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The Pm-1440gt Has Landed

jbolt

Active User
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#1
Well 6-1/2 months later it has finally arrived. It was supposed to have been delivered yesterday but UPS messed about and didn't deliver until today. They gave me a 4 hour window today and showed up 45 minutes late.

PM put the factory crate on another pallet so it sits really high. I had to cut away the middle section of the pallet and crate to get my engine lift under it. Between an engine lift, a floor jack and a toe jack it took me, my wife and daughter about 2 hours to get it undone and in place in the garage. I got the leveling feet on after chasing the 1/2-12 whitworth with a 1/2-13 tap.

Here is a quick picture. The back guard is still off from the move. I will put that back on after I get it cleaned up and the DRO on.

More to come.....

PM1440GT01.png
 

pugslyyy

Iron
Registered Member
#3
Congrats, you did great if it took you only 2 hours to get it in place. I think it took me the better part of a day to get mine tucked into its slot. The multi-level crating certainly added to the fun and games.
 

mksj

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#4
Agonizing wait, but expected given it is a new machine. The wait was well worth it. Great it is finally home and we can get a first hand review. Looks like a wonderful machine for those that need a bit bigger work envelope. :chunky:
 

jbolt

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#5
I got the lathe mostly cleaned up this morning, enough to get going on the DRO install. I got the lathe wired and running so while working on the DRO it has been doing spindle break-in. When I first ordered the lathe way back at the end of February I had originally asked for a single phase machine. At that time the first shipment was not supposed to include single phase machines, only 3 phase. I agreed to the 3 phase and went about collecting all the bits and pieces to do a mksj VFD conversion. I guess so much time passed the single phase machines were available and that is what Matt had built for me. He offered to find a motor but I had him send what he had not wanting to further delay the machine. I have a huge backlog of customer work that needs to get done. The bright side is I can get to that now and worry about the VFD conversion after. FYI - The single phase machines are 2HP, not 3HP as shown in the specs. The 3-phase machines are 3HP. The only other anomaly so far is the shipping weight was shown as 1430 lbs. The machine specs are 1750 lbs. Not sure if this was a typo or not. No way I could verify.

The stand is plenty stout and just sitting on the adjustable feet the lathe is rock solid. All the levers work real smooth from the get go. The ways look awesome. Some real nice castings on the bed. The belts are throwing copious amounts of dust so those will get changed soon. To my pleasure there are no lockouts on the gear cover nor is there a shield. The spindle bore is 2.060" which is perfect. I had fears it would be 50mm and not be able to get a 2' round stock in. The D1-5 spindle nose is a beast compared to the D1-4 I had on my old lathe.

For anyone getting one of these lathes and installing a DRO PRO magnetic system the read head bracket for the X axis will not work. it is too narrow for the two flat spots on the side of the saddle. I just finished making a wider one. Hooray for home shop CNC! Not sure about the Z yet.

I will post more as I get to it. Sorry for the blurry picture.

DRO X Bracket 02.png DRO X Bracket 01.png
 

jbolt

Active User
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#7
Got the X-axis scale installed. I had to make a drill extension to drill the holes for the read head mount. Of course that meant cleaning, mounting and adjusting the 3-jaw chuck ( set-tru type), and cleaning and mounting the tail stock. I swear there was more comoline on the inside of the tail stock barrel than on the outside, not fun. So the lathe has officially made one part by drilling a hole. :D

DRO X Bracket 03.png Drill Extension.png.jpg
 

jbolt

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#10
Day 3....

The DRO is installed and working. The Z has 37.1" of travel and the X has 6.5". I ran the Z back and forth through the full travel several times to a TDI and it returns to dead nuts zero each time. Same with the X. The kit supplied universal drop leg for the Z read head mount was not usable so I made a replacement out of some 0.5" x 2" aluminum bar stock. Instead of drilling new holes on the back of the saddle I placed it under the coolant riser mounting block with longer screws. Works great. The DRO display is temporarily mounted to a piece of bar stock attached to the side of the back splash. This may change after the VFD conversion...or not.

Z-Scale01.png Z-Scale02.png

Cover installed. DRO display and LED light (Thanks for the light Matt)
Z-Scale03.png LatheSetup02.png



Whoever installed the back splash needs a refresher in measuring. The side attached to the head stock is 1-3/4" too far back compared to the tail-stock end. This left a gap that would allow debris to fall on the floor behind the machine. I re-drilled the holes an inch further in and installed a 3/4" spacer on the tail-stock side. This keeps the back as far out as possible and still able to contain debris. There is still an open gap between the ways and the motor so if that becomes a chip magnet I will add a secondary guard to cover. The back splash is made from 1/16" steel and is very stout.

