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Feed speed chart
Posted: Mon 14 Oct , 2019 19:47 pm
by Artysmarty
- Hi could any body throw some light on the top line labelled "stud Gear" when selecting feeds. Are they referring to "change gears". I can find no references anywhere to the ABCDEFG to which it alludes
- DSC_1112.jpg (433.89 KiB) Viewed 10764 times
Re: Feed speed chart
Posted: Mon 14 Oct , 2019 20:25 pm
by LesT
Hi,
If you open the change gear cover at the left end of the lathe there should be a " parking " stud with a collection of gears on it, towards the rear.
If you have these gears, and examine them you will find they are marked with letters, A to G, if you don't have them you are in a bit of trouble !
Regards,
Les.T.
Re: Feed speed chart
Posted: Mon 14 Oct , 2019 20:51 pm
by Artysmarty
Hi Les
Not only do I not have the gears but also there doesnt appear to be a stud on which they should be hung.
Were do you position the gears (if you have them)
Re: Feed speed chart
Posted: Mon 14 Oct , 2019 21:07 pm
by rpwilson
Don'[t worry about the stud. Theres supposed to be one inside the hinged cover on which are stored the spare gears A-G, but my 280 Synchro didn't have one from new. Its a convenient storage spot, so I fitted one. it also makes it much harder to lose them.
Not having the gears is a problem, as you've already been told. They should be 'A' 16T, 'B' 18T, 'C' 22T, 'D' 24T, 'E' 26T, 'F' 27T, 'G' 35T.
If you remove the gear from the end of the tumbler gear output shaft, you should find that it is one of these, the letter will be clearly stamped on it. They are 16DP, 20 degree pressure angle, which is the modern standard, so if you have to get replacements from HPC or Moffet gears, the teeth will be the right shape.
Richard
Re: Feed speed chart
Posted: Mon 14 Oct , 2019 21:07 pm
by Andy B
As in attached picture - the stud with the stack of unused gears is circled lower left, and the stud gear in use is circled in the centre.
Andy
Re: Feed speed chart
Posted: Mon 14 Oct , 2019 21:34 pm
by Artysmarty
Hi Richard
Thanks for the info.
Will get hold of my vendor and see if he can shed some light on whats happened to the change gears (fingers crossed)
Re: Feed speed chart
Posted: Tue 15 Oct , 2019 13:16 pm
by Artysmarty
Hi Andy removed the stud gear on my lathe as per marked photo.
No letter on it just the number 24 which from your description makes it the "D" gear.
Does this mean I can only use the combination of feeds that has the D listed on the plate.
Regards Art
Re: Feed speed chart
Posted: Tue 15 Oct , 2019 13:38 pm
by Andy B
Artysmarty wrote: ↑Tue 15 Oct , 2019 13:16 pm
Does this mean I can only use the combination of feeds that has the D listed on the plate.
Correct - but that still gives you as good a range of feeds as you'll need for most jobs (as amateurs we don't need to optimise speed / feed rates) and a lot of the common metric thread pitches.
Andy
Re: Feed speed chart
Posted: Tue 15 Oct , 2019 18:24 pm
by Artysmarty
Thanks for that Andy