# My first attempt at Basement Framebuilding...



## stuntnuts (Dec 7, 2010)

This is a Flatland BMX frame that I'm building. I took the UBI 4130 TIG class way back in May of 1999 and I'm finally putting what I learned to good use. I'm using a JD2 NotchMaster and am actually quite impressed with the results. It's really going to be a challenge utilizing it for the rear triangle, but I'm gonna give it a shot.

I picked up a Miller Maxstar 151 w/ SnapStart shortly after I took the class. Aside for using it a few times for automotive projects, it has been sitting patiently on the shelf. I literally haven't welded in about 7 years!

I built a jig based on 80/20 extrusions over the past year and I'm hoping it performs as designed. It's gonna be a long journey


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## febikes (Jan 28, 2011)

Your jig looks awesome!

The miters look like the could be tighter but I think you can make it work if you are careful on the welding. You might want to use a file and/or grinding wheel to tighten up the miters but it is hard to tell from here. Still, you look way ahead of me; good job.

-mark


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## Clockwork Bikes (Jun 17, 2006)

Looks good. Keep going and post pics.

-Joel


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## Smokebikes (Feb 2, 2008)

Nice work space and jig...........*1999*, you definately are in the running to get the "award" for the longest frame project turn-over on MTBR.  Keep it up and post often. :thumbsup:


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## biketrials25 (Jan 20, 2008)

Looks awesome! Did you make the ht and st cones for your jig?


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## pvd (Jan 4, 2006)

Where did you get that head tube?


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## stuntnuts (Dec 7, 2010)

Thanks guys. The headtube and BB shell were purchased through Aaron Huff at Solid Bikes. The HT and ST cones are custom made to my specs.

The miters are pretty tight, they just don't look it because the centerline of the tubes is all over the place because it's laying on a flat surface and none of the tubes have the same O.D. None of the tubes are actually laying parallel to the table. These miters are straight out of the NotchMaster, no filing yet, as my tubing blocks are still in the mail. They should be here tomorrow and I plan to do some filing then.

What's the best chemical to strip the coating off the tuning?


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## Clockwork Bikes (Jun 17, 2006)

Hot, soapy water and a round brush for the inside. Then emery clothe then acetone right before welding/brazing. Don't forget to clean the filler too.

-Joel


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## stuntnuts (Dec 7, 2010)

Clockwork Bikes said:


> Hot, soapy water and a round brush for the inside. Then emery clothe then acetone right before welding/brazing. Don't forget to clean the filler too.
> 
> -Joel


Thanks for the info, what grit do you recommend?


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## Clockwork Bikes (Jun 17, 2006)

80. Cheap stuff for removing grime, 3M stuff for finish work.

-Joel


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## D.F.L. (Jan 3, 2004)

Do tools exist for reaming Mid/Spanish BBs?


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## stuntnuts (Dec 7, 2010)

D.F.L. said:


> Do tools exist for reaming Mid/Spanish BBs?


From what research I've done and builders I've asked, it's not a common practice. If needed, I will make some heatsinks to put in there while I weld it up. I'm concerned with the HT more than the BB shell. I know my Hoffman frame I ride now wasn't reamed and definitely has some warp-age in the HT when I drop the bearings in.


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## HomeGrownSS (Jan 18, 2006)

Clockwork Bikes said:


> Hot, soapy water and a round brush for the inside. Then emery clothe then acetone right before welding/brazing. Don't forget to clean the filler too.
> 
> -Joel


personally i think cleaning with acetone for brass brazing is a waste of time and materials, unless something is contaminated. if your emery is relatively clean then there is no need for acetone. brazing with brass is a dirty process, the flux does a good job of floating impurities out of the joint.
for welding and silver brazing i do prep with acetone beforehand.
thats just me though, do as you will! :thumbsup:


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## stuntnuts (Dec 7, 2010)

The front triangle all mocked up in the jig!


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## Feldybikes (Feb 17, 2004)

Jig and frame look rad. Are those angle adjust pieces off the shelf 8020 items?


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## stuntnuts (Dec 7, 2010)

Feldybikes said:


> Jig and frame look rad. Are those angle adjust pieces off the shelf 8020 items?


Thanks.

Yes they are off the shelf pieces (part number 4337), but the slide plates they bolt to behind them are custom.


