How many have scraped their machine?

[lowcountrycamo]

I read many post that casually mention "scraping" their machine. I would think such a project would be on par with "building a shop" or "restoring a corvette". I have scraped small surfaces with only one plane. Obviously aligning different planes and especially dovetails would be the hardest part. I understand that scraping in a lathe compound vs a bridgeport table is in a different ballpark. I am curious, how many of you have attempted/still working on vs. completed a scraping project? And if so, where you able to bring your machine into proper alignment?

[John Stevenson]

I often think about scrapping this POS Bridgeport........................

[TexasTurnado]

I read many post that casually mention "scraping" their machine. I would think such a project would be on par with "building a shop" or "restoring a corvette". I have scraped small surfaces with only one plane. Obviously aligning different planes and especially dovetails would be the hardest part. I understand that scraping in a lathe compound vs a bridgeport table is in a different ballpark. I am curious, how many of you have attempted/still working on vs. completed a scraping project? And if so, where you able to bring your machine into proper alignment?

Yes, it is a large, time consuming project that requires much patience and dedication. I have scraped in my 15x50 Colchester, but I cheated in that I had the bed precision ground and thus avoided the hardest part of the project: getting the bed into proper alingment. Commerce Grinding in Dallas gound the two prismatic ways, the two flat ways on top and the two flat ways on the bottom (to prevent the saddle from rising with load) for less that $900 - which I thought was money well spent!

I aligned and fitted the saddle, the cross slide and the tailstock, as well as aligning the headstock to the ground ways - here is a pic of the nearly completed project (chip pan and other sheet metal not yet attached:



During the process the whole lathe was stripped of paint, refilled, primered and painted - here is what it looked like soon after I started on it:



I have written a series of articles for HSM on its rebirth that should, with luck, start appearing sometime this year...

My current project:



This is a Graziano SAG 12 and is receiving the same treatment: stripping to bare metal, refilling, primering, and painting plus the bed has been ground and I am currently working on rebuilding the electonic transmission (four gears speeds are electrically selectable from a joystick, in addition to forward and reverse. The scraping is complete at this point, so I should be finished before July 4.....

So, yes, it can and has been done at home.... check out other threads here and on PM.

[toyjeep73]

I read many post that casually mention "scraping" their machine. I would think such a project would be on par with "building a shop" or "restoring a corvette". I have scraped small surfaces with only one plane. Obviously aligning different planes and especially dovetails would be the hardest part. I understand that scraping in a lathe compound vs a bridgeport table is in a different ballpark. I am curious, how many of you have attempted/still working on vs. completed a scraping project? And if so, where you able to bring your machine into proper alignment?

I think a more relevant question would be:

How many people have scraped their machines that don't do machining for a living?

There is no shortage a professional machinists (or at least people that get paid full time to machine) on this board, which is a huge difference than someone who is dabbling as a hobby after working a full time job in a completely different field.

[JCHannum]

I have restored a '69 Camaro, '68 El Camino and most of a '72 Corvette. I would not begin to attempt to scrape in a lathe or milling machine.

I suspect more machines have been destroyed by by amateur attempts at scraping than have ever been salvaged.

[Forrest Addy]

I scraped machine tools for a living for a couple years. I went into it with my eyes open having done a lot of study and having scraped in many smaller projects.

I'll present my standard comment. Re-scraping a machine too is indeed like completely restoring an old car but in spades - more like restoring an old airplace to FAA specs. Every danm part has to be restored to original fits, finishes, alignments, and accuracy.

This places large demands on the physical assets, persistance, and mental powers of the doer. Scraping all the parts so they fit accurately in mutual alignment is only part of it. The other half is the mechanical work and about 5% of that is the prepping and painting on which many place too much epmphasis. I would guess that it would take a telented and efficient amateur about 600 hours to re-scrape a 16 lathe or a turret mill provided he is practiced and has the tools and apparatus on hand.

Not much is said about the apparatus. I know old time carpenters who could built whole houses with a box of tool they could carry in one hand. These are highly skilled people and it took them about twice as long as a carpenter with modern equipment Same goes for the would-be scraper. All you really need is a scraper, a surface plate, a large precision square, a precision level, and a tube of blue to start with. A canny scraper hand soon accululates scraped straight edges including what the Brits call a fettler's flat, any number of scraped polygons and angle blosk, a dosen clever little dial indication gadgets, and quite possibly a version of the Kingway allighment system.

