Thread: Questions about a second hand set up.

Thanks Pete and Bob . looks like going cheaper larger steel may not be the way then . Its just going to be a less efficient slower air flow in the main line then.

I just drew this up as a way of visually getting my head around it . The pipes seem only slightly larger but the cm2 is a big jump with the 300 .

IMG_7075.jpg

Originally Posted by BobL

BTW 9" PVC is not 225mm - instead its closer to 240mm ID which while not that different to 300 mm but it will still be significant in terms of air speed.

Yeah thanks Bob your right . That was a surprise. I just rang and checked with the local Tradelink .

225 stormwater PVC is 250 OD and 240mm ID ! Thats pretty misleading !

This cyclone of mine has a round intake aperture of 200 mm diameter which is 314cm2. And a rectangular exit 180 x 295 which is 531cm2 .

Are these things designed with smaller a diameter on the intake and larger on exit for a reason ?

Would it be better if the intake was more closely matched to the exit size ?

Ive now got two options .

I can buy new metal spiral duct product which comes in 200 id to match my intake for the main line . Option 1

Or I can go with the 225 PVC with the 240mm ID and alter the intake of the cyclone to match that. Option 2


IMG_7087a.jpg

option 1 is 314cm2 intake to 531cm2 exit
option 2 is 452cm2 intake to 531cm2 exit

The area of the intake line on option 2 is over 25% larger , incredibly ! And still under the exit size.

This is a good thing isn't it ? Its speeding up the intake and not slowing
it as the 300 D main line I spoke of earlier was going to do ?

Edit. I didn't ask the Spiral Duct company but they may even sell a 250 ID which works out at 490cm2

Originally Posted by auscab

This cyclone of mine has a round intake aperture of 200 mm diameter which is 314cm2. And a rectangular exit 180 x 295 which is 531cm2 .
Are these things designed with smaller a diameter on the intake and larger on exit for a reason ?
Would it be better if the intake was more closely matched to the exit size ?

Doesn't really matter as long as the outlet is not smaller than the inlet.

Ive now got two options .
I can buy new metal spiral duct product which comes in 200 id to match my intake for the main line . Option 1
Or I can go with the 225 PVC with the 240mm ID and alter the intake of the cyclone to match that. Option 2

I wouldn't mess with the intake diam as you might upset the separation efficiency.

Originally Posted by auscab

...A factory worth of similar size machines to me with metal Gal main line at 300mm and 150mm and 100mm branches joining into it has become available to me.

15 meters of 300 mm and 50 meters of 100 and 150 with enough branches for all my machines and floor dust sweep gates . Some larger duct as well . And its cheap! Compared to the PVC ...

Originally Posted by auscab

...Ive now got two options .

I can buy new metal spiral duct product which comes in 200 id to match my intake for the main line . Option 1

Or I can go with the 225 PVC with the 240mm ID and alter the intake of the cyclone to match that. Option 2...

Maybe take the factory lot of steel duct and ditch the 300dia. section. That leaves you with 50 metres of 150 & 100 duct.

Buy the new 200 metal spiral duct for the main trunk. Use the second-hand 150 and 100 for branches and connections to individual machines.

My tuppence worth.

Cheers, Vann.

Originally Posted by Vann

Maybe take the factory lot of steel duct and ditch the 300dia. section. That leaves you with 50 metres of 150 & 100 duct.

Buy the new 200 metal spiral duct for the main trunk. Use the second-hand 150 and 100 for branches and connections to individual machines.

My tuppence worth.

Cheers, Vann.

I have considered that but the price wasn't going to be any different, and with the time to go get it plus the price, it works out that just buying new was a better deal.

Also , Its 2.5 hours away from me . And Ive been getting more accurate updates and some great videos sent by a good woodwork Mate who has been visiting the site regularly . What I first thought was 300 main line is something more like 450mm from the fan , Its not measured just a visual guess.
It starts at roughly 450 and drops to 350 300 250 and then 200 main line. The 200 is pretty short.
And about 14 or 15 branches coming off it . With a couple of nice old Gal floor sweep parts as well going up 150 pipe up the walls.
So just the branches are not worth the effort I decided.

But there may be one last ditch idea that Ive been discussing today with said Mate.
Ill know more about that Monday .

It would mean using the whole system, from the other end of My workshop and trying to find a use for what Ive already installed .
Which has SWMBO telling me off !! Sounds great to Me and Mate .

I have ideas of one day moving the wood turning lathes out under a semi enclosed lean to up the west end where the already installed cyclone is . So that the wind blows through . I had that at the old workshop . I loved Semi outdoor wood turning with a strong fan nearby .
That installed cyclone could also suck at the lathes , the three of them . One of them , the big faceplate lathe needs good extraction at the cutting contraption I made for it . It machines MDF and creates a huge amount of the worst type of wood dust Known to Man I think . So that first cyclone would fix that problem right up. There is a good use for it . There's a lot of other stuff to do first though .

