Newbie introduction

[IowaDave]

Here's the backplane with the original PWM board nix'd, and the OSC1.0 wired up.

Installed, there's 12vdc applied to the terminal on the big stud-mounted diode to the left.  That diode is called a 'freewheeling' diode... when a motor is spinning, but power is disconnected, it's internal magnetic field collapses, BUT... the motor becomes a 'generator'.  With an open circuit, that 'generator' voltage goes straight to the moon for a moment, and any circuit that happens to be connected takes a hefty beating.  The diode, however, shunts the 'generated' voltage back to ground, and thus, protects all the other circuit elements.

The MOTOR connection goes to the direction drum switch's ORANGE wire.. as far as the MOSFET is concerned, that's the DRAIN connection.  While a heavy BLACK wire connects the SOURCE terminal to ground...

The OSCv1.0 board has red and black connection (between the 12v screw and SOURCE terminal), and the purple wire comes from the V1.0's CLOCK terminal (it serves as PWM output whent the STEPDIR/PWM jumper is set to PWM. 

Here's the OSCv1.0 mounted to the front panel via it's speed potentiometer.  Notice the MOV I installed across the 1.0's power?  That's to keep power transents from zapping the 8-dollar board.

And with that in, and the belt reattached, it gets right down to business on a piece of Black Locust.

[IowaDave]

My buddy and I rescued these...
And cut it up (looks like an aircraft carrier!!!)

[IowaDave]

Well over 12" wide, this one's about 7ft long... black walnut!

The next one is 23" diameter, about 7ft... it yielded 157 board feet.  According to Doyle's Law, I was short by about two and a half board feet.  Probably just bad technique!   

[customsawyer]

Your off and running now. 

[Magicman]

........ I'm also gonna recycle a piece of old nylon truck strap, sew it into some sort of a draw lanyard that I can drop on the ground just off the lift arms, and toss over the head of the log clamp or turner, to use the hydraulics to pull the beasts up onto the lift arms........

Yes, Lynn, but I was referring to hic comment quoted above which a magic hook will help with. If he has an FEL, your double log hooks on a chain might work well for him too to lift and move those logs.

I invented the Magic Hook, which are repurposed logging tongs, for exactly that:


I use a short section of 1/4" chain to roll and adjust logs.  Also when actually loading, continue to roll them onto the loader arms which will help to position the log over the loader pivot and take the work off of the loader.

Sadly I lost my pictures showing the various uses for the Magic Hook.

[NaySawyer]

Thanyou IowaDave!!

Sorry about the loss of your friend .. l have tools from a few mentors who shaped my life, it is always a happy moment when l use them and we reconnect. 

I have been following a current similar chaotic diagnosis of a similar (ok..sorta) control box dilemma in the "watcha sawing" thread.  Your knowledge, logic and willingness to document the process was most help full.  I have a couple of wikipedia lookups stii to do but did you confirm the original potentiometer was not the problem?

I have often thought a FF Basic electronics/diagnosis thread would really help the site.
This thread (not my reply!) should be archived.
Thanks again.

[IowaDave]

Hi Nay!

Yes, the potentiometer was NOT the problem.  IIRC, the poteniometer was a 10k Bourns Clarostat... that's an industrial-grade component, USA made, and built stout for decades of service... so the likelyhood of it failing is very low...

And because of the way the poteniometer works, IF it fails, the failure is due to the wiper rubbing away the carbon or nichrome wirewound resistor surface (which takes well over a million cycles for the Clarostat), or it gets fouled with crud, in which case, you do what we do with old HAM radios and electric guitars-  you spin it back and forth with the side of your hand a dozen or so times, to rub the shmegma away, and then the 'scratchy audio' goes away.

Without a potentiometer wiper, the control unit will act 'normal', just assume the lowest (stop) speed.

In my case, the control module's fault LED (I think it's the one beside the label OV) comes on as soon as FORWARD is engaged... and once moved to the STOP position, it takes a second or three to recover.

