Sometimes Everything Goes Wrong

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It's been a while since I had time to get in the shop.  Between helping my daughter fix up here 1940's house and a mandatory "optional" Project Management class for work that took 3-4 hours a day for the last 4 months I haven't had a spare minute.

I did manage to get into the shop long enough to plane some rough cherry lumber and in the process break the 735 planer.

Generally, when planing with the 735 you can tell the blades are getting dull since the boards move through slower and the planed faces are not as smooth.  Also, the planer starts screaming louder and moving slower.  No problem, at some point, you stop, take the top off and flip the blades.  Sometimes, it over amps and trips the breaker and everything stops.

Before I go any further, I want to also make sure to let the reader know what the conditions were.  The cherry was dry, boards are 8" wide, and I take off about 1/32 (1/2 turn on the handle per pass). 

The planer stops.  I switch off the machine, back off the planer heads, remove the board, and start to remove the top.  Or should I say try to
remove the top.  The 4 bolts that hold the top aren't coming out.  They spin freely but aren't pulling out.  Finally I have to resort to using brute force and pulling them out.  Here's what I found:



The nylon lock nuts were set into the plastic housing and looked like they had stripped out the plastic so that they spun freely.  That was a surprise since I only hand tightened them whenever I took the top off to flip the blades.  So I dug around in the miscellaneous nuts and bolts bins  and found some T-slot bolts, nuts, and star knobs.  The nut held the T-bolts tightly in place and the star knobs made it easy to tighten the top down.  I had to enlarge a couple of the holes.







I flipped the blades, put the top back on, plugged it in, pushed the reset breaker, and .......nothing.   What???  Tried again, checked the GFI on the outlet, checked the main electric panel.  Everything was good.  So I went to the source of all knowledge - Youtube!!!

There were a couple videos that suggested checking and replacing the 3 most common items that fail on the DW735.  The motor brushes, the breaker /reset on the front, and the microswitch that is engaged when the lid is set in place.  I ordered replacement parts for all of them just in case.  When the  parts arrived from E-Replacement.com, I took the top back off, pulled the brushes out.  They looked fine.  I replaced the breaker/reset, then I took front panel off and found the problem.  The spade terminal connector was melted and it looked like the connections had overheated, melted and then caused a short.



After ordering replacement terminal spade connectors and replacing the micro switch, everything worked.  However, it got me thinking about the amp ratings on the various components.  The spade connectors for that size (and maybe the wires) are 15A, the breaker is stamped 18A, and I recall having a discussion on LJ sometime back about needing a 20A circuit so it didn't trip out on start up.  If the microswitch trips out again, I might just eliminate it since it looks like the only reason it is there is to ensure the top is secure before the machine can be started.  I'm quite certain I won't run it without the top on it.

After everything was put back together, it runs fine.
I had to put my 735 on a 20A circuit, and still the breaker trips about one start in five, and I have to walk over to the panel. I wasn’t aware there were parts rated for less than that inside the unit. Glad you figured it out.

For what it’s worth, my most common failure with the 735 is the plastic housing that catches the chips and blows them out the back. Because it’s plastic, and because the humidity here it so low, I frequently have to take it apart enough to pull out that plastic housing and poke it with a stick to clear a large clog of wood chips out so the machine will suck properly again.

May you have the day you deserve!

The discharge of the little blower that is inside the hood or the area above the blades?  I've had problems with the blower getting plugged if the wood is really fiberous and the shavings are too long and curly.  Then the shavings start coming out of the sides and the front and back.  Makes a real mess.
Glad to hear your (sorta) back in action Earl  🙂

In general those "FastOn" style connectors are fine, but in a vibration type environment they are not the best option,

The connection is maintained by the spring action where each side of the connector curls over, If this weakens, given the current load the higher resistance creates localized heating. A self-energizing spiral to failure.
Aside from the lawyer inspired lockout feature provided by this switch, a bypass is a good fix (you own it right?). It'll also bum up the reliability a notch.

These switched can be bought with screw down lugs for ring terminals which would be better suited for the environment, but as with you, I'd rather just get back to the hobby and git-'r-done!

This is a good data point of routine stuff to check for 735 owners.
Earl, good to see you posting again, sounds like you have been busy and keeping your hands full.

Thanks for the write up, some things to keep in mind with mine. All of my outlet circuits in the shop are 20 Amp, the lighting in on 15 Amp. I only tripped the breaker once so far with the planner, hit the reset and further problems (as of yet). Now watch it happen. 

Main Street to the Mountains

dang earl not a very good welcome back to the shop. well at least it's working again and you can make some dust. glad your back with.

working with my hands is a joy,it gives me a sense of fulfillment,somthing so many seek and so few find.-SAM MALOOF.

Hi Earl. we have a DeWalt 733 in our Az shop. It would not start one day and I checked and  it had power to the unit and still would not run. I tried to get the  breaker out to check it and the flange broke off when trying. I got it out and it tested fine as did the switch. So I took out the one brush on the top right side and looked at it. It was long enough and not damaged so I put it in and tried the machine and it worked !!!!!!!! What caused it???????? I'm thinking some chip got under the brush somehow and held it away from the armature. It happened like that that about 3 months later- took out that brush, put it back and away it went. Must be  wood gremlins!!

Cheers, Jim ........................ Variety is the spice of life...............Learn something new every day