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Building a DIY Homemade debarker for my Woodmizer LT35HD

Started by MikeySP, February 23, 2019, 12:08:28 AM

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MikeySP

Thank you Crusarius. 

After eliminating the largest and smallest sprockets, I cut off the excess piece of crank I had left on earlier. I had left it thinking it needed the extra strength to turn the sprocket; however, after considering that the torque I will be applying is very little in comparison with an athletic bicycle rider, I cut it off and just added a coulpe welds from crank to sprocket.

I cut the "D" shape on my sprocket to sort of match the OEM pulley; however, I don't know if this made any difference because I have a toothed sprocket vs the OEM cable which perhapsm needed needed tension pinch points at the corners of the "D". I am at a loss as to any benefit gained, but I did it thinking it would speed up the swing arm to move toward the log and only afterwards took the time to consider it may have done zero to effect the operation. Maybe help it to swing more speedily at the pivot point, but I just cannot tell with my limited abilities. Pity as it was a a little tedious trying to match the 1/2" pitch (point to point) with the homemade straight section of sprocket. I traced the edges of the actual sprocket onto a piece of cardboard. Then I drew a straight edge line at the approximate location I wanted to cut across. Then I took the chain and tried to tension it in place on the cardboard and matched both ends up to traced teeth that would remain on sprocket while tracing the side of chain. Then I used a small circle template that matched the U between each tooth and traced that out. Then I took some metal and used a hammer and hard screw to transcribe points and onto the metal through the cardboard. I then placed the chain on the sheet metal and traced it. Used an angle grinder and cut out the metal as best as I could and used a die grinder and kept grinding until the chain fit ok. Then I matched it up on the sprocket and traced edge where I needed to cut to ensure a matched set. Ground off a little where needed and welded it up.... and maybe for no reason :)



 

Additionally, if you look at the photos of my control handle posted earlier, you will see the tab that the cable will connect to is on the bottom side, but the OEM is on the top. I decided to fix that to give max space between the handle for the adjustable roller guides and the debarker control handle.  

In earlier photo you may notice a small tab on the release handle for connecting the cable end. The OEM has a bolt at that location and the OEM cable has a doughnut hole that slips over the bolt to connect it. I decided to copy that, so off came the tab and I drilled a hole for mounting a bolt.

Undoubtedly the most complicated element for me thus far has been the control mechanism and that should not be too bad. My rusty springs failed. I tried a couple .120 inch diameter 5" springs and no joy either. The OEM has a 7" .105" at the cable end and a 5" .105" on the opposite side of the pulley. I could not find this at my hardware store, so I tried a couple .8" o .9" springs at 7 and 4.5" lengths. Well, my buddy's son got a little helpful before i could stop him and when I was testing the mechanism, he got the idea I wanted to get the spring as far as possible and he super extended the long one  :D turning it into a permanent 10" spring so that ended my Saturday attempt at mechanism completion. I am probably going to order the debarker blade when Woodmizer opens this morning and will probably get the OEM springs and control arm cable. 

All I have left beyond the control mechanism is electrical hookup 

I need to ask someone smarter than me what on earth the diode on the solenoid is for? Two things seem apparent to me:
1. Woodmizer Engineers are smarter than me, so it must be there for a very good reason.
2. I can personally see no reason for it since an energized solenoid closes a circuit or simply flips the switch on.

Perhaps it has something to do with the on/off switch and relay side, so I will include a photo of that also. 

 If you know what is up with the diode, please let me know. I also notice the OEM has a positive and negative terminal whereas my solenoid gets its negative straight through the body of the solenoid. Is there a rhyme or reason as to why the ground appears isolated? 



 



Why the relay and driver in the following pic?  I envisioned something more simple: a positive lead, inline fuse, on/off toggle and lead to the positive coil post on the solenoid.


 


Saturday evening I painted the debarker assembly and control arm. Note, my main handle is backward in the following pics. About a minute to remove bolt and flip it, but to get the progress photos up, I include my photo with backwards assembly error.



 

 

 

 

 

 

Since I do not know what I am doing, I am pretty slow. Overall, I am quite happy with the results. If I did not use the bicycle crank, but rather fashioned the swing bearings, I would have added additional bearings for an electric swing arm control mechanism. The entire mechanism for the electric swing arm model is free swinging and has a torsion spring to give it tension and flexibility.  It will be toward the end of the week I imagine before I have my parts in and installed. One could possibly use the solution from my initial options drawing at the beginning of the thread, but I would ad a stop on the cable to avoid super extending the springs, and perhaps a limit switch to stop the motor at the end point? If my mechanism does not work out for me, I will try that. 

Have a good day.

