Spine Joining

I've already made good progress on this jig before posting to the forum so I'll try and provide quick updates.

To join the spine I first did a light skim cut on the end of the extrusion after aligning it to the mill table. The cut was already pretty square but because of the long arm being attached to it, I though it was very important to get it as good as possible.
Cutting the end:

Next I drilled and spot faced the 80-40 piece for the M12 bolts:

To clamp it together, I used the mill table as as datum while tightening. This setup worked okay but still required some tweaking.

Assembled:

 

looks like a good start I did the same thing, did a little internet R&D (review and duplicate) and did an 80/20 jig I think total cost was $400 or so....The guys jig I copied PM'd me saying he went and looked to see if it was still in his shop I didn't think I copied it that close.

 

Dummy Axle Holder

My last update might be stuck in new poster purgatory but here is the next round. Again, I'm nearly done with the jig so this is more of a documentation for others in the future.

Here is the full dummy axle assembly complete (without axle)

I made the horizontal support and used two screws plus dowel pins to secure it to the vertical sliders. The pins allowed for a very clean and snug assembly that kept things on center. I machined the slot for the axle with a 1/2" ball end mill, leaving 0.02" of clamping room.

I did, however, mess up cutting the side reliefs and overcut. The plan was to do the slot at 2.5" so I could use Anvil axles but since I'm planning on making my own anyways 2.25" works just fine!

More blind joints to hold together the extrusion and then I counter sunk two M12 bolts in the support plate to hold it on. Here is a good view of the assembly:

You'll notice I didn't face the 1/2" slider plate that mounts to the 160-40 spine. I debated this but all three slide plates were within 0.002" which seemed to me to be as good as I could expect of myself. When you consider all of the stack contributing to the center line of the frame, this seemed pretty good to me! If I wanted to go crazy I could have bought the cast mic aluminum remnant but that was $6/lb vs $2.5.

 

This is a jig I recently built for another builder. There are more pics on my Flickr page here https://www.flickr.com/photos/starrcycles/ if they help you with any ideas for yours. Some of the ideas were borrowed from Kris Henry at 44Bikes.

 

For extrusion I used Misumi 40 series stuff. 160-40 for the bottom rail and 80-40 for the vertical. I HIGHLY recommend Misumi for your extrusion, it's really high quality and much cheaper than 80/20 brand. They also custom cut for no extra change so you only pay for what you need. My only complaint is that this series is drilled for an m12 blind joint hole. That's a big bolt!
Total spend on extrusion: $153

Never tried the Misumi extrusions. Did you buy directly from them, or do they have an outlet store, kind of like how 8020 has 8020 garage on Ebay?

Alistair Spence,
Seattle, WA.

 

Never tried the Misumi extrusions. Did you buy directly from them, or do they have an outlet store, kind of like how 8020 has 8020 garage on Ebay?

I bought direct from the Misumi website. It's a little bit clunky since the site configures a part number each time but it works pretty well. Their applications support is also super knowledgeable and ready to help and provide ideas. I can't say the same for 8020.

DSaul nice jig! Very similar to how mine will turn out. How did you align the measurement tape/pointers? I assume just make some measurements off the jig locations and glue it on?

 

The scales I used are self stick vinyl from McMaster-Carr. For convenience, I had to offset some of the pointers from the actual centers. I just took measurements from the bottom bracket and aligned the appropriate mark on the tape with the pointer before sticking it down. The pointers are from a Skil miter saw(I think). I was able to find them at eraplacementparts.com They still needed some modification, but I'm happy with the way they worked out. I can probably find the part number if anyone wants it.

 

Bottom Bracket/Seat Tube Fixture

Here is some more:

I didn't like the idea of the floating BB that some of the 8020 designs use. The clearance is nice but I didn't think my manual machining and no-rotary table setup would get me the tolerances that I wanted.

I decided to go with a fixed pivot. For this I made a block for the end of the seat tube and then bored and pressed in a brass bushing. After pressing it in, I reamed to size and counterbored for thrust bearings. The counterbore on the backside is sized so that the bushing sits just slightly proud of the housing.

I turned the shaft from 0.75" steel bar stock

Assembled on the jig:

 

Head Tube Fixture And Cones

Head tube fixture is very similar to the bottom bracket but in this case I elected to put the pivot in the middle of the 8020 by pressing in and boring the bushing.

