[rolfinator2002]

I'm toying with the idea of documenting (film and photo) the way reconditioning of a bridgeport mill clone and wanted to know if there was interest on the matter.

[mactec54]

rolfinator2002

That would be a really good subject to post on, A dying art of hand scraping, that needs losts of support
to keep it going

[MBG]

I would LOVE to see.

[diyengineer]

As a noob i have no clue what way scraping is, but would love to learn! haha

[ImanCarrot]

I know it's a dying art but nothing else about scraping- would love to learn!

I also have an old Bridgeport clone that needs resoring so would be very interested from that point too.

Good subject!

[mikemck]

Definitely! Would like to see as I'm trying to learn

[MBG]

So, it looks like the votes are in. When can we start learning?

[ImanCarrot]

I was wondering why folk actualy scrape things flat... why not use a Lapmaster to lap it flat, check it with an interferometer or an optical test plate under monochromatic light- you could get it flat to 1/20th of a wavelength of light.

The only thing wrong with this I can see is that you wouldn't have the tiny grooves, presumeably to allow oil to flow between the surfaces... but surely you could then Jewel the surface like you get on some rifle bolt actions?

Wouldn't this be more accurate and less time consuming (ie: cheaper)?

Or am I totaly off base?

I'd still like to learn it though: simply because I don't know how to do it.

[ThomD]

I'd be interested, in such info. I got a lot of scraping gear by good luck. I also need to fix a knee mill which is pretty good but tight on the in out axis. So it needs reconditioning in the Y axis.

[rolfinator2002]

Lapping probably takes more time and usually reserved for harder surfaces/materials. Grinding is a good alternative IF the shop has a grinder large enough and accurate enough to perform the job, then one of the mating surfaces are flaked or frosted and spotted for heat checks or hard spots. A power scraper lets the mechanic recondition ways/slides of larger machines in situ.

[ImanCarrot]

A power scraper lets the mechanic recondition ways/slides of larger machines in situ

Good point, didn't think of that- the hassle of taking everything apart, lapping them, reassembling them and trying to figure out where the spare bits left over go whilst slipping on ball bearings would make scraping in situ a most attractive option

Gonna get a power scraper and mess about on some spare stock. Will post piccies (if it works lol).

[the4thseal]

yes yes yes. this would be great.

[ImanCarrot]

Poo, no info as of yet and it's been days. I'll find out from somewhere else. Usubscbrided from this this thread.

[allrounder]

Hi. I've been using a badly worn South Bend 9 inch lathe for 35 years. It won't fit on my milling machine, so I'd be very interested in resurfacing the ways with hand tools or a simple portable jig of some kind. It'd be great to find out how it can be done decently when only the bed ends would be unworn.

[voltsandbolts]

Nice!

This is a topic that’s been on my back burner for a long wile, always wanted to know more… Bring it on, I’m ready to soak it all in.

RobW

[pmx]

Hi,
just a basic info, to help some people to know what they will vote for

Scapping allows to make surfaces flat, with at surface finish that will help smooth operation, i.e. for lathe ways, etc...

Hand scraper - Wikipedia, the free encyclopedia

Surprisingly enough, hand scrapping allows a precision that can't be achieved by regular milling, and only by precision lapping, electrolytic methods, or "superfinishing". But for that, you need to move and clamp the "target" in the lapping machine.
In the other hand, hand scraping can be done "in place".
Achievable "roughness" (arithmetic mean) from 0.8µm to 0.2µm.

For hand scrapping, you need a control plate, or bluing plate, some marking blue (can be prussian blue artist oil paint), and an hand scrapper (a kind of chisel).
Also an ultra fine oil stone for honing the hand scrapper (unless it uses a carbide insert) and deburing the roughing passes.
An expensive alternative is the swiss made Biax electric scrapper tool.

A 7 parts video showing the whole process of machine tool ways scraping. Shows both hand scrapping tools and Biax scrapping

(link to the first video)

[nomedia="http://www.youtube.com/watch?v=90KpLbyvlPk&feature=mfu_in_order&playnext= 1&videos=9lrzMjTRsR8"]YouTube - Scraping in a Myford MG12-M cylindrical grinder / part1[/nomedia]


Also a link to the "swiss scraping" method that uses a long scrapper hold over the shoulder. (I'm not the guy on the video, although it's name is Pierre, like mine )
Text is in French, but the movie is self explanatory !

[nomedia="http://www.youtube.com/watch?v=TFCVO0fXW1ka"]YouTube - Le grattage à l'épaule[/nomedia]

Pierre.

[service_bb]

Way Scraping is what I specialize in

[BH_Nomad]

I am trying to teach myself scraping and I have made 3 12" straight edges out of HRS and am scraping two sides flat and also I cut up a old man hole cover and am am trying to make 3 90 deg angles. So all the help I can get would be good.

[austin.mn]

Although I did scraping for a while, I am a bit out of practice.... I would love to see a knee mill get redone and it would a great thread to have up.

[prasad]

I,d still like to know more through this .Because it is simply superb.Thanks.