A new scraping-video by me :-)

Hi!

Made a new and lengthier video about scraping. for now only part 1 while work is in progress.

It's about my Myford MG12-M that I'm restoring from ground up. Paint stripped, filler, putty, etc.

And scraping!

Enjoy and don't point me to spelling errors. :-)

Nick

Reply to
Nick Mueller
Loading thread data ...

You got a mouse inside your camera .. :)

looking good Nick..

Just looking at the way you are doing it with that biax machine ...and it occured to me ...if i was carefull ...i could do that with an air powered 10mm finger belt sander.

like so:-

formatting link

..I know then, it wont be then called scraping ..but hopefully same results..if careful...or am I wrong.

all the best.markJ

Reply to
mark

, no, that's the auto focus I guess. Cheap camera, good enough for WEB-stuff (after editing the audio-trace, I suppose).

And put what sanding belt in? Plain paper without any abrasives?

You know, that scraping works in the µm range. No, I wouldn't even try it.

Nick

Reply to
Nick Mueller

Nick

It looks good to me, I followed your introduction regarding the straight edge, taking measurements etc, but what did you use as a master to apply the blue?

Ian

Reply to
Ian P

Get a roughing blade :-)

or braze a bit of carbide to a piece of 20x3x75mm steel.

regards Mark Rand RTFM

Reply to
Mark Rand

Makes me want a Biax........

Charles

Reply to
Charles P

I didn't show that, sorry. It was a so called camel back. A ruler with a broad (about 55 mm) flat side, on the other side a bowed reinforcement (looking like a bridge).

I'll show it in the next video, or have a separate one about the tools.

Nick

Reply to
Nick Mueller

Yes, I was too slow in the beginning. I need to learn to be more aggressive when starting. OTOH, an excuse, the oil channels prevented harder cutting. I didn't want to get stuck in them.

Nick

Reply to
Nick Mueller

On the very little bit of scraping that I have done (by hand, no Biax unfortunately) I realise that I have not been aggressive enough at start. Experience has proven that "relatively heavy" blueing of the "master" and aggressive cutting pays! Otherwise one gets tired and the job seems to go on and on.

I very much look forward to your work on the Vee. I have an Eagle grinder (Courtesy of Charles P) that I have been slowly working on. The Knee ways are "better" than they were but the table ways need some work. It will never be a "perfect" machine but is a good exercise in scraping.

Anybody:- Where can I source a Sandvik Coromat hand scraper in the UK. I am currently working with a home made, it works but not good enough.

Nick:- Is the cutting action of the Biax side to side or forward and back?

Thanks for the video.

Richard

Reply to
Richard Edwards

Nick

This is really interesting. I look forward to the next installment (and some further information about tools). The Biax looks like a fine piece of kit.

Thanks

Mike

Reply to
mikecb1

But really hard cutting is kind of an art by itself. Not the cutting per se, but knowing where to cut and keeping the really hard cutting for many enough passes. I'm not really at that level yet. But I do know when to start point spotting and I'm quite quick at that now. I think there are three phases: hard cutting, rough cutting and point spotting.

One can start with point spotting, but it will take forever. BTDT. :-/

BTW: I think the Sandvik blades are the best. Got some and they stand much longer and make a finer cut.

Back and forth. The stroke of my BIAX (a BL40) can be adjusted, also strokes per minute. BIAX does have several models. So if you buy one, get informed! The "L" in "BL" stands for light cuts. But they seem to have a different understanding of "light". Maybe they are thinking of huge machines with millimetres to cut off. :-) Anyhow, I'm happy with that model. It is heavy enough to scrape a rough casting if you want. And you don't want a heavy model, considering that you'll scrape for hours and days.

You're welcome!

Nick

Reply to
Nick Mueller

Snip

Another query Nick. What cleaning liquid do you use to clean off the surface after scraping and before re-testing with your flat?

I know that some feel that highly volatile liquids cause cooling and therefore distortion of the part. I admit that I use "Carb Cleaner" (Mainly Naptha) as I always have an aerosol around.