Rob

Rob, have you resolved your collection drum sizes yet? I installed a cyclone into a commercial situation a while ago and the biggest issue is the 200 litre drum is nowhere near big enough and can need changing after using the straight blade thicknesser on one job. If it is not changed then the cyclone backs up and spits shavings out of the exhaust. You can get an air tight lock that would enable dumping into a trailer, I have never seen one and don't know anything about them apart from they exist for larger commercial systems. To overcome the problem on the one installed we are going to put a Y in the drop and use two drums and see how that goes. It might not be a perfect solution but if one drum fills before the other which I think is absolutely guaranteed then when that drum backs up it will all fall into the the other drum. If I am really lucky it might work really well but time will tell on that.

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I was going to either weld 2 x 200 liter drums together as high as I could go Chris .

Or go Larger and weld up a square frame , rivet Ply that's well caulked and sealed to it and put 4 wheels on the bottom .

Since I raised the unit there is something like 7 to 8 Feet of space under the outlet . Its just a matter of "Can I handle such a container full of sawdust ? "

IMG_7124.jpg

Then there is the problem of how would I know its full ?
We used to use a 200 liter drum at the old workshop . It was a drop box with plenum box after (right name ?) with multiple filter socks hanging . 150mm main line and a small Richardson cast iron blower .
A bit of a dangerous blower because of the internal bearings . Thankfully they never had a meltdown .
Anyway we got quite used to judging when to go check the drum . As long as you checked and knew what you were starting off with . Bit of a Pain really though .

I was just thinking yesterday if its possible to use a pad that works like a set of scales . That is a weighing scale but with a remote display . I was wondering if it was possible to have a display showing the weight of the dust container or the dust in the container. Set it to zero at empty and watch it grow as machining is being done .

Bob, naturally, has played with bin load sensors. "Saw dust bin full" Sensor He may have more to add.

Look into pelletizing / briquetting machines. It compresses the sawdust into pellets or briquettes that can, if of clean material, be burned for heat or barbecuing/smoking. If disposing of the waste, reduces the volume. There are lots on Alibaba and the like in all sizes. There was a small one locally on FB here for making feed pellets for well under a grand. You could either dump the waste into a hopper and run until done or use the airlock Chris suggested, possibly using a grain auger to fill a hopper.

Pete

Originally Posted by QC Inspector

Bob, naturally, has played with bin load sensors. "Saw dust bin full" Sensor He may have more to add.

It worked OK at home but I never got it to work at the mens shed because the VFD upset the electronics. Have since worked out how to fix it but the last thing I need are more projects.

Originally Posted by BobL

It worked OK at home but I never got it to work at the mens shed because the VFD upset the electronics. Have since worked out how to fix it but the last thing I need are more projects.

Originally Posted by auscab

What I first thought was 300 main line is something more like 450mm from the fan , Its not measured just a visual guess.
It starts at roughly 450 and drops to 350 300 250 and then 200 main line. The 200 is pretty short.
And about 14 or 15 branches coming off it . With a couple of nice old Gal floor sweep parts as well going up 150 pipe up the walls.
So just the branches are not worth the effort I decided.

I've looked at several "used galv systems". The first one sounds a lot like yours, 450mm main going on down. There was heaps of it, enough long ducting that it would have required a 20ft long truck to carry it all. It had been advertised on/off gumtree for a couple of years starting at about $400 - prices dropped until it was advertised as "a couple of cartons - must take the lot" I went to look at it twice (second time with a truck) but there was just too much of it.

The second one was an entire DC system (DC, loads of ducting, blast gates and several floor sweeps), from a 1960's High School wood working class room that we stumbled across on one of our mens shed scavenging expedition - we went there mainly looking for scrap wood and metal. On first look, apart from only 4" drop downs to all machines, it looked like a goer, well at least the 9" trunk, 6" sub trunks bits. We got it all back to the shed on a 10ft flatbed trailer (borrowed from the school) and it sat there for several months while I payed jigsaw puzzles with it. In the end we decided that adapting it to suit our setup was going to be too much work and went for PVC. We sold the galv system to another mens shed for $100.

With regard to the drum container being too small, in one of our workshops years ago the old man sewed up two enormous socks from calico type cloth and mounted the outlet section of the dust collector up on the wall about 12 feet up from the top of two 44 gallon drums, then used the two big socks to connect the two. Usual metal strap arrangements to seal them. When we were only doing tablesaw stuff the drums got emptied each week or whatever. Then when there was serious wood machining happening, the drums and socks filled up with shavings and it was a simple matter of backing the ute up and taking the socks off the drums and directing the waste into the tray of the ute, easy. Then cover and take them to the happy people at the horse stud or the piggery. It worked pretty well.

