I need a large surface plate - Texas

A few years ago I read a book written by a Formula 1 mechanic. He said that one of the first things they did when they arrived at a track was to position and level a set of supports for the car in the pit shop area. They obviously didn't bring a surface plate with them and they also had to deal with tweeked frames so they would use the aligned supports as a reference.

If you like, I can try to find the title of the book for you.

I would think that even a long carpenter's level and some time and care should get you better than

If you just need a few level points (rather than the entire surface), water in a clear tube makes a fine long distance level. Just tack the ends pointing up where you want to measure, make a mark and fill with water to the mark. Go to the other end, and mark the level of the water. Now you have two points separated by X feet and level. 1/16th would be easy to do. I'd think you could easily get half that. Carpenters often use this technique when framing a long wall. Dan

|Rex B wrote: |> I'm about to start a frame-off rebuild of a formula car. In the process I need a |> very flat surface with which to check the geometry of the frame and suspension. |> The ideal would be a surface plate about 5-ft x 10-ft, but that would be very |> expensive. I don't know that I need it any more flat than about 1/16 total |> variance. I've considered one of those poured concrete floor toppers to get a |> flat floor, but I'd much prefer to work on this thing at workingbench height

- |> 30" or so. |> Looking for ideas and suggestions. |> Can I get a steel plate and get it that level? I might be able to get by with a |> 4-ft x 8-ft if that makes it easier. Certainly would be easier to transport | |A few years ago I read a book written by a Formula 1 |mechanic. He said that one of the first things they |did when they arrived at a track was to position and |level a set of supports for the car in the pit shop |area. They obviously didn't bring a surface plate |with them and they also had to deal with tweeked |frames so they would use the aligned supports as |a reference. | |If you like, I can try to find the title of the |book for you.

I'd be interested. I have a very extensive collection of technical books on formula cars but that doesn't ring a bell.

|I would think that even a long carpenter's level |and some time and care should get you better than |1/16" over 10'

Oh sure, I just want a clean, level surface to work from. Maybe I just need to go prowl the scrapiron yard. Rex in Fort Worth

I would go with 4 points. Perhaps a book on building frames?

Homebuilt wings suffer the same issues. They usually build a table first. Hit some homebuilt pages.

Joel. phx

At auction large granite surface plates generally do not get bids. I have seen 5' X 10' X 3' (that is feet) plates get no bids. I have no idea what they weigh. If you ask around you can probably get one for free. You could set it into the floor and drive on it.

Pete.

I would suggest some pipe jacks and pipe. Lay a piece of 1/8 th or 3/32 plate on top of that then you can level it with pipe jacks 4 jacks would probably do it.

IIRC granite is about 170#/cu ft.: 5 * 10 * 3 * 170 = 25,500 lb..

You could purchase a one inch plate from a steel supplier. Five foot widths and twenty feet lengths are common. A five by ten would be easy to get. You are looking at forty pounds per square foot. When you order you must request a relatively flat plate. Guys in the steel yard are careless and can bend the stuff when handling it. It goes without saying you will need a forklift at the least. You will still have to level the plate since it will sag if you only put it on two steel horses. I would recommend four steel horses for feet long. Small steel wedges located underneath will level the thing off. A piece of aluminum flat bar quarter by four and about ten feet long would be handy anyway for your rebuild and would aid in levelling your plate. Randy

Surveyors transit or a laser level.

Cheers Trevor Jones

Why not build a very stout bench with lots of center supports, and then make some sort of trusses. Now make a plywood form and pour 4 inches of concrete and then use the floor topping compound? That would not only give you flat but also level, and rigid.

You could then use a relatively thin sheet of metal to provide a wear layer. This could be bonded to the leveling compound with some contact cement just like they do when making a Formica toped counter.

Rex

Consider a "Lakeshore" engine test bed. They make slotted cast iron bed plates of the type you describe and in all sizes.

JRW

Hey Rex,

Well, in the category of WOW!!!, have a look at this:

You might also consider floating a piece of float-glass on either plaster-of-paris or concrete. I made a decent enough 24" x 24" surface plate like that many moons ago. It is self-leveling if done on the bench where it will reside too.

Up this way, there are/were large cast-iron or cast-steel lay-out plates called "audit plates", which were used to check auto manufacturing projects. Some were pretty large, maybe 12' X 25'. At the time, these were in open areas in the auto plant, but now the QC and this type work are done in closed access areas, so I don't know exactly what they use. Probably large CNC CMM's.

Have you considered making up a table from a bunch of say 24" X 24" pieces of 1/2" Blanchard ground plates with adjustment jack-screws underside. A manageable size. Get somebody in with a laser transit and level them off to each other. Done in a pattern, you could even space them from 1/2" to 1"apart, to suit what you have now for your mill table, so they form a bench with T-slots. Well, maybe not really true T slots, but you get the idea.

Take care.

Brian Laws>I'm about to start a frame-off rebuild of a formula car. In the process I need a

I think in 2004, you'd use optical controls. A laser bench might be economical compared to granite, and you could use it to establish 3D control.

Buy a couple (dirt cheap) construction-grade lasers and play with them. They might be good enough for a race car.

Even if you're a devoted revivalist, you can get what appear to be decent used jig transits for a grand or so.

Hth, Fred Klingener

As we closed our plant here in Lansing, MI, I inventoried the plates we had. Three cast iron ` 12' x 15' with MORA CMM's, a Zeiss 6'x8' with computer control (old). About a dozen 4'x6' to 6'x8' granite. A couple

Of course, the plant we were 'consolidated' into had a huge traveling column boring mill, capable of mounting two complete car hood or roof dies at the same time. They paid about 1/3 of a million to have someone torch it into pieces to haul to the scrap.

Wow, those are some great ideas - Thanks!

I'll do some more research on some of those. Don't think I can handle that 5-ft thick granite job though :)

I really appreciate the out-of-the-box thinking avialable in this group.

Rex in Fort Worth

|Hey Rex, | |Well, in the category of WOW!!!, have a look at this: | |

Hey, that's perfect! Except it's in Maine, and I'm in Texas. Anyone headed this way with a trailer? Rex in Fort Worth

Rex, mostly guys get some 2 x 4" .125 wall tubing and weld up a rectangle. Often no table top at all. Sit it on some saw-horses and shim it level. You can tack your chassis down and away you go. I visited Colchester Racing Developments, who made the Merlyn cars in the 60's and 70's, and was shown the table that my car was made on - it was just about exactly what I've described, but on castors so it could be rolled away. Here's the chassis build table at Multimatic, and a current Daytona Prototype chassis being built.

Build a good sturdy workbench but build it about 8" lower than you want the frame. Vist the nearest flea markets and pick up a few (at least four) old screw jacks. (Hydraulic won't do since even the best slowly leak down.) Use the jacks and a surveyors level or a laser laevel to set things up. I have used screw jacks (for which I paid $2 or $3 each) for various large welding projects.

I used a Nikon surveyors level since I bought one when building this house. Saved its cost several times over. I made a special "rod" from a metal slug and a 6" rule calibrated int 0.01". Easy to read 5 thou from across the room.

Ted