Late last night I ran the spindle for the first time! It took about 2 min. to program the VFD. The spindle spins up in 5-7 seconds and it is soooo much smoother and quieter than the PC router that came with the gantry. It also feels beefier and more controlled. I am happy with the spindle I have so far and am looking forward to integrating it with the proprietary Techno electronics.
I have not run the spindle longer than about 5 min for lack of a pump to push water yet. I am afraid of overheating the bearings without the mass of the water there to cool them.
I took a look at the Mech Mate web site for cooling options. They have some good ideas with small radiators, but they look like more work/weight/cost on the gantry than what we need.
Perhaps would recomend looking into pumps from a company named flojet. they make water pumps like you would use in a motorhome. In anycase perhaps not the cheepest but they can makey plenty of pressure don't need to be submersed (ie don't heat the water on their own). I've used a couple of them for radiator load cooling projects pumping water through some pretty tight passages and they worked very good.
for pumping coolant to a cold saw blade. But it does not make much pressure so pumping as far as it would have to for this I don't think would work.
For Radiators go here http://www.dtekcustoms.com/index.asp They have a LOT of different off the shelf radiators kids are using for cooling their overclocked gaming processors. Their unpainted pro radiators are like 19 bucks and will pull a lot of heat.. Couple with one of their plastic shrouds and a small fan and it would pull alot of heat.
They also have Reservoirs to so you can have a closed system rather then having an open one with a submersible pump .
It didn't work. Instead I took the aquarium pump that I have and put it into a gallon water jug. I mounted the water jug on one of the legs of the gantry. It was a perfect fit! I cut out 3 ft of lift and 20 ft of tubing from the pump head. I taped up the opening and did some tests to see if the water would spill out. Finally I did a quick flow test. The water just trickled out through the return hose. I then did some testing to see if the spindle would get hot. I've been running the router at what I believe to be 13000 RPM for the past 3 hours under a load. The router does not even get above room temp!
I have stronger pump on order and I think I'll see if I can reduce the amount of water in the reservoir without effecting the heat.
The spindle cuts real nice and is really quiet compared to the PC router I had. Overall I am happy with the spindle and I am thinking of getting a smaller one for my smaller fixed gantry router. I'll try and post pics or a movie when I have more time.
I'm interested in swapping my PC 890 for a spindle, mostly for noise control. The router is spec'd as a 2.25 HP (peak), but 12A*120V = 1440W, or more like 1.9 HP. Regardless, it seems like a 1.5kW or 2.2kW spindle would be a reasonable replacement.
Mainly I am doing light duty work where power needs are modest. In most cases, I'm taking very light cuts so the 890 is already plenty. My preference would be for an air cooled spindle. I often run 1/2" shank bits, so I would need a collet system that supports that. I believe the ER20 is a good choice, as ER11 seems too small for that.
My understanding is that the runout specs on these units are fairly good (.005 mm), much better or certainly as good as the router - which I have found to be very usable.
I have yet to see a 1.5KW spindle from china with a ER20 collet or a 2.2KW spindle that is air cooled. The benefit of the water cooled 2.2KW is that it's much quieter than even my super quiet Hitachi router.
Just my opinion which you can read and discard as you choose.
Can't help thinking people are complicating something that is simple. With gantry mounted radiators, expensive pumps, large diameter tubing, etc.
You can read all I know of thermal dynamics on the back of a weaties packet so I will quote Gerald D,
"If your water flow fills a beer glass in a whole minute, the water temp will not rise more than 20C [36F] while cooling a 3kW [5HP] spindle that is
only 80% efficient and running under full load. . . . if my memory of thermal calcs still serves me right. . . . "
My experience with a 1.5kw chinese spindle backs this up. You don't need a great deal of coolant flow.
My small pump pushes coolant through 10 meters of 1/4" ID tubing (5m up and 5m back) at 700ml/min. 24 fl/oz
The spindle has never got more than mildly warm. Just taken the chill off it.
IMO chasing high flow with fancy pumps, large diameter tubing, short runs (gantry mounted), fan cooled radiators etc is just overkill.
Moderate flow will do, coupled with a good sized heat sink. 2 or 3 gallons of coolant.
KISS principal comes into play here.
Good sized reservoir, somewhere out of the way. (not travelling on the gantry)
Cheap plastic 1/4" tubing. Easily replaced if it looses it's suppleness after a year or two.
Can be routed in existing cable management system (cable chain).
Good quality larger sized aquarium pump.
One thing I will add to that is it probably should have a flow sensor which will trigger a fault
in the controller (Stop spindle and motion) if pump stops while machine is untended.
But this goes for any system, simple or complicated.
Well Greg - so is this available to be purchased on the internet? lets find one so that atleast this switch can be used to prevent any burnouts - i will start searching for one
and keep you guys posted.