1440GT Upgrades and Additions

[Dabbler]

makes me think towards the future and my LeBlond. One day that servo shift will die, and then VFD for me!

 

[Jake P]

Some additional thoughts on the VFD conversion.

It might be obvious to some, but there is a notable difference in the new motor beyond just the power. This new motor is almost silent compared to the stock motor. The stock motor did not run smooth nor quiet compared to this Black Max. If you had nothing else to compare to then you might not know how much noise and vibration there is in a cheap motor by comparison.

Another issue that I am very happy to have resolved. Startup. Starting with the stock motor was a jolt to the system. Throw the power lever and the motor would lurch to life from zero to max RPM as fast as it’s windings could take it. And I cringed every time as the gear box was slammed into motion with a clunk. For those not familiar, with a VFD many parameters are changeable and the current program spools the motor up in 4 seconds. It starts very smoothly and spools up to the selected HZ in a smooth linear fashion. So much nicer than the pounding the machine got every startup before!

One more item. According to specs this system should require a 30 Amp breaker. My shop was wired on the 240 side with 10 guage wire, which by code could handle 30 amps, but we put a few long runs in and decided to put in 20 amp breakers and outlets to be on the conservative side. I’ve been running the lathe now for a week on the 20 Amp breaker without issue. Disclaimer: I’m not an electrician and I did not sleep at a Holiday Inn Express last night

 

[Cletus]

.............I’m not an electrician and I did not sleep at a Holiday Inn Express last night

hahahaha! .....gotta love it!

 

[Ken226]

Some additional thoughts on the VFD conversion.

It might be obvious to some, but there is a notable difference in the new motor beyond just the power. This new motor is almost silent compared to the stock motor. The stock motor did not run smooth nor quiet compared to this Black Max. If you had nothing else to compare to then you might not know how much noise and vibration there is in a cheap motor by comparison.

Another issue that I am very happy to have resolved. Startup. Starting with the stock motor was a jolt to the system. Throw the power lever and the motor would lurch to life from zero to max RPM as fast as it’s windings could take it. And I cringed every time as the gear box was slammed into motion with a clunk. For those not familiar, with a VFD many parameters are changeable and the current program spools the motor up in 4 seconds. It starts very smoothly and spools up to the selected HZ in a smooth linear fashion. So much nicer than the pounding the machine got every startup before!

When I first upgraded from single phase to a 3 phase Seimens motor on my lathe, I noticed the same thing. Drastic improvement in surface finish and parting performance.

 

[Jake P]

Part Four, Spider and Mister System:​

Nothing special for either of these two.

The spider is about as standard as they come according to most designs. I did watch Gavintoobe on youtube and ordered the same piece of steel from the same supplier that he used for the spider on his 1440GT. Main difference is that I used the entire 4 inches and he made his about 3 inches long. My spider slips onto to the full length of the exposed spindle.

Edit: I should add that Mark configured this system for me so that the stock coolant system can be used. I however at this time do not even have it connected as I have no intention currently of using flood coolant. But the system is there and ready to run should I change my mind.

Here's some shots,

Initial boring:

Of course there was some end cover modification required:

As I stated in the first post, paint touch up will come in the spring when I can spray outside again.

I just leave these out unless I'm using the spider:

As to the mist system, it's very straight forward as well. I have the exact system on my mill and have been using it for months without issue. It's the cheap $20 mixing block and nozzle system from Amazon with a bit of air fittings from various sources. If anyone is interested in links just say so and I'll post them.

This is the same shot that I put in the post about the tailstock DRO, but you can see some of the system in the background here:

The reservoir is the cheapest clear water filter holder I could find on Amazon. Got two! One for the lathe and one for the mill.

It mounts under my tool rack with magnets I got from Harbor Freight. Easy to take down and refill and the magnets keep it securely in place. You can see the air hose coming from the supply through the end of the backsplash.

I made a bracket that fit's between the flood coolant mount and the carriage unto which is mounted one end of a Small Rig camera arm. Small Rig is a company that makes gear for the video crowd and their stuff is very well made and cheaper than most. This little arm was about $20 and comes with a 1/4-20 stud at both ends making it easy to adapt to most applications.

If there's any questions on anything just fire away.

 

[Jake P]

The Marathon BlackMax Y541A was definitely a tight fit, they hold very tight RPM regulation over a wider speed range with sensorless vector control.

Mark, I've been pondering something regarding RPM on this new setup. I was going to email this question to you, but I thought it might be good to have it here should anyone else have the same thoughts.

