Die grinder “scraping”

[Richard King 2]

I have been grinding hardened ways for several years. I am the one who told Chris German on Practical Mach and he did a vertical mill with hardened ways. Then he made this one ----> ttps://www.youtube.com/watch?time_continue=18&v=YXLk0mJOwJM&feature=emb_title

Andy, in My professional opinion. Leaving those dep gouges look bad to a professional machine builder, machine rebuilder or a machinist. I also have used a belt sander to grind down worn wide ways so it looks like they were surface ground. Also use the 2 color like Ben said. Toss that Permatex away and buy some Dykem High Spot, Carbonnel or Canode.

 

[ericc]

Those "gouges" do not look much more than 0.0001" deep. This represents a significant improvement over much of what I've seen on Youtube.
,
Often, when someone thinks about (maybe in a fit of anger) taking a grinder to the ways of a lathe, they are dealing with ridges 0.025" deep. If I read the complaints correctly, this is "25 thousandths". Can a misstep of 0.0001" ruin something that is already so far off? Maybe so, because then the carriage could get stuck at the low spot? But so much material has to be removed that a 0.0001" slip might not be so bad. I have seen worse stuff on Youtube. Sometimes, it is just interesting to see something new which kind of works. It may not be suitable for industry, but it may be intriguing nonetheless. For example, I got curious and wondered if anybody could do a DCEN TIG weld on aluminum with pure argon. Not much on Youtube. So, I tried it out and it worked. Not well. Certainly not well enough for industry. But it was strong, and there were no inclusions. I'd have appreciated it if someone put this up on Youtube, just to look at for entertainment, not necessarily to build a career out of.

 

[AndySomogyi]

So this was an experiment on my part to determine the feasibility of a technique.

I’m absolutely certain many have used a grinder for scraping, but it’s *not documented* anywhere, and in my background (science), if it’s not documented, it doesn’t exist.

Anyways, never did this before, and on my first try, after about an hour of messing around, the depth of the scratches is about 0.0005” and average surface flatness is about 0.0001.

Compare that to this disaster. I bought my Grizzly mill USED (another mistake), and the bonehead I got it from removed the way wipers to install a DRO, and all sorts of chips got in the ways and destroyed them. When I bought it, I didn’t know to look for that, I’m not a machinist or machine repairman.

So used it for few months and decided to take it apart. Basically I was thinking just clean it out and stone the bottom way. Doesn’t need to be perfect, just needs to work.

The bottom of the saddle here is a complete disaster from the factory. It was clearly worked with an angle grinder and it’s out of flat by about 0.015”! Yeah, the big dips here are almost fifteen thousands deep.

So yeah, I think my little hour of just goofing off with a die grinder Is about an order of magnitude better than this disaster.

Anyways, I think I’ll use the die grinder to get this saddle within 0.001 flatness, and give it a finish with my little hand scraper.

Again, this mill doesn’t need to be perfect, just needs to work well enough to make some parts.

 

[Eddyde]

So this was an experiment on my part to determine the feasibility of a technique.

I’m absolutely certain many have used a grinder for scraping, but it’s *not documented* anywhere, and in my background (science), if it’s not documented, it doesn’t exist.

Anyways, never did this before, and on my first try, after about an hour of messing around, the depth of the scratches is about 0.0005” and average surface flatness is about 0.0001.

Compare that to this disaster. I bought my Grizzly mill USED (another mistake), and the bonehead I got it from removed the way wipers to install a DRO, and all sorts of chips got in the ways and destroyed them. When I bought it, I didn’t know to look for that, I’m not a machinist or machine repairman.

So used it for few months and decided to take it apart. Basically I was thinking just clean it out and stone the bottom way. Doesn’t need to be perfect, just needs to work.

The bottom of the saddle here is a complete disaster from the factory. It was clearly worked with an angle grinder and it’s out of flat by about 0.015”! Yeah, the big dips here are almost fifteen thousands deep.

So yeah, I think my little hour of just goofing off with a die grinder Is about an order of magnitude better than this disaster.

Anyways, I think I’ll use the die grinder to get this saddle within 0.001 flatness, and give it a finish with my little hand scraper.

Again, this mill doesn’t need to be perfect, just needs to work well enough to make some parts.

Andy, I be happy to watch your videos on YouTube "Professional" or not it's all about the journey of learning and making something better than it was.

 

[Ianagos]

Well I’m the guy that made the video on scraping the tool steel.

I found that my grinder marks were much shallower than a typical scrape mark. I started by using lower rpm but found that the high rpm gave a much smoother surface finish and was still very easy to control.

If I really tried I could get it to within .0001” on the surface.

I did it as an experiment as well and figured I’d document it. I have decided I will not be resurfaceing my ways with this technique but I would consider it on your machine.

My ways are 4” wide and about 30” long x2 só a huge surface area to grind. I just did not want to get into that as once i replace the turcite it will probably be good enough.

 

[Richard King 2]

I'm not condemning the grinding of ways, I have been grinding ways for 45 or so years. In soft ways to get them close and then scrape them, I did a 100" Blanchard Grinder that was worn .100" and it was easier and cheaper to grind it with a 6" electric angle grinder then it was to rig it out and have it planned. When I was an apprentice 45 years ago my Dad rebuilt a 6" Lucas Boring Bar Machine that had hardened bed ways 12" W x 15' L and we used belt sanders to sand or grind the ways using emery cloth belts for the same reasons. I helped another rebuilder in Richmond VA. We used a 6" electric angle grinders on 8" wide x 10' steel ways on a 500 ton extrusion press that was worn 5/16" The press made aluminum windows and they used carbon to hold the semi molten ingots and it acted like lapping compound with the grease lubrication. There was 4 of us grinding over the Thanksgiving holiday and we wore out 2 grinders, we worked 18 hour days 2 guys inside the machine for an hour and then switched, as one group ground the other group rested.

I told Chris German (CG Precision) and the readers on PM forum 6 years ago these stories and one when I taught a scraping class at Gloyes Gear https://www.cloyes.com/tech-center/ down in Paris, Arkansas that had a hardened bed slant bed lathe that was in the center of a 100 machine factory and they would have had to shut down production to move the machine and send it to be ground down at Commerce Grinding in Dallas TX. So I showed them how to use 2" snap in grinding disks on a air angle grinder. Instead of scraping we hand ground it. I would bet that people watch CG Precision on You Tube after he learned the technique from me where Chris German grinds a hardened bed of a small vertical mill.

What we did was use a 60 grit disk to get it roughed in and progressively finer grinding disks and a final step of using a cast iron lap plate we made out of a 1" x 2" x 4" with diamond milled shapes in it and diamond lapping compound until it looked like a new as if it had been ground. So as I say I'm not debating hand grinding ways should not be done. What I mentioned in my other post was the appearance. If someone wants to let the ground ways look bad with scratches as seen in the photo's so be it. I like to teach in my professional opinion, to make it look like it was done on a way grinder or surface grinder or a scraped surface as Chris German shows.