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## Evil4bc (Apr 13, 2004)

stuntnuts said:


> From what research I've done and builders I've asked, it's not a common practice. If needed, I will make some heatsinks to put in there while I weld it up. I'm concerned with the HT more than the BB shell. I know my Hoffman frame I ride now wasn't reamed and definitely has some warp-age in the HT when I drop the bearings in.


Just dont weld right on the bearing races , keeping the heat away from these is key.
As long as the tubes are mitered and welded into the center of the HT you wont have an trouble with Aaron's HT's warping at all .

Post weld reaming on these isnt really needed as your never going to get them a acurate as the CNC machine can with hand tools .

Frame and jig look great !:thumbsup:


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## stuntnuts (Dec 7, 2010)

Thanks for the info on Aaron's HT's and the positive feedback.

I'm REALLY struggling right now with bending seatstays. I'm almost ready to throw in the towel. I am so NOT a woodworker and don't really have the right tools for it either. I decided to try some bending on some .049"x3/4" 4130. I want an 18 degree bend over a 3.5" CLR.

Flatland BMX bikes have very short rear ends and the radius has to be very tight. I used 3 layers of 3/4" plywood, cut with a jigsaw, and bolted together to make my "form" and I used some 1/16" strap steel to hold the tube in place. I filled the tube with some Maine beach sand and went to town.

I used an old 1" BMX fork as a lever over the tube being bent. The form was clamped in my vice. The bend surprisingly came out really good as far as no kinking, etc. but I didn't consider "tubing spring" when I made my form at exactly 18 degrees. I ended up with only a 13ish degree bend.

The form I made is tough on the body to use and I'm not sure how I can control a consistent 18 degree bend with each stay even if I reshape my form to have more degrees in it. Should I scrap this idea and try using a vice to "press" the form into the tube? I will be bending .035"x3/4" for production, will this size be easier on my body to bend with this style bending process? Any advice?


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## HomeGrownSS (Jan 18, 2006)

thats a pretty nice bender that you cobbled together. id say since you got it to work you might as well rebuild it to get the bends you desire.


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## biketrials25 (Jan 20, 2008)

Did you weld caps on the ends to keep the sand in?


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## stuntnuts (Dec 7, 2010)

biketrials25 said:


> Did you weld caps on the ends to keep the sand in?


Duct taped both ends, nothing more.


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## stuntnuts (Dec 7, 2010)

So here goes round two for seatstay bending. This is the same CLR as before (3.5"), but with more of degrees in the radius. I did not pack this one with sand to see what the results would be. The outside radius of the tube definitely squished some. I was however able to get the exact angle I was going for, 18 degrees.

I would bend in small increments and recheck the angle with the Wixey until it was good. After the desired angle, I put the tube itself in the vice and squished it in the opposite direction to get it's shape back. This was another .049"x3/4" tube. I think I'm going to try one more "form" similar to this one but with a larger CLR, probably 4" or 4.5". I guess 3.5" is just too small. I'm gonna try it on .035" tubing with that "form" and see how it goes. I'll pack the first one with sand and post the results.

If the next attempt fails, I will probably purchase a JD2 Model 3 and play around with that.


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## stuntnuts (Dec 7, 2010)

Well, I made a 4.5" CLR "form" today and tried to bend some .035"x3/4" 4130. I packed with sand and it still squished the hell out of it. Not even worth posting pictures. A MAJOR setback here, and I have no idea what my next move is.


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## dr.welby (Jan 6, 2004)

stuntnuts said:


> Well, I made a 4.5" CLR "form" today and tried to bend some .035"x3/4" 4130. I packed with sand and it still squished the hell out of it. Not even worth posting pictures. A MAJOR setback here, and I have no idea what my next move is.


Well, there's the "pack it full of welding rod trick" if you're looking for a next move to try.

Does the new form support the tube at its sides?


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## stuntnuts (Dec 7, 2010)

dr.welby said:


> Well, there's the "pack it full of welding rod trick" if you're looking for a next move to try.
> 
> Does the new form support the tube at its sides?


Good call, I forget about welding rod. I'm gonna try the ice filled tube in the AM, if that fails welding rod is next. I'm getting sick of wrecking tubing. 

The form really doesn't support the sides. It's 3/4" plywood (which is just under 3/4") and 3/4" tubing. The tube just kinda sits in the groove.


