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View Full Version : Jet 1024P Y Lathe help needed

dw1307
11-25-2009, 08:16 PM
I posted this in the third hand section,,, maybe it would get some response here. I have a Jet 1024P Y that is missing the feed reverse gears and I need some help identifieing them. This is the feed reverse selector on the LH side that has 3 gears on it, I need the two small gears. Does anyone have a 1024 Y that they could measure the gear OD and give me the tooth count, so I can make the gears. Thanks to anyone that can help.

Mike Burdick
11-25-2009, 10:24 PM
dw1307,

If no one posts the exact answer to your question perhaps you could determine the dimensions needed...

I'm sure you know all this so please bear with me if I don't understand your question correctly.:)

You'll need these gear formulas...

http://www.engineersedge.com/gear_formula.htm

First determine the Diametral Pitch (P) of the lathe's gearing by using this formula with measurements from one of the other gears:
P = (N+2)/OD.

Since this is a reverse mechanism, the two gears needed will have the exact same OD and tooth count - this can be determined by measuring the center-to-center distance between the two studs (I am assuming those are still there). That will be close to the OD of the gear needed but not necessarily the exact measurement since clearance is designed into that spacing. Now use the formula above. You know P from the first step and you now know an approximate OD. Plug those values back in the formula and you'll get a value for N (number of teeth). As you know, N has to be an integer, so take the calculated value and round it down to the nearest whole number and recalculate the OD. This is the OD that should be used.

Now, look over the situation and determine if those values make sense with the gears they are supposed to mesh with. In other words - use your common sense!

Now for the hard part - to determine the pressure angle. That's not going to be apparent and I'll get into that if the above works out and I understand what you are needing. Generally, if the lathe isn't too old, the pressure angle is mostly likely 20-degrees. If it's really old then it most likely will be 14 -1/2 degrees.

dw1307
11-25-2009, 10:33 PM
Well,, I have another Jet lathe, a 1236 and it has a very similar setup, but the gears are larger AND they are not the same # of teeth. One I think was 25 and the other 29 (or some other odd # of teeth). Yeah, I know I could do the center distance thing and figure it out, but I guess I'm getting lazy. They appear to be 20 degree angle and the pitch figures out to 14.5 roughly. So, I'm wondering what kind of gears are these? Are they module or diametrical pitch gears? I wouldn't mind buying them, but I understand good ol Jet doesn't even know they sold these lathes, let alone supply any parts.

Randy
11-25-2009, 11:00 PM
I responded to a similar question a few months ago. Here's a link to that thread:
My machine might be somewhat different from yours, but maybe you'll find it helpful. I'll check back to see if you have more questions.

winchman
11-26-2009, 12:08 AM
Have you tried putting the gears from your 1236 lathe on the one that's missing the gears?

It would help if you posted a picture of your lathe. Mine is a 1024P, but it's different from some others with the same designation.

Roger

dw1307
11-26-2009, 08:08 AM
The gears from the 1236 are too big. Same design, but center distance is larger.

alanganes
11-26-2009, 08:25 AM
Hi,
I have a Jet 1024. I'm not sure if mine has a letter following 1024 or if it matters. I can take a look at the gears later on today or tomorrow and get you some numbers if you have not gotten that info from someone else yet.

-Al

dw1307
11-26-2009, 08:49 AM
Mine is a 1024 "Y".. I think there was also a "T". I believe the letter denotes the who built the lathe. They appear basically of the same design, biggest difference I see in the different models is the toolpost mounting. I still need the dimensions of the gears, Thanks

winchman
11-26-2009, 09:18 AM
Since the gears are only idlers, the number of teeth isn't critical. Look at this picture:

http://img.photobucket.com/albums/v21/rykrisp/1024photo.jpg

You can approximate the diameter of the gears needed for your lathe by measuring from the center of the stub shafts to where the OD of the gear should be between the teeth on the lower gear and where the two idler gears mesh. Then figure out how many teeth it takes to fill them up.

If you're off by a tooth or two it might be a little noisy, but I'm thinking you can get it right on. It is important that you get good engagement between the mating gears when they're meshed and clearance when they're not without having to mess with the locking mechanism on the handle.

Roger.

dw1307
11-26-2009, 09:46 AM
The number of teeth is critical as they have a fixed center distance and have to be of the same pitch as the other gears to run with each other. Coming up with the OD by working with the center distance doesn't quite make sense, as these gears have different OD's. If they were the same, it would be easy. I still haven't figured out if these gears are module or diametrical pitch. In another posting (re Jet 1024) there was a question as to the number of teeth from the lathe mentioned and what the Jet parts list stated. Counting the teeth in the photo it looks like 20 and 24.

alanganes
11-26-2009, 09:47 AM
OK, here is what I have. Mine is a 1024P, made in Taiwan. It looks like this:
http://img.photobucket.com/albums/v479/alanganes/lathe/IMG_6953.jpg

http://img.photobucket.com/albums/v479/alanganes/lathe/gears.jpg

They are two different tooth counts, one is 25 teeth, one is 30T. The 25T gear measures 1.589" and the 30T gear measures 1.884". Those measurements were done just with a digital vernier across the teeth with the gears in the machine, but ought to close enough for you to deduce the nominal dimensions. Note the "raised" hub. The gears are 0.600" wide in total, and the tooth faces are 0.399" wide.

They are of course metric, and it was dumb of me not to push the button on my calipers to read in mm. But I'm sure you can work out the conversion without my help.

I've had this machine for a long time. It is actually a pretty nice machine, has the typical asian lathe fit-and-finish shortcomings, but is much nicer that the newer Chinese versions and is quite beefy for a smallish lathe. It's not a 10EE, but has given me great service. I like it.

Hope that helps,
Al

dw1307
11-26-2009, 09:56 AM
Thanks for the info... It gives me something to start with. Does your lathe have a "Y" after the 1024P ? It appears to be the same lathe as mine, as it looks like your compound only has the tapped hole for the toolpost and not the T slot.

dw1307
11-26-2009, 10:08 AM
I just checked my 1236,, it has same tooth counts as the one mentioned above, but the gears are larger dia., Obviously that makes them a different pitch.

alanganes
11-26-2009, 10:31 AM
Thanks for the info... It gives me something to start with. Does your lathe have a "Y" after the 1024P ? It appears to be the same lathe as mine, as it looks like your compound only has the tapped hole for the toolpost and not the T slot.

You are most welcome.

No "Y" in my model number, just 1024P. My compound does have a T-slot, it is just not visible under the toolpost from the angle of the photo. I have no idea what the "Y" designation means.

I have a copy of the manual for this machine, but it is pretty sparse on details. There are exploded views that are helpful for dis-assembly and re-assembly, but the parts list gives no specifics, just a part number and a so-obvious-it's-useless description like "screw", "post" or "gear".

dw1307
11-26-2009, 10:44 AM
When those lathes were sold new they had two nearly identical lathes they sold at the same time. The catalogs showed a "Y" suffix or I think a "T". It meant who built the lathes and they were basically the same, but had details that differed. The compound being one of the obvious differences. I have a 1236P that my dad bought new in the early 80's. It's been a good machine, no real problems in nearly 30 years.

winchman
11-26-2009, 01:09 PM
alanganes has a lathe like mine. I was told mine was made in 1978. I've had it since the late '80s, and haven't had any serious problems. It's been a great investment, and it's paid for itself several times in making things I've sold and in making things for fun.

Roger