PM1440GT Is in the shop!

[B2]

Hi Mark,

Yes, I am aware of @jbolt threading chart. We have been in contact and have been discussing what I am doing. I also wanted to see how many other threads and feeds that one could get. Anyway, hopefully when I am done one could use the spread sheet for many lathe models. You just select the gear ratios that you have or that you want to get data on and then it will generate an entire table listing the lever, knob, external gears that are used. It took me a while to figure out the internal 1440GT gears as the manuals drawing has errors and makes no sense to me. While I was doing it I also calculate all of the TPI values you could get if using the apron feed lever rather than the threading 1/2 nut. It also includes these in metric. as well as English values. I will attach an untested preliminary table print out of all of these, where I selected the external gears to be 60 and 30. Using your proximity sensor threading technique one does not need, and cannot always use, the phase monitor so the feed rod should work, but probably not as accurate as using the lead screw. The lead screw turns anytime the lathe is not in the "I" gear. Anyway, just using the normal levers and knobs there are 64 = 4*4*4 possible positions, but adding the apron feed will double this and yield some threading values which are not normally calculated. When lever position "I" is employed only the feed rod turns as the lead screw is not engaged.

My older SouthBend 10 does not have a feed rod. It only has a lead screw for doing both threading and feeding. I suppose having a feed rod saves some wear on the lead screw and especially on the 1/2 nut, but otherwise I do not see the reason to separate the two functions.

Let me know if you agree, or not, with the numbers.

Dave L.

 

[LVLAaron]

Got some of the easy stuff taken care of. Still a little anxious about working the lathe controls in... I'll get there.

 

[B2]

Don't get discouraged.

I am not for sure the large relays that come with the lathe will fit in there, but if you purchase small solid state relays, especially if they are DIN Rail ready they would probably fit. The only relay that needs to carry an current is the one to the coolant pumb if you have one. That pump is 220V and needs about 0.4 amp so a 0.5amp or larger current rating on the relay contacts should do. Search the Amazon Seller "Electronics-Salon" DC 24V slim Din Rail mount or other formats. They sell both solid state and small inductive relays mounted on circuit boards. You can probably even fined listings for multiple relays all on one mount in a small package. By the way Electronics-Salon has a lot more variations and other products on Aliexpress.com, but shipping time is usually drag. Think 4-6 weeks. Try this link Electronics Salon then search on relays.

My transistor circuits would definitely fit. However, most importantly you should think through your wiring and cables. I found that routing and connecting the cables are bigger problems and, if you are not careful, they make the whole thing messy and confusing and so prone to wiring errors. Colored coded wires help a lot. I listed the shielded cables I used in my build write up, Part 2. I purchased and used two 8 lines plus ground and shield. 20AWG. See if this amazon link works: HERE

 

[LVLAaron]

I got new relays from automation direct... Honestly forget how many or what kind it was so long ago. Not sure if I'm going to use the factory contactors or swap them out.

 

[xr650rRider]

Factory contactors are working fine on my PM-1340GT. They've never had high voltage ran thru them, so using for control voltage works fine.

 

[xr650rRider]

Got this to chamber rifle barrels. So probably several really poor rifle barrels.

Buy yourself a least a dozen pieces of 12"x1.25" OD 12L14 on Ebay. Watch Joe Pieczynski videos on threading away from the chuck. Get left hand threading tools and run them upside down (with a spacer) for external threads and run left hand tool on backside of material for internal threads. I have yet to have a need to thread toward the chuck. Saves a lot of headaches. Then you can focus on threading with out worrying about crashing. No proximity sensor needed. By the time you've bored, cut tenons, cones, counter bores, threaded, cut-off and started over on 50 practice pieces, you might be ready for try on 1st rifle barrel. Lot cheaper to practice first. I also had a dozen older barrels that I cut the tenons off and did all the operations above plus indicating in to <.0002" and then chambering.

 

[LVLAaron]

Buy yourself a least a dozen pieces of 12"x1.25" OD 12L14 on Ebay. Watch Joe Pieczynski videos on threading away from the chuck. Get left hand threading tools and run them upside down (with a spacer) for external threads and run left hand tool on backside of material for internal threads. I have yet to have a need to thread toward the chuck. Saves a lot of headaches. Then you can focus on threading with out worrying about crashing. No proximity sensor needed. By the time you've bored, cut tenons, cones, counter bores, threaded, cut-off and started over on 50 practice pieces, you might be ready for try on 1st rifle barrel. Lot cheaper to practice first. I also had a dozen older barrels that I cut the tenons off and did all the operations above plus indicating in to <.0002" and then chambering.

Yep - I have a lifetime supply of 1.25 barrels that are no longer in service. Plenty of practice material on hand already.

 

[B2]

Hi @xr650rRider ,

The factory contactors/relays should work fine if he has space for them in his box. From the photo it looked like there was not much room left and that was the issue.... not if they would work. He does not need the breaker that comes with the contactors for the 3 phase motor as these will just be the low current VFD signals , but should use some sort of breaker or fuse for the pump motor power. I am not for sure how it mounts if he is not using the original pump motor contactor. I just threw in a fuse for my solid state conversion and a huge solid state relay, that I had laying around, for my pump motor.

Even if you are not going to use it for threading the proximity stop is a nice lathe feature to have. The biggest issue with the Proximity stop seems not to be with the stop itself, but with the time it takes to brake the motor to a stop. Until the motor actually stops turning the apron keeps moving. So if you want to work real close to the chuck you have to figure that in and trip the stop at an appropriate distance prior to the chuck. However, even if you are feeding by hand having the proximity stop can be a safety feature to prevent mistakes. Of course you cannot be lazy about setup. I suppose the mechanical clutch might also work, but I have never really put it to the test. Likewise, the proximity stop will not work well if the motor belts are worn or are loose so that they slip during the braking .... There seems to always be something that can fail....

Dave L.

 

[LVLAaron]

I'm planning on using the factory contactors in their factory location for now.

Once I get a more full understanding of how everything is tied together I'll work to move my aftermarket relays into my external cabinet.

 

[xr650rRider]

I'm planning on using the factory contactors in their factory location for now.

Once I get a more full understanding of how everything is tied together I'll work to move my aftermarket relays into my external cabinet.

That's exactly what I said. I bought all the relays. I have the proximity sensor as well. When you get it wired, moved in to place and it works well.......you'll still have them in the boxes a couple years later.

I did run a 4 wire service to my lathe. That way I have 120 volt at the machine and put 1 dual receptacle on 1 side of panel that I can plug in DRO display and light. They come on when I close the disconnect. The other side I mounted a dual receptacle that is wired to a solid state relay controlled by coolant switch. I can plug in my thru barrel coolant flush system or regular coolant pump and control them with front panel mounted switch.