Thread: Scraped 1941 SB10L
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02-15-2021, 04:58 PM #21
How much experience did you have scraping prior to this? At least enough for the 18" and 48" straightedges, I assume.
How tricky was it getting the three vee's in alignment? I've religiously watched Keith Rucker's series on redoing a Monarch lathe, but he didn't scrape the bed on that one and it only has one vee and a flat on the rear to contend with.
Any plans to scrape a larger lathe? Is this one for sale?
Power scraper or only hand scraping?
I think a heavy 10 is worth rescraping, however I don't know if the same could be said about a run of the mill south bend 9" or 10k lathe. Sorry about the battery of questions, I think i've been wanting to get into hand scraping eventually.
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02-15-2021, 07:51 PM #22
I have a few long term projects, and was wanting to start working in this direction as well. I think not so aggressive as serious machine rebuilders/reconditioners. But maybe take the edge off some inaccuracies, add better bearing surfaces to sliding surfaces. I think hand scraping for me.
For handscraping some links I got from from Richard King. There's more than one way, or one product to use, even under his recommendations. So consider asking questions in the reconditioning section. You can also PM Richard, and he will just as likely call you on the phone, as its quicker than typing.
Store bought scraper handle:
Universal Hand Scraper - Use with All Biax Scraper Blades & Inserts | DAPRA Corporation
His recommendation is to use that handle in conjunction with catalog #30 scraper blade which is 1 1/4" x 3.5" due to the quality of parts. As some other blades the soldering or brazing may not hold up.
He did mention using a 4 sided blade about 1" square, or 25mm square. That gives 4 cutting blades. I see the #30, and at the bottom of page a 4 sided deal here:
Scraper Blades, Inserts & Holders for BIAX Scrapers | DAPRA Corporation
He said you can also use a 1" square Sandvik carbide insert, to also get 4 cutting edges. And make your own holder out of of 1" flat stock, something a little springy, not too stiff.
He also mentioned using a 3.5" radius on each cutting edge, not a flat or square edge. And when sharpening that edge to grind it to 5 degrees.
For scrapper handle, measure from the inside of your elbow to finger tip, than add maybe 5" for cutting blade, depending the set up, as that will give you good visual when leaning over to look at work.
Should use a diamond wheel for dressing the cutting edge of scraper.
He said Dyken high spot blue works best, but stains your hands, and according to op his new paint:
DYKEM HI-SPOT BLUE INDICATOR PASTE 0.55oz TUBE #83307 | eBay
Something that works well, but does not stain is Canode die spotting blue:
Canode Blue Die Spotting Ink
He also uses a yellow highlighter while scraping, which can be thinned with Windex:
Canode Yellow Die Spotting Ink - 32oz - ARTCO - American Rotary Tools Company
Would also want a camelback straight edge of some type atleast as a master or standard. Maybe a surface plate depending how far down the rabbit hole you want to go.
I like this short post from Forrest Addy as well:
What type of Hand Scraper to use????
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jwearing liked this post
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02-15-2021, 08:17 PM #23
I have done about a dozen straight edges, surface plates, some nice 45-45-90 triangles, and miscellaneous fixtures and things. This was my first machine.
Getting the V-ways parallel takes some patience, but it's not as hard as you might think. You do the tailstock ways first. Then with the indicator on the tailstock base, sweep over the carriage ways for alignment. I did the front carriage way before the rear, then using the front as a datum I made the rear parallel, using the saddle as a master. When the carriage ways are done, recheck parallelism with the tailstock ways using an indicator on the saddle.
I'll probably sell it eventually but I plan to enjoy it for a while first.
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02-17-2021, 12:35 PM #24
Just my luck - the dye-chem stuff is back-ordered at MSC, and my tube of blue permatex goop is nearly empty....
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02-17-2021, 03:26 PM #25
Ed Dyjak in Michigan (a search on PM should find address, phone etc.) has been good for me for Biax parts, carbide blades, and dye. Personally I’d rather buy from a small business like him than a big nameless corp.
L7
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1yesca liked this post
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02-17-2021, 04:21 PM #26
Couldn't find him as a PM member. First found a mention on another forum from 2015, then subsequent company name search found a something here from 2018:
Looking for scraping services in the West Michigan area for a Bridgeport table/saddle
E S Dyjak Company Inc (248) 684-4260
3801 Stobart Road
Milford, MI 48380
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02-17-2021, 04:36 PM #27
Beautiful work on the lathe, it's really nice to hear it described as a straightforward process rather than some mystical lost art.
You might consider using Charbonnel Aqua Wash Etching Ink instead: Takach Press - Charbonnel Etching Ink . It's infinitely easier to clean up than Dykem due to being water soluble. It's so easy to clean that my pink granite surface plate remains un-stained from scraping. Also I find it just as easy to spread as dykem while also cheaper. Tom Lipton was the first to demonstrate it on his youttube channel, but since then I've seen Richard King use it as a scraping class, even over dykem or canode.
I've scraped several straightedges and a surface plate, plus rebuilt a compound slide using charbonnel. I haven't touched my dykem since purchasing it.
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02-17-2021, 06:22 PM #28
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02-17-2021, 06:56 PM #29
Yeah, being able to blue up a pink granite stone and clean it without staining would be nice. It's too late for my stone though.
Also the Dykem will stain painted surfaces, and anything that can clean it will damage the paint. Do you think Charbonnel can be cleaned from paint?
