Re-Machining a worn out shaper

Any spec recommended for tipping the table ways back in relation to the ram ways to compensate for table loads and cutting forces? I am practicing on trueing up a worn out machine and was just curious as my inspection seems to indicate that there was a factory built in tip of about .003"/foot. I don't know if that is normal or if that was just as good as they got it back in 1890 something.

Hi Brian, Just watched your vid' on cutting the base of the main body casting. Nice work.
when I rebuilt and scraped in my 14" shaper I aimed for c 0.0015" rise on the Ram at end of stroke. So about half what you say you are seeing. I would add, when you are machining it consider that the ram slides will have some clearance (I was advised around 0.0005" each side on the dovetail ways - so this affects the outcome. Cant say how much in terms of thou' per foot but it matters. Then there is the fact the Ram slides in and out to set the stroke position.
There is a thread i started a year or so back and in it ref' to a set of spec's for the finished machine tolerances drawings and dims' in a table.

Good luck
Mat

Take a look at item 5a on page 87. It says Movement of Ram to Table .0006/12" table rising in front.
The Schiesinger book. "Testing Machine Tools"
http://totallyscrewedmachineshop.com/documents/Testing Machine Tools (Dr.Schlesinger).pdf

Also as Lurk points out Item 6a - .0008 in 12" but You can scrape better then that. .0002" 12" is easy for you.

It shows using a level but if you have a good precision blade square and after you have the column scraped you could clamp the square stock to the column and indicate the blade. A 18" B&S or Mitutoyo would work nicely.

For those who are wondering what we are talking about is, as the top ram moves forward and is unsupported the ram will sag or bend down, so we scrape the top of shaper ways so as it moves out it rises to compensate for the sag of the unsupported part do to gravity. Then it feeds out straight. We scrape many things out of square on purpose so as it sags to non support or weight added to it sags as it rises.

This what I mean when I say "it's easy to scrape, but knowing where to scrape and how much is part of the trade" (Machine tool Rebuilding)
Rich

Ooops have to turn the laptop....and Brian was pull scraping at Keith Rucker's shop 2017 class

Thanks for the response. I think I will shoot for .0005"/ft on the milling then. Matching the alignments to the original to remove as little as possible while still getting things square and parallel is proving to be a good challenge.

Remember to be the detective and look for the original surface that never saw wear, measure ridges, then remove them. How about a few pictures or are you going to do a You Tube show on it? If so please link it on here. Rich

There will be a whole you tube series on it. Trying to hold .001 flat and square over a couple of feet is proveing to be a good challenge on my mill. It may need a scrape fest sooner rather than later if I am going to keep doing this kind of work!

I have openings in Jan, Feb, March, May, June, Sept, etc. etc.
Scraping a shaper is easy, a lot easier then your rotary table. You don't need me to help in my opinion, but you name a time and open up your shop or one near by and lets do a scraping class. The You Tube is Lurk I think. He and you are equal in experience I would think. If you want to rebuild something complicated, lets do one on a Crank Shaft Grinder, a Studer Grinder, a Moore or Pratt & Whitney Jig Bore, A swiss screw machine, etc. Something difficult. Shapers are a step up from a punch press in my opinion. Rich

I suspect my HBM would be a good challenge simply because the size exceeds the masters to check it with so printing and determining alignments would be challenging. I need to get my 4x6 granite plate certified first and then get that big cast plate trued up. So much to do so little time!! I agree scraping in this shaper would not be a hard job. I wasn't tasked with that part though, just trying to get it as best I can so Mike doesn't have to work so hard scraping it in to finish it. It also is a good test for me as I haven't yet worked on any large pieces like this to see how true my mill is running.

Video Series started here.
Milling a Machine Tool Super Accuracy Challenge - YouTube

New video up including some machine realignmnet based on my findings milling this large block. Machining a machine Tool: Rebuild back to Spec Part 4 - YouTube