More than I bargained for.

stumpjumper400 · Jul 29, 2020

I recently acquired a 1966 model 612/1610. This machine was listed as having a 7.5 hp motor. I haven't really gone into it other than starting to clean up the outside so far. The original paperwork from Monarch suggested that it was sold with a 15 hp motor so this made me open it up and look. While I can't find the ID tag on it, the motor is definitely not 7.5 but more along the size of a 15. I have gone to some of the phase converter sites and it seems as though a 30 hp phase converter is needed to run at rated capacity. Will I use it at that capacity, probably not. What are your thoughts on converter size? Single phase is the only thing available to me at the shop at this time.

For what I want to do it also needs a steady and taper attachments so I'm on the hunt for those.

For those that run this era of machine, have you found a cheaper supplier than Monarch for the headstock hydraulic filter? I ordered one and wouldn't you know, there are no numbers on it and looks very proprietary.

This is my first lathe of my own so any and all help is appreciated.

Thanks,

Steve

texasgeartrain · Jul 29, 2020

Physical size of motors can be deceiving. A lower hp motor can be physically larger than a higher hp motor. So you really want to confirm. Some Monarch's have motor tag on access door or door frame. I'd really go over it to find a tag.

Even if a 15hp, you could de-rate to 7.5 if you have smaller line in voltage to building. And the size of wires powering the building, even though single phase, would be a factor in how big you can go with a phase convertor, as you'll know how many amps those wires/breakers can handle.

I'd like a 15hp convertor to run a 10 or 7.5 motor on lathe.

rke[pler · Jul 29, 2020

Even if the motor is a 15HP you could use a soft starter - it's sort of a VFD in that it reduces the starting current in the motor by spreading the peak out over time, but it's cheaper than a VFD (usually). For about twice the price you might find a VFD and program the acceleration curve to do the same thing.

stumpjumper400 · Jul 29, 2020

I didn't have much time when I went over it with an inspection mirror. There is years of grease/oil film in the compartment. This one is internal to the casting not outside like some. I found some ID tags but one was for different voltage wiring and the other had verbiage about greasing the motor. The access door may have something but I didn't notice it or it may be covered up. The motor casting is about 15 inches in diameter and since it was sold with a 15, judging by the size, it probably is. Just going off the original sale record, it was sold to a shop and then that shop was bought out and the new owner was selling what he didn't need. I picked it up in the same town it was originally sold in. The shop it sits in has no issue with service. I have 400 amps of single phase available. Looking at the converter websites, it takes 70 amps of single phase to run a 30 hp converter so I have plenty. I don't think turning barrels and actions will require 15 HP. That isn't the only thing that will be done on it but that is it's purpose.

Phil in Montana · Jul 29, 2020

To retofit a taper attachment is a very big deal... It is possible but you need to find a donor lathe to steel the parts from, no one is going to cut one up just to sell the ta...always buy a lathe with a ta if you need a ta...Phil

stumpjumper400 · Jul 29, 2020

I was looking for one with the taper but this one came up at a really good price that I couldn't pass up. A phase converter looks like it is going to cost more than what I paid for the lathe. I can adapt a steady rest if I can't find one for it. Most of the original steady rests I see for it have rather small throats. That is OK for what I want to do if I can find one for sale. I don't think I would try to adapt a taper attachment. I'm sure it is possible but I want an original. What I don't know is, what other models use the same attachment. I am not familiar enough in that respect.

stumpjumper400 · Jul 29, 2020

Phil in Montana · Jul 29, 2020

No other models were the same... I have spare a type 61, totally different, the 1610 or type 62 is a one of a kind...Phil

stumpjumper400 · Jul 29, 2020

Correct me if I wrong. The 612 is the later version of the 62 right?

Cyclotronguy · Jul 29, 2020

Don't want to hijack this thread but curious as hell about soft-start devices for lathes and mills with no clutches running off phase converters.

moonlight machine · Jul 29, 2020

stumpjumper400 said:
I didn't have much time when I went over it with an inspection mirror. There is years of grease/oil film in the compartment. This one is internal to the casting not outside like some. I found some ID tags but one was for different voltage wiring and the other had verbiage about greasing the motor. The access door may have something but I didn't notice it or it may be covered up. The motor casting is about 15 inches in diameter and since it was sold with a 15, judging by the size, it probably is. Just going off the original sale record, it was sold to a shop and then that shop was bought out and the new owner was selling what he didn't need. I picked it up in the same town it was originally sold in. The shop it sits in has no issue with service. I have 400 amps of single phase available. Looking at the converter websites, it takes 70 amps of single phase to run a 30 hp converter so I have plenty. I don't think turning barrels and actions will require 15 HP. That isn't the only thing that will be done on it but that is it's purpose.

You don't need a 30 hp phase converter to turn barrels, you will probably need it to start the motor!I have an American Rotary phase converter, I recommend A.R. highly. I have about 15 trouble free years on mine.

JohnEvans · Jul 29, 2020

If the lathe has a clutch a 15HP converter will work ,it's just lathes without clutches that need double HP to reliably start the entire power train. Plus you can always add a 5 or 10 booster motor if needed. 10to15 HP 3 phase motors are alot easier to find and cheaper than 25-30s .

stumpjumper400 · Jul 30, 2020

JohnEvans said:
If the lathe has a clutch a 15HP converter will work ,it's just lathes without clutches that need double HP to reliably start the entire power train. Plus you can always add a 5 or 10 booster motor if needed. 10to15 HP 3 phase motors are alot easier to find and cheaper than 25-30s .

