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The Pm-1440gt Has Landed

jbolt

Active User
H-M Supporter-Premium
#72
Worked on the spider a little tonight. I started roughing it out from a bar of 3-1/4" A36 hot rolled steel.

This is the largest steel stock I have done on this lathe so far and hot rolled is not my favorite but I had it on hand. All I have right now is some general purpose carbide inserts. I am a little blown away at how well it machined. This was at 600 sfm (750 rpm) / 0.01" feed rate and a 0.05" DOC. It could definitely take a deeper cut with ease.

spider01.png



Third and final pass at 0.025 DOC. 800 sfm (1000 rpm) / o.o1" feed rate. Cut was +0.002" over my target of 3" without really trying to be too precise. The finish is close to a 220 grit. I can't wait to see what it will be like with the proper insert.

spider02.png


After cutting off the turned end with the band saw to a little over the overall length I faced the ends to size and started roughing out the bore. First drill was a 1/2" followed by a 1", the largest have. RPM was 250. The new motor is amazing with the RPMs holding rock steady no matter how hard I feed the drill bit. The factory single phase motor growled a lot with heavy drilling in aluminum.

spider04.png

Cutting steel on this machine is like cutting aluminum on my old one. Makes me smile.Very cool!!!
 

jbolt

Active User
H-M Supporter-Premium
#73
I have a question for the PM-1340GT owners. What is the actual cross slide travel on your lathe? My 1440GT is speced at 7-1/2" but the actual travel is only 6.4".
 

mksj

Active User
H-M Supporter-Premium
#74
Hi Jay, looking mighty nice, and beautiful finish for the feed rate. Going 3 phase with a good motor and a VFD, world of difference. The trigon and the 80 degree rhomboid inserts are go to cutters. Travel on the PM1340GT cross slide is 6.5".
Mark
 

jbolt

Active User
H-M Supporter-Premium
#75
Hi Jay, looking mighty nice, and beautiful finish for the feed rate. Going 3 phase with a good motor and a VFD, world of difference. The trigon and the 80 degree rhomboid inserts are go to cutters. Travel on the PM1340GT cross slide is 6.5".
Mark
Thanks Mark. I'm a bit annoyed at the less than advertised cross slide travel. I confirmed with another 1440GT owner that his was the same as mine.
 

jbolt

Active User
H-M Supporter-Premium
#76
Here is the completed spider. The fit to the spindle came out perfect. The spider is locked to the spindle with 3/8-24 flat bottom set screws so it wont mar the spindle. The clamping screws are also 3/8-24 but in stainless steel with 1/4" brass tips.

The mods I did to the cover allowed the upper stud that holds the belt cover on to be reduced in length as well as the thumb nut. The clamping screws will now clear the thumb nut so the spider can be used with the cover on.



Turning finished
spider05.png


Spider installed. Note the recessed magnet for the tach sensor.
spider06.png


Completed spider. Clamping range is 1/4" to 2"
spider07.png
 

Dan_S

Active User
Active Member
#77
Thanks Mark. I'm a bit annoyed at the less than advertised cross slide travel. I confirmed with another 1440GT owner that his was the same as mine.
Are you measuring total travel, or just on the one side of the center axis?
 

jbolt

Active User
H-M Supporter-Premium
#79
Here is the start of the next two projects for the lathe, the proximity sensor mount and a rack for the QCTP tool holders.

This is the front plate that holds the P-sensor to the micrometer stop. The milling was done on my PM-932 CNC conversion. I was going to thread mill the p-sensor hole but decided to use the lathe. To cut the 1mm pitch thread I had to change the upper gear from the 30T to a 28T and move the lower 60T gear to the 120T center gear.

The upper and lower gears are held in place with a 6mm socket head cap screw and the center idler gear is adjusted at two locations with a 17mm wrench. The gear changes are fairly quick taking only a few minutes. Having to remove the belt cover to swap the gears made me miss my old lathe that had a hinged cover. The gears and spacers are broached with a key-way. The broached area is rough from the factory and needs a little dressing up to remove the burrs so they will slide on and off easily. Before I de-burred the 60T gear I had to remove it with a gear puller.

Being able to use the forward and reverse jog makes metric threading, where you can't disengage the half nut, a breeze to do.

P-Sensor01.png P-Sensor02.png



Here are the QCTP tool holder holders. :confused:

They will be mounted a piece of 1/2" x 1" 8020 t-slot extrusion attached to the back splash. The holder base is made from 3/8" x 3/4" aluminum bar. The back side is machined to create a boss that keys into the 8020 slot so they won't pivot. The tool holder captured by two 1/4" dowel pins are pressed into the top of the block.

QCTP01.png
 

Lonewolfgun

Swarf
Registered Member
#88
JBolt,

Looking at your pictures it looks like your only using leveling pads to level the lathe. Did you have any troubles with getting it level and now keeping it level using on the pads?
 

jbolt

Active User
H-M Supporter-Premium
#89
No issues with leveling or keeping it level. The machine is very easy to level and true. The final tweaking is done with the lock nuts on the leveling pads.

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