Bridgeport Scraping/Rebuilding DVD Review
Some of the folks on PM posted that there's a new DVD being sold on Ebay by Mike Stets about scraping and rebuilding a Bridgeport:
I just finished watching the first DVD, so here's a quick book review
- The video so far is great. The first disc is only an hour and 13 minutes, so he could have gotten both discs onto one, but that's no big deal to me.
- The video quality is great -- much better than Mike Morgan and Rich King's scraping videos, which were both VHS recordings. Audio quality is good, but not great. The Bridgeport is set up in shop with a blue curtain behind it, and there's a deep echo, but you can hear the script just fine.
- The pace of the video is slow. He could have edited it down some, but I think professional scrapers are methodical by nature, so it's just a nit from a high-strung Type-A
- The video is all about measuring, assessing and aligning a Bridgeport 1J. There's very little mentioned about scraping technique, so if you're looking for that, get Mike Morgan or Rich King's video.
- The scraping is entirely with a (modern) Biax power scraper.
- Mike uses yellow Canode (Dapra water-based) spotting compound as "highlighter" on the workpiece (Rich King calls it that too), and he uses Dykem Hi-Spot on the spotting master. He uses a really thin coat of spotting compound on both surfaces.
- Mike uses really basic tools for all the measurements. He makes extensive use of a common beam square and feeler gages, especially to find hollows on the ways. He has a very simple take on a Kingway dovetail jig: he lays a 6" metal (steel?) parallel on the opposite way, and clamps a magnetic indicator to it, and stretches the dial indicator across to the opposite way. I really need to get a set of cast iron or steel parallels -- that's not going to work on my granite parallels. I also need to get a 12" micrometer for measuring the parallelism of the dovetails using the two-pin method.
- Mike starts with measuring and scraping the column, then the knee. The saddle and table are on the second disc, which I haven't seen yet.
- Mike scraped the column ways flat, and then the scene cuts to him measuring the column and dovetails for flat and parallel. He casually mentions that he also scraped the dovetails, but how the heck do you scrape the dovetails on a 1,500 pound casting that's laying on it's side on the floor??
- After he's finished scraped the column to 20 spots per inch, he does a final check for flatness, and one column way was off by what looked like 2 thou. At that point, Mike looked at the camera man and says "did you see that?" I'm guessing there was something funky about his setup, but after a quick scene cut, the column way had less than a thou TIR from top to bottom.
- The knee on the victim machine was low by 5 thou and there was a hollow under the saddle where you'd expect it. Mike scraped the column-side ways to bring the knee back up, since that's a lot less material to remove. After he had the corners and ends of the knee parallel, then he scraped the top knee ways flat.
- I was surprised that the Bridgeport knees have about a third of the column-side ways cut away as a recess, so the knee won't rock. That makes correcting the knee droop by correcting the column-side ways even more time- and cast iron efficient.
- One thing that kept occurring to me: he kept transferring the knee from a giant surface plate to a worktable to scrape it, and he does several passes to get the knee scraped flat and parallel. Scraping a machine this big is not a one-man job.
- Mike Stets looks a lot like Ed Begley Jr.
hey lazlo, thanks for the good review, sounds like a keeper - are you recording your effort for the dvd as well
..... and whats that about a12" mic? baaaaa. Modernists. real men use sprung calipers and cigarette paper
Hey that reminds me... wasn't someone on here talking about something like a 36" specialty mic the other day? Used in the oil field industry for something...
I thought a 10" mic was huge...
Now I'll have to get one...