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## dr.welby (Jan 6, 2004)

stuntnuts said:


> The form really doesn't support the sides. It's 3/4" plywood (which is just under 3/4") and 3/4" tubing. The tube just kinda sits in the groove.


Support on the sides could help. Maybe rebuild it with higher sides and add a shim to get it 3/4 wide. Or since it bolts together, loosen it up and clamp the tubing between taller side plates. The center piece would benefit from a round or V groove too.

There's also this approach:

http://www.instructables.com/id/Easy-Fork-Blade-Benders/


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## stuntnuts (Dec 7, 2010)

I tried the ice trick on a .035" tube, it sucked. I tried filling one with welding rod, it sucked too. The welding rod worked better than the ice though. The tightest part of the bend started to wrinkle, squishing wasn't too bad, definitely better than with the beach sand. 

I'm now convinced that I need to use a larger radius and I need a round or v-groove center piece. The flat center piece just blows. I have no desire to build anymore "forms" out of wood, myself. I hate working with wood. It's messy, I don't have the right tools for it, and I'm sick of failing. Plus I don't like the fact that I have no precision or control over how many degrees I'm bending until I end up going over the degree I'm after.

I think I'm moving on to some sort of off the shelf bender. It's very discouraging because the front triangle went absolutely perfect and I'm only in the beginning stages of the rear triangle and I want to quit. I still haven't begun to battle mitering or dropouts.....ugh!

Any advise on the bending matter would be greatly appreciated. Stay tuned.


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## HomeGrownSS (Jan 18, 2006)

i thought you were using a v-form all this time.
if you can find someone to help you out you could probably make one with a v out of wood that would work.


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## stuntnuts (Dec 7, 2010)

HomeGrownSS said:


> i thought you were using a v-form all this time.
> if you can find someone to help you out you could probably make one with a v out of wood that would work.


Nope, unfortunately no v-form, just a flat edge of plywood. I guess that's the root of all my evil huh? 

My problem is I really don't know anyone currently in the woodworking field. :madman:


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## HomeGrownSS (Jan 18, 2006)

hmm if you are really desperate you could probably get it good enough using handsaws and files!


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## stuntnuts (Dec 7, 2010)

True, but again......no patience or desire to work with wood.


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## Clockwork Bikes (Jun 17, 2006)

I know less about wood than I do about carbon fiber and I was able to get a nice v-groove by cutting out two mirrored shapes with my jig saw set at 45*. Then glue and screw together,

-Joel


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## dperalta (Dec 31, 2008)

Here's what I have done. Clamp a small iron dumbbell weight to my welding table. I use 2 prices of angle clamped to the table to fix the length and support the back side. Heat with a rosebud flame to cherry and it will bend like soft butter. I scribe the angle into the table and use that as a guide. 


David


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## stuntnuts (Dec 7, 2010)

Clockwork Bikes said:


> I know less about wood than I do about carbon fiber and I was able to get a nice v-groove by cutting out two mirrored shapes with my jig saw set at 45*. Then glue and screw together,
> 
> -Joel


Joel,

What size tubing and wall thickness are you bending on this setup? Any pics of the bender and the results?

Thanks


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## Clockwork Bikes (Jun 17, 2006)

Pics here: http://forums.mtbr.com/showthread.php?t=565074

2' radius for bending 1.125" x .035" toptubes. .028" didn't work. I haven't tried smaller radii, but I suspect you'd need to reduce the tube diameter or increase the wall thickness.
I also bend 16 and 19mm seatstays on my fork blade bender with a 10" radius.

-Joel


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## Francis Buxton (Apr 2, 2004)

I get the sense that you're OK with spending a couple of bucks on a tool if it helps you get things done right. Buy a good jig saw (or router) that will let you set your cut at 45 degrees Make your internal radiused piece out of two pieces of wood (mirror image) that are cut at 45 degrees and sandwiched together.

See the Hammill Engineering bender for reference:
http://www.cycle-frames.com/bicycle-frame-tubing/FORK-BENDER-HAMMILL-ENGINEERING.html

I happen to have one that I got from a friend, and it does a good job. I can bend .035 5/8" and 3/4" tubing with no flat spots pretty consistently. Everything I have read says that you get about a 10% springback rate, so undersize your radius by that much.

The guy that I got the Hammill bender from made a bending form the above way out of two pieces of MDF to make twin top tubes and it worked well. I think you're really close, and the V notch in the center should get you the rest of the way.