Back Splash02.png Back Splash04.png



The T-nut slot for the stock tool post turned out to not have been machined parallel to the top of the compound. The T-nut I machined for the Aloris QCTP is was higher on one side than the other. My T-nut was machined within 0.001". The Slot is about 0.008" out of parallel over 2". The stock T-nut was installed and ground with the compound. If you turn the stock t-nut around it wont sit flush. I used some stainless steel shims to bring everything true and parallel when cinched tight.

QCTP01.png QCTP02.png



Here are a few shots of the stand. It is made from 3/16" steel with reinforcement in strategic places. It is very sturdy and rock solid without being bolted down. Matt did a good job on the specs for this one.

Stand01.png Stand02.png Stand03.png



Electrical for the single phase version. Nice and tidy with easy access. FYI when the machine is plunged in the transformer is powered regardless of the e-stop position so beware.

Electrical01.png



And finally the coolant pump and reservoir. I'm not thrilled about the access from the inside. PITA the deal with. there really should be an access panel on the outside. The get the pump and reservoir out the drip funnel must be removed. The drip funnel is kind of funky and I suspect will not contain any splashing. I will see if the tray can be replaced with a hose and still allow the chip pan to pull forward.

Coolant01.png



Almost ready to be put in service. Next up will be final leveling and some test cuts!

LatheSetup01.png
 

jbolt

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#11
I've done the first fine leveling with a machinist level. This is the first test cut. over 8" it is 0.0021" narrower at the far end. I will let the machine sit overnight, take another cut and adjust from there. Finish looks good for the single phase motor.

TestCut01.png
 

mksj

Active User
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#12
Hi Jay,
Machine looks great, and very clean DRO install, nice. A few things to consider checking the cutting alignment, you may need a precision level to check for any bed twist along the ways. I have some precision ground test bars and I look at the +/- TIR from 0 at different points along the bar. If the swing in the +/- value is skewed in one direction as you get further from the chuck, then you may need to align the headstock. Most of us have had to do this, it takes the slightest change in the alignment bolts. I would also do a test cut with the 4J chuck to see how it compares.

Overall, it appears to be a very fine machine, and that is close to a mirror finish cut on the test cut. Hopefully you have more room for a larger motor in the back if you go the VFD route in the future, Impressive, if I didn't already have a lathe, this is the one I would get today.
 

koba49

H-M Supporter - Premium Content
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#13
when I got my 1228 leveled I took a cut on a 1-3/16 chunk of steel with a HS tool bit over 5 in I got .0045 taper same direction you have small on the end big by the chuck this is with out a center in the part. by just lowering the front feet on the tail stock end I took out .002 taper I had to unbolt the machine and put a .006 shim on the back side of the foot at tail stock end, bolt it back down and I was .0001 high on tail stock end over 5.500 distance the machine is not dead level any more but it is aligned your machine is heaver than mine but try dropping the leveling feet or foot on the front tail stock end you may get it out by just doing that, it may not be level but I do not think dead level is needed to get a precise alignment
 

jbolt

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#14
Hi Jay,
Machine looks great, and very clean DRO install, nice. A few things to consider checking the cutting alignment, you may need a precision level to check for any bed twist along the ways. I have some precision ground test bars and I look at the +/- TIR from 0 at different points along the bar. If the swing in the +/- value is skewed in one direction as you get further from the chuck, then you may need to align the headstock. Most of us have had to do this, it takes the slightest change in the alignment bolts. I would also do a test cut with the 4J chuck to see how it compares.

Overall, it appears to be a very fine machine, and that is close to a mirror finish cut on the test cut. Hopefully you have more room for a larger motor in the back if you go the VFD route in the future, Impressive, if I didn't already have a lathe, this is the one I would get today.
Hi Mark,

The only problem with the DRO is it covers the lock screw for the X axis. I need to re-think that one as it is necessary for doing precision work.

I chucked up a 1" precision test bar and over 4" I get 0.0009" toward the operator at the far end. Unfortunately two of the head-stock jacking screws are blocked by the motor capacitors. For the moment the work I need to get to is 12" or less so I'll see if I can get it acceptable adjusting the bed twist. I'm finding the lathe too be too low for my height so I think I will wait on adjusting the head until I do the VFD and raise the lathe.

