DIY Epoxy Granite Lathe #2: Scraping Lathe Ways with an Angle Grinder 

My thoughts exactly lol

Thank you! I hope so!

Thank you so much for the kind words. That process sounds extremely interesting! I will be returning to do a final flattening pass once the lathe is operating to get it completely dialed in and I’ll definitely be remembering to use a dremel cutting wheel for fine adjusting! Thank you!

Hi Carlos there are two videos I've watched. One German with a Proxon grinding stone wheel, other one American with an angle die grinder. I hope these help German: migru59 "Tuschieren mit Schleifer / An alternative to hand scraping" and American: cgprecision "Hand grinding hardened ways"

Really interesting! Im not going for something nearly that precise, if I could get within about 1-2thou over the full length I would consider that a huge success. What a great project though, I’ve almost never even heard of a straightedge that flat!

Actually no, Interestingly enough! I thought the same thing, but I did tests with a micrometer and a piece of ground steel of known thickness, and one complete pass removed approximately .0003in from the whole surface. Im sure a grinding wheel would remove a ton more though which is why you need to use a cutting wherl

Haha it would have, I wasn’t really sure what I was going to do at first so I started with just the one rail. Would’ve been better to do both together though for sure. Thanks!

That’s great! Sounds like a really cool project. I made a video on epoxy granite that would answer hopefully most of the basic questions, but there’s a ton of info on cnczone.com in a thread called something like “main epoxy granite” which is many thousands of posts long, they did some good research and it takes a little bit but they got very solid info in the end. That is probably the biggest collection of info I ever found on epoxy granite, and they do some fantastic work. If you’re interested I’d very much advise at least skimming through for the main findings they came to. I think there’s a summary page of what they learned Not to be rude necessarily but there’s a user peteeng very late in the thread who joins the discussion and gave a lot of information which does not seem to be well researched. Generally his info did not agree with anyone else’s and he couldn’t provide much supporting evidence, so that’s the only info there Id really shy away from.

It’s much more difficult and much more time consuming but yeah to a point it can be done, I flattened it to about .001in and that was about as accurate as I could get over the full length

To be totally honest Im not sure I remember exactly what that 30 thou was in reference to, do you remember when in the video I said that? (Sorry to ask for a timestamp for my own video lol) Those 2 steel inserts are hot rolled steel and quite warped. I tried to bolt them to the surface of my mold and that helped a bit, but they were still further out of plane than Id have liked. I would strongly recommend going with cold rolled and using 1 solid piece instead of 2 separate ones if possible. At least thats what Id do if I could go back, my friend is making an eg machine at the same time and used cold rolled inserts, his inserts started flat within about 8 thou Id love to see a video even just showing the cad file though, sounds like a great project!

@@robertsteinwandel6658 Thanks for the response, makes sense with the hot rolled and being in two pieces. Here is the first of my video series. I'm a few videos in now. I'm a beginner at the videos too. Sometimes the videos are harder than the design, ha ha. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-zW7GurXszDw.html

Nick P Im halfway through episode 2 now, great videos! You’ve got a sub here for sure hahaha

@@robertsteinwandel6658 Ha ha, as do you. I actually was just watching 1 and 2 myself after I linked them. I forgot myself what I said on them. ha ha.

Nick P hahaha thank you!

Thanks

Lol I appreciate the comments. The audio gets a little better although admittedly not much, the first video was just an explanation for another engineer, I never realized people would go back to watch it later hahaha. It was only the next videos I started really making with people in mind at all Taking it to a machine shop would have been way easier for sure. Partly I did it myself because it’s basically free, but also it was pretty interesting to try to make a precision flat surface with an angle grinder in a garage haha Glad you’re at least able to get through the vids hahaha

Newer vids are better with that lol, pretty sure this was before I had access to basically any editing Still not amazing but hey it’s getting there

Thank you! Honestly thats a great idea, I haven’t seen that many videos about it. I still need a tripod but the video quality is hopefully considerably higher than before with editing and all now lol. Thats great!! I had heard of it but never got a chance to read it, Id heard it’s incredibly useful, thank you! Yeah bending over for that plate got brutal after a while. The casting is about 300 pounds though, I could lift it onto those buckets (with difficulty) but couldn’t get it too much higher without some type of setup to lift with some mechanical advantage. I might use a jack or something to lift it a little higher so its better to work on haha

@@robertsteinwandel6658 Audio is more important than video. People will accept wobbly video more than inconsistant, or bad audio. Yours is not too bad, but a 15 buck lav mic from Amazon plugged into your phone will make it more consistent (although the cable is a PITA). I used a cheap lav mic into a cheap sony Dictaphone for the first year, synching in post. Also a bit of a pain.

Hmmm. I wonder if it's more accurate to reference the ways using an equally long and "reasonably flat" surface, say a melamine board, just to identify the high spots for the initial scraping. Once "reasonably flat" follow it up with a more precise scraping of the sections using the granite block. My only concern about using the block alone is that it may be straddling deep and wide bows and crowns leading to a false reading, as RotarySMP cautioned.

@@RotarySMP I think your commenting helped the algorithm show me his channel, only 5 months late instead of 5 years late for Tabletop Machine Shop (canada) and his cool suitcase slantbed lathe ;o)