-Mike
 

btulloh

The diode is there to discharge the reverse EMF pulse that is generated by the coil in the solenoid.  This pulse would destroy the driver if not discharged.
HM126

doc henderson

very cool mike.  looks like you putting a lot of work into it.  If you run your business like you build your de-barker, you should do well.  If you had it to do over, would you still build it from scratch, or just buy one?  best regards.
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

Southside

Having had to replace the Fwd/Rev joystick after sawing in the rain one time too many I suspect the relay is there as that joystick is at most 5V output, maybe even less.  So my guess is the relay takes in the lower voltage and closes sending out 12V to activate the solenoid down stream, basically just keeps bumping up the juice.  
Franklin buncher and skidder
JD Processor
Woodmizer LT Super 70 and LT35 sawmill, KD250 kiln, BMS 250 sharpener and setter
Riehl Edger
Woodmaster 725 and 4000 planner and moulder
Enough cows to ensure there is no spare time.
White Oak Meadows

MikeySP

thank you for the electrical answers gentlemen. It of course generates other questions now: 
1. Why not draw off a 12v source rather than 5v?
2. Why use a driver instead of just a 12v wire?

Doc, Thank you. I fully intended to give my answer at the end, but I am close enough to do so now.

I "think" I would build it again, but when I began I thought 3 days max.  :D 

I would not have considered building it if I had work lined up or if we did not have so much rain during this building time. 

I do not regret making it; but, I don't think the math ads up to make one if you are as slow as me. I put many hours into it. A skilled fabricator or millwright could probably build this thing in 1/5th the time, ,maybe less. 
 
If I was making money off the bat, I would never consider fabricating one, so I could be making an income.

Also, if I had some work to do with the sawmill, I could have gotten further down the road in sawing experience, so the question is: do I want to saw or fabricate, and it would be foolish of me to answer fabricate, when I make money sawing. For my part, I really need to make some money. For perhaps half those days I spent on it the rain was a falling, or the ground soaked from just fallen rains and flooding throughout my area, so these days are not so lost on the build. 

My personal counsel would be to saw and buy your debarker if at all possible if your goal is to be a sawyer. 

However, when I see some men who can fabricate like they were born too it, they have an afternoons work for them, and it might not be so much. 

In my case, this is a very singular time in my life, sort of my own life's great depression (nothing so bad - just metaphor) so indeed I would build it over; but, it may be because of all the pressure I feel to turn pennies into dollar bills, thus distorting my judgment. 

I do also consider that I was able to attend another school, that of debarker fabricator. 

So, I would absolutely, maybe, possibly build it again... perhaps  :o

The Sawing Philosopher.

-Mike

btulloh

Quote from: MikeySP on March 04, 2019, 11:11:27 AM1. Why not draw off a 12v source rather than 5v? 2. Why use a driver instead of just a 12v wire?


1. It depends on your overall design.  Logic components live in a 5V world (or 3.3V or 1.8V).  At some point this needs to interface to things like 12V solenoids, etc.  If your design was simple enough - composed of switches and relays for instance - you could keep it all in the 12V world.  

2.  Same answer really.  Just depends on your overall design.  At some point, pretty quickly, logic outgrows switch and relay implementation.  The point at which it does that depends on several factors.  If it's a one-off, home brew design, it may be better to use a brute force approach with switches and relays.  It it's more complex or is a production design it's going to more cost effective to go with electronics.

Start with the result you need to achieve and work backwards until all the details are resolved.  It may be better to ignore the Woodmizer control design and just do what you need in this particular application.  In any case, the reverse polarity diode across a relay or solenoid coil is good insurance against premature failure due to arcing even if it's not protecting a solid-state driver. 

If you're going to actuate the debarker independently, a simple approach using 12V switches and relays will be fine.  If it actuates automatically as a result of several other operations you'll probably find yourself in need of logic components.

You have a nice mechanical design there.  Looking forward to seeing it all working. 
HM126

Crusarius

Quote from: MikeySP on March 04, 2019, 11:11:27 AMI do not regret making it; but, I don't think the math ads up to make one if you are as slow as me. I put many hours into it. A skilled fabricator or millwright could probably build this thing in 1/5th the time, ,maybe less. 


a skilled fabricator builds stuff. But the real trick is designing it as you go. anyone can build something quick off plans. What you did was engineer a solution. Completely different from just fabricating.

Good job.

btulloh

A simple solution would be to just have two switches to control the debarker.  One for the motor, one to actuate the arm.  Even it gets more complex later on, that would be a good way to start without getting bogged down in timing and logic issues.  