I haven't looked too hard for motors yet. The max motor body length is 11-1/2" with an overall length of 14-1/2". Max diameter could be up to 9". From what I can tell most 3HP #PH motors have a 1.125" shaft which will require a new pulley.
 

mksj

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#15
Hi Jay,
I have found the cross slide lock to be very important to maintain accuracy and often you want just a slight tension/resistance on the cross slide. I have seen two approaches, one is to standoff the DRO scale on blocks, and machine a threaded post with a lever arm or a hex nut head bolt which applies pressure on the gib lock, or you can put a friction lock on the other side. I did the latter and it works very well, I uses some naval bronze for the friction lock,very easy to set both a slight drag or a full lock. Since it is softer then the metal cross slide there is no wear. I subsequently added a rubber gasket between the mounting plate and cross slide so it does not get fowled with swarf. Also on the tool post slide, I made a small lever arm that is spring loaded, so it holds it position when loosened. There is a small ball bearing that is between the gib and the lock, do not loose it.

Example of lock with standoffs for scale: http://www.hobby-machinist.com/threads/installing-dro-on-pm-1340-gt.48653/#post-413797

On the 3 phase motor, a tight fit and probably only a TENV type motor will fit. The Marathon E470 motor or the Y541/Y527 inverter motors would be top of the line, but looks like it would be a tight. You would need to cut off the rear jack shaft, the main shaft would be 1.125". Pulley should not be a problem, but you want to go much smaller than stock, as I recommend running these up to 120Hz.

PM1340GT Lathe Cross Slide Lock - text.jpg
PM1340GT Lathe Cross Slide Lock.jpg
PM1340GT top slide   lock.jpg
 

Attachments

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jbolt

Active User
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#16
I likey the friction lock. I don't like to have standoffs on the scale cross slide. Good thinking on using the follower rest mounting holes.

I'll take a look at the motors. How much smaller would you go on the pulley?
 

jbolt

Active User
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#17
I did not take much adjustment to get the machine cutting straight. I think I moved the front left foot about 1/4 turn. It took 4 test cuts to dial in. After this test cut I ran a TDI along the front and it had a 0.0003" difference over 8". I see no reason to mess with the head stock.

TestBar04.png



Even though the cuts are nice and shiny it does not tell the whole story. I ran some 400 grit lightly over the cut to highlight the finish produced. 700 rpm at 0.0026" feed, CCTG 32.51 insert. You can see the slight undulations. Nothing to complain about but not like my old lathe that was a 3 phase belt drive. It will be interesting to see if there will be a difference with a 3 phase motor.

TestBar05.png
 

jbolt

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#18
I don't have a manual yet so I'm not sure is this information is in there but I thought I would post it anyway.

Wires 1 & 2 are 24vac.
Wires S1 & R1 are 110vac.
Wires S & R are the 220vac in.

I have the light hooked up the the 24vac and the DRO to the 110vac.

PM-1440GT Electrical.png
 

wrmiller

Chief Tinkerer
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#19
Just my opinion, but I'm just a hobbyist and not looking for mil-spec finishes, so that would more that work for me. I'd be more than happy to take that thing off your hands for ya once I land somewhere. :D
 

mksj

Active User
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#20
You are not going to get any better than that unless you buy a 10EE, spec is something like better than 30 millionth of an inch. I still would check your machine with another chuck, and also check that the headstock is for the most part running true. I mark all my chucks so I always put them on in the same position.

On the pulley size it all depends on the motor and the maximum RPM, most 1750 RPM motors will do 2X their base speed, but the performance can drop off erratically after about 90Hz. The inverter motors maintain full Hp to at least 2X their base speed, the Baldor I use is rated to 6K RPM at full Hp. Still I think on an inverter motor 2X the base speed is a reasonable top end for the motor. Since the 1440GT already will top out at 2000 RPM, I would reduce the pulley size to around 50-60% diameter of the current one with an inverter motor, 75-80% with a standard motor taking it to 90Hz. The faster you run the motor, you have more poles per spindle RPM, so it should be smoother. Hp delivered to the spindle is 2X and torque 1X at 120 hz, vs. the a 60Hz motor at the same spindle speed using a higher gear. I would say the sweet spot is running in a higher gear and using either 30-90Hz or 30-120Hz depending on the type of motor. Braking with a VFD is also quicker when using a higher speed gear for the same spindle RPM, there is less rotational momentum. A VFD on the 1440GT, you will probably just use one of your speed levers to select a general speed range and leave the other in high.

