Thread: < $1500 cyclone

Originally Posted by Stanger

Anyone know of a system that would get up near 1000 cfm for less that $1500?

Mike

How about these? http://www.machines4u.com.au/view/ad...200-cfm/35661/ http://www.machines4u.com.au/view/ad...ackage/205873/
Don't know what cfm you'll actually get at the machine.

10m is a bloody long way, I don't think any single phase unit would be able to move enough air to make it.

Why 10m from workshop?
It only has to be outside a workshop on a wall opposite the major opening to the shed.
Have you got a 15A GPO?

A requirement for a DC that incorporates a cyclone should be secondary to the requirement for a system that generates max air flow.

Unless the cyclone is well designed and incorporates a large blower it will make things worse by generating too high a back pressure reducing the flow before you even start collecting dust.
That's what BPs cyclone is all about and why most other cyclones are best avoided.
BPs examination of smaller and old design cyclones and chip collectors demonstrated they reduced their potential flow by as much as 50%.
In contrast BPs cyclone reduces the flow by around 5%

However, to get ~1000cfm in a small shed you don't need a BP cyclone as most 3HP DCs (e.g. the DC7) will pull more than 1000 CFM
PROVIDED
6" ducting is used all the way to a machine
Ducting is not too long
For machines like Bandsaws 3 x 4" ducts are needed to be equivalent to 1 x 6" duct
The machines are dethrottled i.e. the air flow paths are opened up, this may necessitate putting holes in machine cabinets.

BTW the same 3 points above apply to a BP cyclone anyway. Connecting a BP cyclone to a machine via a single 4" duct will still only draw 400 cfm.

Adding a standard cyclone to a DC7 will reduce its flow to less than 1000 CFM but of course has the advantage of not needing filter bags.
Ultimately it's up to you - if you feel on the lazy side use a cyclone and live with ~7-800 cfm - if you want max air flow be prepared to clean the bags regularly.
If you want more flow and less filter bag cleaning you could look at pleated filters.

The Cyclone plans on Bill Pentz' site are not that difficult to make up. I cut mine out, then took it to a sheet metal worker for rolling and spot welding and then did the final assembly myself. I used polyurethane seam sealer rather than soldering. The whole thing, with a S/H fan was under $200. Once you have the cyclone running the ducting and sorting out the machine ports is the largest and most expensive part of the job. I found the whole thing a very interesting job.

Regards

Ian

This cyclone looks very similar to my friend's 2hp "other brand" cyclone. If it has the same performance it is inadequate to be much more than a chip collector. What we find is that the ratio between cone length and impeller housing diameter is wrong so that there is very poor separation between chips and dust. The bag beneath the filter fills up almost as quickly as the waste barrel. 2hp is definitely not enough to work a system like this and his whole system is only 10 metres from cyclone to the furthest machine, so your distance of 10 metres to your shop before you start the machine ducting will be totally inadequate and a waste of money.

Perhaps the best bet would be to set up a 3hp bag system and site it closer to your workshop if possible. Follow BobL's example because he seems very happy with with his gear.

Thanks for the suggestions and replies.

Would locating the cyclone and blower in the corner of the workshop and then running 10m of discharge pipe (6" or larger) to atmosphere be better than adding 10m on the inlet side of the blower? I.e. Does it make a difference if the 10m is on the inlet or outlet of the compressor?

One more question, if I go for a 3hp blower will I need to get a 15A GPO installed?

At the moment I am leaning towards making a BP cyclone and buying a 3hp (DC7?) blower. I will probably make a sound enclosure for the unit as well. Anyone know what sort of dB to expect from a unit like this with no sound proofing?

Mike

I still don't get why you need to send it 10m away

Stanger,

Welcome to the Forum .....

You'll notice that in the responses to your initial post, there are a few responses where people say that they don't understand your requirement that the dust collector be "10 meters from workshop". I also can't understand the reason for that requirement. So that people can better understand your requirements, and then be able to provide pertinent advice, I'd suggest that some photographs, or maybe a sketch plan, would help explain the constraints that you're working under with regard to the "10 meters".

One thing that forum members soon work out when they join the forum, is that when posting on almost any subject -- a photograph (or a sketch, diagram, etc) is worth a thousand words. Post a couple of photos, or maybe a sketched plan would be clearer - it's up to you. You don't need a scanner to post a sketched plan - just draw up the sketch on paper and photograph it. You'll find forum members to be very helpful and willing to contribute, but in order to answer your questions well, they need to fully understand your requirements.

Anyway - that's my ten cents worth.

Regards,

RoyG

Originally Posted by Stanger

Thanks for the suggestions and replies.

Would locating the cyclone and blower in the corner of the workshop and then running 10m of discharge pipe (6" or larger) to atmosphere be better than adding 10m on the inlet side of the blower? I.e. Does it make a difference if the 10m is on the inlet or outlet of the compressor?

I don't know why you feel you need to move the outlet 10 m away. 10 m of 6" ducting will cost about $100 and drop you air flow by around 15%.
If it is because you shed is not air tight on that side of the shed them I would just make it so.

One more question, if I go for a 3hp blower will I need to get a 15A GPO installed?

Most likely perhaps others can comment if they know of a 3HP DC that does not use a 15A GPO.
If you only have a 10A line running to the shed you will need more than just a dedicated 15A GPO but a new line run to your shed.

