Thread: Cyclone blower motor advice

Don't know the answer but if there is a reply out there can you actually get a matched blower and motor suitable for a small unit is Aus. Seems to be a few large units available but small options seem to come back to the bag units.

JohnC

Originally Posted by Moo73

This is for Wayne Davy and any other Cyclone afficionados...
I'm embarking on the great Cyclone adventure and am in the process of sourcing a good motor (I'm starting from the ground up, only relatively new to woodworking, but want the best dust protection I can get - $$ allowing). I've been in contact with an electric motor company in Aust and provided them with the details of the motor Bill P recommends online from electric warehouse motors in the US - problem is his preferred motor is a 3hp compressor motor running at 3450rpm on 230v at 60 hz.
Best match the guy I've spoken to can do is a 3hp (2.2kW) motor with 2800rpm on 240v at 50Hz - I must admit, I'm going cross eyed trying to figure if I can get 800CFM using this motor...what's the best way to work it out?

The US motor will be running at 60Hz ( hense 3400 RPM), speed of an induction motor is a function of frequency. In Australia you will only get a motor to run at 2800 RPM (using a 2 pole motor) unless you use a variable speed drive to change the supply frequency this is an expensive excersise. The formular for working out the theoratical speed of a motor is Synchronous speed = Supply Frequency X 120 / number of poles in the motor (less friction losses).

There are a couple of things to consider with motor speed and fans (read blowers) if you speed the fan up by say 10% the increased load on the motor will be considerably more (I have been told it is quadratic) that is a S**T load more load on the motor. Fantec put out a good industry book that explains fan laws and the charastics of various fans.

To design a fan and motor combination will need the advice of a fan engineer.
The easiest way would be to find an old dust extractor strip the fan and motor from that and design your cyclone around that.

2.2Kw is about the maximum size single phase motor you can safley use on a 10 Amp ciruit, there are some motor sellers that have larger single phase motors for these you will need a 15 Amp circuit. Try WEG or AEG they have them.

My Cyclone will be a small one ( about 250mm high and 230 dia made from 1mm plate) sitting on top of a 13 Gal drum driven by a 1.3Kw vacume cleaner motor, these motors are available from Stokes for around $100.00

I will post pictures and info when I have finished.

Hope that all this helps

Phil

Moo73

I went through all the permutations of options for motors, impeller sizes, etc and trying to get max air flow from a 10amp power supply unit. The impellers are almost impossible to source in Aus for reasonable cost. BY FAR the most ecconomical option is to use the blower unit from a bag type dust collector. This also saves considerable time in construction. I suggest you keep an eye out for a second hand 2hp unit (3hp if you have a 15 amp supply) and use it to build your cyclone. The only drawback is that the cylinder diameter increases to acommodate the lower hp unit and maintain separation efficiency.
I must say though, that I couldn't be happier with the way the cyclone I built works. In over a year of weekend warrior work I have less half a cup of fine dust that has come to the trap after the filters.
Cheers

Originally Posted by rev

...keep an eye out for a second hand 2hp unit (3hp if you have a 15 amp supply) and use it to build your cyclone...

I agree with Rev and Phil.

Cheers

I also looked in to this some time ago.

Finding motor sizes and impellers to match Bill's recommended set-up.

The motor was not really the problem more the impeller, the local company's simply were not interested, I got close but no cigar.

The best option by far was to simply buy a 2-3hp unit [3hp unit had no bigger fan] and use the blower and motor and build the rest.

Maybe you could source the impeller from north america, not sure if this would work with the suggested motor.

You could email Bill, and others in the US who are teriffic in offering advice.

Good luck if could find another solution.

Pulpo

I also looked in to this some time ago.

Finding motor sizes and impellers to match Bill's recommended set-up.

The motor was not really the problem more the impeller, the local companies simply were not interested, I got close, but no cigar.

The best option by far was to simply buy a 2-3hp unit [3hp unit had no bigger fan] and use the blower and motor and build the rest.

Maybe you could source the impeller from north america, not sure if this would work with the suggested motor.

You could email Bill, and others in the US, who are terific in offering advice.

Good luck in finding the best solution.

I'd be very interested if you manager to build your own blower.

Pulpo

Like others, I looked into this quite some months ago. It is possible to purchase (I lost all my info in a H/drive crash, so from memory...... a Jet 14" ) motor and impeller assy for around $500............I REPEAT, this is just from memory.............this is probably the closest locally available assy to Bill Pentz's recommendations.

Phil,

Re your figures on the increased motor load when increasing impeller RPM...........I had considered doing this with a v-belt/pulley drive using my Hafco DC's 2hp motor and impeller assy but wasn't sure of any potential problems until earlier today, when I noticed on BP's site, he makes favourable mention of some people having succesfully done this same thing to increase their cyclone's performance. I think one point is that in these circumstances, it is better to have the motor running "almost" continually rather than turning it on and off all the time.

Rev,

Would you care to share details (dimensions, etc.,) of your cyclone for those of us with 2hp motors.

Originally Posted by Pulpo

3hp unit had no bigger fan

Thats true... but the 3hp motor can take a bigger load before burning out so the inlet hole to the fan can be bigger to move more air.

Originally Posted by HiString

Rev,

Would you care to share details (dimensions, etc.,) of your cyclone for those of us with 2hp motors.

HiString,
The diameter of my cylinder is 500mm (I am using an air ramp a-la BP's design). It is easier to build than you might at first think - just be patient when soldering! I used a cone ratio of 1.64 and the length of my cylinder is 632mm. All this fits under my 9'6" shed roof height quite comfortably but leaves me with a smaller bin underneath to collest the chips than I would really like.

Most of the 2hp blowers are hampered with the airflow they can achieve by using a 5" (125mm) air inlet. They are capable of considerably more. Be careful though not to make the motor work beyond its design spec. I drilled out the spot welds to remove the 5" inlet collar and then opened up the inlet hole to 160mm diameter. This quite noticeably increased the air flow but to what extent I don't know because I have no way of measuring it. Actually my concern was to not exceed the 7.7Amp rating for the motor. With the diameter of that inlet hole at 160mm my motor draws 7.6Amps with unrestricted air flow (ie max continuous current draw - you need a clamp ammeter to measure this). Hope this helps.
Cheers

Originally Posted by Moo73

This is for Wayne Davy and any other Cyclone afficionados...
I'm embarking on the great Cyclone adventure and am in the process of sourcing a good motor ?

I usual spend my time on the Triton user group but just typed in cyclone and got on to your message - vey late.
I am heartened as I have gone through the same - The UK website think I am from the planet ZOG asking about the US Pentz site. alll these motor problems - followd by where to source the products!
The filters are also a major problem. At least I now know there are more people also pulling out the few remaining hairs that I have.
The US sites are so simple - call this number.
The only thing that I am convinced about is that I should build my own blower- as the China based blowers + casings are wrong to get the fine MDF dust out of my workshop. I have found that if I go to gym after a day cutting MDF I am totally cream crackered.
The problem with the dust extractors are that the input and exits are to small and the motor is short of air so that the motor runs on low amps and does not stretch itself - no return to supplier during the first year.
Building the cyclone as well is a pain as you have to source all of the components locally - a new learning curve
The experience in the gym drives me to complete the project - keep going
Barry

Have a look at this item.
Should make interesting reading.

http://cgi.ebay.com/ws/eBayISAPI.dll?

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Hooroo.
Regards, Trevor
Grafton

The Gingery books are well regarded so this should be a good book