Apparently this isn't an unusual failure... and my buddy's father noted that they were about halfway through the project (so about 70 running hours) when it $#!t... they were not in any circumstance to stop everything (he was amidst countdown-to-deployment), so he did what any 6-and-a-half foot 320 pound Minnesota guy would do-  Remove the belt, and push it by hand.

But to be fair here, WoodMizer's control scheme on this machine is pretty darned simple and straightforward.  The motors are all permanent magnet DC, and they layered the controls so that things weren't running unnecessarily... i.e., the debarker and blade lubricator only run when in forward... and the hydraulics only operate when the carriage is pulled back far enough to not get tangled up in flippin' logs and stuff.

IF I was designing it in THAT era, I would have done it the same way.  In TODAY's realm, I'd probably use a stout stepper motor with a planetary reducer for both the lift and feed, and I'd tie the lift feed into an encoder with a control panel to identify true elevation, then identify alongside that the setpoint for whatever thickness... and to make it even slicker, a function that raises the blade a bit for backup clearance, then brings it down to the next increment automatically.  I think they have that as a 'feature' now, but it's so inexpensive to build it into the design from the git-go, I'd do it that way...

[IowaDave]

There's some things I'm gonna do to mine... here's a short scratch-list, and if anyone has suggestions or warnings about 'em, I'm all ears... cuz I'm a newbie, right?

A manually-operated throttle-up mechanism.  I like the fact that it'll idle 'till I engage the blade, and it idles when I disengage, but cold starting doesn't go well with throttle at idle, and cranking it with blade engaged doesn't seem so sensible... and of course, when running the hydraulics, having the alternator spinning at idle speed just doesn't cut the mustard... so being able to spin it up WITHOUT the blade engaged is really a necessity.

Alternator.  I see mine has the factory original, which I THINK is 35-45A or so.  This thing is a bit power hungry, especially if running the hydraulics often.  I also see that there was a factory product change, and that guys have swapped to larger alternators... it don't take an English degree to read writing-on-the-wall..

Lighting.  I tend to work when it ain't so light.  I have good lighting in my lot, but shadows in my sightline suck... I'm gonna place some LED lighting tape in strategic places, and some floodlights around, so that I can work safely after dusk.

A second battery... probably under the tongue, connected to the hydraulics... with a trickle charger, mebbie a solar cell with an MPPT controller, to keep it charged.  If I park the carriage on the end, it'll keep the main battery charged, too...  and besides helping the hydraulics, I'll hang about a 2500w inverter, and an extension cord on a retractable reel... enough to power a 120v electric chainsaw for lopping off those little problem appendages...

And a ready-use scabbard for the chainsaw...  a holder for a cant hook... a pouch for tape measure, paint-pen, toolbox for screwdrivers and wrenches, another for gloves, eye and ear protection... 

It'd be nice to have some sort of box to keep a dozen extra blades on-hand, and a box for the dull ones I've taken off...

And some sort of clips somewhere that I can attach the engine, control panel, and debarker covers to, so they don't blow away or get lost in snow or weeds...

And a bracket underneath for a spare tire/wheel...

[Magicman]

My factory recommended idle speed is ~1500 which keeps the alternator producing above 14V.  That is also a good cranking/starting engine speed.  I have never seen nor had the need for more battery power/reserve.  My sawmill is the "SuperHydraulic" which has two hydraulic pumps, 3/4hp motors, and a higher amp alternator.  (It over 100amp.)

The spare will collect much sawdust and duff if permanently mounted.  I strap mine just in front of the front bed rail when traveling.

I use my Magic Blade Can for my blades.  I only carry sharp blades in it.  Dull blades are brought home loose and coiled.

My engine, etc. covers go back on the sawmill at the end of the day's sawing.

I would recommend reading the Useful sawmill mods topic.  It is very long but contains much (and maybe also not) useful stuff. 

DanG is the official cuss word for Forestry Forum use.  DanG.