My Alignment Table

It has taken a while but here it is. Top plate is 29.00 x 22.50 x 1.00" steel and blanchard ground flat. NO it's not big enough, but I think it's better than nothing. Plate and grinding was donated by a friend, I bought the tubing for the legs and traded some work for the welding. I drilled some holes to mount a BB Post and some other "fixturing" I plan to use. I also machined all 4 sides so it is nice and square. The plate has some "extra" holes in it from it's previous life, but who know maybe they will come in handy for something. Tried building my 1st frame without a nice flat surface and wasn't very successful, hopefully the 2nd one will be better with this.

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nice - i've been looking to do something simliar for frame #2. was lucky enough to use an anvil jig for frame #1, but back at home my tooling is much more limited. alex meade made me a flat plate fixture which is extremely nice, now i just need a suitable surface for it and some place to set it up.

Eric- I think this plate will work well enough for you. A little creative placement and gauging might be needed but that's part of the fun of making your own stuff. Andy.

That looks like a very usable table.
I couldn't find a piece of steel that big so I got a big granite chunk from Grizzly: Not too expensive:

G9657 24" x 36" x 4" Granite Surface Plate, 2 Ledges
Here it's in a table I made:
Head tube method | Flickr - Photo Sharing!
Used a hammer drill to make a hole for the post.
All those extra holes probably will be of some use I bet:)
cheers
andy walker

Andy,
Did you just use a masonry bit? I was thinking of using a diamond hole saw and just a drill press because I was worried I'd split my granite.

OP, table looks great, wish I had a steel one it would be nice to drill and tap easily for fixtures and such.

-Todd.

Todd, you can drill granite in different ways, a masonry bit is a small risk of fracturing the granite, I used a diamond core bit, use a drill press or jig to start a straight hole, break the core off and pull out with forceps, after first core the hole will self guide rest of hole, keep drilling, breaking core, and removing till you get through, use clay to make a damn to hold water in hole. Takes a while but got through my 6" plate. Or pay a headstone manufacture to drill it for you

Sam,
Thanks for the tips! I'm planning on trying it out this weekend!
-Todd.

Todd,
Actually used cheap HF masonry drill bits and a hammer drill:
6 Piece SDS Masonry Bit Set
Used lots of water and it went great!
cheers
andy walker

How much abuse can a granite surface plate take? I found one on craigslist that is 24" x 36" and is fairly inexpensive that I might pick up to start frame #2. Whatever flat surface I get I plan on laying out the tubes and checking miters on the surface with v-blocks and then tacking on the surface. I'll be finishing brazing or welding on a welding table to keep the surface plate from getting too much abuse.

So I was just curious if a granite surface plate will take that kind of abuse or if I need to keep looking for a steel flat surface to build on.

Thanks for you help!

Hey Jim - Phil from Cedarboro bikes has an alignment table for sale at the Philly Bike Expo. It was a granite surface plate with BB post. I think it was pretty small, and maybe the same one on craigslist. I don't remember the price but it was cheap enough for me to be interested (even though I have a one already). Phil is an excellent machinist and all his tools are top notch.

rich adams

Thanks for the tip Rich.

How durable is a granite surface? Is it going to hold up if I tack my frames on it as long as I don't routinely get flux on it or put heat directly into it?

Hmm, that is a good question. The granite surface plate is insanely flat (the best feature), won't rust and the flux will clean off easily with hot water and not damage the stone. Shooting the torch directly on the stone for a long period may not be a good idea. With that said, brazing on metal in the vicinity of the plate (with v-blocks for instance) shouldn't be a problem. The plates are durable. As with all your tooling, if you want it to last you have to take care of it. Cover it will newspaper when you find yourself loading stuff on it.

Made some "Fixturing" for the table. Just about ready to start cutting some tubes.

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nice job.

Eric- Any thoughts to your brazing/aligning process yet? Tack in the fixtures, align on the plate and free braze? Andy.

Andy- Yes, the plan is to Tack/Pin in the fixture, align on the plate and free braze. Planning on doing the front triangle as an assembly and then building the rear. My 1st frame was built without a plate or fixturing and I wasn't happy with the alignment. This one should be better.

Quote:

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Originally Posted by jim_mt

Thanks for the tip Rich.

How durable is a granite surface? Is it going to hold up if I tack my frames on it as long as I don't routinely get flux on it or put heat directly into it?

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Why not use a plate of material under the joint you are brazing to protect the surface plate from heat and flux?

I've used simple plates of steel or Alu for this protection. I've seen Asbestos as well. Andy.