Failed micro switch from a DeWalt DW735 thickness planer (correct diagnosis this time)

[@MattWarfield]

Nice technical failure analysis. Really highlights why proper specs on a component matter. I could easily see the casual person seeing reports of a number of switches failing as the switches are junk. The real source(s) of a failure usually isn't so obvious. And well done on keeping the analysis to the facts and evidence available to you.

[@steveh8724]

Yes, need to identify root cause, not just proximate cause.

[@Erik_The_Viking]

Nice diagnosis. Funny what happens when a simple part fails. Dewalt definitely needs a more reliable switch.

[@steveh8724]

Ah, maybe, but the switch failure was a symptom, not the underlying problem, which was the excessive heat that developed in that part of the circuit because the wiring was being subjected to too much current for it to handle without getting entirely too hot.

[@samfly87]

Hey this was so helpful! My planer died mid-cut. The outlet still had power and the internal breaker wasn't popped. But sure enough, that little switch was cooked. Only the tiniest bit of browning on the plastic, would not have noticed it if I hadn't been looking for it thanks to your video! FWIW, I think mine failed in a slightly different way than yours. The little piece that carries the upper (moving) contact was only moving at the end opposite the contact, so it never touched. I.e. never turned on. Now I've got it going again. Excellent tutorial, thanks!

[@TheSnekkerShow]

Excellent, thanks for commenting.

[@sassafrasvalley1939]

Yup, that’ll do it! Good forensic on the switch. My Fluke went swimming in the bed of my pickup during a deluge… When I changed my 735 cutter head to a carbide spiral cutter, I didn’t have a way to test the amperage draw. Bit, I did have a power strip that couldn’t handle a 10” white oak, with a 1/32” cut, using the old three knife blade. I put the new cutter head through passes up to 1/16” and the power strip never overloaded. Amp draw matters… if the components are under spec… something’s gotta give! My son-in-law didn’t want to pay for 12Ga wire when he ran wiring for his air compressor. The 14Ga run across the rafters in his shop almost burnt it down… electricity has a way of weeding out the weaklings!

[@TheSnekkerShow]

Air compressors definitely push the limits. When I bought my first one I read the manual, which said that it was better to buy longer hoses than a longer extension cord. I doubted, but was later convinced by a breaker trip and hot cord.

[@woodshopnerdery]

You need a classic Sitcom clip show intro for these, "Remember the time Monica and Rachel were secretly dating the same guy, and Snekker broke his thickness planer?" "Ah, those were the days."

[@tombrown8428]

Very good job.

[@mikedurkee7296]

I have the same planer... so in a year or so when mine does the same I'll have an idea where to start looking. Thank you! Also, the video(s) on the Shelix blades was top shelf and as soon as my stock blades bite the dust Shelix is on my gift list... could you mention that to your wife around Christmas time :) (now that my tongue is firmly implanted into my cheek)

[@TheFalconJetDriver]

Outstanding explanation as to why the switch is behaving the way it is! it would be interesting to know what your line voltage is in your shop. Possibly the line voltage could be less than the nominal 120/125 volts. In my shop the it reads127 volts. I am certain you know why I am asking this!

[@TheSnekkerShow]

I haven't measured for a while, but it was 120 with no load, and when I started planing 10" wide red oak (drawing 35 amps) it dropped as low as 115.

[@TheFalconJetDriver]

@@TheSnekkerShow Wow That is a lot current even for a start up! no wonder the switch is failing.

[@sjlarue1]

I bet a lawyer was involved in the placing of that switch.😁.. Which begs to wonder, if making it a relay controlled circut would appease the legal eagles...or would that cause twitches because it is a safety switch...

[@wolfwoodworkingcreations4321]

you're like an electric genius. LOL Very good explanation, now rip that sucker out and toss that switch.

[@TheSnekkerShow]

Slightly above average maybe, but I play a much smarter person on the internet. I should probably toss the switch before I get tempted to find out how much electricity it takes to melt it.

[@wolfwoodworkingcreations4321]

@@TheSnekkerShow ooohhh now you must do that video.

[@MikeBramm]

CSI - DeWalt Edition.