LumberJocks

mini roubo #3: the death of a jointer -- help troubleshoot?

  • Advertise with us
Blog entry by kaaahl posted 03-14-2012 06:50 PM 5176 reads 1 time favorited 7 comments Add to Favorites Watch
« Part 2: progress pics to date Part 3 of mini roubo series Part 4: testing the switch on the planer »

I am in the process of making a workbench for my father and am using his tools—this is an important detail. Last night I was truing up two 3”x8”x6’ oak laminate bench top pieces and the planer died. I’ve been trying to this on the cheap and as a gift for my dad. It would really stink if my “gift” is a half-finished work bench and a broken planer. I would appreciate any tips or suggestions some electrically minded lumberjocks might have. So here’s the story with as much detail as I think may be helpful.

The offending bench top (now laminated together). The planer broke before I could smooth out some of the dips from my poor feeding technique. I needed to use a router to fine-tune the bench top anyway, so I figured I would take care of it then.

The poor machine that I fear I may have ruined. Hitachi F1000A. Purchased back in the early 1990s, it has been a workhorse for 20 years. During that time, it never seemed to fail on him. I would like to think that I just happened to be using it when it failed and not that my using it broke it. But I can’t be sure about it.

The planer and jointer blades were not in great shape. You can see from the pictures there are nicks, dings, rust, and general malaise. I thought that might be relevant because a dull blade may put too much pressure on the electric motor?

I knew that 8” of oak would be very taxing on this planer. It’s not quite a home depot version but it isn’t a massive industrial beast either. I tried to take precautions about how I used it. I snuck up on the depth very, very slowly. I fed it through front and back so that the blade didn’t touch at all. Then I snuck up a little more and shaved it close enough to only remove some hardened glue that was raised up from the surface. Then I would move 1/4 to 1/2 turn of the crank and do one side, flip the piece end for end (in case the sharper side of the blade could get something that the duller side couldn’t), flip the piece over, and then swap end for end again. After that process, I would crank down another 1/4 to 1/2 crank and repeat the process. Here’s what 1/4 turn and 1/2 turn look like (turning two quarters, start, +1/4 turn, +1/4 turn)

I began to notice some weird sounds coming from planer—it didn’t sound as high pitched as normal. But it was only slightly off so I just chalked it up to my forgetting what the planer sounds like one day to the next. But the piece was having problems feeding as well—going much slower than normal. Again I chalked that up to the wide oak—of course it wouldn’t just zip through it, it would have to work a bit. On what was my last past through, the feed slowed down significantly and the motor audibly bogged down a lot. I was on the opposite side of the planer at the time ready to catch the board and so rather than lowering the table to reduce the pressure, I tried to just help feed the last 6” of board through as quickly as possible. As I was doing that, I noticed that there was an extra amount of blue arcing illuminating the motor housing. (There always seems to be a little bit of blue lightning fuzz going on in there, but this was much more).

I pulled the wood out and left the machine running. It now sounded significantly different from before—and a bit worrying. I shut it down and let it rest for a few minutes. I don’t know if that actually would make any difference, but I did it anyway. After it had rested, I flipped it on again to see if the sound came back. But nothing happened—no click, whirl, nothing. I thought the breaker may have tripped, but I plugged in the shop vac and it worked fine. There was power to the machine, just nothing was happening.

I closed up shop for the night and headed into bed to check what the forums said about this machine in particular, about burned up planers in general, or about burned up motors even more generally. I clicked through the top 15 results on google.

I couldn’t find anything specific about this problem. I did find an instruction manual as well as a number of engineering diagrams with exploded views of the machine.

So after a very basic review of electric motors 101 courtesy of wikipedia, I think it could be one (or several) of three problems.

—failed switch
—failed brushes
—siezed bearings

Of course, siezed bearings could lead to failed brushes. I guess my main question is how to go about identifying the exact problem.

I started removing easy pieces to get at the machine.

Looks like no one has serviced this machine in a long time. May be indicative of neglect in other areas (maybe gummed up rollers, which were causing overload issues for the motor?)

Vacuumed out.

Dammit. I stripped this screw, despite taking precautions otherwise—give the screws a light tap with a hammer to break any seal, giving the space between the washer and the screw head a light tap with a cold steel chisel to see if I could break any seal. I’ll go find my screw extractor set and order a new one from Gainger or McMaster-Carr.