Since I don't have a debarker I'm not familiar with the intricacies.  Is it ok to actuate the arm before the log is in range?  After the cut is it ok to let it swing in?  How long does it take the debarker blade to come up to speed?  
HM126

doc henderson

I like that you improved the design based on others experience and your own.  The education may have been worth the time.  I am an er doc and based in part on the way I was raised and my desire to learn new skills, I built my own splitter and conveyor over weeks and months.  So even if you won the lottery, there are benefits to building your own.  If you have problems with your debarker and call customer service, I will be curious to hear, who answers the phone.  lol.  We do a lot of things at my house despite our income, drives my wife a little crazier.  but my kids have learned from it.  when my sprinkler system does not work, I don't call anyone, since I built the system.  So I respect that you did it yourself.  I understand that your CFO probably did not want you spending money that was not coming in.  I think you have done a great job.  We all choose our battles.  Best regards sir.
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

MikeySP

btulloh, thank you very much for the technical help. I just spoke with Woodmizer Technical and they are awesome!

Here is what I learned:
The debarker is setup to only run when two conditions are met:
1. the debarker switch is on.
2. the sawmill power feed is going forward.

This serves to make sure debarker is off, when not feeding forward and is safer for offbearing and accidentally tearing up wood in reverse.

Thus, the blue wire off the forward feed joy stick goes through the on/off switch to the relay providing the (-) 5v.
The power feed driver gives the +5V coil voltage to the relay and when the coil is energized it triggers a 12V signal to the solenoid.

The solenoid WM uses is 200 amp continuous duty and has TWO coil posts (isolated ground) and the diode is to drain out the voltage and improves solenoid life.

I purchased a 200 amp cont duty solenoid also, but it only has ONE post for positive and the body is the ground. I can run it as is without a diode, but life expectancy will drop. 

As I am understanding it: a diode only allows voltage flow in one direction. So, when operating the solenoid, it blocks proper direction from crossing the solenoid so the coil gets the 12V low amp voltage and closes the contact for the high amp side switching on the debarker motor.  However, if any volatage is sent the other way (reversed) it does not go through the coil because it has an easy path straight through the diode, thus preserving the coil from any over voltage....so, do I have this correct?

Here is what I want to do:

Near copy their design since it doesn't appear that difficult to get spun up on understanding it.

Questions I need to answer still: 
1. What diode do I need to order? Never installed one before.
2. What relay do I need to order? Are these the same that are in my truck and operate on 12V? Does the coil have a varied range of voltage and works with 5V or 12V or do I need to find a relay specifically for 5V?



 

Doc, the kind gentlemen at Woodmizer asked me the same question about how much has been the savings :) and was it worth it? Thank you for the encouragement.

Crusarius: thank you for your encouragement and for the VERY helpful clarification of definitions. I did indeed have them confused.  

I discovered a few years ago that I really should have been an engineer. I tend to be able to spend many hours contemplating how something works. When I see anything mechanical, my mind thinks about how it works, and why. Even when in Special Forces Weapons Sergeant course, three decades ago, I was busy at home building things I won't mention. I think I would have liked building a new gun more than I liked shooting them. I think I would have been very successful at it and loved it. It was a grievous thing for me to discover at about 48y/o that the bully's of my childhood actually won. Here I thought I defeated them when I was 16 when I started punching them in the face. Sadly they picked my career, but I think I missed my calling for all that anger and bitterness drove me to want to kill commies (stand-ins for the bullies). Thank God I didn't have Columbine fever, but that may have been from my feeding on Spiderman and Captain America as a boy rather than Grand Theft Auto. Oh well, water under the bridge, press on toward the goal!

-Mike





MikeySP

Since the drawing schematic I included was my interpretation of and isolation from the schematic fromt he manual, here is the OEM schematic from the manual:



 

doc henderson

Mike it has been a pleasure and I am happy that you direct your energy in a positive direction.  Never know if you had been directed in another direction.  Might have been a corporate engineer and hated it.  I think the solenoid is voltage specific.  ac/dc also.  If the signal coil requires a certain energy to activate, may not work at lower voltage or worse can pull more amps at a lower voltage and fry an expensive part upstream.  May want to buy parts from WM if they have been so helpful and then the diode as well.  I know TK will hold back a little if you are not a customer, although on the down low will help if they can.  I am not an electrical engineer, so others will chime in I bet.  But I have stayed in a holiday inn express.   :)  .   smiley_beertoast
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

btulloh

A garden-variety 1N4001 diode will be fine.  (50V / 1 amp).  Almost any diode will be fine if it's >=1amp.  You can probably find a suitable diode at an auto parts store, but they always start with "what is the make and model of your vehicle".  Good luck answering that question.  Too bad Radio Shack is not around anymore.  They had that stuff.