Richard

Reply to
Richard Edwards

I have tried around and found this working the best: Normally, I use spray-on oil *like* WD-40 :-)), no not THAT ONE!. The cheapest I can get. It's best if it has no MOS2 in it (unlike the one on the video). I oil the *stone* (Arcansas is really the best after trying different ones), deburr (all over the speck, swarf, blue) and then wipe off with an rag. If that rag got dirty enough, I use it for a first wiping pass and then go over it again with a clean(er) one. I do know, that people say that any remains of oil are bad. But that what is left behind this way doesn't hurt. So I don't fully agree with that. Only if I do have problems with the blue, I use whatever solvent is in reach, there's no difference. Aceton is working perfectly, and isn't health-hazardous. And I like the smell. :-/

Use rags that have been washed several times, so they doesn't lose fine "hairs" (don't know the word right now).

Clean the surface plate (where you spread the blue) and the camelback / prism at least once a day (when you start). Fine dust is collecting on it and the finer the work, the more you will see fine stripes of blue on the work. Then it's time to clean all tools with a solvent.

Someone told me the trick to wipe over the granite plate with the hand. Before spreading blue . Thus, you feel any dust on it and the bit of grease will pick up fine particles.

A short question, a long answer! :-))

Nick

Reply to
Nick Mueller

"Nick Mueller" schreef in bericht news: snipped-for-privacy@mid.individual.net...

Nick, nice video! Where did you buy that handscraper? Dirk.

Reply to
Dirk PG1D

At fleeBay through an agent (read: friend). I personally never buy something there. Call me nuts! Again, pay attention with their models!

Taking the chance to answer a question I got by eMail (please ask here): The rubber roller (not show in that video but an other one) is made out of rubber. I think it's PU? You get them at art shops. Has a closed surface, nothing foamy. Use the technique (also in that other video) with the two places for the blue. It really works perfect.

And again a comment about rough-cutting. It seems, that it is angst*) that you might destroy something. Even with hard strokes it is quite complicated to remove too much. But this is a longer process to understand learn and judge. The only place to pay attention is the boundary of the surface. Stay a bit away from it and thus get a slightly concave surface. With a few strokes in one pass, the "border mountains" are set back to the inner level. Avoid chatter and try to get not too many scratches (through bad edge). Oh and to the edge: In one of my other videos, I used a green grinding wheel. Now, I do have some diamond wheels. Much better! There are different namings for the grids. One that works is "D54" (or D52?). Something around that ballpark works. But I'm still making a few strokes with a diamond lapper mesh 1200 over it. And radius: It depends a bit of the work you are doing. I'm fine with an R90 .. R120 for roughing and mostly an R60 (or R40) for spotting. The more acute the angle between work and the blade is, the bigger the effective radius. If the angle gets too big, tendency for chatter increases. With a big radius, it is harder to exactly hit a spot. Takes some practice and I'm still having a bit of problems with that with the BIAX, but quickly learned with a hand scraper.

*) I'm using that word, because I know the specific meaning for you.

Nick I think I'll write a book. :-)

Reply to
Nick Mueller

snip

"Lint Free" I feel

So rolled out blue on the plate to get an even coat on the roller, then the roller onto the "Camel Back" Yes?

Richard

Reply to
Richard Edwards

Right. And two areas on the plate. One for spreading in initial picking up blue (a small area) and a bigger one for picking up blue to go onto the ruler. That second area avoids having "fat" spots of blue on the roller. Strictly speaking, you can leave out that second area when using a ruler or prism if you get an even coat on the ruler / prism.

But you can't leave out that second area when touching on the plate.

So the point is, that the roller is used to *transfer* blue, not to *spread* blue.

Nick

Reply to
Nick Mueller

Thanks Nick, a book on CD with lots of video's would be a good idea ;-) Do you happen to have a article number of the hand scraper? I've been e-searching a few hours and can't find in anywhere, E-bay, Sandvik Deutschland nor Sandvik elsewhere. Does your friend has more handscrapers in stock perhaps? MfG, Dirk

Reply to
Dirk PG1D

No, that won't happen. Too much work. But I'm willing and happy to share my findings here and at youtube. Once, I'll make a compilation on my homepage.

Here is my BIAX power scraper:

And here a hand scraper:

Funny data sheet! ROFTL!!!!

You might have a look at for other sizes and blades etc.

The handscrapers were bought at Hoffmann-Group. The BIAX has a prohibitive price tag and was bought used (through my agent ).

Nick

Reply to
Nick Mueller

You can hardly claim it is a hand scraper if the thing is motorised

Regards, Tony

Reply to
Tony Jeffree

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.