Then there is the mechanical work where every shaft, bearing, pulley, belt, and gear is inspected, repaired or replaced, the electrical work where the electrics are modernized and perhaps brought to modern standards. Thene there are the placards and label plates, lube systems, coolant system, splash guards, sumps, etc that have ot be refurbished and refitted before paint work can start.

2000 spare time hours is not too large a figure for the mid-sized machine too resoration. Cleaning and painting and re-pnning a handwheel is no more "rebuilding" than sweeping dirt under the rug is houscleaning It's a bunch of damn hard work that few people can appreciate before they commit. In the end however you will have accomplished an enduring good, resurrection from the foundry ladlle a machine tool and restored it to productive use in like new condition.

JC Hannum's final sentance is tragically true and should be burned into the consciouceness of all who untertake to rebuild a machine tool.

Good luck to anyone taking on the task of rebuilding a machine too. if I was to wish them anything practical it would be persistance, talent in scrounging, and selection of a suitable caarcass to start with.

[Martin0001]

I did not scrap my ML 7 though part of this job I have done under supervision of patient professional.

Before you go on to butcher your machine and then send it to a *scrap*yard try to scrap 3 square cast iron surface plates referring "circularly" them one to another.
Start with not very finely ground stock.
Carry on until they are in your opinion adequately flat, go to some place where they have large surface plate and professional planer and ask to check ones you have made.

*Then* try your lack with small *flat bed lathe*, make sure you have adequate reference surfaces (long slabs with good *scraped* surface).
Make sure you can catch the angle correctly as well...

You must be comfortable with the work (means few small flat bed lathes like Myfords or Boxfords restored & sold to someone who will later use them, not just paint them and watch how great they look).

Then and only then you may begin to think about *vee* shaped bedways lathe.

Anyway, I would just employ professional.
Let poor bugger earn a bit...

He might have a wife and six hungry kids but no job because it was outsourced to China...

[RussZHC]

If you take the "natural", that one in maybe 100 000 who has a natural affinity for something, out of the discussion, the rest of us have to spend time acquiring a particular skill or larger skill set.

Though I am certainly interested in process, to get to a comfort level that would enable one to make the correct decisions as the project and its procedures came up is a long ways away, at least for me.

The length of a complete project itself would be daunting, in that, again with the exception of those rare few individuals, many of us would need to take time off...it is just too intense to go at it for hours, days and months on end. And that needed "intensity" bleeds over into other work...if you put it down to rest for a bit, does just moving to other machining tasks really "rest" you?
Just saying for me, if I get in 4 hours 3 or 4 times a week, I feel pretty good, add in maybe a 10 hour weekend day, that is still only, at best maybe 30 hours per week, the math adds up pretty quick.

I can see myself attempting the most simple versions, a single flat surface say or a 90* angle but I think my attempts would stop there.

[A.K. Boomer]

I scraped mine getting it into the basement - brand spanking new too - really bummed me out but it came with some touch up paint.

[Mcgyver]

I've done a couple. They worked out very well, its not a difficult per se but requires the right sequence of events and Herculean discipline to keep at each step until its right. Don't bother if you aren't prepared to be exacting and disciplined, you will just dig a deeper hole - its not something to do half assed or without puzzling through the how and why of each step before making (tiny) chips.

The next, and perhaps last (as i can fit no more), one I'll do will my 10ee. I to will have the the bed ground and moglice the saddle, removing a significant amount of scraping and tedious way alignment. The crossfeed and compound aren't a big deal, headstock shouldn't be either (when i fashion a lift over it)...haven't yet finalized the approach for the tailstock, it'll be trickier.

Overall, its a way to drive a 911 turbo on a chevy budget......but there's no free lunch, the upgrade from chev to 911 is through hard work. But like all things we do as hobbyists, it holds its own pleasures and sense of accomplishment. I've surprised more than a few skilled men with multi million dollar cnc machine shops with the ability to make something say parallel with simple hand tools such that a tenth's indicator needle won't flicker. Easy as pie for someone even moderately into scraping

Also, its one heck or a lot cheaper than doing an old car, a lot more useful, and if oiled properly will outlast you and the old car