Two Pentz cylcone motor questions

[Tom Trees]

Hello everyone
It's about time I started getting some dust extraction sorted.
I have been looking to get a flange mounted 3 or 4HP motor for a long time with no avail.
I've some experience by now, with wiring up VFD's to three phase motors, which I used on bandsaw/tablesaw.

On a recent thread, I was told I could de-rate a 3hp tablesaw motor to 2hp to use one VFD for the two tablesaws I have.
I chose not to, but it raised another question for me.....

I figure I am using close to the max voltage concerning my supply on this house.
I don't know for sure, but It seems like a good idea to think about a 4hp motor for an extraction system,
as Bill Pentz recommends a 5hp system.


Sher if it's too much, I can de-rate the motor to 3hp anyway... right?


And my other question is about the lack of flange mounted motors available.
I'm doing this on a shoestring, so I am way more frugal than most ....stubborn as a mule too.

I will be making this cyclone on a big heavy frame ...I have a hoard of metal that I can weld up.
So whats the story on using a foot mounted motor for this application ? ...

Would it be possible, if welded up a beefy bracket, to bolt a foot mounted motor to,
so in essence it would be flange mounted then ?
I'm guessing a big plate in theory, would be needed to fit the motor casing inside, as to not reduce shaft length?

Or could I make some plate on this beefy frame enclosure to bolt the foot mounted motor to ?

Just thought I'd ask since I've been seeing some motors recently for sale
Thanks folks
Tom

[Bill Dufour]

Voltage should not be an issue on a normal house. How far is your house from the pole?
Look for c-face motor. have you considered a belt drive setup. It would allow fan rpm changes with available horsepower. A vfd for a fan is overkill since you do not really need the variable part.
\Bill

[Tom Trees]

I am running these machines off a 13a plug and a 30a MCB.
The lights go dim when I start my 750w single phase pillar drill for instance.
Single phase is a no no for me.
I have not seen a proper cyclone with belt drive, and I'm presuming there is a reason for this.

Tom

[Adam Herman]

you use current, not voltage. voltage for a house should be constant enough, unless you are a mile from the transformer. i would use a belt drive setup with a couple pillow blocks for bearings if i was rolling my own DC.

I think you may need a little electrical education.

are you running your vfd's off of 110v or 220v ? what is the amperage of the main breaker to the house?

[Tom Trees]

Hi Adam
You are probably right, current, not voltage ....although I won't get into that.
The house supply is 60A and as i said my shed is a 30A MCB.
Running these machines off 230v

All I can find is flange mounted cylcones
Has anyone here made a cyclone in the method you describe?
Tom

[Tom Trees]

I take it there's nothing wrong with de-rating a motor ....
Otherwise I would have got told off
So many reasons to go with a VFD
Tom

[Dan Friedrichs]

I think you're misunderstanding motor ratings.

A 5HP motor will only draw 5HP of power if you're putting that much load on it. If you build a dust collector with a 5HP motor and seal the inlet tube shut, it will draw almost zero power. If you open the inlet very wide and remove any restrictions on the outlet (filters, etc), it will draw much more power (potentially more power than the motor is rated to handle continuously). Nothing about the motor rating prevents it from drawing less (or more) power. It's just the maximum it should handle continuously.

So when you design this, if the motor draws more than its nameplate rating, just restrict the airflow. There's no need for a VFD.

[Tom Trees]

Hi Dan
I think there is defiantly a need for a VFD in my case.
I don't have three phase so the single phase starting current would blow the fuse in my 13a plug
I might not be able to handle a 4hp either.
So the ability to have a bigger motor if I move to somewhere else (rented), and the ability to have a ramped startup
suggests I do.
Also I would be able to get the motor and VFD for cheaper than a single phase and not have to wait.
Single phase motors in Ireland are sought after and nobody wants to know bout 3 phase.
I have not decided how many runs I will have, as I am a bit of a machine hoarder....
this will not be in the equation yet.
I am a fan of designing mobile bases anyway

It seems that de-rating the motor is a viable option it seems,
and will enable me to go bigger in the future as I amass more machines.

Can de-rating provide a quicker ramp up time to get a motor running in certain circumstances ?

Anyone have a link, or put me on the right track to find a non flange mounted 3-5hp cyclone example ?
Tom

[David Kumm]

The only way to reduce amperage on a motor is to slow it down. When collecting dust, reducing speed can really reduce the cfm and make the collector mediocre to awful. Is there any way to deal with the real problem- too little service to the house? Any way to run a generator when you are needing amperage?

