On Sunday 23 December 2018 09:10:50 Bruce Layne wrote: > On Sat, 22 Dec 2018 at 23:50, Gene Heskett <ghesk...@shentel.net> wrote: > > The only thing I could not find with any > > search terms was a 1/2 to 1 gallon water tank to bury the water pump > > in. > > I have a Chinese water cooled spindle on two different home built CNC > routers. I used a 5 gallon plastic bucket for the coolant tank on > each. They were free with a cat litter purchase. The plastic snap on > top is hinged. The back 1/3 stays snapped in place and the front 2/3 > can be hinged open in case I ever need to dump the coolant, add to it, > etc. The lid keeps dust and debris out of the closed loop coolant > system. A small pump is submerged in the coolant and the power cord > for the pump and the coolant inlet and outlet hoses are routed through > the back third of the lid that remains snapped onto the top of the > bucket. > > You don't need a big pump regardless of the size of the spindle > motor. I use a small Little Giant pump that's often sold for > fountains, hydroponics, etc. I get the best version they make and > it's still inexpensive. Good brands include Superior and the upper > end versions of Little Giant. Here are a couple of possible examples. > > https://www.ebay.com/itm/362400850664 > > https://www.ebay.com/itm/233055122922 > > I like the magnetic drive submersible pumps for reliability. I'd pay > a little more for a long power cord to get any electrical splices well > away from the coolant and a pipe thread outlet port so you can easily > find a fitting to connect to the weird metric sized very flexible hose > that connects to the spindle motor. > > These small pumps don't produce much head pressure (aka "lift"). On > the larger CNC router, I tried to hide the coolant pump under the > enclosure and route the coolant lines on top of the enclosure and then > down to the spindle motor. That didn't work because the pump couldn't > push the coolant that high. I tried a much larger pump trying to > power my way through the problem and the head pressure was marginal. > It barely worked, most of the time, but the pump is cooled by the > coolant and the coolant temperature rose quickly. The coolant was > cooling the pump more than it was cooling the spindle. I finally gave > up, went back to the smaller pump, and put the coolant tank on top of > the CNC router's enclosure so it was pumping down to the spindle motor > and back up to the coolant tank. The pump only needs enough head > pressure to clear the top of the coolant tank. A possible down side > is that a coolant leak could siphon most of the coolant out of the > coolant tank, but I used good hose and it hasn't been a problem. On > the small CNC router, I placed the coolant tank on a shelf behind the > CNC router, and it also pumps down to the spindle motor. > > I continue to be impressed with the Chinese water cooled spindle > motors. The quality is very good. They brag about the precision > "German" bearings and they are very smooth and have a very precise > feel, certainly much better than a Porter Cable or Bosch wood working > router, even though I suspect that "German" is the deliberately > deceptive name of a company or town in China. Still, good is good. > Like comparing a Portor-Cable 692 to a Hitachi MV12, The Hitachi is about another 50 bucks, and worth every penny. Soft start, dead smooth at any speed. Too much gingerbread on its outer though.
> Using four gallons of coolant allows the larger CNC router to run > pretty much indefinitely now that the garage shop is air conditioned. > When it was hot in the summer, the coolant would get a bit warm in the > summer after five hours of hard use of the spindle motor. Which is probably 4x longer than it would get run here. This panel with all the bells enabled is 66 minutes on the 5 to 10 ipm HF toy. With a faster spindle 30 minutes. > Less coolant means it will get hotter sooner. More coolant is an > easier and cheaper solution than adding a radiator. And I have one or two of those buckets. The square ones I might be able find room for, behind the mill, but will probably have to make a table/cabinet for the whole thing as I'd think its too tall to fit under the operator console as it only clears the floor about 48". Somebody mention 55 kg but I've not been able to find the weight. With free shipping, ebay doesn't tell you. 55kg = 121lbs. I'd best put castors on the back and and levelors on it, the shop floor sags with nearly half a ton in the middle of the floor now. And its been there close to 20 years. Only treated 4x4's on 24" centers, with 2 layers of 3/4" osb for a topping. Been tempted to build a better one, but theres not enough of me left to get it done. I'd start with a much better foundation, filled with foam and 18" sq pads for support posts down the middle, and maybe another 4' each way. Structural Foam panels for walls and roofing. Maybe then I could heat and cool it. That 14x24 garage? One two speed electric heater keeps it toasty, or a 5k btu AC keeps it comfy in the heat of the summers. I have an old old steel skinned garage door one of the neighbors gave me when he saw I was building it. I glued another 2" of R11 styro to the inside face of 10 years ago, and with the 6" walls filled with cocoon, and another foot on the ceiling, keeping it T shirt comfy is not a problem. > I use the pink RV safe antifreeze as the coolant. Thats propolene glycol, same as KY or wet divers suit lube. And a good idea. One I hadn't thought of yet, thanks. > I don't think it will corrode metals as readily as water and it won't > freeze in your unheated shop. Unheated is relative, I have enough electrical heat to keep it above the dew point most of the time. Otherwise everything is bright red quickly. Definitely not "slow rust". :( > Unlike some automotive coolant, this is used full > strength. > Yup, its already diluted. > I buy liquid LCD thermometer strips on eBay and I'll wrap one around > the spindle motor and I'll stick another in the electrical panel so I > can see the temperature at a glance. These are passive thermometers > with no electronics. They're sold for use in pet terrariums for > lizards. Direct reading with no batteries to replace. Be sure to get > one that goes as high as 40C or 104F. The selection isn't as good as > I remember. > > https://www.ebay.com/itm/253864383162 Thanks. > I wanted to measure the spindle motor temperature rather than the > coolant temperature to catch a fault where the pump stops pumping. I > still need to install a thermal switch on the spindle motor to E-stop > the CNC router if the spindle motor starts to overheat. I wired the > gantry for the thermal switch but never installed it... or I installed > the switch but never wired it into the E-stop circuit. These projects > all blur together in my old brain. LMAO! I have half done similar projects too. We must have grown up next door to the University of Hard Knocks, which I'm an official graduate of since its just over in Philippi WV. About 30 miles from here. Its basicly a student loan fundraiser operated by Alderson-Broddus University which is a Methodist operated school specializing in the nursing arts with a heavy emphasis on music and the Faith. They graduate RN's and Nurse Practitioners & music teachers BoA's. The missus has a Batchelors in music from there. Until the missus started to fade (copd), I used to try and make the annual Alumni dinner with her. Cheers, and a joyous Christmas Bruce, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
