When should one switch to a VFD

I need some input on the pluses and minuses of retro fitting a VFD drive system. I am having trouble with my 10EE not running. Please see the thread "Monarch 10EE not running" as to part of the why I'm considering changing the drive system. Let me fill you in on my particular situation. I know there are many on this forum who would have little trouble discerning what is wrong with my current system and repairing it. Unfortunately I don't fall into that class and have very limited electronic abilities or understanding. My brother is an engineer and is very familiar with VFD drive systems and there applications. He also "speaks in electicaleze". The problem is he is 600 miles away but can have someone come and help me {read do) the wiring for a VFD. I'm thinking it would be much easier to find local help in the future with a VFD than a WIAD tube system. Parts should also be less of an issue. As I understand it I would need to replace the 5 HP DC motor with at least a 7.5 HP AC motor and adapt the two speed gear box to the new motor. I have other lathes that are running and should be able to do the mechanical work. Please advise as to exactly what would need to be done so I could determine it would be in my realm of ability. I'm not a complete moron. I work on older double shotguns and can make most of the parts I need. I also make bamboo fly rods among other things so I do have more than an average ability to perform things I understand. Just not electrical things!

I hope I've sort of painted you a picture of my needs and short comings so you can advise me as to whether or not this is a feasible idea before I get in to deep. Thanks so much for your time and help! All the best, Don Hansen.

You don't have to send away 600 miles to get a genius to wire up a VFD. I did it myself and most members of this forum will testify that I have no knowledge about anything whatsoever.

On the other hand it isn't clear if a VFD will solve your problems. Replacing the motor and hooking it up to your lathe may not be trivial.

one option would be to keep the DC motor and and go with a solid state drive. Here is a link to what I did.
http://www.practicalmachinist.com/v...ee-modular-332092/?highlight=parker+eurotherm

If you use search, they are many threads on VFD retrofits.

donhansen said:

..whether or not this is a feasible idea before I get in to deep.

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I'm sure - at least at times - I was as much hindrance as help to Mark on his one.

But what matters is that his thread covers the "easy way" - keeping the DC motor - and by phone or email, he (or I) can skip over the "experiments" we have each made to take you directly to what works.

Zero machining. No new motor to be sourced. Go by our distilled extract from the maker's manual - and it IS in the manual, all of it, even the ripple filter - you could be up and running, same day.

A VFD is a "magic box" with all the complications - easily a thousand times as complex as tube drive - safely trapped inside of it. It fails, you don't repair it. You replace it.

A DC Drive is also a "magic box" with its own complications "mostly" trapped inside of it. It fails, you don't repair it, either. As with a VFD, you just replace it.

There are DIP and rotary BDC switches to set, programming is done with a screwdriver rather than number codes and pushbuttons.

Even so, once all the side-trips in the manual had been discarded, my new Sears garage door opener was more of a nuisance to set up.

Because.. the hard stuff specific to both 3 HP AND 5 HP Dee Cee 10EE has already been done ahead of you.

All you have to do is copy it, not re-invent it.

You will not be alone. You will not long be in the dark.

Ask your Brother to have a read of that thread Mark linked - even download the Parker-SSD 514C manual.

And... I'd still like to see you keep the hollow-state drive.

It isn't really even as complex as a 1929 table radio. A cheap radio at that.

Reading up on how to sort it is cheaper than parts, any conversion, or even its own scarce ones.

Once it IS "sorted"? They usually run so damned long 'til next failure you'll need PM to remind you what it was you did. Unless it has outlived you, of course. As they do.

I agree with the remedy to replace the DC drive IF the WIAD is not something you want to support. The difference in doing a DC drive or VFD is, the VFD requires a motor and other mechanical changes along with the electrical aspects.

The DC drive is not only less things to change, it preserves the features of the DC motor that the 10EE is noted for. I have a replacement DC drive in my 10EE that was an unknown when I bought it, it is an older type of drive than the above mentioned system. It is ready to go the instant I power it up, runs and brakes well and delivers the high speed and low torque the DC motor is famous for. While I don't envision having to replace the drive any time soon, the current DC solution is the option I would take if faced with an incurable problem.

Steve

Steve in SoCal said:

delivers the high speed and low ^^RPM ^^^ torque the DC motor is famous for.

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Fixed that. Great gobs of low-end. Mid-range as well.

And.. Shackleton Systems Development's SSD 514C was so rugged, so configurable for anything Dee Cee, hence so widely used, globally, JFDI, BFBI + elegance British-wise, that some used units are even coming home from China.

Parker were not dummies to have bought the line. They still sell them brand-new.

When should you change to VFD only when your DC motor is beyond economic repair a 10EE with a VFD is a castrated lathe.

labeeman said:

...a 10EE with a VFD is a castrated lathe.

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Well.. not quite "castrated". Bigger d**k but softer is all.

And VFD's do sing well in the higher-pitched RPM registers, just as the "Castrati" were famous for!

So yeah... terse and accurate.

A great many of the folk who have done VFD conversion did NOT have a fully-functioning DC system to compare to, never knew what they had given up, are happy as clams with the leftovers.

This is like an engine swap in a car. If you drop a big v8 where a little 4 banger was, it can be easy and cheaper than fixing some old clapped out 4 banger.

but swap out one 4 banger for another? hmmmm, starts getting dicey.

I would suggest that in this forum there is so much info on EE drives, that I am certain you can get it running, probably in the hundreds of dollars. A VFD conversion? It is not twice as good and is bound to be more than twice as expensive.

If you machine the gearbox and get it all commissioned well, it will be fine.

But better?

Hmmmmm

Thank you all so much for sharing your wisdom. I'm going to have my brother take a look at this. It certainly looks like it would be much easier and have better outcome to go with a DC controller rather then the VFD conversion. It is so awesome to have all this knowledge at my finger tips! Thanks again, Don Hansen and keep the comments coming. I need all the help I can get!

gustafson said:

This is like an engine swap in a car. If you drop a big v8 where a little 4 banger was, it can be easy and cheaper than fixing some old clapped out 4 banger.

but swap out one 4 banger for another? hmmmm, starts getting dicey.

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Good analogy. As if the first "4 banger" were a Cummins Diesel. The second a Honda with higher nameplate HP - but only at higher RPM.

GOOD VFD conversions load regulate better where the DC motor has to be operated deep into its "Field Weakened" mode.

DC controls - "Field Regulators" have long existed to counter that.

Built-in on mainboard or plug-in PCB on MOST modern 3-Phase ONLY DC Drives, too. A Royal PITA to implement on SINGLE-phase-only DC Drives, simply because there is scant MARKET for them and OEM production (SSD once built them) ceased long ago.

As I prefer to make tests, rather than chips? One of those two Phase-Perfect t'other side of the wall may yet power a 3-Phase-only DC Drive enhanced 10EE.

Archaic Dinosaur Current? So are birds. Owls and Eagles among those.