A modular frame building system

[Will Neide]

Put heavy duty rare earth magnets on the bases and mate them to one of my Alignment tables.

That's my next step.


My table is granite and things can annoyingly slide. Your table with magnets embedded in the blocks would speed things up quite a bit.

[devlin]

I was thinking of trying to modify some of the magnetic bases, like the ones used for dial indicator stands etc. and mounting my head tube and seat tube locators on them. Then I could set the two tubes and have my jig and alignment table in one place. Access to a machine shop is my limitation.

[devlin]

Put heavy duty rare earth magnets on the bases and mate them to one of my Alignment tables.

One of your tables is a goal of mine. Total bad ass bit of gear.

[Mark Kelly]

Don't use rare earth (NdFeB) magnets anywhere near heat, they have low Curie points. Use Alnico instead, just remember to use a keeper if the magnet is not in use.

[Mark Kelly]

BTW if the posts are made from ferritic or martensitic steel, you could simply put the magnets on top and they'll hold the posts onto a cast iron plate: an attractive force is generated if that allows more flux lines in the field to flow through a material with higher permeability. Aluminium or austenitic SS won't work.

Here's a crazy idea for your current setup: since you are probably going to need a vacuum pump sometime, buy one now. Drill holes in the bases of the posts and drill and tap a cross hole that connects these holes. Screw push on pneumatic fittings:

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into the tapped holes, connect them in a daisy chain with say 5mm PU tube and connect this to the vacuum pump. A bit of silicone grease on the bases as a vacuum seal and the posts aren't going anywhere. Silicone grease has very low vapour pressure so it's recommended for vacuum seals, it's available from any lab supply.

[devlin]

Oh man. That's just getting complicated now.

[incepi]

All of the suggestions so far are very helpful, but I will test the system as is just to get a frame built. After that I will consider modifications based on experience. I just want to get something built. I enjoy designing to perfection. Sometimes though you just have to make do with what you have. I still have to develop the rear triangle fixture. The challenge will be to make it as simple as the front triangle fixture without sacrificing precision and flexibility.

[David Tollefson]

...After that I will consider modifications based on experience...

The irony is strong with this one.

[Will Neide]

Look into the Sadoff method for rear triangles.

what's up in Santa Cruz: Here's how I use my rear triangle jig

[incepi]

The irony is strong with this one.

No comment.

[incepi]

A little update on the tube holding system. Nothing of substance. Just an excuse to show red anodized parts.

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