Frame jig build.

[afwalker]

alex wetmore's fork kit is great. Just add 8020 from the ebay store and off you go. It's looks about the same price as the item extrusions fwiw.
Alex Wetmore is always busy with something… » Store: Framebuilding Tools
but,,,
he's sold out. Maybe an email to him and see when it will be available.
cheers
andy walker

[Alistair]

Andrew, I was under the impression that 8020 was pretty flat. Do you know the tolerances? I should probably call and ask I suppose.
I'm guessing I'll have to shim some stuff anyway, even if the extrusion is perfectly flat. I've also thought about planing it on a mill. It will difinitely be checked for flatness on a surface plate once it gets here.


I've been thinking that too. Someone on the internet is selling kits to make a fork jib from some 8020. I think a lot of people might be interested in that.

I'm not speaking for Andrew, but here's my take.

When I built my jig last year I looked into the tolerance spec's for 8020. Don't remember the numbers off the top of my head, but my conclusion was that it was easily good enough. I checked it on a surface plate and with calipers when it arrived and found it to be very accurately made and twist free.

I looked into the German made item stuff at the time I was sourcing extrusions and at that time it was much more expensive than the 8020. Maybe the price has come down now? I don't know though, I haven't checked recently.

I went with 8020 because I didn't feel the extra cost (and tighter tolerances) of the item product was justified, or necessary, for frame building. I guess that decision will ultimately be up to each individual builder to make.

The 8020 fork jig that you mentioned was being made and sold by Alex Wetmore, Alex Wetmore is always busy with something… » Store: Fork Fixture Kit Assembly Instructions
It's no longer available but looking at the pic's in that link will help you with making something similar.

I built one, with a few extra tweaks of my own, here's a link to some pic's that might be helpful,
Fork jig. - a set on Flickr

Alistair.

[ScottB]

When I built my jig last year I looked into the tolerance spec's for 8020. Don't remember the numbers off the top of my head, but my conclusion was that it was easily good enough. I checked it on a surface plate and with calipers when it arrived and found it to be very accurately made and twist free.

I looked into this as well when I purchased some 8020 last year, and felt the straightness and flatness tolerances were adequate for framebuilding. I found the spec in their catalog. Page 644 here:

Straightness 0.32mm (0.0125 in.) per 304mm (1 foot) of length, not to exceed 3mm (.118 in.) over 6.1m (20 feet) of length

[adarn]

Hey Scott,

Thanks for the numbers. I think that should be just fine. And as I said, everything will be calibrated on a surface plate and shimmed if necessary before I use it. That should be a fair enough starting point though.

[dsaul]

This is a fork jig I built from 8020.

Fork Jig - a set on Flickr

I would have used flat plates to join the section with the v-block, but these were the fasteners I had on hand. The angle brackets with the bolt through them are to register the fork blades so they are parallel with the dropouts. I'm also planning to make a block for an Anvil dummy axle to replace the 8020 pivot that I'm using for a dummy axle now.

For cutting the 8020 extrusions, or any aluminum for that matter, I used the Freud D1080N blade in my miter saw/table saw. It cuts the heavy extrusions easily and leaves a very clean cut.

Dave Saul

[ToddFarr]

I get all my extruded aluminum from the Japanese company MISUMI. I like it because I can use there CAD configurator to generate a part number with pre position bolt holes and cut to size to the 1mm increment. Every piece that has come into my shop as been perfect and the length had been within plus or minus 0.1mm. Great stuff, tons of profiles, and quick shipping. Way better than 8020 and item in my opinion. It does only come in metric though. Check it out.

[adarn]

I'll definitely look into that. It seems there are a lot of different extrusions out there.

8020 has their whole catalogue available for solidworks as well. You can find that here: Free CAD Models, Free 3D Models from 80/20 Inc.

[ToddFarr]

Yeah I know they have CAD for 8020, but MiSUMi actually assigns a part number to a modified part Aluminum Frames - 8 Series, Base 40, Four-Side Slots | Mechanical Components for Assembly Automation - Misumi eCatalog.

Take a look at all the stuff you can alter Misumi PDF Viewer.

So say if I was looking for a 40mm X 40mm extrusion 105mm long with the right end tapped, MiSUMi will generate a PN for this GFS8-4040-105-LTP, I can go and order that part anytime it will be cut to length 105mm, tapped on one end and shipped to me in 2 days for $10.52 + shipping. That saves me serious amounts of time not having to worry about cutting or machining the Extruded Material when it gets here.

There are a lot of different extrusions, and they are mostly all the same, just don't want the value of this mass customization to be over looked, especially if you are building the jig yourself.

-Todd.

[adarn]

Oh wow, I didn't realize that you could do all of that stuff. Thanks for bringing that up, Todd.
I'll definitely go through and see how that stuff might work.

-Adam

[adarn]

Well I did a pretty terrible job on keeping this updated. Things went really slow for a long time and then really fast, and I was really busy with school and all. I just got the fixture finished though. It came it really great. Everything is within .001" pretty much which is way more than good enough for me. Really excited to start building on it. Let me know if you have any questions.
Adam

[fortyfour]

Well now... look at how THAT turned out! Nice work. Time to start makin' chips as they say.

[adarn]

Well now... look at how THAT turned out! Nice work. Time to start makin' chips as they say.

Hey, thanks Kris! I bet it looks a little familiar, eh?
I'm real excited to get building in it, should be getting started here soon.

[Mark Kelly]

Looks really good. Anybody else interested in a copy?

Adarn, would you consider sending the drawings to Alex Meade (or Todd if he's interested) and getting a price on multiple sets?

Maybe we could set this up as a group buy with a kickback to VS. We could ask TT if he'll allow it as a sticky in the new classifieds. If you want any help administering the group buy I hereby volunteer.

FWIW I tried to set up a group buy on BikeForums last year and got lots of interest. The project died when I realised my jig design was a POS.

[adarn]

Hey Mark,

I'll send you the solids or drawings if you like. I'm not really interested in organizing anything, but if you'd like to look at my design or have it made, you're welcome to.

[Too Tall]

Resounding YES. I've been following this. Love the collaboration efforts. Y'all rock. Make it happen. PM me when the new thread has been created and I'll stick it.

Looks really good. Anybody else interested in a copy?

Adarn, would you consider sending the drawings to Alex Meade (or Todd if he's interested) and getting a price on multiple sets?

Maybe we could set this up as a group buy with a kickback to VS. We could ask TT if he'll allow it as a sticky in the new classifieds. If you want any help administering the group buy I hereby volunteer.

FWIW I tried to set up a group buy on BikeForums last year and got lots of interest. The project died when I realised my jig design was a POS.

[David Tollefson]

Looks really good. Anybody else interested in a copy?

Are we talking a copy of the jig, or the plans?

[seankanary]

That jig looks great!

[Jussi Kettunen]

Adarn, very nice jig! That reminds me that I need to make some upgrades for my jig.

Is bottom bracket post drilled for back purging? Can you send me drawing of bottom bracket post?

[Mark Kelly]

Are we talking a copy of the jig, or the plans?

I'm currently talking to various parties about organising a group buy of a kit version of the jig.

The plan is to get a quote on getting all the tricky bits machined, with each participant to add their own extrusions and common hardware.

If this is doable for a reasonable amount of money*, I will run the group buy on VSalon classifieds, pricing it at cost plus 10% to VSalon.

*IMO the total would have to come to less than the cost of doing Todd Farr's mods to a Bringhelli for this to fly. It is by no means certain that we can get the machining done for that much.

[triathloner]

Depending on pricing, I'd be in for the machined parts as well, this jig is looking Nice!