Planning To Build A Layout Table, Pics Needed!

[degull]

Hi everyone. I plan on fabricating a layout table out of 1" steel plate that has been stress relieved and blanchard ground. I was quoted $500 for the steel plate. I plan on using it to manufacture my own bicycle frames and use it as a welding table. Most of the posts I have read on the subject on this forum have eluded to a 3' x 4' size. I know it is a simple project but I would love to learn/see the experience of others. Please post some pics of your layout table!

[Will Neide]

http://www.velocipedesalon.com/forum...tmo-21294.html

This may be helpful.

Good luck!

[sam]

degull, you can usually find an actuall surface plate for 500. Im not going to be the most informed on metrology, but I see alot of the steel plates that some have made, and they look real nice, but I wonder are they as flat as they believe. I know we are not measuring things down to a tenth in the bike world, but if you are going to spend the money on a table might as well get a good table for the money. A real surface plate is made of thick aged cast iron, with heavy webbing to add structure. I steel plate ground, and I think it needs to be ground on both sides for stress reasons but I could be wrong there, then legs welded to it, beaten on, etc. I just dont see them being straight for ever. Just my 2 cents, get a granite surface plate, and then get a cheap welding table. Sorry I know I did not offer you any help. Here are some pics of my plate and stand, its main function is a surface plate for our machining, and a frame alignment table for our service department, frame building will become one of its functions in the future but not the original purpose. 3x4' 6" thick, stand is 4x4" square tubing with 3 points to hold table, and wheels 1000lb capacity each with locks rolls like butter.
surface plate resize.JPGsurface pl resize.JPG

[progetto]

An alignment table is an alignment table, not a welding table.

[degull]

I contemplated a surface plate as well but my reasons for going for a steel plate is simply because of the mass of 4x3x8" surface plate tops over 1300lbs as opposed to 350lbs 4x3x1" surface plate. My space is limited and I was hoping to get double duty out of the table.

[progetto]

You will need to cover up with a thick piece of ply and hang past the edges. A quick way to ruin a nice plate is to use it for something else.

My space is limited and I was hoping to get double duty out of the table.

[degull]

I am a little slow but I get it. Some times the correct answer in not the one you were looking for. I have lead on a 4x3x8.25" granite surface plate which I will look into more seriously now. I have plans to add a mill to the list and I am sure I will get more for my money in good surface plate. I just have to figure out how to move a 3/4 ton of stone around the garage.

[afwalker]

I use the granite plate from Grizzly for my surface plate to check alignment both by clamping it by the BB and by holding it off the plate and checking headtube twist.
8142842137_beb479b41f_m.jpg http://farm9.staticflickr.com/8474/8...b479b41f_m.jpg
granite plate: Grizzly.com

It works but I find I could also use a dedicated alignment table that I could do some setting on. I appreciate the au natural method, but I don't have enough hand muscle memory from building thousands of frames to hope that they come out pretty close to perfect that a little bit of cold setting is needed for me. Maybe it adds new stresses that just come out when riding the bike hard the first time, but hey, that's where I'm coming from. So there probably isn't just one table that you need:) Welding table yes. Surface plate/measuring table yes. Alignment table yes.

cheers
andy walker
walker bicycle co
Walker Bicycle Company | | Walker Bicycle Company
Flickr: afwalker's Photostream

[Jacques]

It's worth noting also, that a 1" by 4' steel plate will be so flexible as to be pretty much useless for verifying flatness. No amount of grinding and stress relief will keep it from bending under its own weight.

[Michael Gordon]

A different question, but still on the topic of alignment... Has anyone ever taken one of their frames where the alignment was dead on, ridden it for a few season, then re-checked it on their alignment table. If so, what was the result?

Mike Gordon
Highland Park, IL

[Andrew R Stewart]

Mike- Well since every time you remeasure/reinstall a frame on your alignment system you're likely to get a different readout...

I have done as you ask a number of times over the years. The usual reason to do so was because my alignment system had evolved and/or the frame was getting different braze ones or rear spread. So again, I got different numbers. The general alignment wasn't really much different. Just when you can be digital a singlnumberer being different has a value. Not much though. Just because you can see .001" on a diail indicator means that you have a different alignment. Andy.

[Curt Goodrich]

A different question, but still on the topic of alignment... Has anyone ever taken one of their frames where the alignment was dead on, ridden it for a few season, then re-checked it on their alignment table. If so, what was the result?

Mike Gordon
Highland Park, IL

I have. Most recently with some team bikes that were in for repaints. After 5 years of hard cross racing combined with lots of other miles they measured the same as the day they were built. To suffice, they measured very straight on my Marchetti alignment table.

[e-RICHIE]

I have. Most recently with some team bikes that were in for repaints. After 5 years of hard cross racing combined with lots of other miles they measured the same as the day they were built. To suffice, they measured very straight on my Marchetti alignment table.

Agreeing with CPG atmo. Frame alignment doesn't change with use.

[Mark Kelly]

It's worth noting also, that a 1" by 4' steel plate will be so flexible as to be pretty much useless for verifying flatness. No amount of grinding and stress relief will keep it from bending under its own weight.

By my calculations if it is simply supported* at the ends it will sag by 0.2mm in the centre. I'm not sure that's much of a concern.



* "Simple support" in engineering parlance means the edges are supported but free to rotate. This would be the case with the plate spanning between two benches.

[sam]

By my calculations if it is simply supported* at the ends it will sag by 0.2mm in the centre. I'm not sure that's much of a concern.



* "Simple support" in engineering parlance means the edges are supported but free to rotate. This would be the case with the plate spanning between two benches.

Actually it can add up to be quite a bit, all the numbers stack up. Take a BB tower mounted to a table where it has a slope, but a BB on it that has its own inperfections, and have the table slope in the opposite direction on the other side of the table, then multiply that times a 56cm length of a tube. You could easily think you are a few millimeters off from where you really are.

I think some people over think alignment, and the truth is you dont need a fancy table to build a nice frame. But if you are going to build a table why build a crappy one.

[Mark Kelly]

The max slope at the edge of the table under the load described will be 0.03 degrees. Multiply by your 560mm tube will give an error of 0.4mm, not "a few mm"

If the BB itself is out that's a different issue.

[Alistair]

By my calculations if it is simply supported* at the ends it will sag by 0.2mm in the centre. I'm not sure that's much of a concern.



* "Simple support" in engineering parlance means the edges are supported but free to rotate. This would be the case with the plate spanning between two benches.

Good point Mark. Supporting it by the Airy points will bring that deflection down to an even smaller number,
Airy points - Wikipedia, the free encyclopedia

Alistair.

[EricKeller]

I dont think there is any reason for a (three point) kinematic mount for something like this. My granite slab is sitting on compliant mounting pads. You obviously don't want to pull it out of flat with the mounting.

[Alistair]

I dont think there is any reason for a (three point) kinematic mount for something like this. My granite slab is sitting on compliant mounting pads. You obviously don't want to pull it out of flat with the mounting.

Eric,

agreed. Just throwing it out there as a possible consideration for those building a surface plate stand from scratch.

Alistair.

[Jacques]

Oops, I just checked the numbers and Mark is totally right on this one. I thought it'd be quite a bit more, but that's what you get when you follow your "gut".

That 0,2mm is still 20 times the flatness tollerance of a "shop" grade inspection plate, but likely more than adequate for putting bicycles together. That said, I think P.I.Y.* epoxy is probably the best buy for most framebuilders.



*that's pour it yourself