I'm not sure you wouldn't be better off with a direct to bag or filter system. A cyclone is great but adds sp so you need more hp and impeller diameter than with a direct bagger with oversize bags and short runs. Dave

[Chris Parks]

99% of Clearvues in Australia are run at 220V through a VFD, I developed the motor and VFD combination using a TECO 3kw motor. Reading your posts I do not understand what you are trying to achieve to be honest. An electrical motor demands current as load increases and uses less when it is under less load so I guess it automatically derates itself to suit the load. My impression is you are thinking about it the wrong way round, the VFD controls the ramp up speed and this in turn controls the motor's demand and limits the current draw. A 15 inch impeller wide open runs at around 13.5 amps and at idle with everything closed well under 10 amps, maybe four or five but my memory is vague on that. Every one of the CV's in Australia runs from a 15 amp plug with no reported issues. Your biggest problem is not going to be the motor it is going to be where you source an impeller from, I would worry about that first and the motor later on.

[Tom Trees]

Hi again
The startup will probably be the issue I would have the problem with, everything else can be changed.
As was said I can have less amprege with less runs, maybe even one or two runs as I am fond of machine mobility.
It would be nice to have the option if I move house to have more runs.

I am not sure what the impeller route I'm going, nor the size.
I know it would be nice to match impeller size with current and also shaft diameter, but I'm not afraid of starting all over again.
I have to source all materials before I decide how things are going to go.

No one has brought up de-rating a motor as a non option, so that seems to me like I'm getting a 4hp dual voltage motor.
Unless a 3hp falls into my lap.

Now has anyone built a Pentz cyclone without a flange mount ?....
I really wonder why, as it seems theirs a lot of folks with low ceiling basements would buy a cyclone, but don't due to height restrictions.
Thanks
Tom

[Bill Dufour]

with only 13 amps I do not think you can run a dc and a decent saw at the same time. if you are talking 240 volts single phase you are looking at about 4 amps per horsepower. that means total horsepower should be under 3. So maybe 1.5 horsepower for the saw and the same for the DC.This does not include any lights on in the shop.
Bill

[Tom Trees]

Thanks Bill
Sorry, I should have mentioned, as it probably confused lots of folks ....
I wasn't talking about running these both at the same time.
I probably would have to make some mini cyclone thing like Marius Hornberger for use at the same time with the machines.
The cyclone is for cleaning up after a few cuts at a time ...that kind of thing.
Maybe one day I can get a place with proper power and swap the 13a cable with 16a.
I won't hold my breath though

Tom

[Chris Parks]

I am not sure what the impeller route I'm going, nor the size.
I know it would be nice to match impeller size with current and also shaft diameter, but I'm not afraid of starting all over again.
I have to source all materials before I decide how things are going to go.

No one has brought up de-rating a motor as a non option, so that seems to me like I'm getting a 4hp dual voltage motor.
Unless a 3hp falls into my lap.

Now has anyone built a Pentz cyclone without a flange mount ?....
I really wonder why, as it seems theirs a lot of folks with low ceiling basements would buy a cyclone, but don't due to height restrictions.
Thanks
Tom

My apologies but I simply do not know what derating an electric motor is or how it is done or even why you would do it. Using the VFD and the load placed on the motor is what defines the current draw. It was me who did all the work to use the CV outside the US in countries that used a domestic supply of 220 - 240V at 50hz.

Before you go any further forget the electrical side and find an impeller, that will be your single biggest hurdle. The Asian machines all use a maximum of 14" and a BP cyclone because of internal losses should use a 15" impeller. He explains on his site why he went for a 5hp motor instead of a 3hp and in the US his reasoning is sound. In the rest of the world a 3kw motor is perfectly adequate as we in Oz have proved over many years. If you want PM me your email address and we can discuss this further offline.

[Tom Trees]

Thanks Chris
I only heard about derating a motor using a VFD on another thread recently.
I asked if it was possible to get a VFD wired up for 2 tablesaws ...

http://www.sawmillcreek.org/showthre...age3&p=2645667
Basically,
I got the impression, I could derate the 3hp motor of one saw to match the other 2hp saw I have also.
It seemed that changing the max amp in the parameters was the only thing to do ...
I just figured this would have less of an starting/running current.

I have seen Matt Mattingley make his own impeller out of metal on the Canadian forum years ago.
And seen Marius's wooden one also
I just thought I'd be able to make do as I went along, and make some compromises probably.
I have lost out on two opportunitys to get some materials, and just figured this will happen no more
It's about the time to get stuck in.
Thanks for your time everybody
Tom