How to True up the table/box?

[tcarrington]

MadModifier - Latinrascalrg1's approach might be the easiest if the table is out consistently in all positions. I would allow use, further testing, and make some of the setups easier.

A very interesting problem. Based on the geometry of the machine, it looks like either or both of the up/down or cross ways could be worn enough to allow some "sag". I am assuming the table is lower as it gets further out (ram extended position). I would also take a close look at tracing the same path on the surface when the table is to the left and right positions. That should reveal whether the cross slide is worn, likely in the middle.
Figuring which surfaces are worn will be require a lot of work and disassembly.

What I am suggesting is map the table top in at least three positions - left right and center. You should map at least 9 positions on the table in each position. With enough math and data points you can isolate the flatness of the table with how the cross slide moves it. In a similar fashion, testing it at a few vertical positions would show how straight / flat the vertical movement is. Testing / indicating the sides of the table have not been considered in this suggestion.

Someone who knows better than me should weight in.

Best of luck.

 

[madmodifier]

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.

Yes, it can cut the whole surface but its close.

 

[madmodifier]

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

Thanks, No universal table on this one.

Now I am thinking that I will remove the box and put it on the surface plate and inspect.

I was just referring grinding as in another type of machine that can resurface it's own table. Though that might be an option size wise for me.

 

[madmodifier]

MadModifier - Latinrascalrg1's approach might be the easiest if the table is out consistently in all positions. I would allow use, further testing, and make some of the setups easier.

A very interesting problem. Based on the geometry of the machine, it looks like either or both of the up/down or cross ways could be worn enough to allow some "sag". I am assuming the table is lower as it gets further out (ram extended position). I would also take a close look at tracing the same path on the surface when the table is to the left and right positions. That should reveal whether the cross slide is worn, likely in the middle.
Figuring which surfaces are worn will be require a lot of work and disassembly.

What I am suggesting is map the table top in at least three positions - left right and center. You should map at least 9 positions on the table in each position. With enough math and data points you can isolate the flatness of the table with how the cross slide moves it. In a similar fashion, testing it at a few vertical positions would show how straight / flat the vertical movement is. Testing / indicating the sides of the table have not been considered in this suggestion.

Someone who knows better than me should weight in.

Best of luck.

Thanks, I am certainly going to mesaure more before doing anything. I need to check with the vise on too.

 

[Bob Korves]

The box shaped table should be square, sides square and parallel, and should be square to the vertical reference surface at the front face of the shaper main casting. The ram ways and ram travel should also be square to the front reference surface. The reference surface is provided so you have an original plane that does not wear to check the wearing surfaces against. When new, or when reconditioned, it is common practice to not make the surfaces perfectly square, but to make them slightly high from where they will wear to with use (a milling machine is typically set up with the front of the table .0005" higher than the rear of the table, NOT perfectly square, to allow for wear.) Guessing for the shaper, .0005" high at the front of the ram ways compared to the rear, and .0005" high at the farthest out top surface corner of the table will allow for some wear before any sag starts to be noticeable, passing through perfectly square along the way as it wears. Another issue is the weight of the work, which also warps the table downward, the table being slightly high at the outboard end also helps to compensate for the movement caused by the weight of the vise and work. I would allow another .0005" high at the outer end of the table for the weight, .001" total including the wear allowance. All this is after making the table gibs and ways for the cross slide fit tightly and properly and with the correct geometry, with no allowances needed. I checked "Machine Tool Reconditioning" for recommendations for shapers and planers, but there are no chapters in the book for those machines. Perhaps someone with more experience rebuilding shapers will chime in here as well, I may be off with my suggestions. Richard King, are you out there?