The single lug solenoid should be fine.  The relay needs to have a 5V coil and sufficient DC contact rating for the the solenoid coil.  (Are you using 5V in your carriage control?)  The relay is just a way to get from the 5V world to the 12V world.  The relay would be unnecessary if your carriage control is 12V.


The background on protection diodes:  Any time a voltage is connected to or disconnected from an inductive load (coil) it produces a sharp voltage increase across the driven load.  This is a high voltage, low current spike of short duration and is opposite polarity.  In this application, the diode is wired so that conducts in the OPPOSITE direction of the coil so that the spike will effectively be shorted out though the diode.  This protects the coil from over-voltage conditions and eliminates arcing in the contacts of the relay controlling it.  All coils, relays, solenoids etc. driven by solid state require this or the reverse-voltage spike punches a hole in the semiconductor. 

If you're still awake after that you can get more detail here: https://en.wikipedia.org/wiki/Flyback_diode

===

I'm with Doc.  Sometimes it's better to DIY.  Just because it is. 
HM126

MikeySP

Ok, I just ordered most of parts I lack from woodmizer. 

Here is what I I figured out: When I forward the joy stick on auto feed it is a momentary on switch; but, that momentary on trips another relay which makes the circuit feedback on itself so the 5V keeps feeding through to the forward driver and in my case, to the debarker switch and on to the 5V relay which feeds on to the solenoid and so on. 

From WM I ordered a relay, relay holder, waterproof toggle switch, diode, debarker blade, springs for my control mechanism, and the swing arm control cable.

I will do some wiring while I wait, so install will go fairly quickly when it arrives. Need to get some 8 Gauge wire.  I also need to figure how to polarize the diode. Once I think I have it, I will get a verification. Also need a breaker/solenoid box.

Hopefully, my control mechanism performs, so i don't have to resolve that. Talk to you folks soon. Thank you for all the help. I learned a bunch today.

-Mike

btulloh

The diode should have a band on end.  That is the cathode.  Connect the banded end to the + side and you'll be good to go.
HM126

MikeySP

btulloh, awesome! Thank you for that very helpful information. 

Since oreilly's did not have the correct size terminal lugs, I went ahead and ordered some AWG 8, terminal lugs, braided sleeve tubing, and cable clamps to get the wiring in order.

If all goes well, I shoul dbe able to give everyone an update by Saturday. 

-Mike

btulloh

D-day.  Looking forward to seeing it in operation.  I'm curious to see how the the whole mechanism functions.  Nice job.
HM126

Crusarius

be careful with the braided steel tube. it gets nasty when it starts to frey.

MikeySP

Thank you! Crusarius, I should have clarified. The braided sleeve I purchased was PET (polyethylene terephthalate) which is a plastic. Same stuff used to make 2 litre soda bottles. Here is what I bought: 

Amazon.com: Wang-Data 50ft-1/4 PET Expandable Braided Sleeving ?Black ?Cable Management Sleeve Cord Organizer for wrap & Protect Cables: Home Audio & Theater


-Mike

Crusarius

ahh. thats nice. thats good stuff. but after its been in the sun for a while do not rub it on your skin. its very irritating.

doc henderson

thanks mike, I just ordered the 1/2 and 1 inch stuff.  as well a hammer struck mandrel for larger lugs.
Timber king 2000, 277c track loader, PJ 32 foot gooseneck, 1976 F700 state dump truck, JD 850 tractor.  2007 Chevy 3500HD dually, home built log splitter 18 horse 28 gpm with 5 inch cylinder and 32 inch split range with conveyor powered by a 12 volt tarp motor

MikeySP

Nice Doc. You are welcome.

Myself, I wanted to buy the 10 ton hydraulic crimper for $39, but figured I could make due borrowing a crimper to get it done or even accomplish the same with some hand tools. I need to resist the temptation to add "nice-to-have" tools to my collection, at present. 

-Mike 

Crusarius

Quote from: MikeySP on March 05, 2019, 12:25:20 PMI need to resist the temptation to add "nice-to-have" tools to my collection, at present. 


Is it time for an intervention?

MikeySP

:D Nahh, no intervention necessary; but, I usually purchase tools when on a project that requires such. However, it would not be too wise for me to do such at this time. I looked at it hard and thought it would be a good purchase, but decided it was not a necessity and needed to wait. 

BTW, I put this small box together this afternoon to house the solenoid and breaker.



 

Solenoid and Breaker:


 

-Mike  

MikeySP

btulloh, I received my parts today (minus the springs) and am headed to start install.

However, the diode (pic below) showed hidden under heat shrink. It has a red and a black lead; therefore, I "assume" that I just need to follow the cable polarity (red to + and black to -), but because it may be serving a different mission than normal, I do not want to be presumptuous.

Can you confirm which end goes where in this application.

Thank you.

-Mike



 

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