Dust extractor issues

[loz]

Hi Guys,

Am i stupid, or missing something ?

I have a record rdse1 bin type extractor with 1000 mil tubing, this tubing i have jigged at the rear of my lathe bench so i can easy move along any project worked on,

Now i also have a bandsaw, with a ( looks like 2 inch ) dust port,

Now ! - what i thought was a good idea, was to run ( stolen from work ) 2 inch tubing from the bandsaw dust port, over the shop rafters, and ending nicely at the end of the 100 mil pipe,

i then turned a nice funnel type plug, which is secured to the end of the 2 inch pipe from the BS, this i popped into the end of the 100 mil pipe.

ok so - extractor - 100mil funnel/plug - 2inch - BS

Switched on the Dust extractor - and sucked its way up the 100mil pipe !, and it jumped up on top of my lathe bench, and tried to get over the lathe and over the rafters at my BS !!!!

:shock: :shock:

So,

How an i supposed to do this ?

I have simply made something like this - http://www.recordpower.co.uk/index....380&cat=194&sef=100/32 MM ADAPTOR C/W 2M HOSE


Why the hopping and jumping ??

Tahnsk

Loz

 

[Paul.J]

Loz.
Do you mean the funnel was sucked up the pipe :?

 

[loz]

Loz.
Do you mean the funnel was sucked up the pipe :?

No the funnel stayed wedged at the end of the 100 mil ( a 2 metre length ) .

The 100 mil tube compressed on itself and ended up 5 inches long like a closed concertina, and the dust extractor jumped up on my lathe bench,

im at a loss,

its like it didnt like to move from 100mil to 50 mil, and tried to eat the shed.

 

[Jenx]

Hiya Loz..

I too have got a bit lost in your description of what's actually occurred there... any chance of clarifying ?

As a Heating and vent engineer.. There's a half decent chance I can sort out your air movement problem for you hopefully. :wink: 8)

 

[Jenx]

Loz ... what size is the OUTLET on your machine ? ...

 

[loz]

Hiya Loz..

I too have got a bit lost in your description of what's actually occurred there... any chance of clarifying ?

As a Heating and vent engineer.. There's a half decent chance I can sort out your air movement problem for you hopefully. :wink: 8)

OK,

Rather than dust flowing gracefully from my BS to my Dust Extractor, the Extractor seemed to suck itself up , and ran at the BS.

god im crap at explaining !

 

[loz]

Loz ... what size is the OUTLET on your machine ? ...

the BS ? - its approx 50 mil

 

[loz]

ok - pic



number 1 is off
2 is on - and the extractor sucks up the flexi 100 mil pipe and tries to attack the shed,


im wondering if i need to split at the extracor maybe like in 3 ?

 

[Paul.J]

What i think as happened than Loz is that the tubing you have used as blocked the flow and just pulled the DE out.
You need to use something that is more rigid or stretch the tubing out and fix it at intervals so it stays open when the DE is switched on.
Is This the sort of thing you made.

 

[Jenx]

Loz, what I mean is the size of the outlet on your EXTRACTOR.

Where it exhausts the air. ( presumably filtered ).

 

[mikec]

Hi Loz,

I assume the Record dust extractor is a high pressure low volume type like my Record Dx800. The restriction of flow using a smaller diameter pipe causes the 100 mm pipe to collapse as there is a significant drop in pressure in the large pipe. To allow it to function normally you need a solid, substantial 100 mm pipe, or a long enough length of flexible 100 mm pipe so it can collapse without dragging the extractor around, or a splitter to run several small diameter pipes at once.

I have used option 2 when running a single smaller pipe, I just let it collapse into a shorter length.
I have a splitter box on my lathe with a 100mm connection from the extractor and two 60-70mm outlets as pickups on the lathe which does not collapse.

Hope this is not too confusing. :?

Regards,

Mike C

 

[DaveL]

So you have a long length of flexible pipe which concertinaed back to its shortest length! :twisted:

My recommendation would be to use a rigid pipe, I have used soil pipe in my system, two reasons, it does not move and the resistance to the air flow is less, hence amount of dust that can be picked goes up.

I have soil pipe that goes near to each machine and then link, via a blast gate to the machine dust port. 8)

 

[Jenx]

Reson for the question ... going by your sketch there ok, ...

