How to True up the table/box?

M

madmodifier

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Hi All,

I have been playing around with my "new" 7" rhodes shaper and I am finding that the parts are out quite a bit. I pulled the vise and ran an indicator over the table and it appears to be .005-.006 out. I pulled up on the ram when it was fully extended and did not get much movement. I think the solution is to true up the table since I cannot see a good way to shim up the table/box. I do not have much in the way of experience grinding HSS shape tools. I have ground a couple roughers that work well in Steel. I am guessing that the correct tool to cut the box would be a shear tool? I tried searching around the interwebs but I could not find a book or article that speaks to doing this.

Has anyone trued up the table on their shaper? Advice?

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Before I mess with the box, I would look hard for where the error is coming from. With the dial indicator again, Map out the high low spots. Then move the box to the top, and to the bottom limits, and look for changes. Then to the left, and to the right.

If you have an error from a worn spot on the saddle, or body way, skimming off some of the box, can make things worse. Just stand back, and take a look at what moves, and slides against what, and those are more likely where your issues are coming from, then a twisted/worn box.

The old saying, measure twice, cut once, really applies here.
 
Superburban said:
Before I mess with the box, I would look hard for where the error is coming from. With the dial indicator again, Map out the high low spots. Then move the box to the top, and to the bottom limits, and look for changes. Then to the left, and to the right.

If you have an error from a worn spot on the saddle, or body way, skimming off some of the box, can make things worse. Just stand back, and take a look at what moves, and slides against what, and those are more likely where your issues are coming from, then a twisted/worn box.

The old saying, measure twice, cut once, really applies here.
Click to expand...

I defiantly will be sure to verify my readings more before moving forward. However I have taken full stroke measurements on multiple location on the table. Lifting and pushing the moving parts to see where the discrepancy is coming from.

I think this is a good question in general. There does not appear to be much info on this online currently.
 
As Superburban said check and double check where the error could be.
That being said I had to surface the table on my OLD Pearless. On it the front of the table was a couple of thou high. That would indicate the ram was sagging. I adjusted the ram gibbs and got the same measurements. I get a couple of thou movement with the ram extended but that is to be expected on an 18 inch stroke. Wear in the table gibs should make the front of the table low. Don't think this machine saw much use.
I used a brazed carbide cutter, was afraid a HSS one would wear removing the amount of material on the large table this shaper has. Don't think you want to use a shear tool, the table needs some roughness for parts to grip when your machining.
The table does need to be parallel to the ram, shimming the vice or parts bolted to the table got old real quick.
Best of luck

Greg
 
I did not think so much about the ram ways wearing. That does also make sense. I wonder if it would be better to think about scraping the ram ways back to level/ parallel with the table. It would be less metal to work on, but how do you determine what and where to cut?

I think I would shim a straight edge to the table, so the front, and back read zero on the indicator, and confirm that in between is all zero. To rule out any curvature in the wear, where ever it is. Confirm that the stroke is all in the same plane, then move on to how to match the table to the ram.
 
OK, whether mine needs it or not is a separate issue. I am interested in hearing how best to true the table/box on a shaper. I believe this is something that would have been done like you grind the chuck on a surface grinder.
 
Now you have me wanting to go out and check my shaper.

Does your shaper even have enough stroke to cut the whole table? I think that is the first question. If you can cover the whole table with you cutter, then whats the best way to cut? I think I would look into a repacable carbide cutter, that way if it chips, or breaks 1/2 way through the process, you can replace the cutter, and keep working.

I can't find it now, but remember a Youtube vid, where the owner mounted a tool post grinder to the end of the ram, and ground the table that way. I can't remember how he handled the area right next to the column.
 
Scraping the ways probably would be the correct way to correct the problem, but refacing the table was a lot easier and removed a couple of signature marks previous owners had left. On my Peerless there's probably more area on the ram ways than the table top.
Mine has a universal table?, rotating it to the other face showed the same error so Im pretty sure it was wear in the ways and ram.
As for grinding the table, it would look pretty but wonder how well parts would clamp to the smooth surface. When your taking a heavy cut there's a lot of force trying to slide the part along the table. Even with a machined surface I often need the stop at the front of the table.

Greg
 
Would it be possible to bolt a "sacrificial" plate to the shaper table top and then use the shaper to cut it parallel to the ram? That way you dont make any permanent alterations to the shapers parts and still get your parallel surface to work on. Im just thinking out loud and know nothing about a shaper so if this is ridiculous please go easy on me and explain why, Thanks.
 
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