variant22 5th July 2014, 11:16 PM I need to cut an m12 1.75 thread. Unfortunately the AL960b does not come with the necessary change gear. I am thinking of getting a cutter so I can make the gear. I have no idea what tooth profile these gears run. Any ideas?
pipeclay 5th July 2014, 11:54 PM Get one of your gears and add 2 to the tooth count divide this by the od of the gear,if its dp it should be a whole number or very close,if its not it would probably be a module,at a guess I would say m1.25.
simonl 6th July 2014, 08:23 AM Hi,
Have a look at the lathe owners manual. The manual for my lathe listed all the gears, No. teeth and the module. Yours maybe the same to similar.
Simon
variant22 6th July 2014, 01:07 PM Get one of your gears and add 2 to the tooth count divide this by the od of the gear,if its dp it should be a whole number or very close,if its not it would probably be a module,at a guess I would say m1.25.
Thanks pipeclay for the help. The numbers I came up with are as follows:
(30+2) / 40 = 0.8
(32+2) / 42.5 = 0.8
Looks like it is module. Now I have to figure out how to measure the profile to confirm M1.25.
Hi,
Have a look at the lathe owners manual. The manual for my lathe listed all the gears, No. teeth and the module. Yours maybe the same to similar.
Simon
I checked the Grizzly manual which is much more detailed and did not spot anything on the gear profile. I will hunt down the Chinese manual..
Ueee 6th July 2014, 01:18 PM Thanks pipeclay for the help. The numbers I came up with are as follows:
(30+2) / 40 = 0.8
(32+2) / 42.5 = 0.8
Looks like it is module. Now I have to figure out how to measure the profile to confirm M1.25.
PC's guess was that it would be 1.25, just a guess. You have worked out above that it is M.8. Finer than i would have thought. What gear(s) do you need to make?
Ew
jhovel 6th July 2014, 01:55 PM Variant22, where are you?
I have a full set of Module 1 cutters if you can use them (for a loan). PM me if that turns out to be the right size.
pipeclay 6th July 2014, 02:11 PM Get the Jesus nails, wood and hammer out.
It should of been OD divided by tooth count plus 2.
Ueee 6th July 2014, 02:43 PM Get the Jesus nails, wood and hammer out.
It should of been OD divided by tooth count plus 2.
Translation: I told you to work it out backwards, it should be 40/30+2, so you do get M1.25
Why PC can't just say that is beyond me. I think he thinks he's funny:?
Ew
pipeclay 6th July 2014, 02:54 PM Apart for waiting for the crucifiction what part of OD divided by tooth count plus 2 wasnt said.
PDW 6th July 2014, 04:08 PM Translation: I told you to work it out backwards, it should be 40/30+2, so you do get M1.25
Not if you pay any attention to the precedence of mathematical operators, you don't.
However 1.25 is the correct answer....
PDW
Stustoys 6th July 2014, 04:48 PM To go just a little OT. Anyone got a chart that says anything about pitch tolerance? I dont ever recall seeing anything about it, there must be something out there.
How long a thread do you need and how good does it need to be?
How about 11tpi with 30 driver 40 driven? I make it 1.732mm............ close enough? I assume not, but I've got nothing to back that up. Over 6 turns thats an error of 0.11mm, I guess it really comes down to what its going to be used for.
Stuart
Michael G 6th July 2014, 05:25 PM Anyone got a chart that says anything about pitch tolerance? I dont ever recall seeing anything about it, there must be something out there.
I think you'd need to start looking at national standards and thread tolerances as it would be covered in there. For our purposes I think it comes down to whether the nut fits or jams.
Michael
Oldneweng 6th July 2014, 10:48 PM I think you'd need to start looking at national standards and thread tolerances as it would be covered in there. For our purposes I think it comes down to whether the nut fits or jams.
Michael
I think it is related more to whether the thread breaks or the nut rounds off myself.:D
Dean
variant22 7th July 2014, 10:27 AM Thanks all for the vigor. M1.25 it is. I will head off and hunt down a cutter.
Variant22, where are you?
I have a full set of Module 1 cutters if you can use them (for a loan). PM me if that turns out to be the right size.
Thanks for the offer Joe (it turns out it is M1.25). I appreciate the offer.
jhovel 7th July 2014, 11:28 AM Maybe we should have a register who's got what cutter sets for gears - I mean us hobbyists of course.
That way we can quickly know who to contact to get a gear made or a loan of the right cutter.
brewer_xl 21st November 2014, 09:41 PM Hi, I have just bought and set up my new al960b.
Regarding the 1.75 mm thread, you can get very, very close using the existing gears; metric transpose gears, use the 32 / 40 gears, and select B5. This will give 1.745 mm thread which is pretty close. You can see that 3.5 mm thread can get close as well using A5. Calculated table below. This is for 32 on the top and 40 on the bottom.
threads mm with 32 / 40 gears
and 127/120 gear
1
2
3
4
5
6
7
8
A
4.8
4.267
4.042
3.84
3.491
3.2
2.954
2.743
B
2.4
2.133
2.021
1.92
1.745
1.6
1.477
1.371
C
1.2
1.067
1.011
0.96
0.873
0.8
0.738
0.686
D
0.6
0.533
0.505
0.48
0.436
0.4
0.369
0.343
E
0.3
0.267
0.253
0.24
0.218
0.2
0.185
0.171
Maxi77 22nd November 2014, 07:21 PM Thanks of the heads up Brewer, I have also got an Al960B and have needed to cut that thread. End up using a die. Would have much preferred to use the Lathe. Funy how when I bought the lathe (April this year) I though I would never need this pitch:B
Maybe a silly question but does the 40t go with the 120 or 127. i.e inside or outside gear? Probably obvious if I had a look.
Thanks
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