Search found 16440 matches

by Harold_V
Fri Jun 22, 2018 3:59 pm
Forum: General Discussion
Topic: not how they teach you to do it in school
Replies: 10
Views: 167

Re: not how they teach you to do it in school

What BDD said. Power tapping demands a tap that deals with chips, so they don't remain in the flutes. A straight flute without a lead at the cutting edge (like a hand tap) lacks that feature. When one attempts to power tap with a hand tap, if the material isn't quite thin, chips accumulate in the fl...
by Harold_V
Fri Jun 22, 2018 3:06 am
Forum: Milling Machines
Topic: Milling a helix
Replies: 55
Views: 1642

Re: Milling a helix

Thanks, Mike. I appreciate your comment. I can't see any reason why you can't achieve similar results. If you have a good imagination and have the equipment, all it takes is the desire. Much of the issue of building most projects is having the ability to see, in the mind's eye, what you want to acco...
by Harold_V
Wed Jun 20, 2018 1:30 am
Forum: Milling Machines
Topic: Milling a helix
Replies: 55
Views: 1642

Re: Milling a helix

I finally have the setup made, and will now turn my attention to a procedure that will allow me to mount the gear (100 tooth) to the resulting part in such a way that it won't interfere with the final machining (after the worm is machined). if you're interested, here's a few pictures. I'll begin wit...
by Harold_V
Mon Jun 18, 2018 2:05 am
Forum: General Discussion
Topic: Before I waste time and $....
Replies: 5
Views: 275

Re: Before I waste time and $....

curtis cutter wrote:
Sun Jun 17, 2018 7:10 pm
Similar to this Harold?

https://www.ebay.com/itm/End-mill-face- ... 3516231492
Yep! That's the one. For a guy who has no cutter grinder, it could prove to be a valuable asset.

H
by Harold_V
Mon Jun 18, 2018 1:49 am
Forum: Casting & Foundry Work
Topic: Aluminum molds for ZA-8 casting?
Replies: 17
Views: 407

Re: Aluminum molds for ZA-8 casting?

No Harold, I did not miss the point. What I said was I wouldn't bother oxidizing the surface and that it would do that itself after a couple of pours. Yeah, you did miss the point, which was that the molten zinc had the possibility of soldering to the mold without a little oxidation to shield it. I...
by Harold_V
Sun Jun 17, 2018 5:45 pm
Forum: General Discussion
Topic: Before I waste time and $....
Replies: 5
Views: 275

Re: Before I waste time and $....

As a matter of need, I've done the odd grinding job on my Bridgeport. The time it takes to mask the machine generally exceeds the time spent grinding, but it bailed me out on all occasions, where I had no other options. In fact, I made such a setup just a week ago. As my mill has a top speed of 4,20...
by Harold_V
Sun Jun 17, 2018 5:30 pm
Forum: General Discussion
Topic: Surface Grinding
Replies: 83
Views: 8651

Re: Surface Grinding

Often the diamond size is noted on the shank. Might help to examine it closely to see if you can find any numbers.

H
by Harold_V
Sun Jun 17, 2018 5:20 pm
Forum: Casting & Foundry Work
Topic: Aluminum molds for ZA-8 casting?
Replies: 17
Views: 407

Re: Aluminum molds for ZA-8 casting?

I wouldn't bother oxidizing the mold, it will do that itself after a few pours. You missed the point. If aluminum dissolves in zinc (and it does), pouring to a freshly machined mold will most likely result in some dissolution, and, most likely, some soldering of the part to the mold, especially nea...
by Harold_V
Sun Jun 17, 2018 1:48 am
Forum: General Discussion
Topic: Surface Grinding
Replies: 83
Views: 8651

Re: Surface Grinding

I did not know diamonds had inclusions, but maybe industrial diamonds do. Inclusions are very much a part of diamonds. The lack of them, along with color and cut, make them all the more desirable. Take a look at a reasonably sized diamond (in a ring) using a loupe (10 power or a little greater). Yo...
by Harold_V
Sun Jun 17, 2018 1:41 am
Forum: Lathes
Topic: ww2
Replies: 10
Views: 999

Re: ww2

I agree. Especially if it turned in to a nuclear affair. There can be no winners. Mankind, in general, would lose, along with many other life forms. The world would go merrily on its way, with or without humans, just as it did without the dinosaur. We wouldn't destroy the world---we'd just make it u...
by Harold_V
Sun Jun 17, 2018 1:29 am
Forum: Casting & Foundry Work
Topic: Aluminum molds for ZA-8 casting?
Replies: 17
Views: 407

Re: Aluminum molds for ZA-8 casting?

Aluminum molds are common in bullet casting. So long as you pour a few pieces to warm the mold, cold shuts aren't a problem, and I suspect that would be the case for zinc, too. Fact is, any metallic mold will require proper pre-heat to avoid cold shuts. Once the mold reaches a desirable temperature,...
by Harold_V
Sat Jun 16, 2018 3:45 pm
Forum: The Junk Drawer
Topic: Installing Bearing on Dremel Shaft
Replies: 13
Views: 338

Re: Installing Bearing on Dremel Shaft

Not Lixey? Is there a schism among the machining poobahs? I was introduced to the Nupla hammers when I entered training, way back in '57. Shortly thereafter I made one---a 1½" diameter body, brass, and a wooden handle, which has been replaced one time. I still use that hammer to this day. I recomme...