CT36 Dust Extractor side clearance?

[prjones]

Does anybody know the specs on the side clearance requirements (for airflow) for the CT36? I'm looking to install it in a cabinet and am wondering how close the cabinet sides can be to the unit. Thanks!

 

[Coen]

It's not only airflow but also cooling.

 

[semenza]

Some annecdotal info. ------------------

      I once had a CT Mini (old style) in a "cabinet".  It had about 2" clearance on the sides but the front and back of the cabinet were 100% open.  After a long run one day it overheated. Probably summer at about 80 degress F air temp and  long sanding session. The vac recovered just fine but it did shut down. It was pretty warm / hot on the vac sides.

      For short runs probably OK in a closed cabinet. But i would want to add a cabinet fan if I put one in a cabinet again.

Seth

 

[mino]

Some annecdotal info. ------------------

      I once had a CT Mini (old style) in a "cabinet".  It had about 2" clearance on the sides but the front and back of the cabinet were 100% open.  After a long run one day it overheated. Probably summer at about 80 degress F air temp and  long sanding session. The vac recovered just fine but it did shut down. It was pretty warm / hot on the vac sides.

      For short runs probably OK in a closed cabinet. But i would want to add a cabinet fan if I put one in a cabinet again.

Seth

CT 26/36/48 series have a different (better) vent arrangment. The cooling vent for the motor is at the back while the intake is at the front. Yhis means the motor always gets fresh air as long as *both* the top and the sides are not blocked. Either the vac needs sides completely free, which is ideal, or*) the top needs to be reasonably free.

*) Having the sides with even 6" free space but no free space on the top is WORSE than having the sides restricted but a lot od free space above the vac. This is because hot air will naturally want to go UP while even a 600 mm wide cabinet will get "filled" with the hot air coming out of the side wents and the front-facing motor cooling intage will keep sucking that hot air in a loop.

@ OP
On the sides, you need very little space. BUT. Per above, if restricting the sides in any way,  do make sure there is a way for the hot air to escape *without* the vac being forced to suck up its own hot air for motor cooling.

I had my CT 36 in a 410 mm (internal width, external 450 mm) cabinet and it was fine as there was about 200 mm (8") free space above the garage so the hot air could easily escape that way. This worked well as it also allowed to place accessories in the garane and be able to easily access them.

Per above, keeping some space above the vac, when the sides are restricted, is more important than having the back exhaust free. The issue is not where the motor-cooling air escapes as the is not that much air involved, the most heat is created in the turbine, so we need to prevetnt the vac sucking its own hot air that is going out of the side vents. And that needs -either- free sides or sufficient space above the vac for natural convection to do its thing.

If you are space restricted, what can help is to add vertical "stiles" as high as the CT which will limit the ammount of hot aire released from the sides inside the cabinet to get to the front motor (and electronics) cooling intake. Making an opening about 370 mm wide, just enough for the vac to fit through, and having a wider chamber, say 430 mm wide behind, with the "opening" inset about 100 mm behind the front of the vac should do wonders. It will foce most of the hot air to escape via the top of the cabinet, preventing it to be sucked-in by the electronics/motor cooling intake.

Easy way to check is to run the vac with a sander or other flow-restricting tool attached at full power for like 10 minutes and then observe where the hot air is going.
If the front air intage grille on the top of the vac is cold /the hot air existing the vac is not being sucked in there/ then you are good for the most part.

Hope helps.

 

[prjones]

[member=61254]mino[/member] This is VERY helpful information, thank you! Here's a 3D drawing of the cabinet design - the blue translucent rectangle represents to CT36 dimensions to scale. The opening for the cabinet L to R is 622mm, and there's about 90mm clearance on top. Back and front are completely open (minus space for two stretchers in the back). Do you think this design would work?

[attachimg=1]

 

[mino]

I think it should be fine, but it would really be better to have an open-top for the vac. That would incidentally fit in your design. Me thinks.

Something like attached:

 

[prjones]

[member=61254]mino[/member]

What if I left the cabinet top as-is for structural integrity, and routed perforations or long "slits" in the top on the CT36 side? The goal is to let the heat escape, would that do it?

 

[mino]

[member=61254]mino[/member]

What if I left the cabinet top as-is for structural integrity, and routed perforations or long "slits" in the top on the CT36 side? The goal is to let the heat escape, would that do it?

Yep, that was just a very quick sketch to show a placement idea/concept.

If I was doing it, I may actually put a bottom board providing structural strength and make it so the board fitr between the whels of the vac. 20 ways of doing it ...

Point was that worry more about space above the vac - which is also useful to leverage the garage for accessories storage -  as compared to around it.

 

[prjones]

[member=61254]mino[/member]

Thanks so much for the technical information and ideas, here's what I finally came up with:

[attachimg=1]

I drew 20mm dog holes in the cabinet top for ventilation, and because I'm a super-nerd and wanted to learn new skills in Fusion. Looking forward to making it reality!

 

[mino]

Just skip the holes, stuff would be falling through ...

With the 600 mm width you will be fine anyway. I was suggesting other way to better use the space mainly.

 

[squall_line]

Just skip the holes, stuff would be falling through ...

This was my first reaction.  And even though it was already posted, I felt the need to reinforce the message; having a second level with holes will just have you chasing sawdust, pencils, fasteners, and other things through both sets of holes.

 

[Cheese]

If you are space restricted, what can help is to add vertical "stiles" as high as the CT which will limit the amount of hot air released from the sides inside the cabinet to get to the front motor (and electronics) cooling intake. Making an opening about 370 mm wide, just enough for the vac to fit through, and having a wider chamber, say 430 mm wide behind, with the "opening" inset about 100 mm behind the front of the vac should do wonders. It will force most of the hot air to escape via the top of the cabinet, preventing it to be sucked-in by the electronics/motor cooling intake.

Mino has some good ideas here.  [smile]

The vertical stiles in this case becomes a pair of chimneys on each side of the CT that allow for the evacuation of hot air while eliminating the mixing of exhaust air and intake air. It's the same way you install the outside venting for a furnace. The intake vent and exhaust vent are in 2 different locations and the openings are turned 180º to each other.

If this were my project I'd also eliminate all of the dog holes. Stuff will just fall through them and you'll have to remove the CT from the box to reclaim all of the lost items...a real PITA.

Each chimney exhaust would end at the lower level of the box cover and the opening would be covered with some stiff wire cloth that would have 1/4" square openings, the type of material you install to prevent mice from getting into a closed area. Wire cloth constructed with .025" wire and with 1/4" square openings should yield a 80% to 85% open area. The 1/4" openings will prevent the majority of items from falling through while allowing adequate exhaust ventilation.

 

[Crazyraceguy]

Mine's a CT26, not 36, but close enough to be a fair comparison. It is in a cabinet that is 18" wide (inside) which leaves a few inches on each side, totally open front and back. I have had this thing running, for multiple hours at a time, connected to the router table, and never had a heat issue.