Sawmill and Timber

Business and markets => Wanted => Topic started by: HaroldCR - AKA Fla.-Deadheader on November 17, 2018, 07:33:39 AM

alt image description alt image description alt image description alt image description alt image description alt image description alt image description alt image description alt image description alt image description alt image description alt image description alt image description alt image description alt image description alt image description
Title: Acme thread tap
Post by: HaroldCR - AKA Fla.-Deadheader on November 17, 2018, 07:33:39 AM

 Needing to make gearbox gears. Saw youtube about using normal bolt thread tap, but, want acme threads if possible.  Gear to be 3.5" dia. or so. Will be used for up/down of new sawmill carriage I am about to start on.
Title: Re: Acme thread tap
Post by: Ox on November 17, 2018, 08:07:19 AM
Are you asking where to get one?

A quick search and I see they're easily available.  A 1/2" was around $50.  Most look like a double thread on the same tap - first it's cut in the traditional beveled threads, then the square shoulder of the acme thread is cut, all on the same, quite long, tap.

Title: Re: Acme thread tap
Post by: HaroldCR - AKA Fla.-Deadheader on November 17, 2018, 12:29:27 PM
Hoping to find a GOOD used one, not Chinese crap. Something from a machinist estate sale, possibly. I would like a 5/8" one. I have searched most places I could find, online. Most are either over $100.00 or Chinese.

 I have found youtube vids showing how to machine one, but, I need to tighten up the slight sloppiness of my homemade metal lathe and also my sloppiness of the brain, to figure out the math.  ::)
Title: Re: Acme thread tap
Post by: bandmiller2 on November 17, 2018, 06:49:25 PM
Most areas have used machinery dealers, probably your best hope. Gears are mostly a standard item, company like Boston gear or Mc Master Carr may have them. I have repaired non critical gears with missing teeth by drill, tap in set screws weld and grind to shape.  Frank C.
Title: Re: Acme thread tap
Post by: joasis on November 18, 2018, 04:25:05 PM
The problem with ACME thread profiles is the nature of the thread, i.e., it is 28 degrees total, 14 each side, and a tap will be probably dead on, and your hand ground threading tool, unless you use an insert, will be ground to fit a gauge, and then remember, it has a "thickness" of the thread, top and bottom.

ACME is a profile typically used for applications where the thread form has a maximum exposure...meaning a lot of material to ride on, and the fit will be class 1 typically.  Used for obviously, jack screws, and bar clamp screws...stiff like that.

If you need to place a gear on the end, the obvious answer is to use 2 ACME nuts, either side of the gear, and drill a set screw in as well, or cut the diameter down to say 1/2 inch, and then use a key and set screw to hold the gear if space is an issue.

Just as an added thought,  most ACME taps I have ever seen are two or even three tap sets...starting, mid, and final cleanup. Dies are the same way.

Hope this helps.....I am a machinist. Or was in a past life.  ;)
Title: Re: Acme thread tap
Post by: joasis on November 19, 2018, 12:38:57 AM
You know Harold, you can get 5/8 rod in a grade 5 or 8, in 48 inch and 72 inch lengths I have seen, standard v thread, and they are not as much as ACME threaded rod in 1018 CR. Might be a better option to consider....a grade 8 is hard enough not to wear excessively. Many machine tool designs are using hardened and ground screws that are v thread rather then the old ACME.

Also, I need to correct what I said below...there are starting taps, "roughing" taps, and finish in ACME...lots of metal removed in even a 5/8 thread.  I had an 1-1/4  x 4 thread tap...the finish one....mainly to use after single point threading. And it was indeed damned expensive.
Title: Re: Acme thread tap
Post by: HaroldCR - AKA Fla.-Deadheader on November 19, 2018, 07:58:35 AM
 Thanks Jay for the info. What I am wanting to do, is, make 2 right angle gearboxes to raise and lower my new sawmill design carriage. I am familiar with the 2-3 section acme taps and why they are so expensive, to me, anyways. I am by no means a Machinist but manage to get decent results in my DIY projects. I may end up turning 2 worms on my lathe and using one as a hob to run the threads on a brass wheel. I have aluminum round stock to practice on and all the time in the world, once I finish my nearly done gasifier. Just need to figure out the math for worm/wheel diameters.

