Is that a cold spindle in your machine, or are you just....

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Rando
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Joined: Tue Jan 06, 2015 3:24 pm
Location: Boise, ID
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Is that a cold spindle in your machine, or are you just....

Post by Rando »

Everyone:

On a different thread, I became involved in replacing the router in my HD+ with a real spindle. A brief flirtation with a defective air-cooled unit got me accepting that in the very near future, my shark will be swimming in water. Sort of. Please forgive the extent to which I've gone; maybe some of this will prove useful to someone else.

My thinking about how and why I did what I did was: they said they wanted it cool. But, there are many fluids better at taking away heat than water. Like antifreeze. Except it's poisonous. A forum post or Googly search indicated that for many, the first step is to make the water reservoir cold, using ice or those blue freezer-packs. Then the aquarium pump moves it around, after you've plugged it in. As I stood in front of my shark, wondering just how I was going to get water to it (withOUT damaging anything on the electronics workbench right next to it), I turned around, and there stands a refrigerator-freezer. Hmmmmmm.....why can't I use antifreeze+water so it won't freeze until like -10F, and put the reservoir permanently INSIDE the freezer? A couple holes to allow the tubes in and out (later re-insulated), and I should be able to pump COLD fluid in.

[Edit: after checking this page (http://www.lytron.com/Tools-and-Technic ... id-Cooling), apparently the heat-transfer is LESS with Ethylene Glycol compared to water. Live and learn, right? But, water does freeze so the fluid can be a colder than if it was just water. Guess I'll just have to wait and see WRT the silicates they say are in there.]

Well, after more than a bit of thinking, about a quart of spilled antifreeze (now glad there are no pets here), I have a system that can take a room-temp spindle and pre-chill it to 35F in about 2 minutes. And, the pump turns itself on and off when I open the valves on the machine.

Here's the list of "what" I chose to do:

- 2.5Ga Antifreeze + 1.0 Ga water mixture, in the freezer inside a 3Ga boating gas tank.
- "Warm" coolant returning to the freezer goes through a small automobile transmission cooler (radiator)
- 1/2" ID vinyl tubing for the main coolant tubes (40 feet)
- 3/16 vinyl tubing on anything attached to the shark. (~15 feet total)
- Boat/RV 2GPM water-fixture pump + 12VDC power supply (pump rated at 5A max draw).
- inlet and outlet quarter-turn ball valves on the shark gantry.
- 3/16" tubing going to the spindle routed with the other wires and tubes.

Here are some additional tips to please, PLEASE do not skip:

- Ethylene Glycol, aka antifreeze, is poisonous. It's a nerve toxin. Avoid contact with it, clean it up quickly with plenty of water, avoid breathing the mists or vapors, keep away from children and pets (supposedly they mistake the glycerine as sweet). Wear rubber gloves to minimize your own skin contact. But most of all, please use clear tubing if you can. Don't run this stuff through anything that might be mistaken for, or later used for, carrying water. Like, say, copper pipe. Anyone who sees that will assume it's for water, and won't know there's actually poison running through it, or remaining in it.

- Even when the hose-barbs seem intact, use hose clamps to make sure. Vinyl tubing loses most of its pliability when cold, and joints may leak. (See first item, just above). To avoid the potential of the pump spilling 4+ Ga of poison in your work area, make sure the joints are sealed!

- Add water to the antifreeze. Most home freezers don't go much below 0F, so it's not like it's going to freeze solid, or even turn to slush. But, pure antifreeze gets more viscous, and that will make the pump work harder and ultimately give you less effective cooling. A 70% mixture should be good, and the extra flow will greatly improve spindle coolant flow-through rate.

- Re-insulate the holes in the side of the freezer so it can cool more-normally, and for God's sake, do NOT try and drill through the back of the freezer....that's typically where the cooling tubes are. The sides are almost always plastic on the inside, foam insulation, and then metal on the outside.

- Use purse-lock or similar re-openable holdings for the tubes. If you do this, you'll want to get rid of a large bubble that will form at "the top", wherever that is. You have to pull "down" the parts of the tube behind the bubble to get it to move through the system and out, so having non-permanent tie-downs is a great help.

Okay, so now on with the pictures!
Inside the freezer (R-L) transmission-oil cooler, thermo, 3Ga gas tank reservoir
Inside the freezer (R-L) transmission-oil cooler, thermo, 3Ga gas tank reservoir
This is the Boat/RV water pump, 2GPM, typically used for a small sink faucet. Only pumps when the valve gets opened....and turns itself on/off automatically.
This is the Boat/RV water pump, 2GPM, typically used for a small sink faucet. Only pumps when the valve gets opened....and turns itself on/off automatically.
A little bit of the tube routing up and over. Note hose clamps everywhere! (The white thing is just some split 1" PVC pipe that forces narrowing kinks out of the vinyl.)
A little bit of the tube routing up and over. Note hose clamps everywhere! (The white thing is just some split 1" PVC pipe that forces narrowing kinks out of the vinyl.)
Okay, well, three attachments only....I'll reply and add more in a reply to this message. Oh bother... :P.

...to be continued....
Last edited by Rando on Tue Apr 14, 2015 9:44 pm, edited 2 times in total.
=====================================================
ThomR.com Creative tools and photographic art
A proud member of the Pacific Northwest CNC Club (now on Facebook)

Rando
Posts: 757
Joined: Tue Jan 06, 2015 3:24 pm
Location: Boise, ID
Contact:

Re: Is that a cold spindle in your machine, or are you just.

Post by Rando »

...and more pictures....
And the down-running tubes. This is the place where all of the weight that can be, is offloaded from the tubes. The 3/16" tubing is what connects to the spindle, as you can see bottom center-left.
And the down-running tubes. This is the place where all of the weight that can be, is offloaded from the tubes. The 3/16" tubing is what connects to the spindle, as you can see bottom center-left.
The gantry view. The valves are closed, and when open the handles point in the direction of fluid flow. I switched from black to "natural" covering on the umbilicals, so I can see the fluid flow, so any condensation can drip out, and so they all run with the rest of the stuff.
The gantry view. The valves are closed, and when open the handles point in the direction of fluid flow. I switched from black to "natural" covering on the umbilicals, so I can see the fluid flow, so any condensation can drip out, and so they all run with the rest of the stuff.
Side view showing where I attached the spindle VFD control and the routing of the coolant tubes to the spindle.
Side view showing where I attached the spindle VFD control and the routing of the coolant tubes to the spindle.
There were some unexpected pleasant surprises along the way

- The spindle's VFD can be separated from the main box using a simple Ethernet cable, so I ran one through the umbilical, and now have the speed control right there on the side.

- That boat/rv pump is awesome. Much more able to push fluid up and over than an aquarium pump. And, the auto start-stop makes it perfect for this application.

Well, that's about it. Enjoy!

Regards,

Thom
=====================================================
ThomR.com Creative tools and photographic art
A proud member of the Pacific Northwest CNC Club (now on Facebook)

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