Meddings M10 VFD?

I have a Meddings M10 high speed drilling machine, it didn’t come with the two high speed pulley sets, as I suspect many don’t. As it has a three phase motor I have been mulling over a single phase motor conversion but today I was hit with the blindly obvious solution of an inverter and just ramp up the frequency to 83Hz to emulate the 10,000rpm pulley set. The only irritation is the motor star point will need to be accessed but this should be doable. The pulleys are probably as rare as unicorn tears which is strange as every machine was supplied with a full set so where did they all go?

Mike

Edited By Mike Poole on 01/12/2019 22:45:27

I too have one, also without the extra pulleys, however, mine is single phase.
Are there any drawings out there for the errant items.
Also, in order to get the extra two speeds, one seems to need two pairs of pulleys; Why isn't it a pair of matched stepped ones?

One thing I've not been able to wok out, is whether the current new crop of single phase inverters from China, actually act as frequency multipliers, or whether they only offer a reduced frequency output of below the 50(60) Hz input?

Bill

Email sent to Meddings, asking if they have any drawings or dimensions available.

I'll let you know the result

Bill

Have you been running it off the mains with the current 3 phase motor? If so then the star point may not be required.

Martin C

Good question! There's no particular reason why the electronics wouldn't cope but the specifications rarely mention the actual frequency range available. Implies to me the general purpose units may be limited to 50/60Hz to stop customers over-speeding motors unwisely.

But go-faster VFD's certainly exist - this example does 0 to 400Hz.

Dave

All 4 VFDs I have had dealings with will work up to at least 100 Hz and one (a Huanyang) up to 400. They don't "multiply" the frequency, they rectify the mains to DC then "invert" it up to whatever frequency you demand. I use up to 75 Hz on my VMB and 100 Hz on my converted Unimat.

Yes I've seen those, but they are 3 phase. I had considered getting one, as I have a 220v 400Hz 3 phase generator and a set of large power tools, but abandoned the idea when I thought about the downstream switching aspect

Bill

For what its worth, I have a 1ph supply and use Mitsubishi VFDs on my lathe, mill, and drill. All will generate frequencies up to 120Hz.

I completely endorse the comments made above.

Additionally I can say I had little difficulty finding the "star" point on my ancient "415v" 3/4 HP Brooks motor when I converted it for VFD use. I think the only motors that may prove difficult are those when the windings have been potted in epoxy.

The only real word of caution is not to rotate the motor at more than its centrifugal limit. Motors designed for 50Hz can do bad things at 400Hz.

Not half, in my case they are a set of Bosch military pioneering kit, all designed to run @ 400Hz, so no use at all without a very noisy 2 stroke generator.

Bill

Folks, FYI, I've now had a reply from Meddings; the parts are available, but come to a shade over £246 for the four pulleys.

Does anyone have one of these drills, complete with the high speed pulleys, who would be prepared to measure the OD's, or shall I go play with a calculator?
Thanks

Bill

Bill, I am looking for a Meddings 5 pulley for a new motor with a 19mm spindle. The largest pulley is 138mm and the top one is 48mm, the overall height is 60mm. Would you be able to make me one?