Lathe thread cutting change gear calculator

[Vernonv]

New version - V1.2

Couple of small changes and a minor fix to the error display when calculating gears (any negative error where always being marked as <0.00001).

Can be downloaded from HERE.

[Vernonv]

BTW Also just added Nuttal as another lathe profile.

[HavinaGo]

Thanks again Vernon

Attached is a zip file with 2 "Lathe" config files I use to represent my Hercus.
One for Imperial, one for metric

Attachment 216954

given the default install, unzip the archive and put the 2 files in
c:\Program Files
(or where ever the LatheGears executable is on your machine)

[Vernonv]

Thanks David.

Would it be ok for me to add them to the standard install?

[HavinaGo]

Hi Vernon,

Adding the config files would make my life much easier and is fine by me.

I would add the caveat that the collection of extra gears I have is not a standard set but so far, does what I want.

Thanks again for sharing your most useful program
(because of it

• I avoided the need to buy a set of metric change gears being able to selectively acquire gears including the 100/127 from Mal/Peter
• I have found gear combinations that fit the jobs (27 tpi being the one that springs to mind)

)

[Vernonv]

Thanks, I've added them.

I have an old Nuttal lathe that only has the 3 standard change gears for imperial threads. I recently needed to cut a 1.25mm (or was it 1.5mm?) metric thread and using the software found that I could get a very good approximation of that metric thread by moving the 120T gear to the centre of the gear train.

I had to make up a special extension mounting for the gear, to achieve that, but it worked really well.

[bwal74]

Hi Vernov,

Just downloaded your program. Thanks a lot. Looks great.

Cheers Ben

[Ueee]

HI Vernon,
I tried to print my calculated gear combinations today for the first time, i got the following error. I just print screened it and printed it but it would be good for future calculations if i could print directly. Any help would be greatly appreciated.

[Vernonv]

Hi Ewan,
I tried to reproduce this error, however it all works fine for me.

What version are you using? - go to the About tab and it will display the version number.
Have you tried downloading again (LINK) and reinstalling?

[Ueee]

thanks Vernon,
I was using 1.2.0.0, but i uninstalled it and reinstalled and it is working fine.

[Stustoys]

Hi Vernon,
I've been having a go at using your program.
Couple of problems. It wont install where I tell it to, only c:/programs files. Then windows wont let your program save to that location, though I can.
No big deal I thought I'll just create my own file.
(problem 3 I hate not being able to resize the window )

The only issue I have is I'm not handling the C B gears correctly.
Like your diagram on tab 6. My 127 can only go in C, the 120 only at B
That works as the file is now but I don't get any ratios with an idler at B, if I add another gear say *B100 then the idler works but I dont get the 120/127 gear ratios.
What have I got wrong?

Great program, Thank you again.

Stuart

[Vernonv]

Hi Stuart,
I'll have a look at those issue and see if there is something I can do.

In regard to the fixed gears, I think you have misunderstood (or I have not explained, more likely) the intent of that function. If you mark a gear as fixed, then that is the ONLY gear that will be used in that position i.e. the gear in that position is fixed and can't be changed for another gear.

What you are wanting, and correct me if I'm wrong, is the ability to put any gear in that position, but have some gears that can only go in that position and no other. I could have a look and see if that is possible.

[Stustoys]

Hi Vernon,

Indeed I did misunderstand.
Currently(though I may change this if the need ever arises) gears 22 through 52 can only be mounted on A or D, the only gear that can be mounted on BC is the 120/127(and only one way around) they cant be split and cant be mounted on A or D.

Apart from a few more errors I found in my file above(which I will delete) the work around I have come up with its to have two files. Stus imp and Stus met with *B120, *C127 in imp and *B120, *C120 in the met. This appears to work.
I tried fixing just *C127 but it then uses the 127 gear in every train.
If I remove the limits (Stus test) it works, though the number of possible gear trains is huge and most are invalid.

I'll post a picture of me gear chart, maybe someone else can use my numbers* the extention needs to be changed to .lat
Gear 5 in the QCGB doesnt get a mention on thread cutting or powerfeed.

I would like to do the same thing for powerfeed.


Stuart

*There may still be a major error in my ratios as I may have two gears in the wrong position which would effect all B, D, 2, 4 combos. more checking.