What do you think of the "Suction hose plug it D 27"?

[image132]

I wasn't sure where to put this.

I just want your opinions on what you think of this new suction hose with the plug it cable imbedded in it because I'm thinking of looking into it.

Has anyone got one, how have you found it, is it worth it?

Chris

 

[woodguy7]

Chris

I don't own one but i am sure i read somewhere that the suction is quite a bit less due to the cable being on the inside of the hose, thus making the diameter smaller.  But it is only what i read & could be totally wrong.

Woodguy.

 

[Rick Christopherson]

There won't be too many comments about the hose here because it is not available in North America. I do have one however, and I love it for the great convenience. I don't see there being too much of a reduction in suction because the vac already has such a high static pressure to begin with. If you can buy them in your country, then by all means I would recommend it. Oh, strike that without one caveat. The benefit of this hose is most pronounced when you are also using the boom arm on the vac.

 

[danrush]

The benefit of this hose is most pronounced when you are also using the boom arm on the vac.

Rick, are you talking suction, or just the hose/ cable tangle?

Dan

 

[AlexThePalex]

I don't own one but i am sure i read somewhere that the suction is quite a bit less due to the cable being on the inside of the hose, thus making the diameter smaller.  But it is only what i read & could be totally wrong.

I doubt it will make much difference. But your statement here made me curious, so let's do the math.

We want to know the percentage with what the cord reduces the surface of a cross cut of the hose. The formula for calculating the surface of a circle is surface = Pi x radius x radius.

The radius of the hose is it's diameter divided by two, thus 27 mm/2 = 13.5 mm.
So it's surface = Pi x 13.5 x 13.5

The radius of a Festool cord is it's diameter (roughly 7mm) divided by two, thus 7 mm/2 = 3.5 mm.
So it's surface = Pi x 3.5 x 3.5

Now the percentage of surface area that the cord takes away from the hose = cord surface / hose surface x 100%

> (Pi x 3.5 x 3.5) / (Pi x 13.5 x 13.5) x 100%  
= (3.5 x 3.5) / (13.5 x 13.5) x 100%
= 12.25 / 182.25 x 100%
= 7%

7 percent is not really a factor to be concerned about I think.

And ......

The way fluid dynamics works doesn't necessarily mean you get less suction when the size of the hole is reduced. When the motor of the vac replaces the same amount of air per time unit, it only means that with a slightly smaller hose the air will move faster through the hose but it's still the same volume.

Another thing to consider is the internal shape of the hose. It is ribbed and these ribs introduce an amount of turbulence in the hose which in turn negatively affects the airflow. Introducing a long straight cord into that stream might actually reduce the turbulence inside the hose a bit and thus affect the airflow positively.

But I mostly think the amount of influence is too small to matter.

 

[CO_JCD]

Chris

I don't own one but i am sure i read somewhere that the suction is quite a bit less due to the cable being on the inside of the hose, thus making the diameter smaller.  But it is only what i read & could be totally wrong.

Woodguy.

It is probably worth adding that the central section of the suction hose is actually larger than the end sections.  That is the end sections are indeed 27mm hose however the central section that actually has the cable running within it is something like 30mm.  So any reduction is largely, if not completely, compensated for by there being a larger diameter to start with where the actual cable runs - I will let Alex re-run his numbers for an exact figure.

What I will say is that whilst the convenience is great, unfortunately the weight and lower flexibility can be a downside for some applications (hence perhaps why Rick is recommending for use with the boom arm).  I tend to use combined hose when I know that I will be using several sanders & Dominio etc for one job and will need to change frequently - for just one tool usage, I tend to stick with the normal hose / separate cable as it is not worth the hassle of dealing with the heavier arrangement.

John

 

[image132]

Chris

I don't own one but i am sure i read somewhere that the suction is quite a bit less due to the cable being on the inside of the hose, thus making the diameter smaller.  But it is only what i read & could be totally wrong.

Woodguy.

It is probably worth adding that the central section of the suction hose is actually larger than the end sections.  That is the end sections are indeed 27mm hose however the central section that actually has the cable running within it is something like 30mm.  So any reduction is largely, if not completely, compensated for by there being a larger diameter to start with where the actual cable runs - I will let Alex re-run his numbers for an exact figure.

What I will say is that whilst the convenience is great, unfortunately the weight and lower flexibility can be a downside for some applications (hence perhaps why Rick is recommending for use with the boom arm).  I tend to use combined hose when I know that I will be using several sanders & Dominio etc for one job and will need to change frequently - for just one tool usage, I tend to stick with the normal hose / separate cable as it is not worth the hassle of dealing with the heavier arrangement.

John

I do not own a boom and I don't think I will because for my workshop it is impractical. I wanted to get it because often when I am working in my workshop I do have to often switch tools and it turns out in the end that I take most of their cables out of their boxes so I don't have them getting in the way when I put it back. This sadly leaves a big mess and rapping the cord around the hose only works for so long before it starts slipping down. I know thats a little silly but it would be nice having all their cables in their respective boxes so when I do work away from the shop I don't have to worry about whether or not the tool I grab has a cable in it or not.

Thanks for all the replies.

Chris

 

[Jonathanerrrm]

Hi Chris,

I use one attached to the boom arm and find it to be very convenient and well worth the investment. I sometimes use it for site work too as I have become used to having fewer cables around when I'm working and feel that they sometimes can get in the way. I agree with the previous comments though as it really comes into it's own when attached to the boom arm. I haven't noticed any loss of suction with the cabled version.
I share a workshop with a friend another Festool fan who is also very keen to get one after seeing the way I use mine, for the time being he tends to tape his plug it cables along the outside of his hose when working on site.