This motor is capable of substantially more RPM than the motor it replaces. And the subject of spindle speed ranges has been discussed before in other threads. This lathe was built to run a max RPM of 2000 at the spindle in the H-1 gear setting. But this new motor with a HZ setting of 100 (where we currently have the VFD parameters set as max.) the motor shaft is spinning at 3000 RPM.

So my thought is this: The stock motor was a fixed 1735(?...ish) RPM and with a given pulley configuration that would equate to a constant RPM at the gear shaft/spindle that is at the other end of the belts from the motor.

Now we can almost double the motor speed and therefore also increase the speed of the gear shaft at the other end.

So my question is this. What kind of bearings are in that first shaft of the lathe head and what is their max allowable constant RPM range? We know that we cannot spin the main spindle past 2000 RPM for any length of time without overheating the spindle bearings as they are not made for higher speeds. But now we are able to spin that first shaft well above the speed that it would have ever turned with a stock motor configuration.

I did a little testing last night with a handheld laser type tachometer. The new motor at 100Z is at 3000 RPM and the spindle that it's turning at the other end of the belts is at 1415. Granted, we have put a slightly smaller pulley on the motor than what was on the stock motor, but this 1415 has got to be a good bit higher RPM than the spindle would have turned in a stock configuration. So at what RPM do we spin that spindle too fast?

For those interested here are some of the RPM ranges that I can get now in various gears.

Using the M-4 - H-2 ranges and running the pot from min to max I can get 55- 2128 RPM.

In the L-4 gear setting (slowest) I get 15 RPM. That's at 20HZ which is supposed to be 1HP. The motor should reach full 3HP output at 60HZ.

In the H-1 gear setting I can get about 3168 RPM at 100HZ. I say about as I did not stay there for but a moment as I don't want to damage my spindle bearings.

 

[mksj]

Hi Jake, very nice work on the spider, you have been busy making chips.

So you bring up a good question as to the rest of the drive train, and yes there are some limitations to the rest of the components. Typically I belt down the motor pulley size so the rest of the gear train is not spinning significantly faster but there is good amount headroom within the gear train. Still, there is increased centrifugal forces as well as oil cavitation (air bubbles) when you spin up the low speed gears. Typically the final drive (high speed) in many lathes is close to a 1:1 with the motor speed, and gears are smaller. I have not heard or seen any issues with running the VFD's in a lathe gear head scenario from 20-100 Hz (using a stock pulley size), I would be uncomfortable with pushing the motors faster unless you were able to belt down the drive train speed. This has been the major limitation on most lathes, as the motor pulley is often quite small. Interestingly, many of the factory VFD lathes will spin the spindle to 3000 RPM (like my ERL-1340 and also the TRL) but they also add a pressure lube system. The ERL/RML VFD models use a 2 speed gear box, and the TL uses a 3 speed gearbox.

So my recommendation is typically is not to use a low speed gear ratio and crank up the VFD, but it doesn't seem to be an issue with the higher RPM gears, and keeping the spindle speed below 2000 RPM for any kind of extended high speed work. Use a good oil with an anti-foaming agent. My last mill had a gear head that they ran to 3000 RPM with 3 speeds, the head got quite hot and the oil foamed significantly. When I switched to a synthetic oil there was a major reduction in heat and foaming. I ran my mill much harder and longer than I would a lathe.

 

[Jake P]

Mark, thanks for the information and advice!

 

[Tipton1965]

Mark, thanks for the information and advice!

I think if it wasn't for Mark, many of us would just be playing with tinker toys instead of enjoying our machine tools.

 

[Beckerkumm]

On the Smart Brown that Mark did the conversion for, the motor drives a Matrix two speed clutch with a 4-1 reduction on the low end. The clutch is rated for 29 lbs of torque and a top speed of 3000 rpm. The clutch is overkill for torque but S and B built in a safety factor. The original motor was three speed 2,4,6 pole but less HP or torque. I was advised by S and B followers that the headstock and spindle on the 1024 was very stout and built stronger than a 10EE but the apron and gearbox was more delicate. That made a 5 hp 4 pole motor a reasonable choice even though the drive train could handle more ( there is also a 8-1 ratio back gear ). The 10EE needs the large motor with no back gear but it is way more than the spindle is engineered to handle. There are a lot of things to consider when swapping stuff and it is really helpful to have someone ( like Mark ) to help you through the process, especially when dealing with oddball machines.

This might be interesting only to me, Dave