Ferrite beads/rings - No love

woodworkerbob
Posts: 244
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Location: SVE - Mesa, AZ

Ferrite beads/rings - No love

Post by woodworkerbob » Thu Jul 30, 2015 10:45 pm

Symptoms: Shortly after the router changes cutting load, i.e. goes from not cutting to cutting, the machine stops. Checked the steppers, each was cool. Job will run to completion with the router not running or running but not cutting. I can sometimes cause the problem by turning on the vacuum while the job is running. Load is 1 1/4 inch Porter Cable mortising bit cutting about 0.5 mm into a MDF sacrificial board. (trying to surface the board)

Plugged the router into a circuit different from the controller; however on the same 240 volt leg. Still get job stop. Carbide Motion shows connection lose. UGS 2.0 does not show connection lose, but job stops as well.

Got 10 ferrite beads from Amazon today. Disbursed as follows one each end of the cable: the AC cord of the Dewalt Router; the AC power to the SO3 power supply; the USB cable(it had two factory installed); on the 24v power cable from the SO3 power supply to the SO3 controller. Still the failure at change of router load.

Suggestions?
Bob
Shapeoko 3 - #13, dust deputy, precision collets, limit switches.
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CastIrony
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Re: Ferrite beads/rings - No love

Post by CastIrony » Fri Jul 31, 2015 2:14 am

Does it still happen if your homing/limit switches are disabled and unplugged?
Shapeoko 3 #192 - Complete! Needs limit switches.

woodworkerbob
Posts: 244
Joined: Tue Apr 15, 2014 6:31 pm
Location: SVE - Mesa, AZ

Re: Ferrite beads/rings - No love

Post by woodworkerbob » Fri Jul 31, 2015 3:34 am

CastIrony wrote:Does it still happen if your homing/limit switches are disabled and unplugged?
Have not tried this. You think the homing switches are causing a connection lose? I don't get a "limit switch" error message. I won't get back to you until Monday. Going dark for the weekend.

Another test would be to use a 1/2" end mill to do the surfacing. See if loading the router via a smaller bit changes things.

Bob
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LTEPM
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Re: Ferrite beads/rings - No love

Post by LTEPM » Fri Jul 31, 2015 4:55 am

Have you tried it without your dust hose connected with the router on? The hoses tend to build up a static charge if it's not the anti static version. Using a Festool anti-static hose on my SO3.

woodworkerbob
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Joined: Tue Apr 15, 2014 6:31 pm
Location: SVE - Mesa, AZ

Re: Ferrite beads/rings - No love

Post by woodworkerbob » Fri Jul 31, 2015 2:24 pm

LTEPM wrote:Have you tried it without your dust hose connected with the router on? The hoses tend to build up a static charge if it's not the anti static version. Using a Festool anti-static hose on my SO3.
The dust collecting hose is not in the dust shoe yet. I usually hand hold the hose when milling. Since the only thing I'm doing is watching the router move, holding the vacuum hose gives me a little something to do. When the upper section of the SO3 housing is added, the hose can be mounted to that so it won't get in the way.

Bob
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wunderaa
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Re: Ferrite beads/rings - No love

Post by wunderaa » Thu Aug 06, 2015 1:41 pm

Same thing here without any dust collection running. Hooked a scope up to the power supply and tried starting/stopping the router and see a huge spike on startup/shutdown of router. Hooked scope up to 24V supply and saw a small spike and a big dip. I don't think the 24V supply has much of an output capacitor to maintain the output during this dip sequence. I'll try adding an output cap to the 24V supply (50V, 2200uF is what I have on hand) to see if that helps at all. Next step will be a choke on the router power feed. Beyond that, I'm not sure...isolation transformer for the power supply?

woodworkerbob
Posts: 244
Joined: Tue Apr 15, 2014 6:31 pm
Location: SVE - Mesa, AZ

Re: Ferrite beads/rings - No love

Post by woodworkerbob » Thu Aug 06, 2015 2:30 pm

wunderaa wrote:Same thing here without any dust collection running. Hooked a scope up to the power supply and tried starting/stopping the router and see a huge spike on startup/shutdown of router. Hooked scope up to 24V supply and saw a small spike and a big dip. I don't think the 24V supply has much of an output capacitor to maintain the output during this dip sequence. I'll try adding an output cap to the 24V supply (50V, 2200uF is what I have on hand) to see if that helps at all. Next step will be a choke on the router power feed. Beyond that, I'm not sure...isolation transformer for the power supply?
Thanks for the info. Be sure to post your results and suggestions for improvements.

Bob
Shapeoko 3 - #13, dust deputy, precision collets, limit switches.
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veng1
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Re: Ferrite beads/rings - No love

Post by veng1 » Thu Aug 06, 2015 3:31 pm

The big dip probably, in and of itself, is not causing the problem rather is may be causing the logic supply to drop out, either +5 or +3.3V. The big cap may help but putting one further down the line before the Vcc regulator may be a better choice.

Physically large electrolytic caps don't help much for sharp spikes but they can be bridged with ceramic caps to get both problems. Because the ESR of ceramic caps goes up negligibly with size or value, you can use the biggest value your budget allows.

I use a separate surge suppressor/filter that has only the router plugged into it.

I also use homing switches and perform a home cycle after I start the router. That way I know I haven't lost any steps improbable as that might be, basically a habit picked up years ago upon learning the hard way that an MC6805 output register could be reset to an input register from a spike. That took weeks to debug as the code clearly was setting the registers correctly. I doubt it applies in this case but on the other hand, even if my pants fit, I wear a belt.

Practically speaking, I run the vacuum all the time while doing a job.

madhatter
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Location: WA, USA

Re: Ferrite beads/rings - No love

Post by madhatter » Thu Aug 06, 2015 5:42 pm

It might be a bit expensive, but maybe having the controller hooked up to a UPS might mitigate this issue. Maybe you know someone who has one that you could borrow for a bit to test?
SO3 #0054
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OttoPilot
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Re: Ferrite beads/rings - No love

Post by OttoPilot » Sat Aug 08, 2015 1:31 am

I'm having the same issue; it's intermittent but once on router startup, and a handful of times on router shutdown I've lost connection.

Very interested in any solution that's found!

Do you both have the 'power brick' style supplies...or the older style supplies? Could the brick style supplies they started shipping later in the pre-orders just be junk?

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