When you trun the machine on .. the 100 flex is compressing yes ? ..

This is 100mm flex, that you have reduced to 50mm at the open end at your lathe, correct ? ( or bandsaw.. doesn't really matter which )...

This may help explain : --
If, as I'm suspecting, your extractor 'vents' through a port approximating 100mm ( the outlet on it )... you need to give it a similar sized INLET .. and the easiest way to get your head round this is to think in terms of, say a coke-can.

If you were to put a drinking straw into the empty ( but sealed ) coke can as your 'inlet' ... then have say a standard piece of garden hose as the outlet ( 1/2" bore ) ... then you yourself take the place of the fan, and "suck" through the larger bore of the hose... you cannot get enough air moving through the drinking straw inlet, in comparison to what you can suck through the hose, and thus the straw will collapse on itself.
... with me so far ? ..


If your machine comes with a 100mm inlet... ( by design the outlet will be balanced for this )... and you've restricted it to 50mm, and the more 'linear length' you give the 50mm section, the more you compund the problem... then that will explain why your flex has concertina'd.

Think of air as a liquid.. it , in terms of fluid dynamics is a liquid .. and it'll behave in much the same manner as water will do, through pipework.

The fan in the machine is designed to perform at a certain cubic meters per second volume , against a given resistance ( 0r 'pressure .. normally expressed i in "pascals", ) and the inlet / outlet dimensions are 'designed in' so as not to 'stall' the fan, or to ask it to perform 'beyond physics', which of course it cannot do.

Its trying to vent out of a far larger 'hole' than you have now restricted its inlet to... without changing the speed of the fan itself ... so its gonna object !

You follow that ok ?




( Note - the 'outlet' could be a bag filter type of affair ... but this is 'designed' to work in balance with the inlet, and the fan's performance curve. it needn't necessarily look like a 4" pipe, if you follow the logic ! )

 

[jpt]

HI

As others have said you need to run either solid pipe to the place where you attach the 50mm adaptor or run the 50mm pipe to the extractor and put the reducer on the extractor outlet.

These machines can work with only a 50mm inlet and Record theemselves say this you just need to adjust the piping.

john

 

[loz]

Eureka !

Ok so i'll replace my floppy pipework with rigid / soil pipe, and split at the extractor inlet. Run 100mil to the lathe as normal, and run 100 mil right up to the NS and then reduce ?

( assuming 100 mil right to the BS will give more suction ? )

I'll put blast gates ( yes i learnt some lingo today ! ) at the splitter also so i can block the BS pipe when not in use.

Thenks Jenx, top explainer !!!! - now that Golden Dimensions thingy ???

Mikec - i'd love to see your setup if you have pics ?

Cheers JPT - i was gonna mail Record Power just in case, dont wanna break the thing !


Loz

 

[Doug B]

Loz.
If you don`t want to go to the expense of soil pipe, i did my high pressure extraction using rainwater pipe (65mm), & made my own blast gates out of perspex & mdf.
I don`t know how to post a link to my workshop tour, but if you want to see photos of the pipework (shown in the first 4 photos), look in the workshop tour section, my tour is on the second page now entitled "one more workshop tour".
It was very easy to make & very inexpensive, hope this is of some use.

 

[mikec]

Hi Loz

I'll try and get some photos tonight

Regards,

Mikec

 

[loz]

Doug - Your workshop is WOW ! - Thanks for the link, helps a lot.

Mikec - Much appreciated - just of the splitter box if possible.


Cheers

Laurence

 

[boysie39]

Hiya Loz. I have one of the Record Power RSd5000 dust thingamigs. I got one of those 100mm vee pieces and and put it into the section of the pipe that comes out of the extractor which allowes me to attach two other sections to the end of the hose and attach anywhere I wish.
the only time I get a suction problem is when I'm hoovering up and if not careful it will catch square on the floor and then I get some wrestling practice. I also bought a couple of 100mm caps that I can out onto the end or ends of which ever pipe I'm not useing. Regards Boysie

 

[loz]

Hi Boysie,

That 5000 bin is super, I'm going to get a vee splitter also but put it at the bin inlet.

LOL @ wrestling practice, I nearly ran out the shed when mine attacked me !

Loz