Home built scrapers

Got a chance to put some scrapers together today. Thought I would show a few pics since it gives a general idea what the desired result should be, though some of my grinding work isn't the best. They're lapped at the cutting edge though, where it counts, and all cut nicely. See if you can find the test piece in the pictures as we move along.

All the parts and pieces had been ordered over the past 3 months or so, with the exception of the diamond wheel. MSC had them on sale lately so it was time to get on with this.

Put the new wheel on the HF grinder, which required a trip to the hardware store to get it all married up.

Steel blanks were cut for the shafts, tangs cut on the bandsaw, ends tapered to match the carbide(roughly). Lengths were determined by holding my wood lathe tools as if they were metal scrapers, deciding what length would feel good for which scraper, and then turning the wooden handles for each scraper. Once the handles were made, steel was cut to the target length.

Next step was to braze the C2 carbide to the shanks. The carbide was .125" x .375" x 1" from MSC. It was pretty rough and I wound up using some diamond paddles to dress the joined edge.

Here's the deluxe brazing jig:



The silver solder I had was round, and it took a bit of playing before I realized I had a hammer, and, voila, now we have ribbons of solder. After a couple of false starts to figure out how much heat was needed, the tips got stuck on.

Grinding the tools to shape was the next step, followed by installation of handles. After screwing around for a couple of hours with the brazing, I decided to forgo carefully fitting the handles and driving them home on the shanks. I ws worried about breaking the carbide, so some basic stabbing with a hand drill and a dollop of JB Weld later, shanks are in the handles with no shock applied.

Here's the shanks, rough groud tips, awaiting their handles. The one with the handle on it already is my official "cheap ass" scraper, presented with much ceremony to me by one Forrest Addy ("Here's your cheap-ass scraper.") Also note the radius gage in the photo (the red thing).



Along in here I had to stop and turn a lap for the little grinder. All I had in the size I needed was aluminum, so aluminum it was. It needs some more refinement (screw heads countersunk), but I don't have a CS that big, will have to borrow one from work on Monday.

At the scraping class Forrest showed us a tool that was basically a ball bearing on a little axle on the end of some scrap. Purpose of this roller is to mash the diamond paste into the lapping wheel.

Having mounted the lap and found the diamond paste, I needed a masher. Since this is basically a redneck operation, here's my version:



This next picture is an attempt to show the negative rake applied to both sides of the blade. The one in the foreground is off the 220 diamond; the one in back has been over the lapping wheel.



Here's another close up showing the different radii; the shallowest is 1 unit of coffee can. Then smaller than that, and then real tight for picking at stuff. These are based on my experiments in Savannah.



And finally, all done. Not real pretty, but they work. I noticed at the scraping class that scrapers get a lot of "patination", so I didn't waste a lot of time polishing and so on in areas where it didn't matter.




At last I'm ready to go. Maybe tomorrow I'll try a little test project, had enough fun for one day. Having attended the scraping class made this a lot easier. It gave me a clue as to what sizes and shapes to try, and most importantly, what it should feel like when it's cutting.

Hope this isn't too basic, thought seeing some pics might help someone else.

Rob

Rob, looks like your in danger of great success in scraper making. Your handles are handsome and they look very comfortable. It's good you're trying different shapes and styles. Time and experimentation will winnow your designs to ones that best suit your purposes.

Maybe I didn't go into this one detail sufficiently. Those of you who received a piece of carbide and a cheap a$$ scraper from me will note the carbide was mirror finished on the sides. I did that on a diamond hand stone before I departed for Savannah. It was a nice job to do in a recliner while watching the news. It's easier to lap the carbide faces before brazing than afterwards.

Dont forget you may also have to scrape a dovetail or three.

[ 09-04-2006, 06:03 AM: Message edited by: Forrest Addy ]

Wow, looks great! I am envious wanting to get started and I see you are way past that!

How hard was it to turn the ball-handle on the top/longest scraper? (and do you do the turning work with the ball-end closest to the spindle or towards the tailstock end?) I used a wood lathe exactly once and my Dad has one so next time I'm there I'll want to try to knock out some of those....oh yeah, also want to try to run it a little more than a single trial cut too.

