Shaper Scraping Help

[Pete301]

I started scraping a SB shaper awhile ago. Teaching myself to scrape because I wanted to save this shaper. I have the ram scraped and wanted to move on to the next step, which is, I think, scraping the flat ways on the main column. The shaper has dovetail on ram/columns. So I first measured to see if the ram was moving out at a right angle to the vertical table ways on the column. I put a right angle straight edge against the ways (see photo) and used a DTI to measure along the straight edge. I had .003 of raise. I know I should leave .001 of raise in the ram shaper.
I’m embarrassed to say this, but I can’t seem to confidently figure out how much to scrape off the flat ways on the column to leave a rise of just.001. Not sure I’m figuring it out right, but the last photo shows the amount of material to be removed and locations I came up with. Am I anywhere near right?
Pete

 

[cjtoombs]

Richard should probably chime in on this, but this is my take. You need to get a piece of scrap cast iron and measure how much you remove per pass when you scrape. It will probably be around .0003". Once you know this, you can draw some lines with a marker, like terraces or elevation lines on a map (which is what they actually are). Once you have that done, start at the high side and scrape both directions up to the first line, then both directions from the end to the second line (re-covering the area you scraped on the first pass). Continue this across the surface until you have reached your last line This will reduce change the slope by the number of passes you take off times your removal rate per pass, so you can keep track of where you are based on how many passes you have made on the high end. You can re-measure as you go along to ensure you don't overshoot. Once you get there angle wise, you can scrape it flat. Another option would be to scrape the cross slide and table in so that they are at a slight angle, to match the ram ways so that the ram and table are parallel, which may be easier from a scraping standpoint. The way a shaper is set up and worked, the perpendicularity of the front ram ways is less important than the ram being parallel to the table.

 

[eeler1]

Good question! I’m interested in the responses.

Why not indicate against the top of the table instead of the square? Or something clamped in your vise? If it cuts straight and true, you might already be done.

 

[Pete301]

Richard should probably chime in on this, but this is my take. You need to get a piece of scrap cast iron and measure how much you remove per pass when you scrape. It will probably be around .0003". Once you know this, you can draw some lines with a marker, like terraces or elevation lines on a map (which is what they actually are). Once you have that done, start at the high side and scrape both directions up to the first line, then both directions from the end to the second line (re-covering the area you scraped on the first pass). Continue this across the surface until you have reached your last line This will reduce change the slope by the number of passes you take off times your removal rate per pass, so you can keep track of where you are based on how many passes you have made on the high end. You can re-measure as you go along to ensure you don't overshoot. Once you get there angle wise, you can scrape it flat. Another option would be to scrape the cross slide and table in so that they are at a slight angle, to match the ram ways so that the ram and table are parallel, which may be easier from a scraping standpoint. The way a shaper is set up and worked, the perpendicularity of the front ram ways is less important than the ram being parallel to the table.

Thanks, I appreciate the info and I’ll keep all that in mind when I start the step scraping. But first, I’m hoping someone can tell me a formula or method to figure out how much to scrape off. I have a rise of .003 over 6” of indicator travel. I guess I should have paid more attention to my high school geometry teacher, but that was 50 plus years ago !!
Pete

 

[catsparadise]

I'll see if I can help with this. I have a 10" shaper sat in my garage waiting to be restored and the ways will need scraping. Unfortunately for the shaper it's got to wait for me to finish rebuilding my surface grinder!

If I understand it correctly, 6" of travel of the ram raises the ram by 0.003" and you're after a rise of 0.001", a change of 0.002" over 6" or 4 thou per foot. You'll need to adjust the angle of the column ways by the same amount, that is, if the column ways are 12" long, the tops of the column ways would need scraping to remove 0.004" whilst the bottom of the column ways would be untouched. If the column ways are not 12" long the amount to remove from the top needs to be scaled accordingly, ie 9" column ways need 9/12 x 0.004 = 0.003" removed.

The angles are too small to have to resort to trigonometry.

I'd get someone to verify what I've written above is correct before you remove any metal, ... please!

Rob

 

[Pete301]

I'll see if I can help with this. I have a 10" shaper sat in my garage waiting to be restored and the ways will need scraping. Unfortunately for the shaper it's got to wait for me to finish rebuilding my surface grinder!

If I understand it correctly, 6" of travel of the ram raises the ram by 0.003" and you're after a rise of 0.001", a change of 0.002" over 6" or 4 thou per foot. You'll need to adjust the angle of the column ways by the same amount, that is, if the column ways are 12" long, the tops of the column ways would need scraping to remove 0.004" whilst the bottom of the column ways would be untouched. If the column ways are not 12" long the amount to remove from the top needs to be scaled accordingly, ie 9" column ways need 9/12 x 0.004 = 0.003" removed.

The angles are too small to have to resort to trigonometry.