It is clutched and after looking at the 15 hp models, they still give a 42 amp rating which is about what a 15 hp motor is rated to pull at max load. I don't know how much of that is starting load or max running draw. I can work on airplanes and cars but never got that much into the sparky stuff. Yes it would be a helluva lot cheaper by 1k.

stumpjumper400 · Jul 30, 2020

thermite said:
Well surely buy vs make is faster, but.. whilst a TA might be hard for a house-painter or a Lawyer to make, any machinist as can't figure it out should be in some other line of work.

While I may be able to figure it out, I would rather try to find one that was made to fit. This is a personal quest to get into machining not a job. Although anything you learn can be turned into a job, that is not my ambition. Call it hobby machining with the proper training. Gunsmithing is just one of those things I want to do myself without farming it out. I can get blanks that are already contoured but it would be nice to profile my own to match a stock or something that isn't a standard taper. Thanks for your insight.

stumpjumper400 · Jul 30, 2020

thermite said:
That is running, max rated HP @ RPM, all other numbers on the nameplate on or close to what is displayed as well.

STARTING a 15 hoss, clutched or never, can be a sunovabitch for an RPC.

IMNSHO, you aren't wrong as to 30 HP worth of idler. I'd just do it in modular hunks of no more than 10 HP, each.

That because an RPC looks even WORSE at start, given it is still a "motor" and also working with only a single-phase source at that point.

Scaling linearly - and it might NOT be - from a 10 HP Phase-Perfect or earlier 10 HP RPC?

- 55 A to 58 A, 240 VAC, input side, split-phase, 10 HP P-P or 10 HP RPC idler

- 28 A OUTPUT side, 3-Phase, fom 10 HP P-P or 10 HP RPC idler.

CAVEAT: A 10 HP RPC will not ordinarily START (nor always even RUN) a 10 HP load motor. 7.5 HP is pushing it.

A 10 HP P-P WILL do. Either of start or run.

Wuddja believe just tripling both figures for a 30 hoss?
For running, AND NOT starting!

For starting, check this out:

Calculate inrush for 3-phase motor

I somewhat understand what you are saying about being able to even start the motor. I don't have the required info from the motor to use the calculations on the website you provided. With an inspection mirror, I haven't been able to find the data plate for the motor. Based on your comments, I am back to needing a 30hp RPC and maybe even higher just to start the motor. Am I understanding that right? I don't know what a P-P is. Even though I am retired military and am used to acronyms, this one escaped me. I really need to get knee deep in that cabinet and find the motor ratings.

Rob F. · Jul 30, 2020

PP is phase perfect, a brand of converter. RPC is probably more reliable and longer lasting, Only use the PP if you need "perfect" 3 phase, like a CNC machine etc.

jlegge · Jul 30, 2020

For Steady rest. The bed is the same between the Series 62 model 1610 and the 612 model 1610. The Series 610 model 1610 has a narrower bed. The Series 613 is a combination of the 612 and 610 beds where the model 1610 is the narrow bed. Series 614 only came in the model 2013 and 2818 which has the same bed as the Series 62 and 612. I would look at these same machine for taper attachments. Do not see many donor machines out there.

The series 612 was introduced about 2 years after the Series 62 and mainly differed in having a mechanical shift headstock in place of the Dyna-shift hydraulic shifting headstock.

texasgeartrain · Jul 30, 2020

thermite said:
Page Three:

"Just me", but "small shop", my 200 A residental service and neighbours sharing the transformer?

I wouldn't try to do a 30 HP single-idler RPC even with a "pony motor" start.

The 28 HP max "all active" one I have is one or two idlers more complicated than you need - partly because I have some really LIGHT loads at under 2 HP, each machine, total. Then ALSO machines with NO clutch, and others with very different loads, same power-cord.

Your load is simpler? Break it up sanely. 2 could do yah, 3 at most.

The goal is that your RPC IDLER starting load goes more easily managed as well as having the balls to START the load. It does not KNOW you will actally run it below 1/4 of its max power most days. Starting load "is what it is".

With a multi-idler rig, yah do the hard work of the load startup, then drop one of the idlers off the line for running the machine-tool at - quite realistically - far lower loads than its maximum.

Or leave it online for any period of use when more serious chip must be ripped. AND/OR .. there are to be a LOT of starts and stops. Andsatrts, again. My larger drillpress - with a foot-switch, yet - is one of those that drove all the "extra s**t" under this roof. "YMMV"

It's a nuisance to do that for 10 HP RPC or less. Any genuine gain is in the higher loadings or squirrely variations in loadings. I just don't happen to have anything that is actually SIMPLE!

I'm going to need to upgrade my rpc as well. Using the op's current example. Does he need a 30hp control box, and let's say three 10hp idlers? Or a 10hp control box that uses three 10hp idler motors?

My guess is a 30hp controller. If desiring to start a 15hp load motor, do you start all 3 idlers at the same time, or bring idlers 2 and 3 on after idler one is up ?

I do like this idea of multiple idlers, where you can run just one idler for most 1 to 3hp loads. Beats sucking down all that electricity for a single high hp idler. It was on my mind actually, as I didn't want to run so many amps on an idler for smaller machines.

I'd downgrade a 15hp to 10hp in a machine for home shop though. If I'm buying idlers, I can buy a motor for the machine. Then use a 20hp rpc, with a 10hp and a 7.5hp idlers. Use the 7.5 for smaller machines 1-3hp. 10hp idler for machines with multiple motors. Use both together for 10hp machines.

Greg White · Jul 31, 2020

Perhaps you could call American rotary, I bet they could answer your ?s and perhaps surprize you with data you are searching for. I have two of their units, one running a bigger CNC machine,excellent products, I like you, never learned much aboot sparky stuff.
Good Luck.
Gw

More than I bargained for.

Plastic

Titanium

Diamond

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Stainless

Plastic

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Plastic

Stainless

Diamond

Titanium

Plastic

Plastic

Plastic

Diamond

Stainless

Titanium

Titanium

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