I guess I could have worked out the standard gear by comparing the 42T gear threading options with the others, but over the 10 years I've owned the lathe, I've never done any screwcutting, so somewhat lacking in knowledge (and you might say common sense!). All much clearer now.
Nope, but that would have been quite helpful! It has a plate on the screwcutting gearbox casing giving gearbox settings for availabler common threads, with mention of exchanging the standard driving gear for a 42T gear to provide additional threads, but nowhere on the machine does it state...
The gear ratios were causing the problem, not helped by my initial use of the tumbler reverse... good quality threads every time now! Thanks all, for your help and advice.
TGrim_d, it is splined, but thanks for the offer. I'd like to find a 21T gear, but not sure how common they are.
Pete, what do you mean by end gearing?
Currently running a 22 driver to a 35 driven. I was originally trying to cut a 20 TPI internal thread for a collet closer. Just...
Thanks Agroshield, useful info. Looks like I need to source a 21T driver gear. Meantime I should be able to use my 42T gear in it's place and set the gearbox for twice the TPI required. Excellent forum, been a good learing day, thank a lot everyone!
Seadog, no VFD on the lathe, just a rotary phase convertor. VFD definitely the way to go!
Pete, thanks for that. I did wonder if there may be a mix of imperial and metric gearing but not sure how to check.
I'm missing something obvious wrt the threading dial. I ran the saddle back and...
Good point Brad, I had been using the tumbler to reverse the geartrain. Didn't realise the implication of this so I tried again, this time stopping the lathe with the start/stop lever and brake, then backing the tool out of the work, stopping then reversing the motor to traverse back to the...
Can anyone help with advice on the following? I am having problems cutting threads successfully due to the tool seemingly cutting a different path on each pass. The result is a mess of multiple pitches, rather than a constant pitch thread. I have tried keeping the half nut engaged throughout...