OldJarheads Milling Thread...

[OlJarhead]

I know I'm a little weird but I do love having a sawmill! 
Watch this INCREDIBLE remote SAWMILL in action!! [Woodmizer LT40] - YouTube

[OlJarhead]

OK here is the latest on my hydraulics:

When engaging the hydraulics, the motor is not hitting full RPM resulting in the pressure being lower than it should be (not by much but enough to drive the hydraulics only slowly).  Once the motor hits higher RPM's (where it should be) everything works as normal.

The Hydraulics shop tested power during operation and saw no significant change in power (11.9v vs 11.8v) between low rpm and not working right and full or at least high rpm and everything working.

They suspect the motor and believe the electrical components are all working as they should (since power is showing the same regardless of how it's working other than a slightly lower voltage at high rpm which is expected since it's drawing more power).

Any thoughts?

I've ordered a motor and we'll replace it unless someone can advise me on anything else to check.

Oh and they advised they could not check flow rate as it was too low for any of their meters and due to how the mill runs vs how they normally check for flow.

[barbender]

The hydraulics on our WM mills are definitely low flow and I could see where their gauges wouldn't work. I think these pumps put out just a bit over 1 gpm iirc? Maybe it's pushing 2, then a Super like mine has 2 pumps has double the flow (whoohoo!😁) I've never used a flow gauge and know nothing about them, so I'd have to take their word for it. 

What I would do if I was trouble shooting your machine. First, you need a pressure gauge teed in somewhere, it's fundamental in hydraulic troubleshooting. Too bad WM doesn't install it factory anymore, but they should know what parts you need. I'd guess you could get set up for less than $50. 

 You could also install a port and use a remote, quick couple type of gauge. 

 Anyways, the reason I stress the gauge is because I would want to know what the system pressure is doing when that motor slows down. If the pressure rises, you have something causing an increased load on the system, which will cause your motor to slow down.

 Think of how it sounds when you run out of travel with your clamp, for instance. The cylinder is bottomed out one way or another, the pump keeps trying to push if you still have the lever engaged, until the relief pressure is met and it allows the oil to bypass. The pressure on the gauge would indicate the relief setting, if it maxed out at 2200 psi that's your relief pressure. That pressure should never really be seen unless a cylinder is bottomed out, or if you were trying to load or roll a really heavy log. 

 If you are just raising your backstops for instance, and the pressure was high with a corresponding drop in pump motor speed, I would be searching for a mechanical bind, possibly a pinched hose. 

 Now if the pressure is low, and your pump motor speed drops then I would suspect the motor or electrical supply. 

I'm not sure, but if you had an oil supply issue I would think your pressure would be erratic, jumping up and down.

[OlJarhead]

They checked pressure and were getting something like 250 or 270PSI at low RPM on the motor and then it raised 50PSI when operating normally.

They also checked the relief valve and spoke with WM in Indiana (which gives me confidence that they are a good shop) who told them it's set at 2200PSI and that's where they like it.

I thought the pressure sounded low but they were checking it throughout.

Seems, since the motor RPM's were low and pressure was down, and when the motor hit full RPM's the pressure went up they are convinced it's the motor.

I asked about electronics but they felt since voltage at the pump didn't change much at all that it wasn't the electronics which leaves the motor.

I spoke with WM in Wood Village and they agreed it's probably the motor itself faulting out.  I plan to swap the motor and see how it goes since WM had them in stock at a reasonable price.

[Ljohnsaw]

Is that 11.8/11.9v with the engine running? I would expect 14.2 if the alternator was working correctly. The standby voltage should be 13.something. if your seeing less, then maybe your battery is bad.

[OlJarhead]

Their voltage was checked with a charger on the battery so it's a little low, yes.  However, the battery was tested a couple times recently to be sure it's good and it tested great both times (it's a Deka battery that isn't that old).

I'll confess, I didn't test it with the engine running (the voltages) but I didn't see any difference than when I had the 10Amp charger running vs the alternator -- I did however, drain the battery a bit when I ran everything without charger or motor running ;)

I've ordered the pump but I do hope someone might have some insite into what's causing this (hate spending the money on the pump only to find out I now have a good spare pump 

[Ljohnsaw]

Did you check voltage at both the battery and the pump connections? Wondering if there might be a cable or even a solenoid issue.

[Magicman]

but I didn't see any difference than when I had the 10Amp charger running vs the alternator

Something is not exactly right here.  10 amp charger vs a ~120 amp alternator??  Yours is not a Super mill so your alternator may only be an 80 or something like that but still much higher than a 10.  Your voltage should be 14+ before doing any hydraulic analysis.  With below 12 volts, your amperage is sky high and is not doing anything any good.

[Jack S]

One thing I see wrong in your diagnosing is reading just voltage doesn't tell how much load is on the Motor. It only shows it to be in range and no voltage drop with the existing load. Also you need to check the voltage at the motor terminal in case their might  be a bad connection between that and the source.  

You've got to use an amprobe  and read amperage or in the case of real small motors  a watt meter. Its so easy to diagnose if you use the right test equipment.