 I have watched and bookmarked several Youtube videos of ways to achieve my threading goals, and a few of the videos were done by people less talented than me and got decent results. I have 2 problems with purchasing parts, first they don't exist here and second buying expensive parts and shipping down here, because they may not get to me. The last crate I did get was opened and things taken out and I believe NOT by customs. I am waiting for delivery today of sawmill parts and hopefully this crate will not have been pilfered. It's a tough life down here, in the jungle.

 Harold
Title: Re: Acme thread tap
Post by: joasis on November 19, 2018, 08:15:55 PM
Tell me again why you want to live there?
Title: Re: Acme thread tap
Post by: HaroldCR - AKA Fla.-Deadheader on November 19, 2018, 10:48:11 PM

 Too committed to leave.  Everything I have is tied up here.  Have to make do with what I can by staying busy and making things.

 Did receive the crate today fully intact.
Title: Re: Acme thread tap
Post by: joasis on November 20, 2018, 07:48:38 AM
I have a lathe and a mill, and if you send me a drawing, jladwigconstruction@gmail.com maybe I can make the parts you need.

I would guess grade 5 or 8 all thread should be available there...and grade 8  nuts will last forever.
Title: Re: Acme thread tap UPDATE
Post by: HaroldCR - AKA Fla.-Deadheader on November 20, 2018, 08:11:29 AM
I don't think you understand what I need. I need 2 right angle gearboxes. No all thread acme rods and no nuts.

 The gear would be around 3"- 3.5" diameter X 5/8" thick made from brass/bronse stock. The worm that drives the gear would be about 1.25" - 1.50" OD .  Need to do the math to get exact measurements.

 Here is a link that shows the picture. I'm not good at copy/paste images.

 https://www.youtube.com/results?search_query=machine+worm+and+worm+gear (https://www.youtube.com/results?search_query=machine+worm+and+worm+gear)

 Really appreciate the offer, Jay  Thanks again, Jay  8)

 Opened the crate and found our spare right angle trailer winch we used on the bandmill we built.  Son came across it while cleaning up his garage. Now, just need to buy another, if/when I get back to Fl. Only need to lift 500-600 pounds and harbor freight  ::) has them for $30.00 , #2000 rated.  Need to be sure it's not cast pot metal from China. 
 
 Harold
Title: Re: Acme thread tap
Post by: Ox on November 20, 2018, 09:15:06 AM
Small rototillers, the ones that don't have any wheels or tires, have pretty stout worm gear assemblies under them.  Any chance you can scavenge a couple of old ones down around there someplace? 
Title: Re: Acme thread tap
Post by: HaroldCR - AKA Fla.-Deadheader on November 20, 2018, 03:40:06 PM
 :laugh: :laugh: :laugh: Only rototillers down here are picks and shovels and hoes. In the US of A , no problem.  I have this problem solved with the winches. Just keep them greased well. Thanks for the input Ox.  ;)  Wasn't laughing AT you, just at the vision of the info you offered.

 Harold
Title: Re: Acme thread tap
Post by: Ox on November 21, 2018, 09:09:18 AM
It's quite clear I'm completely ignorant to the situation down there.  lol
Title: Re: Acme thread tap
Post by: joasis on November 29, 2018, 06:31:39 AM
Harold! Look what I located for you. They have threaded acme rod and nuts. https://www.mcmaster.com/
Title: Re: Acme thread tap
Post by: HaroldCR - AKA Fla.-Deadheader on November 30, 2018, 07:19:02 AM
Thanks Jay.  I am going with right angle winches on this project.  :)
Title: Re: Acme thread tap
Post by: kbeitz on January 17, 2019, 09:58:57 AM
I build a lot of machines for textile industries. When I need acme threads in a gear or whatever I broach an octagon hole in my gear or pulley and trap in an acme nut. It makes for an easy replacement when needed.   
Title: Re: Acme thread tap
Post by: Crusarius on January 17, 2019, 10:38:31 AM
thats a great idea. now I have a reason for a broach :)