Originally Posted by BobL

I've looked at several "used galv systems". The first one sounds a lot like yours, 450mm main going on down. There was heaps of it, enough long ducting that it would have required a 20ft long truck to carry it all. It had been advertised on/off gumtree for a couple of years starting at about $400 - prices dropped until it was advertised as "a couple of cartons - must take the lot" I went to look at it twice (second time with a truck) but there was just too much of it.

The second one was an entire DC system (DC, loads of ducting, blast gates and several floor sweeps), from a 1960's High School wood working class room that we stumbled across on one of our mens shed scavenging expedition - we went there mainly looking for scrap wood and metal. On first look, apart from only 4" drop downs to all machines, it looked like a goer, well at least the 9" trunk, 6" sub trunks bits. We got it all back to the shed on a 10ft flatbed trailer (borrowed from the school) and it sat there for several months while I payed jigsaw puzzles with it. In the end we decided that adapting it to suit our setup was going to be too much work and went for PVC. We sold the galv system to another mens shed for $100.

Thanks Bob . I think the cheap aspect is affecting my judgement on this . I like to live with an idea and think it right through . The 450 mm set up and huge fan is a lot of system and a long way away and then every branch is in the wrong place so 15 Patches And a lot more repairs as well probably .


With my set up cyclone .
Ive got to do more accurate plans before I order anything , and a few more position adjustments of machines.

This is a rough sketch of my lay out .

If I were going with 225 PVC then the 240 ID would have to be matched to the inlet . Enlarge the inlet .

So If I go Metal Spiral duct rather than just connect the spiral duct at 200 I could do what Id have to do with PVC and
start with a 4M run of 250 at inlet and then step it down to 4 M of 225 then 4M or 6M of 200 and finish with 150 .

150 Branches all the way except near top right where a 225 or 250 branch connects the tenoner on the right.

The other big dust producers are on the right as well . They are conecting in at the 225 part of main line . Down from tenoner is two table saws Rectangular buzzer with a bandsaw next to it and final on right of main line is the thicknesser .

Everything on the left from bottom up is two lathes , three RAS Two connected I think . Spindle moulders, router table, Band saw and chisel mortisers . with some low dust producers on the top wall .

IMG_7137.jpg IMG_7138a.jpg

That would be a better thing than 225 PVC all the way with 150 Branches except on tenoner wouldn't it ?

I don't know how the stepping down of a main line helps things but it looks like its always done on industrial set ups .
Its got to be a good thing ?



Rob

Originally Posted by auscab

If I were going with 225 PVC then the 240 ID would have to be matched to the inlet . Enlarge the inlet .

Increasing inlet size may affect cyclone separation efficiency. Also it is the primary choke point which contributes to determining the max amount of air the impeller can pull. If you do enlarge it make sure you measure the motor current to make sure you are not overloading the motor. Unlike a Table saw, where the motor is loaded in short bursts a small overcurrent does not damage the motor but a small overcurrent over a long period on a DC (constantly loaded) can easily damage the motor.

[QUOTE]So If I go Metal Spiral duct rather than just connect the spiral duct at 200 I could do what Id have to do with PVC and
start with a 4M run of 250 at inlet and then step it down to 4 M of 225 then 4M or 6M of 200 and finish with 150 .

That would be a better thing than 225 PVC all the way with 150 Branches except on tenoner wouldn't it ? [/quote
The step between 200 and 225 is pretty marginal in most situations I wouldn't bother about it.
I don't know how the stepping down of a main line helps things but it looks like its always done on industrial set ups .
Its got to be a good thing ?

Stepped down trunkline sizes are needed to maintain the recommended 4000 FPM especially when there are multiple users constantly using large machines that generate large amounts of dust up and down the line. However, when there are only 1-2 intermittent users it makes little difference and just generates more work in setting up. In a medium/small shed, where machines use 150mm ports and there is only one user then there is no need for any steps and 150mm can be used all the way from machine to impeller.

Fine gradation step down/up trunklines are not possiblewith PVC because there are fewer duct and fitting sizes.
Lets say you want a stepped PVC trunk ie 450, 300, 225(240), 200, 150 and you want to install machine connections at all sections long the trunk. Well, there are no PVC duct or fittings for 450 and 200 mm sizes.

For 24" sanders and large thicknessers I'd be looking for 2 x 150 mm connections.

Not sure about the nature/use of your workshop.
How many full time users, how many hours a week, how many cubes of timber a week, and what fraction of timber is being resawn/thicknessed etc? My assessment of the air flow requirements of most mens sheds, even with 20+ users, don't need large industrial stepped systems especially when mot of teh time the are just making/repairing/turning the odd piece of furniture, kitchen utensils, toys etc.