A quick story I was visiting a friend out in ohio a few years back and he was showing me around the farm and said to me, Ive got this old articulating tractor with a perkins diesel that has starter problems and nobody can fix it . replaced the starter multiple times and wont work. I had my multi meter with me and in no time at all I found no ground between the starter and the engine. Took the starter off and the engine surface area was so rusty it couldn't ground the starter. Cleaned it up reinstalled the starter  and the ol perkins fired right up. Moral of the story  When you have electrical issues with equipment that uses the chassis for grounding ya better keep this in mind. 

I don't don't know your machine but you might want to follow how your pump motor follows it ground path back to the battery also. easy way use a jumper cable from the motor direct to the battery + and - .
If all this has been done accept my apology as I didn't go back and reread all your posts today.

[OlJarhead]

Thanks guys -- while I don't disagree at all with everything you've said, the issue appears to be not related to the voltage as the voltage is up around 14v+ when the alternator is running (can't recall what it was off the top of my head) and there was no difference in the hydraulics with it running vs not running (with or without charger) other than the voltages.

It's been checked at every connection including at the motor.

So, while yes, 11.8v is low, it was doing the same thing at 14v with the motor running (wish I'd completed the video I was doing with it running and not running but I've done that as well).

Now, checking the amp draw would be interesting and I can ask the tech if he did (or has an amp meter because I do ;) ) and see what it shows however, if the motor is bad I think we'd see some strange numbers there (maybe too many amps when running at low RPM and then settling down once kicked into high gear so to speak ;)

It's tough to troubleshoot over the net but I do appreciate all the feedback!
Erik

[OlJarhead]

Just for grins, and to be super sure, I've asked the hydraulics tech to test one more time but this time with the motor running.

I'm impressed with him as I asked if the head was over the power strip or he needed to move it and he said "no, you mentioned something about that but I also saw the sticker that says not to leave the head there so I moved it off the power bar".  NICE!  8)

Gotta love a tech who pays attention.

Now, his amp meter is dead so I offered to bring mine over to test it but I won't be able to do that until Friday (darn day jobs). 

[Peter Drouin]

Brushes in the motor bad? 

[Magicman]

You need an ammeter.  Each of my motors are pulling ~95 amps with the engine running (14+ volts).  Without the engine running (~11.5 volts) the amperage jumps up toward 120. 

I agree Peter, motor needs opening up to check brushes.

I have pictures but the gallery is down right now.

[OlJarhead]

Thanks guys -- I have an Amp Clamp which checks the amps on a circuit by clamping over the cable and reading the amp draw.  Used it in the telecom world for years.

I'm wondering if brushes could be it and have a set but in light of the tech thinking the motor has an issue I bought a new one and plan to save the old one as a spare -- and might as well tear into it and learn a thing or two!  (I haven't looked at the guys inside an electric motor in decades).

Meanwhile, I put out a new video and one thing I realized is that I tend to think like a softwood sawyer and not a hardwood sawyer (probably not a good habit to have) so I talk about milling logs wet/green (wetter is better is often my motto) and then a friend pointed out it's hard to get spalted maple from a green maple log ;)

Hmmmmm going to have to think about that and ask one of you that mills a lot of hardwood (or enough) your thoughts on letting the logs dry before milling vs dropping a big Doug Fir and rolling it right on the mill and letting it rip! (see what I did there?  :D)

[Jack S]

Again I can"t stress  enough bad  grounds will cause some strange things to happen on equipment. If your brushess  are the problem yep no circuit good voltage no amperage. nows the time for visual test

I also stated in an earlier post how about a slipping coupling to the  pump? I believe I read something about different sounds. WE cant help you on that as arm chair techs. Youve got to check it out.

[beenthere]

The spalted maple is likely going to be green, not dry when sawing the log.

[OlJarhead]

The spalted maple is likely going to be green, not dry when sawing the log.

Ahhh....not doing much maple etc I thought it was more like Blue Stain on pine (sits, bugs get at it, blue stain develops etc)...

[OlJarhead]

Again I can"t stress  enough bad  grounds will cause some strange things to happen...

100% agree.  Worked in Telecom for nearly 30 years and you'd be surprised (well it sounds like you wouldn't) the havoc bad grounds can cause (and the money spent to fix them).
It's certainly possible.

[barbender]

I don't think the coupling setup will allow for slippage. It's a direct coupling between the motor and pump.

[OlJarhead]

Makes sense.  Seems something is causing the motor to not spin up all the way so it's running low rpms and the pump therefore, is putting out less pressure (50 to 70psi -- can't remember exactly) then it finally catches up and reaches peak RPM and all is well.

[OlJarhead]

Looks like I'll be heading back up to Badger Mt out of East Wenatchee this spring...I think this will be my 12th visit up there!   8)

You just gotta love repeat customers  smiley_clapping smiley_hollywood_cool

[Magicman]

Seems something is causing the motor to not spin up all the way so it's running low rpms

Most probably you have one brush(s) that is not fully making contact.  

Here is where I did my pump motor rebuild:  LINK

[OlJarhead]

Interesting.  I'll be putting in a new pump motor so will have a spare if that's all that's needed...

[doc henderson]

be careful, gin could start a fire! :D :D :D

[OlJarhead]

be careful, gin could start a fire! :D :D :D

I hate typing on my phone!