what size drive pulley on your gearbox 10ee

I have a 10ee that was changed over to vfd drive. the pulley on the gearbox is only 4-3/4" and I am having trouble getting the RPMs up to 2500. I think the drive pulley is smaller than stock. What size should the pulley be
Thanks
Rich

There is no right answer to your question. Monarch used various combinations of gearbox and spindle pulleys, and made 10EEs with 2500,3000,4000 rpm, and probably others. What RPM do you want, what is the dia. of your spindle pulley and what is your motor RPM when the spindle is at 2500?

rimcanyon said:

What RPM do you want, what is the dia. of your spindle pulley and what is your motor RPM when the spindle is at 2500?

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Yep. "Back into it".

Changing the spindle pulley is a non-trivial task on the basis of space, complexity, and mass of metal wanted to fab it from.

The driving-motor pulley, OTOH - most especially on a VFD conversion - is a primo candidate to be changed.

There is also space enough, though no SURPLUS, to go to a two-stage belt drive, Poly-Vee/MicroVee good choices. That has been done to at least one 10EE, too, IRRC.

Spindle pulley is 7.5"
Drive pulley is 4.8"

When the drive pulley is spinning around 2400rpm, the vfd is about 88hz and the tach on the spindle is about 1600rpm

I think that getting a drive pulley that is about 7" to 7.5" will get the spindle rpm up to 2500 or there about.

I am wondering if anyone has one they want to sell

lectrician1 said:

Spindle pulley is 7.5"
Drive pulley is 4.8"

When the drive pulley is spinning around 2400rpm, the vfd is about 88hz and the tach on the spindle is about 1600rpm

I think that getting a drive pulley that is about 7" to 7.5" will get the spindle rpm up to 2500 or there about.

I am wondering if anyone has one they want to sell

Click to expand...

That sounds close to the OEM driving pulley diameter. I have a spare that measures 6 1/2 OD, I'd guess an "A" section Vee belt pitch-line of mebbe 6 3/8"?, Has a detachable CI hub, four capscrews to hold it, single keyway in the bore.

If not the right bore diameter, I'd suggest fabbing a new hub from 4" Dia. or so steel for truer running than bushing it.

Not exactly pretty, but it should clean-up to workable.

Meanwhile.. all depends on how you expect to USE the beast, but as a generality, one wonders... if the VFD conversion will have enough torque mid-range and down-low with the larger pulley?

Is it a 7.5 HP or better AC motor? Or only a 5 HP or less... and... is that why it has the smaller driving pulley in the first place?

Keep in mind that 5 HP Dee Cee 10EE went to 4,000 RPM rather than 2500 RPM a very long time ago, now.

IF.. I had gone the 3-P + VFD route, instead of enhanced DC Drive for the OEM DC motor?

Rather than a 10 HP 3-Phase rig, I'd have wanted a 7.5 HP 8-pole AC motor.

At 5 HP - or even at 7.5 HP, I'd also want a dual-range belted arrangement in addition to the reduction gearbox.

Just because a 10EE didn't SHIP with a multi-range belted arrangement does not mean it could not benefit from it.

See Lodge & Shipley AVS. Three geared ranges, PLUS the variable motor drive, IIRC, but even so, simpler, mechanically than 12 or 18 speeds, all geared, one-speed motor.

5hp motor in there
splined hub on the drive pulley
I was thinking of cutting off the v belt grooves of the small pulley to a nice clean square surface then cutting a new larger 7" pulley and press fit on the old hub with some tig welds. the original pulley is aluminum with a splined steel hub. I have a nice piece of 1-1/2" ALum plate that i can use to cut the new pulley

lectrician1 said:

5hp motor in there
splined hub on the drive pulley
I was thinking of cutting off the v belt grooves of the small pulley to a nice clean square surface then cutting a new larger 7" pulley and press fit on the old hub with some tig welds. the original pulley is aluminum with a splined steel hub. I have a nice piece of 1-1/2" ALum plate that i can use to cut the new pulley

Click to expand...

Seems too much like "work".

I'd want to put the existing pulley aside, intact & entire. Actually.. leave it in service, so I had the means to turn the new one.



AFAIK, Monarch used a stock / standard spline, so I'd first seek one as a component, then build the new pulley on that one.

Better yet... see if anyone has downgraded a 4,000 RPM WiaD or Modular "Dee Cee" 10EE to 3-Phase & VFD. Most have to use a smaller pulley for the reduced sustainable torque.

The Dee Cee originals would be a drop-on fit.