This ended up working out really well, I wish I had done the same for the BB. The second hole is for the cone mounting bracket. I went with a fixed bottom arm design. I'll swap in pucks of different heights for each head tube diameter to keep the rotation axis at the bottom of the tube.

For the cones, I did a 10 degree taper for the head tube and seat tube tops and a puck style for the head tube bottom. These are located by a dowel pin in the center and 1/4-20 bolts.

The arms were made from two different pieces of .5" bar that I bolted together and then finish machined. Instead of using dowels I put a key into the bottom.

Last step is dummy axle! I don't often turn between centers so this was pretty fun! I think it came out really well without much drama. Messed up centering the slot so it's at 131.80mm not 132mm (starting with a road bike first).

And then, just like that. It's DONE! Mounted it up on an engine stand I wasn't using. Now I really need to learn to braze!

 

Seahuston! I just found this thread. Great work and love the jig man!
-Steve

 

Thanks! Your awesome videos were a huge help!

 

How did you end up machining the curved slots in your plates? You mention a few times that you weren't using a rotary table so was curious how you ended up doing it. Nice work!

 

For the curved slot on the ST extension, I attached the bracket and the pivot point to the plate and mounted it in the mill. I centered the mill over the locking hole for the angle screw. Using the pivot point (screw tightened so that I could just barely move it) to move the extension I drilled a hole and both ends of the angle sweep. Next I swapped in an endmill and with progressive depth cuts, manual swept the extension between the holes.

This worked OK but it was a little freaky (though nothing bad happened). I made sure to stand outside of the arc of the extension and put up safety stops (bolts) to make sure it couldn't over rotate.

For the HT extension, I printed out a hole table for 30 points along the arc and used an endmill to plunge the holes. Quick cleanup with a file and it looked like a pretty smooth arc. I didn't want to do the sweeping approach since the lever arm is so much shorter with this piece.

Both methods worked okay for me but I think I would just to the plunges in the future, feels a lot safer. Because the arc isn't the actual pivot point in this design, it doesn't have to be very accurate.

 

Dear Seahuston - this is just awesome,

it is a great thing to see you creating a jig out of the three

pithy-bikes
tanner W ( instructable)
kristofer Henry (44 Bikes )


awesome: i also work on a 80/20 jig I think total cost gets approx 400 Euro
At the moment i am working on a chainstay-mitering (fixture)

 

dear Seahuston,

many thanks for sharing your awesome project - it looks so great - at the moment i am working on the tanner w. and use his measures:

you mentioned the data of tanner Ws frame jig construction.: btw: what does Tanner W use for the main spine !?


160 x 80 or
160 x 40 !?

see here: Bicycle Frame Building Jig

in the questions below the manual metalmicky asked 7 years ago

Hey Tanner, great post. I've begun my build following your instructions. Is there a mistake in your extrusion materials diagram however? You mention using 160 x 80 in your description on page two. But in your materials list you have a length of 160 x 40...??

and Tanner W replied: 160x80 seems correct

well you mentioned that tanner used the 80/20 brand - but in which dimension

For extrusion I used Misumi 40 series stuff. 160-40 for the bottom rail and 80-40 for the vertical. I HIGHLY recommend Misumi for your extrusion, it's really high quality and much cheaper than 80/20 brand. They also custom cut for no extra change so you only pay for what you need. My only complaint is that this series is drilled for an m12 blind joint hole. That's a big bolt!
Total spend on extrusion: $153

btw: as it seems - you make use of 160-40 for the bottom rail ....

what would you recommend me - should i go with 160-40 for the bottom rail or stay with tanner w s 160-80!?

images taken from the tanner W - instruction here: Bicycle Frame Building Jig

look forward to hear from you

 

wow this is verty awesome - ih fact i love it# very much

 

There are lots of companies offering extrusion channel, and some even will give you CAD to design it and they build it.

Manufacturing Automation, Simplified | Vention is the company that packages CAD with manufacturing your rig.

Other extrusion profiles are ones like

MiniTec T-Slotted Aluminum Extrusions. Modular Aluminum Profiles For Custom Construction From Aluminum Extrusions. Custom Clean Rooms, Ergonomic Workstations, Belt Conveyors, and Machine Guards Are But A Few Applications.

Aluminum Profiles

Frame your factory with the world’s largest selection of aluminum profiles

www.boschrexroth.com

The kicker is that they are all going to be slightly different, and have all different fasteners to put them together that are not compatible between brands.