Resusitating Some Chinese Iron

chevydyl said:
Very nice bro, that looks killer
One question I have about your planer, now that it's super flat, is the base parallel with the blade? Is there anyway you can test for that? Does it even matter that much? I would assume it's the same effect as a mill head being out of tram.
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The plane is a Craftsman version of the Stanley 9 1/2.The blade can be shifted so that it is parallel with the sole. I use the plane to form triangles of bamboo to make split bamboo fly rods. The bamboo is planed in a steel form. The iron is set so that it will shave steel dust across the full width of the form.
 
I've been practicing while waiting for tools and material. The plane is scraped flat, as well as my small angle plate. I'm actually starting to get the idea. A stick of cast iron arrives next week to act as a straight edge. I should be ready to tackle dovetails by the time I get done with it.

I came to the realization that I really need to start working from the bottom up on the little mill, so I took the rest of the mill apart and cleaned up the base. I put it on my newly acquired 12X18 granite plate. The right rear mounting tab went clunk when I pressed on it. The base needed to be trued up in order to mill the extended base dovetail. It turned out that the base was twisted and humped along the Y axis, with the center being high. The whole base was milled flat at the factory, so sometime later it moved a lot. Since the mill ha never moved smoothly, it probably left the factory warped. Using the ground surface at the top of the base dovetail against my other mill's table, I took .116 off the bottom of the base before the cutter touched everything. I will scrape the new machining tomorrow so it is dead flat.
 
How are you checking the alignment of the dovetails, and how are you checking the geometry of the dovetails? I would be especially concerned on the perpendicularity of those DTs to the other axis DTs
 
At this point I'm not checking anything with the dovetails beyond some rough looking at how bad they are. I am still at the beginning. First step is to figure out how to scrape. I am getting there with that. I am currently still collecting tooling - step 2. I thought that all I still needed was a straight edge, but my DTI to a dive to the floor last night when the holder fell apart, just another Chinese manufacturing success.. I am going to follow tertiaryjim's lead and scrape in a piece of durabar for the straight edge. Sag appears to be tolerable. I am planning to stress relieve in my kitchen oven set to a clean cycle. The clean cycles get up to 900F. I've read whole bunches of conflicting ideas about stress relieving cast irons. Durabar recommends 800F to !000F for 1hr/inch @ 1000F. An oven on clean cycle for 4 hours should get mostly there. Stress relief after rough machining is recommended because machining injects stress into the part. I really should cycle the mill parts that I'm machining too... just realized that.

For metrology I'm going with my home made straight edge. I'll scrape in an angle gauge to match the cutter. The exact angle doesn't matter as long as the saddle is scraped to mate with the other dovetail. I am working on a jig similar to the one described by Connely in chapter 16 to go with my .0001 resolution dial indicator, a precision square, and probably more. I'm sure I'll find needs as I go along. I'm just trying to keep the single project tooling to a minimum.

I'm not too worried about perpendicularity of the X-Y dovetails. My other mill is certified at .0004/8". If I do my due diligence with the setup and don't bugger it up with misguided scraping, the perpendicularity will be fine.
 
when i took Richard King's class,
stress relief was accomplished by hanging the piece by one corner, and firmly striking the piece with a soft hammer on the opposing end.
the molecules realign themselves ever so slightly and stress reduction is accomplished.
 
Sounds like a good plan. You did see the post I made about the camelback correct? It was in the other thread you made. I can hook you up with his number if you interested. I priced out some durabar scrap and it wasn't exactly cheap. Only thing is the guy only has 18" castings, but they are pretty dang nice.
I'm itchin to get started on my lathe compound cross slide scraping and alignment.
 
I just read about the clean cycle of the oven in another post, tried it last night on my small angle straightedge, we'll see how it works out. But thanks to who ever for that tip, I had tried just a 500 degree soak but it didn't do alot
 
chevydyl said:
I just read about the clean cycle of the oven in another post, tried it last night on my small angle straightedge, we'll see how it works out. But thanks to who ever for that tip, I had tried just a 500 degree soak but it didn't do alot
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That would be me. The OP was about acceptable machining tolerances for dovetail ways. We sorta got off topic concerning straight edges. I would still like to know how the call out of the dimensions on the shop drawing from a machine maker or the specs the QC people use to certify the ways for manufacturing. You can get away with quite a bit, judging by what is being sold at the bottom end (see my next post). I made a lot of stuff before I got exasperated enough to rip the machine apart.
 
I should be up with a sharpening system and carbide next week, but in the meantime I have been amusing myself with scraping the bottom of the base.
20160221_103354[1].jpg
I flipped it over on the big plate and took some measurements to the top of the reference surface at the top of the dovetail. That surface was as flat as I could measure.I them measured to the flat bearing of the dovetail. It was less than .005, except over the shiny part. That was .oo1 higher than the rest of the bearing. Twisted, warped, and lumpy...
20160221_103749[1].jpg
 
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