But my main questions are these:

1) If I plug in the cord, flip the switch on, and test the back of that switch with a current tester, should I be able to tell if the switch blew out? My thinking is that within that swtich their might also be a breaker / regulator. If it is the kind that heats up and melts, then all I would have to do would be to install a new switch. Do people know, generally, if the switch is a part that can / will fail? Is it likely?

2) Is there a motor controller or overload relay somewhere else in the machine? Again, this is courtesy of wikipedia, but it seems likely that there would be some sort of break between the switch and the full power of the motor. Any thoughts on where to look for that.

3) Reading other random sites, it seems fairly simple to replace burned brushes with new ones. Is this the case? Any special place to order new brushes? Another McMaster Carr job?

4) If the bearings have seized, is this something that is fixable.

5) Other. Something else might be at play that I have no idea about.

If worse comes to worse, I will contact a repair guy. But I am pretty sure that even a visit to come look at the problem will soak up the rest of the budget that I have for the workbench. Any thoughts / help would be welcomed.



7 comments so far

View Bertha's profile

Bertha

12951 posts in 1383 days


#1 posted 03-14-2012 06:55 PM

A lot of the big powertool guys quit this year, but Loren might be able to help you. I can’t imagine the bearings seizing acutely but I could be wrong. It sounds electrical to me. I had a dust collector that did the same thing: sound weird, power down, not power up. I sent mine back, so I’m not even sure what happened. I wish you luck, brother. That’s a really nice looking machine.

-- My dad and I built a 65 chev pick up.I killed trannys in that thing for some reason-Hog

View Tim Dahn's profile

Tim Dahn

1473 posts in 2255 days


#2 posted 03-14-2012 07:39 PM

Pull the brushes, after 20 years they may be worn or if your lucky just dirty.

-- Good judgement comes from experience and experience comes from poor judgement.

View kaaahl's profile

kaaahl

14 posts in 955 days


#3 posted 03-14-2012 07:39 PM

thx, i did some more testing to rule out the switch. i guess it must be the brushes.

View Tim Dahn's profile

Tim Dahn

1473 posts in 2255 days


#4 posted 03-14-2012 07:47 PM

Looks like the brushes are item 16 on page 6 of the engineering diagrams. Based on you saying the motor had arching, I think your problem is there. There is a spring to old the brush against the commutator, dirt/wooddust could be keeping it from making contact.

-- Good judgement comes from experience and experience comes from poor judgement.

View hhhopks's profile

hhhopks

564 posts in 1067 days


#5 posted 03-14-2012 08:27 PM

You never mention anything about a burnt smell. That could be a good thing.

Can you turn it by hand? If yes, that would be good. Any funny noise? Where is it coming from?

Any local overload on the motor? Reset. you may have an overload in your on/off swtich. You should check.

Yes, blue arcing. If you have an opening usually there is always a little bit of that going. When you get a lot more then usual, most likely that your brushes has wearn down to the holding disk/spring. Sometime the springs doesn’t apply enough forces to make good contact. So change them out anyway.
Do it as a set.

Hope this helps.

-- I'll be a woodworker when I grow up. HHHOPKS

View kaaahl's profile

kaaahl

14 posts in 955 days


#6 posted 03-14-2012 09:14 PM

I don’t remember any smell. i can turn the pulleys that connect the blades by hand. i can’t move the rollers by hand though—probably makes sense because they are controlled by a chain drive assembly on the other side of the machine—there may be some interlocking gears in between. No noise when I turn the pulleys. I checked for the overload at the switch and my feeling is no—their is resistance across the two poles of the switch when “off” and no resistance when “on”—seems like the switch itself is fine.

new brushes are in the mail.

thanks for your help.

View TheOtherMrRogers's profile

TheOtherMrRogers

21 posts in 871 days


#7 posted 10-14-2014 05:14 PM

I know this is resurecting an old post, but how did it work out?

-- For what does it profit a man to gain the whole world and forfeit his soul?

Have your say...

You must be signed in to post the comments.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com

Latest Projects | Latest Blog Entries | Latest Forum Topics

GardenTenders.com :: gardening showcase