Looking for some scraping tooling tips

[Liljoebrshooter]

Another real cheap project for scraping is a set of 4" or 5" cast iron V blocks or an angle plate. Get an angle plate without holes. You can practice making a flat surface and then make the other surface 90 degrees. You can find these for less than $50.

Joe

 

[Janderso]

Hardly, but I had the same slap-on-the-forehead moment when I first heard of the technique. Now I use it regularly.

I use gauge pins almost daily in the shop for all sorts of things. Literally today I needed to compare the widths of two trepanned channels to get them to the same width (exactly 3/32"). I often find it useful to place a hole or undercut feature on a part a precise distance above the mill vice jaws — much less fiddly to use a gauge pin from the top of a hole than a depth-mic from the top of a part. Have two features you are turning on the lathe precisely 0.279" apart axially? Find the right pin and insert it between the carriage-stop and the carriage.

I prefer to use 123 blocks, gauge pins, and shim stock for setups or measuring whenever possible. I still screw up measuring with calipers or micrometers or even scales on occasion. The only tricky thing with gauge pins is to ensure you read the label from the correct row (the label below the pin, not above!) — the bigger pins are marked, fortunately.

Less useful (at least I've not had occasion to try it yet) but I read somewhere about inserting two hex keys that are half the size of the one you need if you can't find one large enough.

Another real cheap project for scraping is a set of 4" or 5" cast iron V blocks or an angle plate. Get an angle plate without holes. You can practice making a flat surface and then make the other surface 90 degrees. You can find these for less than $50.

Joe

I'm not sure who said this >>>>>>>""Somebody mentioned something to the effect of their offshore machines not being worth scraping in. I couldn't disagree more strongly. If it's made out of cast iron, it can be scraped<<<<<<<<""

Aren't most Asian lathe bed ways hardened? In fact, most lathes produced since the sixties have induction hardened ways right?
I wasn't aware they could be scraped.

 

[Rex Walters]

Aren't most Asian lathe bed ways hardened? In fact, most lathes produced since the sixties have induction hardened ways right?
I wasn't aware they could be scraped.

I’ve no idea as I’ve not tried scraping an Asian lathe bed.

But the bed isn’t the only thing worth scraping on a lathe, and I’m somewhat skeptical that all are induction hardened. It’s an extra manufacturing process that would add to the cost, no?

I’d WANT a lathe with hardened ways assuming they were ground half decently to begin with. The bed ways are the hardest thing to scrape on a lathe (the biggest job)!

Lastly, there’s hard and there’s HARD. Until I make a test scrape, I’ve no idea if scraping is feasible. I suspect “flame hardened ways” might be marketing speak for a guy passing a propane torch over the oil on the ways for a few seconds. True induction hardening can’t be free.

 

[Rex Walters]

Oh, wait!

I just realized that to Jeff, this is an offshore Asian lathe: https://us.dmgmori.com/products/machines/turning/universal-turning/ctx/ctx-beta-800

I was thinking more on this end of the spectrum: https://www.harborfreight.com/power...nch-x-10-inch-precision-mini-lathe-93212.html

(My tongue is firmly in my cheek... )

 

[macardoso]

My 94' Enco lathe has induction hardened bedways. They are ground true and have little wear. The cross slide and compound are much more lacking and have looseness in the middle of travel and tightness in the ends, not much, but still could be improved.

My CNC converted G0704 is also an import machine and the total fitup of the ways is garbage. If I were to try to scrape anything, this would be where I would start. Could probably cold chisel it closer than it is right now...

 

[macardoso]

Well, I am now the proud owner of a 20mm Sandvik scraper, Machine Tool Reconditioning, and some new marking fluids from Dapra. I need to pick up a beginner scraping project still. Hoping to maybe start with a small cast iron surface plate, then maybe a dovetail straightedge casting, and eventually work up to touching my mill or lathe.

The lathe is in good shape except for some light fitting of the cross slide and compound elements. I'd rather not go crazy on her since I am pretty comfortable holding tenths already. If I could even out the snugness in the cross slide, I'd be very happy.

The mill is much more rough. Most of the ways have very poor fit and the rigidity suffers. I'd like to correct for accuracy, then fitup. Perhaps I can add a central oiling system at this point as well. I bet I could really improve my machine without risking really screwing up a priceless machine in the process of learning.

I do still need to figure out how to sharpen this scraper. I'm leaning towards the 1000-3000 grit diamond lapping wheels you see people using on YouTube. I have a cheap bench grinder I can mess with as well as some small motors and VFDs to build a basic lapping table.

 

[Braeden P]

Well, I am now the proud owner of a 20mm Sandvik scraper, Machine Tool Reconditioning, and some new marking fluids from Dapra. I need to pick up a beginner scraping project still. Hoping to maybe start with a small cast iron surface plate, then maybe a dovetail straightedge casting, and eventually work up to touching my mill or lathe.

The lathe is in good shape except for some light fitting of the cross slide and compound elements. I'd rather not go crazy on her since I am pretty comfortable holding tenths already. If I could even out the snugness in the cross slide, I'd be very happy.

The mill is much more rough. Most of the ways have very poor fit and the rigidity suffers. I'd like to correct for accuracy, then fitup. Perhaps I can add a central oiling system at this point as well. I bet I could really improve my machine without risking really screwing up a priceless machine in the process of learning.

I do still need to figure out how to sharpen this scraper. I'm leaning towards the 1000-3000 grit diamond lapping wheels you see people using on YouTube. I have a cheap bench grinder I can mess with as well as some small motors and VFDs to build a basic lapping table.

I mounted the diamond wheels on my wood lathe but if you use your lathe cover the ways for sure!

 

[macardoso]

I mounted the diamond wheels on my wood lathe but if you use your lathe cover the ways for sure!

Not a bad idea!

Picked up a 1/2HP VFD and 25W 1600rpm motor from the trash bin at work (they are cool with that). Just need to mount it up and get myself a few lapping discs. Took about 3 minutes to get the VFD running the motor with start, stop, reverse, and speed control from the front panel.

 

[macardoso]

Got it! Probably going to need several passes to read and understand.