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+--- Thread: Help with drawing a part (/thread-1949.html)
RE: Help with drawing a part - Mayhem - 01-31-2014
Thanks Tom - I'll take a look into the tolerances and see what I can find. So in the case of the key way, I guess I measure the key and then determine the slot and tolerance?
I've modified the view of the nut and I think I can see why it would need to be rotate 90° CCW.
I've also scaled the screw to 1.250" and Ken will machine it as a 1.250-5 ACME thread.
[attachment=7669]
RE: Help with drawing a part - TomG - 01-31-2014
Darren,
It looks like your keyseat should be 3.5mm deep instead of 3.15 and the width tolerance should be 5.988 to 5.958.
http://www.webpal.org/SAFE/aaarecovery/5_simple_technology/Machinery%27s%20Hndbk/26663_ym4.pdf
Tom
RE: Help with drawing a part - EdK - 01-31-2014
Thanks for the link to that PDF Tom. Looks like it has some real useful information in it.
Ed
RE: Help with drawing a part - DaveH - 01-31-2014
It has been pointed out to me that the ISO drawing standard practice is to draw it in 1st angle projection.
The whole World did in fact draw in 1st angle up until the 1890's when the USA changed to 3rd angle.
I might have guessed
DaveH
RE: Help with drawing a part - PixMan - 01-31-2014
I'm not worried about the drawing views, I'll just make the parts!
I am going to meet up with a guy this afternoon who is going to trade his piece of 600 bronze for "whatever" I may have lying around the shop which he could use. Or, I'll pay him some cash or both. Speedy Metals wanted $35 an INCH for 3" 660 bronze! For the screw I had bought a bar of 1-1/4" 1117 cold rolled steel about two years ago (for $20) and still have about 11 feet of it.
With a few other project for my friend Neil in process I won't be able to start Darren's parts until next weekend, but I'm looking forward to it!
RE: Help with drawing a part - Mayhem - 01-31-2014
Thanks guys!
Tom, that looks like a very valuable resource and one that I will need to take some time to digest. The keyseat is indeed 3.15mm. I used my depth gauge (which I calibrated only a few weeks ago) to measure it. This mill was made in either 1969 or 1970, so I wonder if such a standard was in place.
Ken, thanks for doing the legwork in chasing down the material for me. Did we make the post for my QCTP out of that 1117? Also, there is no rush on this. I don't want Donna cursing my name for you not being home. Thanks again for doing this for me - it is greatly appreciated.
RE: Help with drawing a part - PixMan - 01-31-2014
Darren,
I got the bronze in exchange for some milling cutters and inserts I don't use, so materials aren't going to cost you anything. Big relief! Two pieces Ø 3" x about 5" long of 660 bronze. It's enough that if I screw up the first attempt I have enough for a second try. Fits on ACME threads are always the toughest because you go from "a little too snug" to "like a baseball bat down a hallway" in short order.
Tooling for the O.D. threads should be no problem. For the I.D. thread, I may have to...wait for it....use a ground HSS tool in a homemade boring bar I have. It's such a course thread with a high helix angle, so I don't yet know if any off-the-shelf insert tooling will fit in there.
And yes, that tool post shaft was the only piece of the 12' bar of 1117 I've used yet. It machines easily and is an excellent match for the 660 bronze nut. Little to no chance of them binding together,
RE: Help with drawing a part - TomG - 01-31-2014
Lol Ken. Let me know if you need any help grinding that HSS tool.
Seriously though, the helix angle on that thread will be nearly 5º, so it will need to be allowed for.
Tom
RE: Help with drawing a part - PixMan - 01-31-2014
Thanks Tom. I've actually got years of experience in grinding HSS, brazed carbide and solid carbide tools for turning, boring, threading and milling.
I also have a well-equipped surface grinder and a sine bar vise that I made as my senior project in trade high school. And HSS tool blanks.
Where can I buy blocks of time to do all this?
RE: Help with drawing a part - EdK - 02-01-2014
(01-31-2014, 09:14 PM)PixMan Wrote: ...
I may have to...wait for it....use a ground HSS tool in a homemade boring bar I have....
