On Wednesday 02 October 2019 00:36:41 Brent Loschen wrote: > Gene - rather than a pressurized Coke bottle/regulator, have you > considered using a small peristaltic pump? I just looked on Ebay and > found several for under $20-25. This one > <https://www.ebay.com/itm/Mini-Peristaltic-Pump-Head-With-Tube-Small-F >low-Stepper-Motor-OEM-Package/273419600046?hash=item3fa91400ae:g:h1MAAO >SwMdZbe77a> ($12) fastens to a NEMA 23 stepper. (unclear how the motor > shaft attaches to the pump) Easy enough to build a stand alone speed > controller for it, but if you want to get fancy, you could even > control it with LCNC and have very precise, automated flow control > based on spindle RPM/feedrate/stock/??. This > <https://www.ebay.com/itm/Large-Flow-Micro-Anti-Corrosion-Peristaltic- >Pump-with-Stepper-Motor-12-24v-GH/333151185207?_trkparms=aid%3D555021%2 >6algo%3DPL.SIMRVI%26ao%3D1%26asc%3D20190711100440%26meid%3Da183bfe5f680 >481ba9e42ddaa7cc4a31%26pid%3D100752%26rk%3D1%26rkt%3D14%26sd%3D11270996 >5741%26itm%3D333151185207%26pmt%3D1%26noa%3D0%26pg%3D2047675&_trksid=p2 >047675.c100752.m1982>one > <https://www.ebay.com/itm/Large-Flow-Micro-Anti-Corrosion-Peristaltic- >Pump-with-Stepper-Motor-12-24v-GH/333151185207?_trkparms=aid%3D555021%2 >6algo%3DPL.SIMRVI%26ao%3D1%26asc%3D40719%26meid%3Df3347e48b8ec48c9b7bef >38477395612%26pid%3D100752%26rk%3D5%26rkt%3D11%26sd%3D293251108863%26it >m%3D333151185207%26pmt%3D1%26noa%3D0%26pg%3D2047675&_trksid=p2047675.c1 >00752.m1982>includes a stepper motor. > > I used one like this > <https://www.ebay.com/itm/Pharmacia-LKB-P-1-Peristaltic-Pump-19-4611-0 >2/293251116328?hash=item444720ed28:g:F-8AAOSwXKddjnWY>for my mister. > Very precise flow control from .6 to 600 mL/hour. Another nice one > <https://www.ebay.com/itm/Photon-Systems-Instruments-Peristaltic-Pump- >PP500/143186806912?hash=item2156994880:g:F0MAAOSwvfZZ74m3>, but missing > a 24v power supply. > > On 10/1/2019 2:01 PM, Gene Heskett wrote: > > On Tuesday 01 October 2019 12:05:52 Les Newell wrote: > >> A while back we discussed misters and the mods I did to a mister. > >> The jet is 2mm with a pretty small annular ring around it. That > >> sounds pretty much like what you want. > > > > Precisely. I had one made on the old hf mill, but it kept running > > into fixture bolts and eventually destroyed itself. > > > >> The machining work involved is just drilling one 2mm hole in a > >> lathe and cutting the 2mm tube to length. It needs pressurized > >> coolant but your coke bottle setup would do the trick. > > > > Generally that pressure in the bottle is just enough to lift the > > liquid to the top of the gantry. Max of say 13" of water, or about > > 1/2 psi. Difficlt to set with a $10 regulator. After that, the > > siphon effect keeps it flowing rather gently. The bottle is, unless > > its plumb full, below the nozzle, so flow stops when the air > > solenoid is turned off. The bottle sits on a small sheet metal shelf > > about an inch above the bottom of the gantry riser. Turned off, its > > half an hour back draining into the coke bottle to empty the > > plumbing. And about a minute to refill when the mist button is > > enabled again. The air valve vents when off, taking pressure off the > > whole thing in one grand thup. > > > > I can't remember if there was a time when the mist button was active > > while running a program, but it would be handier than bottled beer, > > hint, hint... OTOH, putting the M7 M9 around the active cut in the > > gcode works well, and reduces the AC duty cycle a just noticable > > bit. Makes me do it right that way ;-) > > > > I'll see what I can do once I see about the missus lunch and todays > > fish wrap, if she's awake, she wasn't at noon local. I'll nip off a > > 1/4" of that cap tube, clean up the ends, and see about soldering > > that into the inner nozzle, then rigging a 1/4" of something to > > bring the annular gap to the end of the brass adjustable cone into > > scale for the cap tube's OD. > > > > Except I've used up the brass tubing I had in 1/32" increments so > > they fit into the next one up or onto the next one down. And the > > old boy that ran the hobby stop up in bridgeport closed up and > > retired about 3 years back. So I need to find another place to > > source it. > > > > Google and hints welcomed. > > > >> Les > > > > Thanks Les > > > > Cheers, Gene Heskett
I sorta went crazy, ordered two kits of telescoping brass tubing to help make better, smaller nozzles. I can solder up a 1/16 od, and redrill it at #80 to get an even smaller tip. Then off this link, which takes a short nema 42 motor with a 10mm shaft (no way do I have a motor that big), but I did find a 12 volt rated peristaltic that looked usable at $6.32/copy. So since even the silicon tubeing has a limited lifespan in service of only a year or so, I bought 4 of those. But they're in china, so a Nov 1 estimated delivery date. Spit. Now if I can write hal code to allow enabling a PWM module to drive this for speed control, at the same time the m7 is on, and some more pyvcp to dial the speed via controlling the pulse width, I should be set better than I am right now. Enough air pressure to keep the work area clear, and just enough fluid to cool things without soaking the neighborhood. The stepper drive is a nice idea, and I may yet pull one of the 225's off the remains of the hf and put it on this 6040's z drive. OTOH, unless I start doing a lot of 3d woodworking, this is fast enough. Famous last words... ========== Speaking of PWM, is it possible we (meaning LCNC) have a means to detect the rise in back emf as the motor starts to turn, effectively pulsing the motor so it has enough power to overcome roller friction, but would them turn it off after 2-10 degrees of rotation? Should make a much more controllable low flow speed control. Somehow, I doubt we could turn it off and sample the back EMF with one of a 7i76's 12 bit A/D's fast enough to make that work, and the docs don't say how long to a valid reading, but can you tell me, Andy or Peter? That way I could use a solid 12 volts to bang it with, detect that the motor is moving, extending the pwm's off time for speed/flow control and that should allow flows that hardly wet a finger. Or have I let my imagination out to play w/o a chaperone again? Won't be the first time, and I hope not the last. :) Thanks. Cheers, 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) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis 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
