PM1228 compound t-nuts

[fradish]

For anyone who has ever had their compound lock at around 45 degrees,
here is what I did to fix mine. I made new t-nuts (mine are on the left and in
the slot, factory on the right) with a rectangular top boss rather than the cylindrical
boss of the factory t-nuts. I also turned a brass plug to prevent the t-nuts from
dropping into the access hole.

I understand this is a problem on many Chinese lathes, not just the PM1228.

 

[jdl6mm]

View attachment 242344 View attachment 242345
For anyone who has ever had their compound lock at around 45 degrees,
here is what I did to fix mine. I made new t-nuts (mine are on the left and in
the slot, factory on the right) with a rectangular top boss rather than the cylindrical
boss of the factory t-nuts. I also turned a brass plug to prevent the t-nuts from
dropping into the access hole.

I understand this is a problem on many Chinese lathes, not just the PM1228.

Yea, I had to make a couple new ones too. Mine broke after years of use. They cracked where the collar joins broad part of the nut. I like the brass plug idea.

Sent from my VS987 using Tapatalk

 

[Bryan40g]

I still have to wait til mid May for 1228 to arrive but I’m doing preparations. Is there a way one of you guys could give me some dimensions of those t-nuts? I have to order some random hardware from McMaster Carr for the stand I’m building for the lathe and seem to sell everything. I’m assuming the thread is m8x1.25? With some luck McMaster will have hold down t-nuts close to the needed size. Thanks fellas.

 

[fradish]

I don't know if these sorts of parts change over the lathe production run so you might be better off waiting and getting dimensions off of your lathe, but for mine I used 3/4" steel round stock and yeah, my thread is m8x1.25. I cut the step on my lathe and then cut down the sides on the mill. I then had to use a file to get them to run freely in the slot. They are simple parts to make and would probably make a good first project.

So they are roughly 3/4" long and about 1/2" high if you were looking for an existing t-nut that you could modify. I think the bottom flange is around 50% of the height so maybe .250-.300 or so? I saw an 8mm t-nut on Amazon which might work, but they mention they are hardened which might make re-machining them a bit more difficult. I've included the Amazon link as they give dimensions.

Amazon 8mm t-nut

 

[nighthawkFmobil]

I still have to wait til mid May for 1228 to arrive but I’m doing preparations. Is there a way one of you guys could give me some dimensions of those t-nuts? I have to order some random hardware from McMaster Carr for the stand I’m building for the lathe and seem to sell everything. I’m assuming the thread is m8x1.25? With some luck McMaster will have hold down t-nuts close to the needed size. Thanks fellas.

Congratulations on your new 1228. It's a damn good chinese lathe!!! At least mine has been so far. Thing was pretty much ready to go out of the box.

 

[Bryan40g]

I don't know if these sorts of parts change over the lathe production run so you might be better off waiting and getting dimensions off of your lathe, but for mine I used 3/4" steel round stock and yeah, my thread is m8x1.25. I cut the step on my lathe and then cut down the sides on the mill. I then had to use a file to get them to run freely in the slot. They are simple parts to make and would probably make a good first project.

So they are roughly 3/4" long and about 1/2" high if you were looking for an existing t-nut that you could modify. I think the bottom flange is around 50% of the height so maybe .250-.300 or so? I saw an 8mm t-nut on Amazon which might work, but they mention they are hardened which might make re-machining them a bit more difficult. I've included the Amazon link as they give dimensions.

Amazon 8mm t-nut

You know I think that’s a good idea to wait until it arrives. Very possible that some small changes could be made. Change in vendor, etc. but I will take note of the details you provided for future reference. Thanks very much.

 

[Bryan40g]

Congratulations on your new 1228. It's a damn good chinese lathe!!! At least mine has been so far. Thing was pretty much ready to go out of the box.

Thanks very much. Super excited to get it. Been wanting a lathe for at least 8 years give it take. I’m a diesel mechanic and at our shop we have a 1953 10”x31” Logan and it’s beat up and in bad shape but I play with it as much as possible. That did it for me.
I spent nearly 3 or so years researching and searching listings and there were a couple I came close to getting but just didn’t work out.
Truthfully I really wanted something older(American made 1950’sish) and restore it but prices are insane. Seems like sky high pricing and just couldn’t justify $4-5000 for a decent or even good condition lathe possibly with some tooling when I could get a new one ready to go for the same price.
I did a ton of research before ordering the 1228 and I feel good about my purchase because of the great feedback people have given about doing business with PM. Sometimes it’s all you have to go on.

 

[nighthawkFmobil]

Yeah I got a lathe before a mill cause I had some lathe specific parts to make that would pay for a good portion if it. I also liked the idea of learning old school on one of the first manufacturing machines invented.

Now it's time for a mill. I'm in the same predicament. I'd like an old knee mill or a ready made vmc but I'm afraid the ones I can afford would possibly end up with me doing more work on the machine than actually making parts. Dun duh dunnnn charge!!!! In comes precision mathews haha I'm still deciding but if i buy new I'll most definitely be getting a 833 or a 940. It's crazy how backordered they are on mills. Amzes me there's that many hobby machinist to buy all these things up. Matts machines seem to always have the best travels for their class. along with guaranteed customer service. The 4 jaw I got from them with the lathe needed a little relief where the spindle sits but they helped me with that and all has been well since. Seems to be pretty decent quality control. You'll find issues others have had but with as many machines they sell and the way people use these things it makes sense.

Cheer! Seth