Grizzly 12x36 lathe (DF1236G, G1003, etc) metric threading chart

[hman]

Some time back in 2014 I posted an "improved" metric threading chart for this series of lathes (including the 12x24 equivalents). The chart included all but one of the currently used metric threads (couldn't find a way to get 5.5mm pitch, used on M56 fasteners), and gave very close approximations to the 0.7, 1.75 and 3.5mm pitches (good within ½%). Today I found an alternate setup for the 0.7mm pitch (using a 46 tooth gear), and I wanted to verify it. Not having the lathe available, I revisited the entire calculation. In doing so, I noticed that I'd made two errors on my original chart. I've revised it accordingly, and double checked all the settings. Here it is:

 

[Dave Paine]

Thanks for posting. I have a Grizzly 12x37 lathe, so relevant for me. I happen to be setting up to cut my first metric thread, 1.5 pitch which is on the original threading chart. I have the 32 tooth gear. I wonder why Grizzly did not show the potential for this in the metric matrix.

 

[Provincial]

I have a question about the 32-tooth gears.

I have a Metal Max 1340, which is a Jet BD1340 that went out the back door of the factory in China with a different label. It doesn't have gears for cutting 1.25 MM thread pitch. I have determined that if I can put a 32-tooth gear on the input to the QCGB (driven by the 127/120 idler) it will cut this thread. Grizzly sells this gear for the G9249, so I am trying to see if this one, or another available from Grizzly will fit, or can be modified to work on my lathe.

My shaft size is 19 MM, with a 5 MM key. The gear is 19.5 MM thick overall, with the face of the gear being 9.64 MM wide and the hub being 9.86 MM thick and 33.94 diameter. I can trim down the diameter of the hub some if necessary.

Would Someone please measure their 32-tooth gears and report the dimensions and if Grizzly still sells them? If your lathe has a 40-tooth gear on the spindle side of the big 127/120 gear, the 32-tooth gear should have come with the lathe in that set of spare parts.

Thanks!
Jock

 

[DAT510]

Here you go. This gear and others were purchased from Grizzly, for their G9249 model, to be used on my Jet1024.

~$25 from Grizzly. https://www.grizzly.com/products/g9249/parts

 

[Provincial]

DAT510, thanks for the response! From your measurements, I'd have to enlarge the bore by 1 MM, and probably deepen the keyway by .5 MM. Otherwise, the dimensions will work just fine.

I wanted to make sure it was practical before ordering one from Grizzly.

To cut 1.75 MM threads (pretty common) I'll have to get a 35-tooth gear to put on the upper (tumbler) end of the gear train. Combined with the 40-tooth input gear at the QCGB, it is an exact lead. I've found a place in Florida that has a gear that will only require enlarging the bore and cutting the 5 MM keyway. That gear has no hub and is 10 MM thick.

 

[Provincial]

DAT510, just to be clear, I will be ordering the gear from Grizzly, and rework it as I discussed. Thanks again!

 

[DAT510]

Not sure if your 1340 Lathe has the same QCGB ratios as my 1024, but if it does, here's a spreadsheet I've posted in the past, that lists change gears (based on the gears I have) and QCGB setting that can be used to achieve many tread pitches that were not listed on my lathe treading charts.
The table is "live" so the change gear values or QCGB ratios can be change and the table will update.

 

[Provincial]

Not sure if your 1340 Lathe has the same QCGB ratios as my 1024, but if it does, here's a spreadsheet I've posted in the past, that lists change gears (based on the gears I have) and QCGB setting that can be used to achieve many tread pitches that were not listed on my lathe treading charts.
The table is "live" so the change gear values or QCGB ratios can be change and the table will update.

Thanks! I guess I did re-invent the wheel. When I prove this out and post it in the Jet (and link that to the Asian machine section) can I get you to post this there? I would like to spread this information out to the other people with less common machines, since they have little support.

 

[pressingonward]

These both look super useful, thanks! I do see a potential error, unless I'm reading one wrong - 32, 30, D1 shows as a ~0.7 thread pitch on the small chart, but a 0.8 thread pitch on the spreadsheet.

 

[SWIGIN]

I know this is an older thread but thank you for putting in the effort to make this chart!