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## stuntnuts (Dec 7, 2010)

My jigsaw does actually let me set the cut at 45 degrees. I guess it's worth a shot. Is a V-notch going to give me as nice a bend as if I made one with a true half-round radius?

Do you have to support the inside of the tube with anything when bending?

So you are saying that if I want a 6" CLR, then make my form radius 10% smaller, so approx. 5.375"?

Thanks for the info


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## stuntnuts (Dec 7, 2010)

Sorry for the long delay. After spending way too much time messing with wood, I designed a proper bender built out of aluminum. After many conversations with members on here and studying many pictures on the internet, I figured out what I wanted. I designed a solid model of it with AutoCAD 3D and sent the prints to my machinist.

This is where the wait began. I dropped the prints and materials off on the first week of May and after still not being delivered two weeks ago, I fired him and sent the prints to another shop. They got it done for me in 6 days :madman:

Anyways, here is the bender finally in my hands. If you've been reading this thread you know I'm building Flatland bikes, using .035" and .049" walled, 3/4" chain and seat stays. The center line radius is 5.5" and the overall range of the die is about 35 degrees.

I got everything sorted and did my first test bends tonight. I pleased to report that I had 100% success! I bent .035" and .049", 3/4" diameter without any wrinkles, squishing, or flattening. I did not use any sand or anything inside either.

Overall I'm very happy with it, the only thing I'm going to improve on is I need to get more degrees out of the bender. Right now the last stop on the bender only gets me to an 18 degree bend, which is what my chainstays are based on, luckily. But I'm only utilizing about 1/2 of the full range of it right now. I'm going to add a few more stops and I should be able to get right up to approx. 35 degrees.














































Here are the results.... The tube on the left is .049" and the tube on the right is .035". Those are the only sizes I will be bending with this bender.





































I'd especially like to thank Lyn Jones (Citizen Kane on here) and Don Ferris of Anvil Bikeworks for answering numerous questions and not killing me. Also anyone else on here I'm forgetting who helped me with this.......thank you!

This portion of the project really was the biggest hurdle by far. I'm thinking and hoping the rest will get easier. I'm looking forward to the remainder.....stay tuned.


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## Clockwork Bikes (Jun 17, 2006)

Looks great! I'm looking forward to the rest.


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## cdn-dave (Jan 6, 2007)

Sweet build, thanks for sharing! Looking forward as well to the rest.


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## todwil (Feb 1, 2007)

Nice bender I like seeing all that aluminum very cool!!:thumbsup::thumbsup:


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## capt.crispy (Nov 17, 2006)

Wow looks great.Can't wait to see more.


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## todwil (Feb 1, 2007)

Any pics of the frame tacked or welded?


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## stuntnuts (Dec 7, 2010)

Thanks guys, I'm psyched on the bender. I'm designing my seat/chain stay notcher now.

No welding yet.....it's coming.


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## stuntnuts (Dec 7, 2010)

Rear triangle time!

I do not have a Bridgeport nor a stay fixture, so I'm screwed right? Not necessarily.....
I decided the best thing to do would be to build a stay fixture and eliminate the need of a Bridgeport all together.

If you've been following my thread, you know that I used a JD2 Notchmaster for my front triangle and had great results. I figured I'd try to design a stay fixture that could somehow incorporate some of the key components of the JD2 Notchmaster.

I modeled up my design in AutoCAD and sent the prints to my machinist and I had Alex Meade Bikeworks build me some custom tubing blocks. I wanted to be able to notch both chainstays and seatstays with the same fixture. I'm very pleased to report that everything has been tested and works great. Enjoy the pics....

We'll start out in Chainstay Mode.

Here is my "cut sheet" specifically for this frame.









Here's the fixture in Chainstay Mode. As you can see, it's very simple. Four tubing blocks, a baseplate, and an adapter piece to incorporate the JD2 Notchmaster shaft and swivel plate. The adapter plate slides forward and back to adjust for different stay lengths.






















































And the finished chainstays....









Now for Seatstay Mode....

Seatystays, all bent and ready for notching.









The seatstay "cut sheet"









Here is Seatstay Mode. As you can see, it's all the same parts with only a different adapter piece to adjust the seat tube/seatstay intersection angle. Again, this adapter piece slides forward and back to adjust for different seatstay lengths. The same parts from the Notchmaster are used, just mounted in a different direction.



































































































And the finished seatstays....


