Jonathan

 

[jonny round boy]

Personally, I don't use one. Instead, I made my own with some braided sleeving and adhesive-lined heatshrink tubing. Cost a lot less...

 

[AlexThePalex]

It is probably worth adding that the central section of the suction hose is actually larger than the end sections.  That is the end sections are indeed 27mm hose however the central section that actually has the cable running within it is something like 30mm. 

I checked that, I measured it after removing the nozzle, and the inner diameter of the hose is exactly 27 mm.

 

[image132]

Hi Chris,

I use one attached to the boom arm and find it to be very convenient and well worth the investment. I sometimes use it for site work too as I have become used to having fewer cables around when I'm working and feel that they sometimes can get in the way. I agree with the previous comments though as it really comes into it's own when attached to the boom arm. I haven't noticed any loss of suction with the cabled version.
I share a workshop with a friend another Festool fan who is also very keen to get one after seeing the way I use mine, for the time being he tends to tape his plug it cables along the outside of his hose when working on site.

Jonathan

Thanks for the photo Jonathan. You have a nice setup there. I would kill to have that kind of space :/ Is that a box mount you were making in that photo?

I agree with Alex. I really don't think suction would change and depending on how much it costs I think I'll go for it. Thanks for all your quick replies and comments.

Chris

 

[Frank-Jan]

It is probably worth adding that the central section of the suction hose is actually larger than the end sections.  That is the end sections are indeed 27mm hose however the central section that actually has the cable running within it is something like 30mm. 

I checked that, I measured it after removing the nozzle, and the inner diameter of the hose is exactly 27 mm.

Alex, did you measure the inside diameter of a regular 27mm hose, or that of the central portion of the plug it hose?
Because the outside diameter of that piece of hose is noticeably larger (the part in between the two "collars" where the cord enters and exits the hose) I can't locate my calipers at the moment, but the part that appears to be 27 mm on the "27mm hose" (the black part in between the ridges), seems to be at least 30 mm like John said.

I recently bought a ctl26 and went for the special offer where you got the plugit hose with it (not for free, but at a discount).  I briefly tried the hose with my domino, but haven't used it much, it was too stiff for my liking, maybe I'll like it more when it's broken in. (I did use the CTL 26 quite a bit, but with a a spare 27mm hose that I normally use with other vacs)

 

[Jonathanerrrm]

Hi Chris,

No problem with the pic, I've uploaded some more of my new setup into my album in the gallery if you fancy a look. As for the frames they are just beech frames for a series of ebony veneered panels I've been working on for an exhibition.

I'm glad you are going to go for the hose, I don't think you will regret it. As for any weight issue perhaps you could add the wire hose holder attachment that lifts the hose up from the extractor. I'm not sure what the part number is but might be worth considering if the boom arm isn't an option.

Jonathan

 

[AlexThePalex]

It is probably worth adding that the central section of the suction hose is actually larger than the end sections.  That is the end sections are indeed 27mm hose however the central section that actually has the cable running within it is something like 30mm. 

I checked that, I measured it after removing the nozzle, and the inner diameter of the hose is exactly 27 mm.

Alex, did you measure the inside diameter of a regular 27mm hose, or that of the central portion of the plug it hose?
Because the outside diameter of that piece of hose is noticeably larger (the part in between the two "collars" where the cord enters and exits the hose) I can't locate my calipers at the moment, but the part that appears to be 27 mm on the "27mm hose" (the black part in between the ridges), seems to be at least 30 mm like John said.

Frank-Jan, I measured a normal 27mm hose. I didn't realise the plug-it cord had a wider mid section. John (CO_JCD) to whom I reacted also didn't mention this. And the first person I reacted to, woodguy, talked about less suction because of a smaller diameter. The plug-it cord still has two ends of the regular size, 27mm and if woodguy's theory was correct, those two ends would still work as a bottleneck. But my calculation was only intended to demonstrate it doesn't matter much, and in the most severe case of a normal 27mm hose fitted with a cord would only lose 7% of it's diameter. And 7% is almost negligible.

 

[moofie]

I have no direct experience with this product and I don't own a Festool dust extractor.  But I do know a little bit about fluid dynamics, and I wouldn't be so quick to dismiss 7% reduction in diameter as negligible.

Consider a biplane.  Upper wing, lower wing, fuselage, tail, landing gear...and the network of reinforcing wires between the wing.  Those tee-niny little wires contribute almost half of the drag on the airframe.

Now, we're talking an enclosed duct, and it may well be that Festool has done the math and formed the wire to minimize its impact on the airflow, but simply putting a cylindrical wire down the length of a vacuum cable might create a non-trivial reduction in airflow.  I'd start my off-the-cuff estimate by calling the reduction in airflow proportional to the twicethe reduction in cross-sectional area.

Now I kinda want to go buy a vacuum and experiment with it...
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Frank-Jan, I measured a normal 27mm hose. I didn't realise the plug-it cord had a wider mid section. John (CO_JCD) to whom I reacted also didn't mention this. And the first person I reacted to, woodguy, talked about less suction because of a smaller diameter. The plug-it cord still has two ends of the regular size, 27mm and if woodguy's theory was correct, those two ends would still work as a bottleneck. But my calculation was only intended to demonstrate it doesn't matter much, and in the most severe case of a normal 27mm hose fitted with a cord would only lose 7% of it's diameter. And 7% is almost negligible.

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