Cutting Acme Screw Threads... 1

[RainyLake]

I have to cut a 2-4" Acme screw thread on a shaft and make 2 mating nuts to match. I made a "go" gauge so that as soon as the "go" gauge is able to fit into the nut I know that I have the proper clearances. The "go" gauge was made slightly larger than a standard shaft would be. The problem occurred when the "go" gauge went into the nut the major diameter of the nut was .040 bigger than it should be.

Sizes:

Major Dia of go gauge: 2.020 (Min of Major dia of nut)
Minor Dia of go gauge: 1.750 (Min of Minor dia of nut)

Major Dia of Nut: 2.078 (Min 2.020 Max 2.040)
Minor Dia of Nut: 1.754/1.756

Any help would be appreciated. Thank you..

 

[EdDanzer]

With Acme threads the width of the thread is probably not correct on one of the parts, so you have to cut over size to make the width correct.

 

[pohbah]

We cut acme pin/boxes everyday, do you know there are different types of acme thread forms? also different classes of fit,ie:- 2g-3g-4g, smaller the number of fit 2g the bigger the tolerance between male and female thread,is the pitch on your lathe ok?---- if you drop me an e-mail with the correct size of thread--example 2" x 4tpi acme class 2g, i will send you a print out from our gage maker system which is software that we use-- where are you based?--we are in Scotland

 

[Bensley]

Hi there pohbah,
I wouls also like the a general print out of the same acme thread as an example.

I would also like to enquire uf you know of a company in Scotland who sells workshop machining equipment, i.e. Lathes, millers, horiz/vert borers, slotters (all non CNC), lapping machines, etc? I require to gain firm quotes for 17 machines in total?