Also drop-on torque, but, as said, depends on how you plan to use your 10EE.

Check out Martin sprocket's line of sheaves. Im sure they have one that is the right size and belt style. They even have them in different bore styles along with taper hub versions. They likely have a taper hub with the spline to match. WAY quicker and cheaper than trying to machine a custom sheave

I put an ad on the want to buy accessory forum

Hopefully someone has one.

Thanks for your help
Rich

lectrician1 said:

Spindle pulley is 7.5"
Drive pulley is 4.8"

When the drive pulley is spinning around 2400rpm, the vfd is about 88hz and the tach on the spindle is about 1600rpm

I think that getting a drive pulley that is about 7" to 7.5" will get the spindle rpm up to 2500 or there about.

I am wondering if anyone has one they want to sell

Click to expand...

The 4,000 RPM machines have a smaller spindle pulley, so you might want to look for one of those. I have an extra that needs some work (it needsto be tig welded to fix a chip out of one of the flanges, then turned down). Gearbox pulleys vary too, I have one with splines that is 4 ⅝" dia. for a low rpm machine, and others with diameters of 6 ½" and 7 ⅝".

What type and diameter of hub do you need for your motor? Do you have a 10EE 2-speed gearbox?

Monarch made at least two types of splined hub pulleys as well as the straight bore with a slot for a woodruff key.

i just bought a 6.5" with splined hub from someone on PM. im awaiting delivery.
I have the two speed gearbox
Thanks for your response I tell you how everything goes with the new pulley after i mount it

The motor is likely rated at 1750 rpm, but is capable of much more. I have a 5hp 1750 Black Max motor its max rpm is 5200rpm. So with the setup you have,so you can hit 5k on the motor is 3200 on your spindle. Go into the vfd setup and adjust the max HZ to 170. Now if the motor is not rated as inverter duty and only 1750 rpm, then you likely are at the top. I often run my BP at 100hz for years.

Toms Wheels said:

The motor is likely rated at 1750 rpm, but is capable of much more. I have a 5hp 1750 Black Max motor its max rpm is 5200rpm. So with the setup you have,so you can hit 5k on the motor is 3200 on your spindle.

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Lest we overlook a "basic". Marathon has had that "line" of wide RPM Black Max for years - HP & RPM @ Frequency often right on the nameplate.

BE AWARE, that those motors are head and shoulders above an "ordinary" 3-P motor for sustained variable-speed applications.

..and seek one if you haveth not..

Just my NSHO, but they are the 3-P world's most worthy counterpart to the Dee Cee world's wide-power-band Reliance Type T, TX, TR. (around 12 thousand bucks EACH, for quite some years, already).

Both are well worth having. Even "coveting". And stashing...

the motor in there is a dayton 5hp 1750 rpm
I was playing with the frequency on the vfd. the speed would increase up until about 88hz before the motor started to slow down. I didn't want to push it so i figure around 85hz was the high limit for rpm for the motor. at that freq it is spinning around 2500rpm. I dont know if that speed will do any damage to the motor. Anyone have any ideas how high i can spin that motor? the model is 3N659A dayton

lectrician1 said:

the motor in there is a dayton 5hp 1750 rpm
I was playing with the frequency on the vfd. the speed would increase up until about 88hz before the motor started to slow down. I didn't want to push it so i figure around 85hz was the high limit for rpm for the motor. at that freq it is spinning around 2500rpm. I dont know if that speed will do any damage to the motor. Anyone have any ideas how high i can spin that motor? the model is 3N659A dayton

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Per Grainger - who have owned Dayton outright - production facilities, not just "brand", but that, too, since forever-ago, that SKU # is Chinese-made "subject to change", read-as "lowest bidder, this re-stock cycle", and is at least basic VFD-rated, quote: "inverter duty".

Seems to be reasonably well-suited to running blowers and fans, 'coz THAT is where a search finds them most commonly listed. There must be multiple millions of Dayton motors in use at that sort of work by this late date. They mostly JF do their job, most especially when buried IN the fan's airstream for great cooling, as most ARE...but...

..that just isn't the same tasking as powering variable-speed machine-tool spindles with LOTS of stop-start cycling and varying loading, NO external fan to help with cooling.

One nameplate shot I found, there is no figure for max RPM. Grainger may HAVE such a figure. Somewhere.

Until proven otherwise, especially as you DO seem to be hitting the wall @ 88 Hz, I'd class it a dice-roll getting your VFD to push it even to 50% overclock eg: 90 Hz, or 1730 nameplate RPM X 1.5 = 2595 RPM.