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02-17-2021, 07:20 PM #30
Those first two points were my biggest issues I've had working over my big 16" Hendey's saddle (still working on it). I ended up using a pair of power hacksaw blades held together in hand to shave the dovetail corners deeper. I milled a lot of material off of the top of my saddle to get past wear and damage (prior owners used the saddles exposed surfaces like an anvil...). I was successful in doing this but ended up with up to .030 variance in some places that I'm still scraping through, due to the Bridgeport table and knee shifting as it would travel. Hindsight I should have done the roughing on a mill with a bigger more stable table, or sent it down the road to a plainer.
Fantastic job you've done!
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02-17-2021, 08:44 PM #31
That link was to oil-based but this seems to be your go-to stuff:
Takach Press - Charbonnel Aqua Wash
But darn too many colors!
The blue permatax stuff came off the pink stone OK with just ethanol though.
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02-17-2021, 11:30 PM #32
I did the same thing with the hacksaw blade, but my itty-bitty South Bend doesn't need such a huge relief so I just used a single blade from a handheld hacksaw. It's easy enough by hand, but it's hard to know when you've gone deep enough. Also it sometimes leaves a little annoying burr.
How did you clamp that huge saddle to the Bridgeport table? It was hard enough with the little SB. The clamps have to go in particular places to avoid distorting the part, and with only 3 T-slots there's not really enough room on the table.
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02-18-2021, 12:53 AM #33
Just watching some vids on it. Saw Keith Rucker cut the dove tail relief with a cutter on the mill. The vid preview pic shows it:
Monarch 16" Lathe Restoration: Part 12: Saddle Cross Slide - YouTube
I don't think he had a specific number in mind, just clearance to get the scraper in the corner.
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02-18-2021, 01:10 AM #34
Yeah I haven’t had issues removing charbonner from painted surfaces on my straightedge. Just don’t leave it for a week; I presume it will get more permanent once dried.
And you got it Jim meant to include link to the water based. I use the Prussian blue color with no issue, and have a yellow and red for when I want contrasting magenta.
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02-18-2021, 08:29 AM #35
Thin woodruff key cutter does a nice job for dovetail relief...
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02-18-2021, 11:18 AM #36
I didn't get any pictures, but given the mass of the saddle (it's about 24" square), I was able to support it on three points centered in the middle of the table with two clamps positioned between the dovetail sides (center front and center back), so that the ends were out in open air, and had enough travel to hit both sides of the cross-slide ways in a single set-up. The Bridgeport I used has a 42" long table and a slightly longer knee than others I've seen. I cut 1/16" off of the cross slide bottom with a fly cutter and touched up the dovetail with a dovetail cutter and that part worked out well. I had trouble because I used the turret and ram to reposition further forward and further back to hit the tops of the saddle 'wings' and ultimately (including the follow up scraping) cut about 1/8" off of them. I failed to account for the fact that at the far ends of travel with the turret moved all around, the whole machine was moving out of parallelism in Z. Luckily this has no bearing on the saddles accuracy. I was mainly cutting the wings for cosmetics, but also to provide a semi-accurate surface for odd set-ups and indicator positioning, so I want to correct it.
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02-18-2021, 12:13 PM #37
Actually I did find a video showing the set-up. After my rough-cutting and some initial scraping, I put the table on our Kearney Trecker mill to put some relief cuts between the cross slide ways and tops of the saddle. I think I had something else running on the Bridgeport at the time, but the K&T had the same amount of travel and a vertical attachment and the set-up was the same.
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02-19-2021, 01:32 PM #38
I had tried something similar with the SB, it didn't work for me. Maybe you got away with it because the Hendey saddle is massive compared to the SB. But in my case, I supported at three points, but the clamps absolutely had to be directly above the supports. When I tried putting just two clamps, with one of them centered between two supports, it distorted the saddle quite a lot. I measured the twist while I was tramming it in, it's really surprising how little clamping pressure it takes to distort the part.
This is what I did. I have some old gage blocks that have been demoted to use as parallels. And three matched gage pins. The first pic is on the surface plate, but I support it the same way on the mill. Obviously the carriage slides have to be scraped first. Then on the mill, I tried to get a clamp over each support. The photo here was my best attempt, but in this setup I only cut the front dovetail, not sure I would have clearance for the cutter in the rear.
BTW this is also why I chose the hacksaw blade to cut the relief vs a slitting saw. I can cut it by hand in 5 minutes, it would take longer than that to get the saddle mounted and trammed and everything.
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M.B. Naegle liked this post
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02-19-2021, 04:45 PM #39
Yes I think on mine the mass of the casting resisted deflection when it was clamped, and I also had the two blocks being straddled relatively close together compared to the size of the part. My bed ways and under-saddle ways are worn enough that I didn't trust them as a reference, so I used the flat machined surfaces besides the under-saddle ways and marked where the blocks are so that they always sit in the same place if I'm inspecting or milling it. Getting the bed plained, scraped, and the saddle built up to height are still in the future, and when that happens I can confirm that the saddle sits level on the bed. For now the cross-slide will just be square and level to the saddle casting.
Rebuilding these machines definitely teaches you just how fluid iron can be. Fortunately it's repeatable if it's a well designed machine or part so you can account for it when cutting and assembling the parts. Some of the best lathes I've set-up and used are straight as wet-noodles, but on a good floor and leveled correctly they keep their position. I think us metal workers tend to think of this stuff as rigid solid pieces, but it's really more like house carpentry where you have to be aware of how boards and beams are supported and fastened together and that they are level during construction and will stay that way later in use.
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