I'm very satisfied with the overall results of my notcher. I'd like to thank Alex Meade for his help making the tubing blocks for it. He's a great guy to deal with and does fantastic work. If anyone wants more info on the notcher, just ask.

Now it's time to get my dropouts cut and start welding these things up!

Stay tuned....


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## todwil (Feb 1, 2007)

those are some real nice fixtures you made there now weld that baby up and take some more pics


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## stuntnuts (Dec 7, 2010)

I finally got my dropouts back from the laser cutters. I got a new 14mm dummy axle from Alex Meade as well. Here's the rear triangle all mocked up.


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## todwil (Feb 1, 2007)

*Saaweet!!*

WOW nice work even the tools you made nice!!!.......Nice!!!


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## Scotty510 (Nov 6, 2010)

Looks killer, now get some weld bead on it!

Hope you don't mind but I totally stoled your frame jig design a few months ago! :thumbsup:

Scott.


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## mwb (Dec 4, 2007)

Fantastic! Looks awesome. Keep up the good work!


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## Foliveira_pt (Oct 30, 2009)

Very cool project!


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## stuntnuts (Dec 7, 2010)

Thanks guys.

Does anyone have any advice for removing hot-rolled mill scale off of my dropouts? I inadvertently ordered hot-rolled plate instead of cold-rolled and the finish is horrible. :madman:



Scotty510 said:


> Looks killer, now get some weld bead on it!
> 
> Hope you don't mind but I totally stoled your frame jig design a few months ago! :thumbsup:
> 
> Scott.


I don't mind at all, I'm in the business of making frames....not tools.


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## sonic reducer (Apr 12, 2010)

stuntnuts said:


> Thanks guys.
> 
> Does anyone have any advice for removing hot-rolled mill scale off of my dropouts? I inadvertently ordered hot-rolled plate instead of cold-rolled and the finish is horrible. :madman:


I work with hot rolled a lot flat grinding it and such things. lightly(lightly) grind it with a grinding wheel to break up the surface(it is very hard on sanding disks) then flat sand it with a 60-80 grit flat disk on a grinder. 
but you might as well shelf the hot rolled and get at least some 1018 cold rolled plate or better yet some 1/4x1 or 1.5 4130 strap. hot rolled is some shitty stuff, poor tolerances, flatness, uniformity of alloy etc. wouldnt dream of using it in a bike frame.


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## stuntnuts (Dec 7, 2010)

I agree, the stuff does suck. Anyone have any leads on .190" 4130 cold-rolled sheets?


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## hardtailkid (Jan 25, 2010)

Damn.


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## sonic reducer (Apr 12, 2010)

maybe not the cheapest but...
Order Alloy Steel 4130 Sheet in Small Quantities at OnlineMetals.com


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## Sk8er07999 (May 12, 2008)

This is absolutely amazing work. I cannot wait to see your future progress! 

Sent from my Nexus S 4G using Tapatalk


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## Campbell (Nov 13, 2011)

Thank you for the great ideas.


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## jgrano (Dec 5, 2011)

Your CS SS Jig looks great. I've been trying to think of a good way to build one up and now I think.. I'll just copy your awesome design!


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## TLKD (Mar 29, 2010)

X2, that Chainstay / Seatstay notching jig is awesome. Maybe the tube holding device could be worked to suit more tubes and angles. 

Very creative thinking.


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## ROSKO (Oct 11, 2009)

stuntnuts said:


> I agree, the stuff does suck. Anyone have any leads on .190" 4130 cold-rolled sheets?


Catch Dillsburg while they still have some. I just picked up a 36x48 sheet:thumbsup:


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## ggodwin (Apr 25, 2011)

jgrano said:


> Your CS SS Jig looks great. I've been trying to think of a good way to build one up and now I think.. I'll just copy your awesome design!


Me too!
Now, if we can also add the CANT mount in here also....


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## ggodwin (Apr 25, 2011)

Bump


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## bikecycology (Apr 26, 2010)

sub'd


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## wms (Aug 8, 2007)

Love the various fixtures you made! Subscribed.


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## stuntnuts (Dec 7, 2010)

I'm alive and well, just not on here very often. Feel free to follow me on Instagram. https://www.instagram.com/stuntnuts4130/


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## MannaDesigns (Mar 5, 2013)

Big props to you man, thanks for all the help outside the forum!


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