Changing motor on an Axminster Dust extractor

[jj74]

Hi All,
Does anyone have any experience changing the motor (upwards in power) on a dust extractor. I'm trying to avoid spending all that extra money on a new one as they're so dear! I have a .5kw old axminster jobby lying around and thought I'd try and put a 2.2kw motor on it and see what happens. The idea is to use it in conjunction with a large cyclone and fine filter cartridge for a very small workshop ducted system. I would also replace the current 100mm inlet with a 150mm. There is no 3 phase power where I am or I would possibly go down the 3 phase extractor route. The idea of a phase converter doesn't really appeal financially either.
This would be a bold new level of tinkering for me so if anyone has any advice it would be much appreciated. Things like you'll die and/or the fan won't be able to cope or any other comments are welcome. Maybe 2.2kw is too much?
The way I see it (mathematically only) is filter cartridge might cost £80 and the motor £140 so that's all in for £220 and new extractors with a lot less power (1.1kw) are like £400 -£500. How hard can it be to knock up your own????!!!!
Best, JJ

 

[Grahamshed]

you'll die and the fan won't be able to cope.



I have no idea but you would think it would work...... though......
You can get Camvacs in three different powers in the same containers but they do it bu having one, two or three motors...... but that may just be for flexibility.

Good luck.

 

[jj74]

3 motors huh?! That's the next level again and then some so I'm going to ignore it. Thanks though. Hadn't heard of camvacs - they look good, how much are they?

 

[carlb40]

I don't think it is as simple as that. Yes you will have a new? motor, but it will still have the same RPM. If you check the specs of various extractors you will also find the impeller increases in size too, and that is what gives you the extra suck.

So swapping a 1/2 hp motor for say a 3hp one will get you very little benefit apart from maybe less strain on the motor over time.

Camvacs are vacuum types, i find one vacuum extractor loud enough, not sure i could stand having 3 on the go. :shock:

 

[JustBen]

So swapping a 1/2 hp motor for say a 3hp one will get you very little benefit apart from maybe less strain on the motor over time.
:shock:

I thought that too.

Other than giving the motor an easier time, there would be no benefit unless it spun faster.

A bigger impeller is the way to go.
Or maybe the same size but shaped better to increase flow.

 

[Grahamshed]

Which is, perhaps, why camvacs etc have multiple motors rather than larger ones ?

 

[carlb40]

Which is, perhaps, why camvacs etc have multiple motors rather than larger ones ?

Different style of extractor altogether, vacuum types are usually better with smaller hoses. So to get more suck they add more motors.

Where as with the HVLP pressure types, increasing the impeller sizes is what increases the suck, without having to add extra motors.


Have a read of the Bill Penz article and he goes into a lot of detail about impellers etc.

 

[Grahamshed]

OP talks about an old 0.5hp dust extractor. He doesn't mention which type it is .... or have I misread something ?

 

[MMUK]

It's all very well saying fit a bigger impellor but you can only do so much before the motor says "smeg off, I'm not having this" and packs up. A tuned up or re-veined impellor of the same O/A diameter will do a much better job on a smaller motor than fitting a larger impellor designed for a bigger motor. You need to consider the forces put upon the shaft by a bigger impellor as well and any imbalance can cause premature failure.

 

[carlb40]

OP talks about an old 0.5hp dust extractor. He doesn't mention which type it is .... or have I misread something ?

Vacuum type extractors are normally sold / specc'd via wattage for the motors. Chip extractor types are normally measured in KW/ hp ratings.

By the way the OP has described his extractor i would think it's this one or one of the axi earlier types.

http://www.axminster.co.uk/axminster-ho ... -extractor

I guess it gets confusing when people just say dust extractor

 

[carlb40]

It's all very well saying fit a bigger impellor but you can only do so much before the motor says "smeg off, I'm not having this" and packs up. A tuned up or re-veined impellor of the same O/A diameter will do a much better job on a smaller motor than fitting a larger impellor designed for a bigger motor. You need to consider the forces put upon the shaft by a bigger impellor as well and any imbalance can cause premature failure.

I wasn't thinking of just adding a bigger impeller to that poor ickle motor. Just trying to explain a bigger impeller is what would give the improvement. But a new bigger motor would be needed anyway. So by the time you have sourced all that and made a housing for the bigger impeller, you might as well by one of the 2 or 3hp extractors

 

[Grahamshed]

OK, back in me box

 

[jj74]

Some good points there folks, glad I posted. It is an old axminster chip collector.

Maybe I should be thinking along the lines of changing the motor on a cheap 3 phase machine with a bigger impeller.

 

[MMUK]

Being perfectly honest, by the time you've sourced materials you'd be better off buying a new extractor that comes with a 2 or 3 year guarantee for similar cost.

 

[Eric The Viking]

A 'sorting bin', I mean a cyclone on the front end, ought to help a lot.

I've got a small Delta (think it's 3/4 or 1HP), the up-and-down bag sort. It struggles with the P/T on a 4" hose. I'm morally certain that much of this is the restriction caused by dust trapped in the cloth of the bags (it's old). The long term plan is a dustbin-type cyclone trap, and a new clean, replacement top bag.

I don't think you'll improve it with a bigger pipe, in fact it will make it worse. The issue is the speed at which air moves along the pipe - the faster it goes, the better the chips and dust stay in suspension and get carried along. If it's slower, they drop out in the pipe, and a clog will start at the first obstruction. A small motor/fan with a big pipe means slow air movement. The more you can reduce the obstructions, the better, and one of the huge advantages of a cyclone is that it shouldn't clog.

Mine has a big steel fan, inlet in the centre and outlet at the edge. I've removed the obstructions on the inlet (pressed steel metal grille with sharp edges). It didn't stop fingers in any case, and it was the most popular blockage point. Obviously this has safety issues if it's not for home use.

E.

 

[shed9]

Put this in context, new extractors of higher motor power can be bought for the approximate cost of the proposed filter and motor replacement.

I would ditch the current unit via Ebay, keep the hoses, anything useful, etc. Buy another extractor 1.5kW or higher, strip the motor / impeller housing, install it on a metal drum with a Thein baffle dropped into the drum and vent the output to outside.

The motor works less as the bulk of the waste goes into the drum before reaching the blades and the lack of need of a filter reduces the restriction on the air flow.....

....and Robert is very much your Fathers sibling...

 

[scholar]

I would save yourself the effort and look out for a used extractor that meets what you need.

I used to use a Record Power DX4000 (2x 1kw motors - LVHP) for all my machines and it coped with these fine, even the 320mm planer/thicknesser. The downside was it made a screaming racket and so I resolved to change it for a decent HVLP machine. Eventually I found a rather beat up Scheppach HA3200 on Gumtree or eBay, it cost me about £100 plus about another £100 for a few missing parts (mainly hose and bags) plus a good day's effort to overhaul it. It takes up a bit more space but is so much more relaxing to use. New would have cost about £900.

I have stuck with Scheppach for all my main machines, but there are of course others. Definitely get one with the fine filter.

There have been a number of these sold on eBay - this one today is typical - a bargain I would say http://www.ebay.co.uk/itm/Scheppach-HA- ... 1270665721

You don't need a cyclone with this type - it is pretty effective and you can reuse the bags - I'm still on my first one...

Cheers