I'd get someone to verify what I've written above is correct before you remove any metal, ... please!

Rob

Hi Rob. Thanks for that info. Exactly what i needed! I was having trouble “seeing” .002 over 6” needs to be .004 over 12”. My column is 12” long so your figures match my shaper. In the meantime I found a video by lookcreations where he used that used that very same method to figure the amount of material to remove on his ram. So with that confirmation I’m going to start.

The fuller story on this shaper is that it has given me problems since the day I brought it home. It cuts a taper up to .006 over 4” on its outboard end. Thought I could just shim the workpiece to get it to cut true. And that worked, but I found I keep having to adjust the shims. Took me a very long time to realize the depth of cut was effecting the taper. Deeper the cut, bigger the taper. The cross rail turned out to be part of the problem. Too much slop. So I scraped it to true. That left me with a smaller, but consistent taper regardless of cut depth ( which was good!). And it’s the ram pointing up that is causing the remaining taper. Or so I hope

 

[Bob Korves]

I started scraping a SB shaper awhile ago. Teaching myself to scrape because I wanted to save this shaper. I have the ram scraped and wanted to move on to the next step, which is, I think, scraping the flat ways on the main column. The shaper has dovetail on ram/columns. So I first measured to see if the ram was moving out at a right angle to the vertical table ways on the column. I put a right angle straight edge against the ways (see photo) and used a DTI to measure along the straight edge. I had .003 of raise. I know I should leave .001 of raise in the ram shaper.
I’m embarrassed to say this, but I can’t seem to confidently figure out how much to scrape off the flat ways on the column to leave a rise of just.001. Not sure I’m figuring it out right, but the last photo shows the amount of material to be removed and locations I came up with. Am I anywhere near right?
Pete

You are going at it backwards. The place to start is at the reference surface of the machine, the front face of the main casting. The flat surfaces there are unworn and in original condition. Carefully stone them with a flat and fine stone to only remove any burs you feel, and then use it to scrape the table ways of the column to match the front surface, then scrape in the table vertical ways and the gibs to fit the table so it travels parallel to the reference surface. Next would be making the top of the table perpendicular to the reference surface in both directions, and only then do you try to align the ram with the top of the table. The sequence of operations is highly important to reconditioning a machine.

Full disclosure. I do not have experience with reconditioning on shapers. The information above is how a vertical mill is approached. It is not clear in my mind how the table and cross slide are actually attached to the shaper, so that may change things. Regardless, use the reference surface that the factory put on the base casting to start the work, and proceed incrementally from there in a logical sequence.

 

[Pete301]

You are going at it backwards. The place to start is at the reference surface of the machine, the front face of the main casting. The flat surfaces there are unworn and in original condition. Carefully stone them with a flat and fine stone to only remove any burs you feel, and then use it to scrape the table ways of the column to match the front surface, then scrape in the table vertical ways and the gibs to fit the table so it travels parallel to the reference surface. Next would be making the top of the table perpendicular to the reference surface in both directions, and only then do you try to align the ram with the top of the table. The sequence of operations is highly important to reconditioning a machine.

Full disclosure. I do not have experience with reconditioning on shapers. The information above is how a vertical mill is approached. It is not clear in my mind how the table and cross slide are actually attached to the shaper, so that may change things. Regardless, use the reference surface that the factory put on the base casting to start the work, and proceed incrementally from there in a logical sequence.

Hi Bob. I’m using the vertical ways on the column because I don’t see a “reference surface”. The vertical ways don’t get much wear relative to the other surfaces so it seemed like the best place to start from. I attached a photo of the shaper in case I’m missing a better reference point.
Pete

 

[Bob Korves]

Pete,
The very top and the very bottom ends of the vertical ways are likely unworn. I would use them for getting the geometry correct, with a long enough accurate square to span the distance. Actually, if you already used the ram ways to scrape the top truly flat and parallel, you could use it as the reference surface, using a large and accurate square to get them square with each other. The issue there is that the entire faces of both the ram and vertical surfaces also need to be perpendicular to each other as well, so something like the accurate version of a framing square could not generate perpendicular planes.

 

[Pete301]

Pete,
The very top and the very bottom ends of the vertical ways are likely unworn. I would use them for getting the geometry correct, with a long enough accurate square to span the distance. Actually, if you already used the ram ways to scrape the top truly flat and parallel, you could use it as the reference surface, using a large and accurate square to get them square with each other. The issue there is that the entire faces of both the ram and vertical surfaces also need to be perpendicular to each other as well, so something like the accurate version of a framing square could not generate perpendicular planes.

Hi Bob. Thanks again! Based on that, I think I’m on the right track. My cross rail is scraped perpendicular to the vertical ways and the table top is perpendicular to the vertical ways. So if I can get the ram to move perpendicular to the vertical ways, all should be good.
Pete