 

[madmodifier]

The box shaped table should be square, sides square and parallel, and should be square to the vertical reference surface at the front of the shaper. The ram ways and ram travel should also be square to the front reference surface. The reference surface is provided so you have an original plane that does not wear to check the wearing surfaces against. When new, or when reconditioned, it is common practice to not make the surfaces perfectly square, but to make them slightly high from where they will wear with use (a milling machine is typically set up with the front of the table .0005" higher than the rear of the table, NOT perfectly square, to allow for wear. Guessing for the shaper, .0005" high at the front of the ram ways, and .0005" high at the farthest out top surface corner of the table will allow for some wear before any sag starts to be noticeable, passing through perfectly square along the way. Another issue is the weight of the work, which also warps the table downward, the table being slightly high at the outboard end also helps to compensate for the movement caused by the weight. I would allow another .0005" high at the outer end of the table for the weight, .001" total including the wear allowance. All this is after making the gibs and ways fit tight and properly and with the correct geometry, with no allowances needed. I checked "Machine Tool Reconditioning" for recommendations for shapers and planers, but there are no chapters in the book for those machines. Perhaps someone with more experience rebuilding shapers will chime in here as well, I may be off with my suggestions.

Thanks Bob! I did go run my indicator all around the table and it's pretty much .005 high in the front all across. I think a dissasembly and cleaning in the next step.

 

[Bob Korves]

I am originally from Pipestone, MN, in the southwest corner of the state, . Gotta' help another Minnesotan. I also invited Richard King to this thread, and Richard is a REAL pro machine re-conditioner, not a wannabe like me. Richard is also a Minnesotan, Cottage Grove. I took one of Richard's five day classes, highly worthwhile and recommended...

 

[Bob Korves]

Thanks Bob! I did go run my indicator all around the table and it's pretty much .005 high in the front all across.

High in relation to what, exactly?

 

[Richard King 2]

Bob and all. I will read thru this tomorrow as It's late now and I've had Bronchitis so I'm taking some meds. One thing, as Bod said he do scrape thing out of square. From wear and on this machine, as the ram feeds out over the base it sags do to weight as it hangs out there. I will attach a copy of Testing Machine Tools by George Schlesinger . https://www.scribd.com/document/107621833/Testing-Machine-Tools-Dr-Schlesinger
free 30 day trial....

 

[tertiaryjim]

Madmodifier
To me the geometry of the shaper is still a bit of a mystery.
The ram can pull down into the cut or be pushed up depending on tool geometry and material.
Thats a consideration for any operation you'll do on that machine.
I spent some time searching through Machine Tool Reconditioning and came up with a oil clearance of 0.0005" to 0.00125" for the ram
ways. This would be for a machine with properly scraped surfaces for oil retention, not a well worn machine, and since I couldn't find
any reference to shapers I determined the clearance from other machines with sliding ways listed in the book.
Perhaps Richard could confirm or correct this figure.
It's easy to check your clearance with a feeler gauge inserted into the ways front and back of the machine and with the ram in at least
three positions. If you cant slip a 0.0015" gauge in there it's really good.
The vertical column ways of my machine, as best I could measure, leaned back 0.0007"/ft.
This would give rise to the outside of the table but when checking the carriage I found variations of as much as 0.004" that was due to
original scraping and not wear. this would prevent perfect adjustment of the gibs and could allow the table to sag and move under pressure.
Further, the vice wasn't true and it's surfaces weren't flat.
I guess what I'm trying to say is that the machine may not have come from the factory correctly produced and with wear and time you will
have to live with some problems or rebuild it.
If you're not going to rebuild it then check the vice for problems that you can correct and cut the table true with a load attached.
One thing you should check, there are four pieces of felt in the bottom ram ways that should be changed. They help keep the ram lubricated
and pull trash out of the bottom way. From memory they are 1/4" thick and 3/8" Dia.
The tapered link pins below the ram push out to the right as viewed from the front of the machine. I no longer remember if there
is a set screw but can check my pictures.
A problem with changing those is the shim pack that sets the clearance of the ram ways might be ruined and you will have to cut
new ones.
You've got a really nice machine there.