A lot of factors affect surface finish, another gent that I helped convert his lathe to 3 phase on a G4003G, the surface finish improved about 70% by just going to 3 phase. Some of that may be pulsation, the cutter and cutting speed plays a significant role. Change the belts and play a bit with the tension/check the belt alignment. I use very sharp uncoated carbide inserts for Al, and can get close to a mirror finish with a skim cut. 1018 steel, forget it.

The 110VAC is usually off the transformer and fused, on my mill it uses a 3A fuse. Ok for a coolant pump and a DRO, but not much more.

Like Bill, I will be happy to stand in line behind him.
Mark
 

jbolt

Active User
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#22
Just my opinion, but I'm just a hobbyist and not looking for mil-spec finishes, so that would more that work for me. I'd be more than happy to take that thing off your hands for ya once I land somewhere. :D
Can't have it. :p

I do customer work to support my hobbies. One of the main reasons for upgrading was to expand my work envelope and be able to produce parts quicker. This lathe is definitely a huge step forward.
 

jbolt

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#23
waaahhhaaHA! I finally ran some customer parts today. What a huge difference. I parted off a bunch of 2" 6061 stock. Something I could not even think about on my old lathe. An ISCAR parting tool with a drizzle of kerosene went through it like butter. Will be even better with the VFD conversion and variable speed.

Here are some parts I have permission to post pictures of. I make a couple a dozen a year for a local shop. Their smallest manual lathe has a 24" chuck on it so they farm out this kind of stuff. Made from 3/8" 7075. The long skinny part is 0.187" dia with a tolerance of +0.0 -0.0005". The short fat end is a 0.25"bearing fit with the same tolerance. The long skinny part is about 2" long and has to be cut in a single pass. I used to scrap about 30% on my old lathe. I did these in about a third the time it used to take on my old lathe with no scrapped parts. Awesome!

Solenoid Shafts.png


I also made up a chuck cradle. I had always meant to make one for my old lathe but never did. A must with the heavier 8" chucks. Made from 3/8" poly and 1" aluminum tube with press in star threaded inserts.

Chuck Cradle.png
 

wrmiller

Chief Tinkerer
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#25
Love the chuck cradle. I'll have to keep that in mind for when I can no longer muscle my chucks around by hand.
 

jbolt

Active User
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#26
Love the chuck cradle. I'll have to keep that in mind for when I can no longer muscle my chucks around by hand.
I change between chucks a lot and it gets interesting supporting the 8" chucks with one arm while engaging a cam lock with the other.:eek: This is much easier. As a bonus the upper cross tubes make excellent carrying handles. :D
 

Rich V

Active Member
Active Member
#27
Made from 3/8" 7075. The long skinny part is 0.187" dia with a tolerance of +0.0 -0.0005". The short fat end is a 0.25"bearing fit with the same tolerance. The long skinny part is about 2" long and has to be cut in a single pass.
You finish cut that long & skinny part to that tolerance? How do you avoid flexing?

Very nice lathe, I have it's kid brother the 1340.
 

jbolt

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#29
You finish cut that long & skinny part to that tolerance? How do you avoid flexing?
That is why it has to be done in a single pass. I use these CCGT 32.51 carbide inserts and kerosene for cutting fluid. The 80 deg inserts with the small tip radius at that DOC will cut without pushing or pulling the material. The 7075 also helps. When I first started making these a few years ago it took a while to get the process down, especially on my previous lathe which was less precise, less rigid and not the same quality of bearings. On my old lathe I would have to run the spindle for a hour or more to get it thermally stable and then run all the parts. My 1440GT has a spindle run out of less than 0.0001" when cold which I think is quite impressive.
 
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oldhank60

Active Member
Active Member
#30
Well 6-1/2 months later it has finally arrived. It was supposed to have been delivered yesterday but UPS messed about and didn't deliver until today. They gave me a 4 hour window today and showed up 45 minutes late.

PM put the factory crate on another pallet so it sits really high. I had to cut away the middle section of the pallet and crate to get my engine lift under it. Between an engine lift, a floor jack and a toe jack it took me, my wife and daughter about 2 hours to get it undone and in place in the garage. I got the leveling feet on after chasing the 1/2-12 whitworth with a 1/2-13 tap.

Here is a quick picture. The back guard is still off from the move. I will put that back on after I get it cleaned up and the DRO on.

More to come.....

View attachment 135507
Looks Nice Hopefully you will have it up and running in short order