Wonderful stuff there Rob - thanks for sharing

Years ago I made a big mushroom handle to fit an original Anderson ferrule from a block of hard maple. These are the kind for powering along with your hip - something I never have mastered

John

Forrest, I did notice that the carbide you gave me had been polished up. I probably should have gone that route, but my story is a bit out of sequence. I didn't have the grinder running until after I had the bits brazed. Later on I found I could dress loose pieces of carbide on the machine. This carbide has a really scuzzy outer layer, and dressing it down by hand takes some time.

Matt, All the handles were turned using a screw chuck. This lets me mount the ferrules, drill holes for tangs, etc. Gripped part of handle is nearest the headstock; ferrules are fit and turned while the piece is on the lathe. None of them were hard to turn, took about 30 min each. Slow since I hadn't turned much in 3 years, and was playing with the shapes some. I've done a bit of production turning to learn speed, so that helps.

John, the mushroom handle grew out my expereince in Savannah. I found a lot of the time I was using a combination of hip and arms, and often used the scraper against my shoulder or snugged under my armpit. A file type handle is not the best for that, so thus comes the big lump on the end of the war club. Besides, I think it looks cool.

Rob

To heck with hip scraping, that's what the BIAX is for!

Rob,

Did you hone the sharp edges off the bevels that you ground on the 4th picture?

I tried scraping with sharp bevels like that on the scraping blade, and had problems with gouging. MTR explains that you should hone the 0 - 30° bevels down to a smooth radius, and this helped me a lot on the quality of my scraping.

Robert

Rob, Forrest,

You mention that you ordered a 220 Grit diamond wheel from MSC.

I'm guessing that the honing wheel and mashing the diamond paste is for finish honing with very fine grit diamond paste?

Based on Forrests' earlier recommendations, I've been finish-honing by hand with a lapping plate and 1200 mesh diamond paste. Is it worth dedicating another wheel for a honing wheel?

Thanks!

Robert

lazlo, are you refering to the short corners at the ends of the width of the blade, or the part that looks like a long parting line across the middle?

The short corners I bump off on shallow radius tools, on the tight radius tool it's not a problem.

The line across the middle, I don't see how that affects anything in my little world so far. I scrape with the tool at an oblique angle to the workpiece, so that part of the carbide doesn't come into play. If you're doing something that requires the toll to be at closer to right angles to the work, and feel it's in the way, round the sucker off.

Honing: I set out to put together a machine for this, so I haven't tried anything else yet. On the other hand I sharpen chisels and gouges and lathe tools with diamond slips,then hone with chromium oxide on a stick, at work all the time because it's qicker than going to the sharpening table.

I figured the grinder helps me get repeatable angles, makes it easier to not round the wrong corner when honing, and generally makes it easier so I can concentrate on scraping.

But I've got all of about 12 hours of scraping experience at this point, so you might ask your dog or someone else for a second opinion.

Rob

Looks great..... have fun using them and the handle shapes sure look comfortable.... enjoy.

Rob,
Nice job on the scapers and lap! I really like the masher, though. Wish I woulda thought of that! Can I get detailed drawings?

Good job Rob. Seeing the 4 different style handles got me remembering.... I read a book by Guy Lautard (the Machinists Bedside Reader, ver.?) that gives a formula for making handles to fit YOUR hand. Take your own measurements and plug them in. I haven't tried it yet but he says it works well. Contact me if interested and I'll forward you more info. Cheers, al.

Thanks for the kind comments all.

Al, I tried the file handle thing from TMBR years ago. To me, the major diameter is too fat, and the necked down portion behind the ferrule is too skinny. It's a place to start though if you want to try something. Did them for several people in the shop; most liked them. And now all our files have pretty handles. Thanks for the offer of sending the info.

Thanks,
Rob

Aren't you guys too inexperienced to be playing around with this high tech stuff? Being a little aggressive here aren't we?

Blackboat;

Nice job & thanx for posting the photos... Helps to get some idea of what all the scraping posts are refering to. Forrest Addy is there a copy of your handout available somwhere?

Aren't you guys too inexperienced to be playing around with this high tech stuff?

Click to expand...

Yeah, it's about like tossing a banana to a monkey, except the monkey probably has a better idea of what to do.

Rob

I have word from DON that the Forrest Scraper Freak Fest will soon be delivered on DVD. I plan to make copies and offer them to the clan. I also have Forrest's material and with his permission will also make copies to go out. Look for a future post to sign up for this upcoming release.