Uk 3hp 240v extractors and impeller sizes....

[Inspector]

This is what the CV-Max's 16"/406mm impeller looks like. It is in the 90db range.

By newer type of extractors do you mean the Harvey or the squat cyclones everyone is flogging? I saw a Jet or a King a few weeks ago but it was a 3hp I think and might have been a little quieter than the 3hp, 4 bagger I had.

Pete

 

[Ttrees]

@Inspector These yokes, it doesn't appear to sound like the same thing.

 

[baldkev]

Hi all, with regards noise, i can put a ply box around the housing and rubbers on the mounting points etc to deaden it a bit, but basically if its running it'll be because ive got a machine running too, so will have ear defenders on..... if ive underestimated the noise, I'll let you know

With regards motor size, the 4kw was powering a 10" duct and supplying enough air movement to cope with 3 550mm bags.... im pretty sure i read that as load decreases the amps went up, not down. It looks like i have to go 3kw to get the shaft size, thats 4hp. I really dont think 3hp would struggle to turn it, so 4 should be plenty. My multico ta1 has a 2.2kw motor and cuts through 3" oak fairly well. Of course, all of this is coming from a person with no experience of these things, so we'll see
im not positive on my duct size yet, but I wont be using it to capacity by any means. The purpose is to draw as much of the fine dust in and away at source, almost certainly only ever one machine at a time. I take petes point re: saw then planer, but i wouldnt want to leave a machine spinning in the background as the container is 8 foot wide, with planer and saw next to each other. I have no doubt I'll be needing to modify whatever i do, im unlikely to get it right first time

 

[Inspector]

Ttrees that is the Harvey. Aximister put their brand name on it. Harvey actually make bigger ones but they are really really expensive. They are supposed to conversation quiet.
https://www.harveywoodworking.com/collections/gyro-airs
Kev how high are the fins on your impeller? The ClearVue is 4"/100mm The 4hp should do it but won't a new single phase motor cost as much or more than a good VFD for the existing 3 phase motor?
Pete

 

[Ttrees]

It seems like it might be worth considering for me
I wonder if this type of machine is even half comparable to a cyclone?

I'd be happy enough not needing a plumbed in unit, using a 3 horse machine, so the cfm would be pretty good I'd imagine.

I'd love to see a proper shop made one of these, just to weigh some options up, (i.e costs for something specific if ya can't scrimp it from somewhere)

PS great to get some measurements of the impeller, as I presume one could slice a bit off a bigger one if it were too heavy (provided the hub wasn't a ton)
it might be just the ticket.

Cheers
Tom

 

[baldkev]

The blades are about 65mm high. Its cast aluminium....

A new motor is around the £180 mark.... theres a couple of things that worry me about the 3 phase setup and bigger motor, im pretty sure my workshop feed is 20 amp, so if ive got a 4kw motor, vfd and then say spindle moulder, will the supply cope? Im guessing the bigger motor plus vfd is going to cost about 30% more to run and having more things in line is more things to go wrong ( i am usually a fairly unlucky person )

I'll do another vfd search, would probable have to find a second hand unit capable of the 4kw

 

[baldkev]

Hi tom, when I have time tonight, I'll pm you a load of the info pete sent me, including piks and links, we went through possibly making something up. I decided with time constraints and hasstle, plus possible failure, itd be easier to find something to butcher.... i had considered a tumble dryer drum as a possible source of starting point to weld my own

Pete, the vevor style cheapy vfds are 135 quid, but im sure there were poor reviews. I have to go out now but will do more looking when i get home tonight

Thanks for your help, kev

 

[Ttrees]

Hello again
Since your motor is 5hp and presumably the impeller is suited to the motor,
I'm guessing a single phase equivalent + dust maker might be pushing it on a 20a breaker, of what type you have though I don't know
i.e type C MCB (i'm a guessing uneducated joe soap) normally is the most suitable for induction motors, as its more suited to the high amp startups.

Say you go a bit smaller with single phase option, then I'm guessing you would have to pay more attention to the ducting in order to be able to close off the gates to get the impeller up to speed.

This is Kev's motor underneath folks.
Can this be run on a step up VFD/inverter? I'd guess it can.

Bob Minchin might have a supply of ones to suit 380-415 delta.


Kev
VFD's are not like RPC's rotary phase converters, which have a slave motor running all the time.
Having a VFD involved doesn't appear to consume any noticeable additional juice,
my 24" 3HP bandsaw running on idle uses about the same juice as my laptop.

Saying that I'm guessing that it's not the same deal with an impeller which has resistance and little momentum.

Don't bother looking for VFD's until you understand what you need,
there is a good likelyhood of buying something wrong for the job.

I think a step up to 380v OUT inverter is what you need.
That's 240v IN.

You might want to de-rate the motor, I can't advise, but mention a VFD route would be likely be easier on an undersized motor.
That might only be an option on some VFD's
Once again I can't advise what the cheapest option might be
or if you could get away with a smaller unit if doing so.

All I've ever run has been 2hp and 3hp dual voltage motors which can be run on 240v delta, not 380v delta, (delta is the low voltage configuration, star or Y, the high voltage configuration)

and I've not needed to use Vector drives for the saws,
so interested to see what folks might suggest.

Matt Mattingly (matt matt) on a Canadian forum made his own impeller, but he's a machinist.
Seems quite a bit of work to make one, as it needs to be precision made to counter
the centrifugal forces.
Saying that, I was under the assumption that all these impellers had a hub for the shaft, and not just a cut out.

I in jest mentioned Vector drives, as one or two has made a wooden impeller on youtube
and should the thing explode, I believe the vector drives might cope better with the motor stalling until you could race over and hit the off switch.

Most of the cheap ones don't offer any motor protection, and might cook your windings
and drive if stalled.
Not the same I believe as the Vector drives which often are used for lathes as it can provide torque at low RPM.

I couldn't tell you what is most suitable to be honest, and what you are able to run on the 20a circuit.
Can it be upgraded cheaply, or does the cable match the CU.
What size of machine is the DC going to be used on ect , what size spindle are you using.
All things that need going over to be sure.

Tom

 

[baldkev]

Hi Tom, thanks for the input.... i have read about half of bobs motor paper and bob has given me info on my motor plate.... the best option is going to be to buy a 240v/415v motor and vfd to match.... i need to figure out the vfd thing too, but pete has goven me a fair bit of info on his ( a powertran unit )

Thank you, kev