That drop-off in RPM you have already logged just MAY be due to an internal corona discharge firing off to "flute" the bearings and pierce insulation rather than make more turns...

Better motor .. and mayhap a better VFD as well, and you can at least make a 3-P conversion work with a somewhat smaller performance downgrade vs the OEM Dee Cee motor and a good DC Drive.

Pulley diameter is only a small part of the challenge.

2CW

The tach goes up to 2500 so I would like to get the machine up around that number even though it will probably never be used in that range. The motor in there is made in Mexico with no max rpm on the nameplate. I will contact granger to see what the is the rpm limit on that model. I received the larger pulley but haven't put it on there yet. I was looking around ebay for a used black max 5hp but I'll try the current setup first. What is a good test for torque? How deep a cut with what feed rate should a 10ee be able to comfortably take?

Not to put too fine an edge here, be sure your chuck can handle your intended RPM. My 8" is rate 2500, the 6" 3500, collet chuck 3500 as well. Its a rare day I go above 2000.

As previously mentioned, Max HZ is set by the VFD, never found a motor to balk at running as fast as the HZ wants it to. The main difference AFAIK between a regular and inverter duty motor is wire insulation, for higher heat in the windings. I purchased My Black Max Motor from Surplus Center in NE. 10+ years ago. My machine was setup as a 4k rpm model, and I found that low end direct drive torque was lower than I liked, so I installed a larger pulley on the spindle to improve that.

My suggestion is boost the VFD hz and keep the low end torque.

lectrician1 said:

The tach goes up to 2500 so I would like to get the machine up around that number even though it will probably never be used in that range. The motor in there is made in Mexico with no max rpm on the nameplate. I will contact granger to see what the is the rpm limit on that model.

Click to expand...

I doubt it will much matter. It is probably good for far higher RPM before it self-destructs, mechanically, than you can drive it, electrically, per prior observations in re corona discharge & c.

I received the larger pulley but haven't put it on there yet. I was looking around ebay for a used black max 5hp but I'll try the current setup first. What is a good test for torque? How deep a cut with what feed rate should a 10ee be able to comfortably take?

Click to expand...

More than you can even get CLOSE to with a mere 5 HP AC medium-RPM motor. It is a sustainable TORQUE thingie, and that is Dee Cee turf.

Not a lot of formal yardsticks around, but the late Harry Bloom (beckley23) included some basic RPM-drop-under-cutting-load tests in his partial-attempt at use of solid-state DC Drives nearly fifteen years ago now:

http://www.practicalmachinist.com/vb/monarch-lathes/10ee-electronic-controllers-98851/

http://www.practicalmachinist.com/vb/monarch-lathes/10ee-electronic-controllers-update-99897/

Over ten years AFTER he made those tests, and not yet then aware of them, I was in the process of replicating the journey, but from the approach of an electronics guru, more than that of a Machinist. We corresponded, in posts and "offline". I have the (basically obsolete, now) Carbide insert ID to replicate his tests. If even it matters.

So... Some caveats:

- Harry noted, way back "then", the need for boosted input voltage, but ceased his experiments before he ever reached even the basic fully-powered DC Drive's capability level, nor matched the OEM DC Drive - which Monarch/Reliance ran at MORE THAN nameplate voltages. Eg; 250-260 VDC, not 230 VDC. Harry had gotten to roughly HALF normal Dee Cee power before he'd run out of still-working DC Drive equipment.. and patience. Or maybe just uncommitted funds and spare time, as Harry was an inordinately patient and persevering individual among men.

So.... he "settled" for a 5 HP AC 3-P motor + VFD conversion.

Suited his needs for the machine. He was happy with that. Harry always had at least one heavier lathe, used such - more than the 10EE, anyway, most weeks, didn't expect his 10EE to hog.

Larger "other lathe" or not, (mine is a 7.5 HP Cazeneuve HBX-360-BC), lots of folks are just as happy with that as Harry was.

Hopefully, you will be among them.

Because...there's NFW your present rig will match the broad power band of even an early 1940's 3 HP large-frame "Round Dial" MG 10EE, as-shipped. "Half" would be a reasonable expectation, and that will, after all, make chips pretty damned well.

ok to test the machine im going to try
.125 depth of cut
.010 feed rate
1150rpm
tnmg 321 insert
1" 1018 crs
as per Harry bloom

i"ll see what happens

Late t the party but I do have a few pulleys and some other stuff including a back gearbox, for future reference.

Paul