig with the correct dummy for a 28.6 or whatever and it will still be c-c. Really lots of things have to be considered for this to work. Buy the Anvil, or really think it through. Actually I just do the seat tube first so it doesn't matter so much what the head tube it, mostly 28.6 on the seat tube, unless it's externally butted but that's just one more dummy tube.
cheers
andy walker


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## afwalker (Apr 26, 2012)

I'll try and take a pic when I'm doing my next frame of how the aligning bits hold the tube in perfect phase when cutting the length. It's the bomb!
cheers
andy


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## Walt (Jan 23, 2004)

Are we talking about a mitering setup or a frame jig? I'm confused.

OP: if you just want to keep miters in phase, it can be as simple as a tube block and a level.

-Walt


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## Eric Malcolm (Dec 18, 2011)

I understand the question to read: keeping the miters in phase plus 90* for BB on the DT. A jig for doing this task for multiple repetitions. 

Eric


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## ggodwin (Apr 25, 2011)

Walt,
I actually ordered a block to do that three weeks ago but was wondering how everyone else did it.

The Intent of this thread is to just see how most of you cut your mitre's.

I'd also like to know how you measure the tubes out also before you cut. 

I am planning a jig that will be setup to match the frame jig. The idea is to become more efficient at tube cutting. (My frames are only aluminum for younger kids)

1.) Make one cut for the BB, Head Tube and Seat Post. (Front triangle only)
2.) Eliminate measuring tubes.
3.) Eliminate special handling to keep the cuts in phase.


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## ggodwin (Apr 25, 2011)

Sorry to confuse everyone. I'm just trying to see how everyone else cuts tubes.


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## danbot2001 (Feb 3, 2015)

Hey! this is awesome! can you tell me more about this set up?

I found this: PRO-TOOLS Tube Benders | Pipe Benders | Tube and Pipe Bender | Pipe and Tube Benders

what are you using as the engine? I already have the fixtures.. some from anvil, some from sputnik, but this looks awesome.


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## unterhausen (Sep 28, 2008)

I think it's intended for you to use a hand drill


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## BenCooper (Feb 25, 2013)

Mine? A cordless drill, running as fast as it'll go (2000rpm).


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## smudge (Jan 12, 2004)

ggodwin said:


> Walt,
> I actually ordered a block to do that three weeks ago but was wondering how everyone else did it.
> 
> The Intent of this thread is to just see how most of you cut your mitre's.
> ...


I did that for myself a few years ago. Based around the clamp that Jeff at Sputnik uses on his. Except I added 4.) c-c lengths accurate to about a thou

Untitled by VertigoCycles, on Flickr

the whole thing by VertigoCycles, on Flickr

Phase keeper by VertigoCycles, on Flickr

I don't seem to have photos of the BB dummy that I use to align down tubes when I cut for the Head tube. Also not shown is a stepped sleeve that goes over the TT phasing doo dad. It's a 1" center bore with a 1.25 and 1.375 OD that I can slide on to key the TT into place. The ST dummies rotate on center so there aren't any conversions or adjustments to do. The whole thing is based on center measurements so there's no marking or scribing. I just put the tube in, set the angle on the rotab and cut.


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