At the moment I am leaning towards making a BP cyclone and buying a 3hp (DC7?) blower. I will probably make a sound enclosure for the unit as well. Anyone know what sort of dB to expect from a unit like this with no sound proofing?

The BP design is specifically for a 4 or 5HP motor and so the design will need to be scaled (I believe its bigger) to get the efficiency but it will NOT be was efficient as the bigger unit.

The 10m is just a location problem where my workshop is located to allow venting to atmosphere. I didn't think the losses associated with running 10m of 6" pipe would be a show stopper.

Anyway I am prepared to sacrifice 15% losses to get the vent to a location I am happy with at my house.

So if I fabricate a scaled down BP cyclone and purchase a 3hp blower and get a 15A GPO installed does this sound like a "reasonable" solution? I know it won't be perfect, but neither is my woodworking

Would you put a 10m suction line to the cyclone or a 10m discharge from the cyclone or does it make no difference?

My 3hp dc7 from H&F is run from a 10amp point (it comes with a 10amp plug but the guy at the shop said I MUST NOT run it from an extension lead). I have 2 x 10amp circuits in the house plus a couple more for the lights, the circuit that the dusty is on actually runs the majority of my house, incl. the kitchen (not oven). I dont have anything drawing power while running the dusty except for things on standby like the dvd player, TV, microwave, phone and tablet chargers.

Basically my garage is run with 2 power points. one 10amp for the dusty or anything else while the dusty isn't switched on such as orbital sander and shop vac and a single 15amp point. If i need the dusty AND a powertool to running at the same time, such as 3 1/4hp router on router table, i plug the router into my 15amp point.

I have everything connected via extension leads (2.5mm^2 cable). Hasn't burnt the house down yet. My plan is to sell up and move and build a new house soon which is why I am taking the risk, otherwise I would just pay the 500-800bux to get another 15amp point inside the garage.

Originally Posted by Stanger

The 10m is just a location problem where my workshop is located to allow venting to atmosphere. I didn't think the losses associated with running 10m of 6" pipe would be a show stopper.

Anyway I am prepared to sacrifice 15% losses to get the vent to a location I am happy with at my house.

So if I fabricate a scaled down BP cyclone and purchase a 3hp blower and get a 15A GPO installed does this sound like a "reasonable" solution? I know it won't be perfect, but neither is my woodworking

Would you put a 10m suction line to the cyclone or a 10m discharge from the cyclone or does it make no difference?

Hi Stranger.

If you need to run a 10m line, I'd suggest having it on the outlet side but increase the pipe size to 200mm. Going from 150mm to 200mm is about twice the pipe cross section so air velocity will be halved, considerably reducing the pipe frictional loss. Unless you have a large fan, you couldn't do this on the inlet side as there will not be enough airflow to carry the wood chips.

if you are building a Pentz cyclone, scaling it down for a smaller fan will only make matters worse as smaller means greater internal friction for a cyclone.

I've had good results with a full size cyclone with a 2HP fan, although with another 10m of pipe, I'd think 3HP would be a bare minimum. If you search my posts, you can find details of my setup.

Cheers, Tim

Originally Posted by Stanger

The 10m is just a location problem where my workshop is located to allow venting to atmosphere. I didn't think the losses associated with running 10m of 6" pipe would be a show stopper.

Anyway I am prepared to sacrifice 15% losses to get the vent to a location I am happy with at my house.

Does this mean you workshop is under the house or you need to position it to suit SWMBO?

With a 3HP blower you "need absolutely every % of air flow you can get".

The 15% loss is for 6" ducting BUT it does not have to be 6", it can be as big as the blower outlet. For example a blower with an 8" outlet would lose about 8%, 10" would lose about 6% and 12" would lose ~2%. Normally I would not advocate this as the sawdust would fall out of suspension but if you have already done this then this is not a problem. This answers your question about where to locate the DC. This ducting does not need to be made out of PVC pipe (which at large diameters will be very ex.) - it could be MDF if it was out of the weather. However it does rely on having a blower with a large exit . If the blower does not have a large exit then you are back at square one. for example the DC7 has a relatively small exit.

Heres my analysis of the situation

6" ducting inside the shed limits the flow rate to 1250 CFM - there is NOTHING that can be done to improve that unless you go to bigger pipe.
10 m external run means losing 15%
The scaled down BP cyclone won't be as efficient so I guess 10% loss for that
Overall losses are 25%

This means you are starting out with 75% of 1250 cfm = 937 cfm.

Then subtract Internal ducting and machine inefficiencies and I reckon you will be operating in the 700 to 800 CFM

My current plan is to buy one of these h&f Cyclones ($350) and pick up a second hand dc7 (if I can find one) and mount it directly on the top of the cyclone. I will run the exhaust from the blower approx. 10m to outside using a large duct of some sort. I may build a bp cyclone in the future to replace the h&f one.

Any thoughts on this idea?

Originally Posted by Stanger

My current plan is to buy one of these h&f Cyclones ($350) and pick up a second hand dc7 (if I can find one) and mount it directly on the top of the cyclone. I will run the exhaust from the blower approx. 10m to outside using a large duct of some sort. I may build a bp cyclone in the future to replace the h&f one.

Any thoughts on this idea?

Save the $350 and run the DC 7 by itself, you will get more airflow by running the DC7 by itself and there's no mucking around.