10 Attachment(s)
Additional Screw Cutting Gearbox
Hello to everyone.
Decided to make additional screw cutting gearbox as my next project.
(once I modify and complete external headstock gearbox)
Already made calculations and drawings for that.
My Chinese lathe CQ6128x660 (also G0602, Birmingham YCL-1126BD, RDX 11x26 and many others)
already have screw cutting gearbox with 9 different combinations with every pair
of change gears, so one additional external gearbox is required in order to have
'full norton' lathe. Read: No more messing with change gears.
Calculation is based on 45 and 40 teeth change gears.
As almost all threads which I did were metric (except 20TPI once) my idea was to have full
scope of metric pitches from 0.20 to 4.0 mm. Excellent for this size of the lathe.
So, I bought the following 17 gears; metric module 1, just because these are change gears
size in banjo gear train: 2 x 22T, 1 x 33T, 2 x 40T,1 X 42T, 4 X 44T,2 X 45T, 1 X 48T,
1 X 50T, 1 X 55T and 2 x 66T. Also bought 3 x 42T in module 1.5 which will be used
For geared rack/shifters.
Without changing gears will have the following metric threads: 0.20, 0.25, 0.30, 0.35, 0.40,
0.45, 0.50, 0.60, 0.70, 0.75, 0.80, 0.90, 1.00, 1.25, 1.50, 1.75, 2.00, 2.50, 3.00,
3.50 and 4.00. And then I got idea to install additional banjo at the gearbox and enable
cutting of imperial threads. When placing 40T gear at 127T gear will get the following
imperial threads (TPI): 6, 7, 8, 10, 12, 14, 16, 18, 20, 21, 24, 28, 30, 32, 35, 36, 40,
42, 48, 50, 54, 56, 60, 63, 64, 70, 72, 80, 84, 90, 96, 100, 108, 120....and plenty more
down to 432 TPI. OK, I am missing some important threads in range 6 - 120 TPI threads like
9, 11, 11.5, 13, 27 and 44, but I am not going to cry about it.
Those who are TPI orientated can use different gears and get full scope of imperial threads
and loose some metric threads.
Also will have pitches for fine feed in range from 0.056 to 0.222 mm, which is better
than smallest one (0.063 mm) which I presently have.
I will start with this job once I am back home but I don't mind if someone of you make it
in the meantime.
Unfortunately I am unable to attach excel file, so I attached 3 printouts in pdf format and by zooming out
it is possible to get clear picture how I planned to do it.
Best regards
LMMasterMariner
