What RPM are you running it at? And what's the temperature in your shop?
Hello all.
I just got my chinese air-cooled spindle working and mounted on my router, hoping to replace a 7518 PC router on a Techno CNC and maybe more 7518s around the shop later....mostly for lower noise. I went air-cooled over water as I'd rather not have the chance of leaks around anything that also has power to it. I'm funny like that, although probably over-cautious too.
Anyways, I think I have all hooked up properly, turns on, setting entered as per another thread, onboard VFD dial sets the speed correctly (near as I can tell). But, I noticed that it was pretty hot after only a few minutes of very light cutting (1/4" spiral bit, ER20 collet so nothing it can't easily handle) . Is that normal? The spindle has a direct-drive fan but seems to be putting out an OK amount of air......certainly I am now considering a separate electric fan instead of or in addition too the direct drive fan.....not sure if it just has a high operating temp or if something is wrong wrong wrong and i'll fry it running it for a few hours. Did a search and only heat issue was for an electric fan model.
Any ideas appreciated!
It's this spindle: 2 2KW Square Air Cooled Spindle Motor ER20 Runout Off 0 01mm GDZ 80x73 2 2 Model | eBay with a 3kw 220v single phase hungyang VFD. (regardless of the listing, I doubt it came with ceramic bearings!)
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What RPM are you running it at? And what's the temperature in your shop?
Gerry
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gfacer
Running it to slow will over heat your spindle,also settings in your VFD drive if incorrect will cause overheating, the minimum speed setting is important, this will help protect your spindle from overheating, correct Hz settings, number of Poles ( 2 )
A water cooled spindle, is a better choice over air cooled, if you are doing any serious work
Mactec54
I will double check the number of poles, although I did set as per your instructions in another thread. I was running at 18000 rpm, and only for a few minutes. For all that, it was really crazy hot. Not quite too hot to touch but after 10 minutes it might have been.
I realize water might better (now) long term, but doesn't help me at the moment! Shop temperature was 20-25C.
gfacer
It might pay to cycle the spindle up & down the rpm scale, just something to try as it may have too much grease in the bearings which is something else that can cause a temperature rise, when new
It says in the spec that it is 10 to 24,000 RPM that's not going to happen with an air cooled spindle like this, not even the water cooled can go that low, you may be able to go as low as 10,000 RPM as the fan will become inefficient if you run it to slow
Mactec54
I'll mostly be running at 18k, have a real hsd for other stuff. So I checked the poles, correctly in as 2 pole. I changed the current max (PID142) to the 6amps on the plate, down from 9 as you a post I read for 2.2kw....but then the speed was going up realllly slow. I am running at 9amps again at the moment. Ambient temperature was about 73, it is not at about 101.5 after maybe 5 min solid and a little off and on before hand. What would the upper limit on these be, I can run with the laser thermometer out and stop as needed (though that stops the fan too).
After about 10min, its at 106. I guess right now I will just see if it levels off. I am noticing the inner part of the motor is running a touch cooler.
At 108F now after 15min.
I've now run for 10-15 minutes at full 24000 rpm and it measured at about 115F, so I am going to just go ahead and use it, measuring from time to time and using 120F as my limit for now (on the thought that it might get warmer before it cools off when at rest). I'll be getting a 250V electric fan to replace the existing spindle connected unit I think, that will solve the warm at rest issue and hopefully a bit better cooling while running, which I suspect is from poor design of the heat sink as much as anything.
Thanks for the help and I still welcome any feedback from other air-cooled spindle owners.
Greg
I have a very similar air cooled spindle. It is marked 3kw. I run it on a Hitachi vfd. It has been running for a year and a half. No failures so far. I had the same issue with it getting hot. Not to hot to touch but more then I liked. I run it from 6-18000 rpm. The warm-up each day is 10 minutes at 6000. Although I don't think it was 100% needed I came up with a solution that made me more comfortable with the spindle. I mounted a corsair cpu cooler to the spindle with the fans also blowing on the body. Now it doesn't get hot enough to bother me no matter how long it runs. I can run it at 6000 or 18000 all day long and never worry. It actually gets hotter at 18000 then it does at 6000 though I have never tried running less then that. Here is the only pic I have of it right now.
Ben
Wow, that's quite the setup! I think I will try a high CFM electric fan and think about having it a little over-sized to also do the outside of the body. As long as the temperature didn't keep ramping up or become a burn hazard, I can live with it as is, but it does do better with constant airflow, getting up to 120 after some rest but only 116-117 max after a few hours running. The electric fan will fix that.
gfacer
It looks like they have a max temperature of 45c, for your spindle,so you are a little over that, it may get better the more you run it
Mactec54
Update:
I have put a electric fan on the Z, mounted above the spindle blowing down. The fan is larger than the spindle so covers the outside of the housing but may not blow down the holes quite so well. Running it for 15min now, but I think the end result will be basically the same as before, give or take a few degrees. However, the fan has the benefit of continuing to cool once after the spindle stops, and right now it has the benefit of being wired up.....but not sure I would recommend the effort for others.
Edit: Basically no difference. I will try (again) to direct the fan output a little better, first go at it had way too much back pressure....more air coming out the top than cooling the spindle!
I think if this one dies or I buy another, I will try the Hertz brand from Turkey, I believe that has a built-in electric fan.
Greg
Last edited by gfacer; 06-22-2015 at 01:06 PM.
Hey Greg,
How did you go with this?
I have just upgraded a 500W Chinese spindle to a 1500W Chinese spindle.
They both get a too hot to hold your finger on (it would be around 70deg C I suppose) at that point I give them a bit of a rest because I’m worried they’ll be a lot hotter inside.
I’d just like to know how yours lasted and anything you might have done.
Thanks
Lindsay
Sold the machine it was on....I think the new owner is here too. Has Keith in the user name I think and maybe a search for techno isel might turn up something.
I think it worked fine.....don't recall if I kept the fan on or went back to the factory setup, although I do remember the electric fan wasn't all I hoped for.....so I think I might have used both with the electric fan just cooling the outside.
The next machine I used a 2.2kw on, I used the round style but just with the factory setup and it seems fine.
Greg
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