No CT wings for me, I guess

[Stone Message]

I have a Numatic NDD 900 which has a safety circuit that first warns when the motor is working too hard and then shuts the machine down. Not many extractors will have that sort of protection and so I would not risk it.

Peter

 

[rst]

i make pattern routed plastics parts, hundreds at at time.  I used a cheap Sears shop vac and the intake on make air compressor for years, sometimes 6-8 hours a day with self made jigs...never burnt one up.  I finally got serious and bought a surplus vac pump.  These are smooth parts so there is serious suction, It may be that for job site use more volume may be needed for leakage.

 

[bror]

Maybe Peter Halle can shed a little light on this,

[attachimg=1]

from: http://festoolownersgroup.com/festool-tool-reviews/gary-katz-reviews-the-ct-wings/

He appears to know some one who knows all about it.

His statement got me thinking in the first place, btw thanks for that Peter.

Don't know about the construction of the CT 26 and family, but I replaced the motor of my old Festo SR151-AS once. (wasn't it originally a WAP?) It had a seperate fan on the back of the motor for cooling.

[attachimg=2]

But still; you can hear the rpm of the motor rise if you block the inlet completely. I wonder what effects that might have.

I usually let the vacuum-jigs bleed air with the aid of the Festool vacuum air bleeding valve:

[attachimg=3]

In this case the valve was closed (for 12 seconds only), but later on it became clear that this was not necessary at all.

To get lifting power you need maximum surface, thats's more important than suction power.

All you have to do is lower the air pressure inside the jig, than the atmospheric pressure provides the force.

When using vacuum jigs I open the bleeding valve as much as possible for the purpose at hand. It is amazing how little suction you need when the surface is big enough.

 

[roblg3]

festool ct's have built in thermal protection.  is that what we're talking about here?

 

[amt]

There may be some rare cases where blocking the flow can cause problems with overheating the bearings, and not the motor, but I doubt it's likely to happen for this stuff.

 

[tbellemare]

I'm not certain it's analogous but perhaps it's the air impeller equivalent of a router dwelling. If the router bit isn't really cutting, the motor isn't really working. The router motor works hardest when the bit is cutting the most.

By the same token, if an impeller isn't moving any air, it isn't really working, it is dwelling. It seems to me that it would work less and draw less current, (which I'm pretty certain it does). If it had a separate fan for bypass cooling, it would remain happily spinning with only the cooling fan's load.

Tom

EDIT:
It's always a bad idea to let a router bit dwell because it overheats. I don't think the same is true of a CT with a separate cooling fan.

 

[amt]

There's some info here regarding my message about the bearings. http://www.centralvacuummotor.com/shopbot.htm
The motors referenced there do have separate cooling for the motors.  However, they all have 3 stage fans, and probably produce a lot more heat than the standard 1 or 2 stage vacuum motor

 

[downtheroad]

Tehdoor just posted his version on YouTube today.

Tehdoor's Vacuum Clamp

 

[jimbouk]

Thats awesome!

 

[wow]

Anybody know which laser that is that he's using?

 

[bror]

I guess the discussion about the possible dangers of restricting or blocking the air flow when using a Festool vacuum has moved to this thread:

http://festoolownersgroup.com/festool-tools-accessories/can-ct-vacs-safely-run-under-blocked-suction/msg349293/?topicseen#msg349293

It would be nice to hear an official Festool opinion on the matter though.

Rogier

 

[Bob D.]

Since it is negative pressure (or vacuum) that does the work and not volume of air moved, why wouldn't a HVAC vacuum pump work? They are made to be dead-headed and pull a higher vacuum than a shop vac or dust extractor is meant to.

There are vacuum attachments that you can use with your air compressor that use the venturi affect to draw a vacuum as well. These can be used for vacuum clamping, vacuum chucks for lathes,  and other applications.

 

[ben_r_]

Wow, resurrected and old thread here. Good one though, still cool!

 

[rst]

I've been using a surplus HVAC pump for more than 20 years...$15.00 from a local surplus shop.  I've used it with self made jogs, Virutex clamping jigs and now with the two Festool stations.  These things are virtually indestructible.View attachment 1View attachment 2View attachment 3

 

[ben_r_]

I've been using a surplus HVAC pump for more than 20 years...$15.00 from a local surplus shop.  I've used it with self made jogs, Virutex clamping jigs and now with the two Festool stations.  These things are virtually indestructible.View attachment 1View attachment 2View attachment 3

Wow! Thank you for mentioning that! Those look awesome (LINK) and much cheaper than the Festool option! Looks like Lee Valley even sells the hold down plate: LINK

Any other brands to check out for similar products? Any suggestions for a new pump? How about a way to add a foot switch?

 

[Bob D.]

From their website 80 PSI gives you ~12 PSI vacuum or ~24 Inches of mercury which is pretty good. What you'll be able to pull on any given day depends on the quality of the vacuum pump and the atmospheric pressure where you are, but 24" should be achievable on any day and possibly better with a bit more pressure than 80PSI from your compressor.

Vacuum pumps require maintenance. The oil has to be changed and there are other considerations depending on the model, so it's not as easy as it might seem at first glance. But if you already have a pump hanging around or want to convert a pump to work in your shop there are a bunch of YT videos showing how to do just that.

 

[rst]

I've been using my pump for 20+ years and never did anything except refill the oil jar.  I've noticed that most of the newer ones are oil-less...not sure if that makes a difference.  There are pumps in all sorts of price ranges on Amazon, I've actually been considering another to use with the Virutex clamps which I held onto for use at home.

 

[peter halle]

A source is joewoodworker,com or veneer supplies.com. 

If you are interested in vacuum clamping basics I have some unedited videos up on youtube that I did years ago.  Search there for Peter Halle.  (note:  this isn't click bait.  I don't monetize my site.)

Peter