Griff
(Well crap, my hypometric precursor device is blown…)
81
@stutaylo, I have that same question, someone will chime in hopefully?
The other thing that needs doing is disabling the lock button in order to simply turn the router on/off remotely.
Edit: Disclaimer, anyone considering this option (router/power supply) please go in with eyes wide open. For me, this is an interesting little experiment. I certainly wouldn’t gamble any sort of production until we have more experience and multiple setups running.
Had a chick come over to the shop last night to check something on her S2000… needless to say I didn’t get any real work done. Fun night though… hahaha
Data! Here’s no load numbers with voltage adjusted to max RPM. Its actually pretty interesting, amp draw peaks right around 25krpm.
Now to do some heavy adaptive. Also I am going to get help from a motorsport wiring buddy of mine to build a relay setup to trigger feed hold on sudden loss of router power.
I don’t think we’ll see 15 amps peak under load. Im guessing 10-12.
Still this option is looking good for a tinkerer. Lightweight power and good amount less vibration I feel than the corded rt701c.
I’m ready to step up to 3/8s and see what happens. I think we’ve all grossly overestimated how much power it actually takes to cut metal
Alright things got interesting, I learned to see the actual peak amps on the meter and they spike a good amount. I actually blew the fuse in my power supply but the weird thing is that it’s a 6.3amp fuse. The power supply was rated at 15amps in the description. Time to return it and get the bigger one that griff is using.
Good news is the TAS is ok!! That was my main concern. I was cutting at 120ipm, 22krpm, 0.200 doc 0.045 opt, decently aggressive. Power supply couldn’t keep up, slowed down a bit then it died. Max amp pull was 13.25 but continuous load was not even 2.
Still no magic smoke but at least we got a “Pop”. Router showed no signs of stress, just needs more juice. 24volt 20amp 500watt power supply on its way!
Oh yeah. Only one Mitee Bite Hex holding the whole part in my custom fixture plate. Wanted to try some minimalist work holding like I saw Saunders do with Ed’s tombstone…but be successful.
4 Likes
Griff
(Well crap, my hypometric precursor device is blown…)
86
Really nice to see some real world numbers Vince.
I noticed the Brushless seems to have a smoother feel too.
Still fighting chatter in Y+ with just semi aggressive adaptive (only toolpaths I’ve run so far). I guess my XL is just too wide to be pushed too hard? But then again, no real need for me to push, I’m in no hurry. Just my nature to test limits.
If these cheap PS’s can’t cut it we can always try the Meanwell’s.
Assuming you’re measuring the input to the router, you’re using a 600A AC current probe to measure pulse width modulated (PWM) DC currents that likely won’t exceed 10A RMS. It won’t work.
All I know is that I was told to put it on the Amp setting and clamp around the positive input. Is there another way I should be doing this? The manual doesn’t cover much
Also what wont work? Sure looked like it was. It is a true RMS meter.
You’re only measuring some of the AC content of the current. The duty cycle of the PWM waveform (whose switching frequency is likely above 20 kHz) increases with increasing router load. It should be pretty close to 100% (pure DC) at full load and your AC current probe would measure 0 A.
By the way,if you can measure the resistance of one or more of the router motor’s windings, that will tell you how much current can be drawn from whatever supply voltage you choose (I = V / A).
@Vince.Fab , I’m in agreement with @gmack. Not to distract you from your main interest in cutting aluminum, you’re in over your head when posting current measurements from a BLDC motor. Meaningful values can get complicated. No offense meant.
Electricity isn’t my thing so just tell me what to do lol. I also have this meter available. I know I’m in over my head. I can take the router back apart if needed.
Also my main interest is trying new ideas, pushing percieved boudaries. I really wanted to give some type of data that would tell us how much power this thing is consuming. Not just make it work after everyone said it wouldn’t.
There are less expensive options that require considerably more effort.
IMO what you’re doing is really worthwhile, even without the power measurements. Cutting power is the product of material removal rate (cuin/min) and the unit power of the material being cut (HP/cuin/min). For 6061 T6 aluminum, that appears to be about 0.2 HP/cuin/min.
You can also get a measure of cutting power by using the battery with the router and measure how long it takes to discharge under various cutting conditions vs. when its not cutting.
2 Likes
Griff
(Well crap, my hypometric precursor device is blown…)
93
@gmack and @CrookedWoodTex, thanks for chiming in. So we need a friend with an O scope? Anything else?
As I added to my previous post, it would be a lot easier to just see how long it takes to discharge the batteries under various conditions. If the battery specs are correct, discharging it over a 5 hours or longer could be quite accurate.
You can measure the power supply’s consumption. Switching supplies are very efficient and what is being consumed should approximate what is being produced.
Output is high frequency, input is still 50-60hz mains. Assuming is a cheap supply, something like 75% efficient, multiply by 1.25. If you have an efficiency rating for the supply, use that. Don’t worry about the output.