Scraping a vertical surface?

agfrvf

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Been trying to research scraping a vertical surface and could not find anything but a special vertically mounted granite surface plate. I have a mill I want to inspect and possibly scrape if I have to.
 
I can’t stick weld upside down to save my life. I had the whole neighborhood over one time to help me turn over a boat trailer so I could weld the underside. I was the talk of the neighborhood from then on. Like said, just turn it.
 
I can’t stick weld upside down to save my life. I had the whole neighborhood over one time to help me turn over a boat trailer so I could weld the underside. I was the talk of the neighborhood from then on. Like said, just turn it.
Trust me, your not missing anything. I can run a decent overhead bead with stick, but it's never any fun. Nothing wrong with flipping it over if possible. Mike
 
Been trying to research scraping a vertical surface and could not find anything but a special vertically mounted granite surface plate. I have a mill I want to inspect and possibly scrape if I have to.
The information you are looking for is in the machine renovation "bible", Machine Tool Reconditioning, by Edward Connelly. You can find it here on this site:
http://www.hobby-machinist.com/threads/connelly-on-machine-tool-reconditioning.41802/

That said, I suggest strongly that you do not start out learning to scrape and rehab a mill by reading part of the book and getting on with it. You will not be very likely to have great results doing it in that way. It is a bit like a guy who has never held a screwdriver in his hand, and has a plan to completely rebuild the engine and transmission of his car, including all the machine work, all as part of his first project and by himself. It isn't likely to turn out well.

I do recommend you read the book and make sure you understand how to properly test and assess your mill's current condition, and read and understand the sequence of operations used to get the geometry of a mill back to flat, square, and parallel like it left the factory. Hint, that sequence is almost certainly not what you think it is. After getting an understanding of the process and how to prepare for the job, then make sure you are up to the renovating task, which can be long and difficult at times, and even more so for someone new to the work, who WILL make mistakes.

The best bet is to find someone who has a lot of real world experience with doing this work and try to get him or her to mentor you for the project.

It is far better not to start rehabbing the machine at all if you are not truly up to doing the learning and hard work required to complete the job to a proper result. That usually ends with frustration followed by a basket case sale.

Machines do not need to be perfect to do very high quality work.

Scraping vertical surfaces is not required, and should be avoided if at all possible.
 
In the shop where I apprenticed there was a guy who did scraping "back east" He told of a job where he laid on the floor and scraped overhead on a surface that the "powers that be" did not want to rig and turn over. Things can always be worse, but at least for smaller machines, it is always best to have your surfaces to be scraped "in position", that is, in a horizontal position.
I quite agree with Bob in that machines do not need to be in perfect alignment to do acceptable work, even very high quality work. Perhaps we impose overly high tolerences on ourselves when much lesser limits would suffice. Think of the phrase "perfect enough".
 
I can see original scraping marks on the machine and spindle accuracy when new was 0.003". I know the .0001 changes if you blow on it. I just want to see what I have and be ready for the worst. I litteraly paid scrap value on the machine. It is cleaning up nicely. My dial indicator isn't moving more than one thou so its in spec as far as I can tell.
 
Assuming the mill is still assembled:
Before measuring things, make sure to adjust all the gibs to their best possible fits. Otherwise you will find geometric problems that can be pretty easily brought closer to what the machine is capable of. For instance, if the knee gibs are loose, then the knee will hang downward at an angle (sag) and that will leave you thinking that the top of the knee and the saddle are badly worn as you move farther from the column. As with machining, lock any axes that are not actually moving. You will then see the geometry more clearly, and it will correctly show less wear. Also note that if you measure from the spindle straight down to the table, and then traverse the table left and right, It might show a very good reading for the entire travel even if the table is actually sagging badly at the ends. A perfect curve will show no needle movement in that setup. Shake the table fore and aft at the table ends with the locks loose to feel how much play you find there. Repeat up and down. With the table at the center, tighten the locks and then loosen the locks just until the table will traverse without much friction, and then see how much the friction increases closer to the ends of the travel, and how much you have to loosen the table locks to reach the ends.
 
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