Way Smoothing, instead of Way Scraping?

[Mister Meeseeks]

Hey guys, I'm restoring an old Jet JMD-18 Mill/Drill. Right now I have it completely disassembled and the painted parts are out getting sand blasted. I'm sitting here thinking about the areas where the tables slide on one another. There are heavy machine marks and I just think like man that has to cause a ton of friction. I want to restore this thing to be the best that I can, and if I can make those tables slide like they are on glass I want to do it. I have heard about way scraping, but I dont know how to do it and no one in my area does either. I'm thinking about hitting those ways with like some 400 grit sandpaper followed by scotch bride pads and some polishing compound. Just try to smooth them out as much as possible.

Question is... Is there something I'm not thinking about that would adversely affect the function of my mill if I do this?

Lastly, just want to mention I'm a hobby mill operator out of my garage. It's not a precision environment where every micrometer counts. Thanks for your help!

 

[Ulma Doctor]

I would not recommend using sandpaper on the ways
You may be better off lightly stoning the high spots with a high quality sharpening stone (150 grit or finer)
I would use dollar store windex as the cutting fluid- expensive windex is not any better for the purpose.
Be sure to wipe off any window cleaner residue , after smoothing.
The idea is to only remove high spots without making low spots lower

 

[MyLilMule]

There's a few things that you're probably not aware of here.

The first thing I would do is get some precision ground flat stones and stone the ways, lightly. The gouges aren't necessarily a problem if the vast majority of the way surfaces are still "flat." The burs on the edges of those gouges can definitely be a problem. If they can be stoned down so they are no longer proud of the way surface, is could probably be "good enough".

Polishing a way surface is a bad idea. The process of scraping ways is to do two things. 1) create bearing points that are spread evenly across the surface in a high concentration and that the tops of those bearing points are all in the same plane. And 2) to create low points for lubrication. Two perfectly smooth surfaces gliding across each other will squeeze out any lubrication and eventually gall and possibly to the point of nearly welding the surfaces together given enough pressure.

So, do NOT use sandpaper or scotch bright on a precision way surface. Stone the burs down. Then do what you can to measure the accuracy or precision of the ways as they are. If they are that bad, the only recourse is to have the ways professional ground and then scraped back in to precision. But I would probably say that this is not a viable option for most hobby machinists as you are talking thousands of dollars to hire someone to do that.

 

[matthewsx]

I would not recommend using sandpaper on the ways
You may be better off lightly stoning the high spots with a high quality sharpening stone (150 grit or finer)
I would use dollar store windex as the cutting fluid- expensive windex is not any better for the purpose.
Be sure to wipe off any window cleaner residue , after smoothing.
The idea is to only remove high spots without making low spots lower

This^^^*

Hope wherever you send them for blasting doesn’t also do the ways. Did you tape them off before turning it over?

John

 

[Mister Meeseeks]

This^^^*

Hope wherever you send them for blasting doesn’t also do the ways. Did you tape them off before turning it over?

John

I did not tape off the ways but it was clear with the company what areas needed to be masked off. Thanks for your input.

 

[Smithdoor]

Hey guys, I'm restoring an old Jet JMD-18 Mill/Drill. Right now I have it completely disassembled and the painted parts are out getting sand blasted. I'm sitting here thinking about the areas where the tables slide on one another. There are heavy machine marks and I just think like man that has to cause a ton of friction. I want to restore this thing to be the best that I can, and if I can make those tables slide like they are on glass I want to do it. I have heard about way scraping, but I dont know how to do it and no one in my area does either. I'm thinking about hitting those ways with like some 400 grit sandpaper followed by scotch bride pads and some polishing compound. Just try to smooth them out as much as possible.

Question is... Is there something I'm not thinking about that would adversely affect the function of my mill if I do this?

Lastly, just want to mention I'm a hobby mill operator out of my garage. It's not a precision environment where every micrometer counts. Thanks for your help!

It not hard to do scraping
It just removing the high lights.

Dave

 

[Aukai]

precision ground flat stones, look into these they are amazing, they will not wear down the surface, only the high spots.

precision ground flat stones - Google Search

 

[Optic Eyes]

Hey guys, I'm restoring an old Jet JMD-18 Mill/Drill. Right now I have it completely disassembled and the painted parts are out getting sand blasted. I'm sitting here thinking about the areas where the tables slide on one another. There are heavy machine marks and I just think like man that has to cause a ton of friction. I want to restore this thing to be the best that I can, and if I can make those tables slide like they are on glass I want to do it. I have heard about way scraping, but I dont know how to do it and no one in my area does either. I'm thinking about hitting those ways with like some 400 grit sandpaper followed by scotch bride pads and some polishing compound. Just try to smooth them out as much as possible.

Question is... Is there something I'm not thinking about that would adversely affect the function of my mill if I do this?

Lastly, just want to mention I'm a hobby mill operator out of my garage. It's not a precision environment where every micrometer counts. Thanks for your help!

The fact you don't know what you are doing is the big problem. Ugly dog has scraping classes in Minnesota, we can teach you how and make it a class project

 

[m1kemex]

Lastly, just want to mention I'm a hobby mill operator out of my garage. It's not a precision environment where every micrometer counts.

You may not require the precision but you certainly need the ways to be tight, otherwise the slop will induce chatter and chatter will wear the machine faster, breaking cutters and ruining parts in the process.

The tighter the ways, the more the machine acts like one solid chunk of iron. The precision of the ways is just to ensure it continues to fit tight along the travel distance. That's why professional machines come with hardened ways: to preserve the original geometry as long as possible.

 

[gard]

You should consider assembling the sliding surface with the gib with no lead screw. Slide it back and give it the shake test, grab the table and try to reef it sideways, measure movement with an indicator if you have one. Adjust the gib and do shake test various points along the travel. Often tables will be tight at one or both ends and loose in the middle. Much easier to do this with no lead screw. By carefully looking at the wear pattern, you may be able to tell where you need to do additional work with the stone or a scraper. If you tighten the gib down some and work the table there should be some shiney spots where there is metal to metal contact. Some ink or dykem may help.