Another build thread... JoshNZ

[JoshNZ]

15" is probably fine.  I have mine set at 20-25" and I just don't adjust it much at all.  Even when I'm down to slicing off 2x4s.

I do have a question:  How are you keeping the rod from twisting and messing up your roller angle?

I will mount a second rod to the saw beam running parallel with the main rod and join the blade guide assembly to it with a sliding bush or something. That should add strength in the vertical direction and stop any twisting about the main rod.

I found some rubber bobbins for $8.50/ea on rs-online. Can't hurt to try at that price 😬

I've been looking at switches etc do I just want two push button momentaries for height adjustment, or do you guys like to have a selector switch too so you can walk away when it lifts for a new log etc.. I've never milled before I'm only guessing what might be practical. Limit switches too..? I'm imagining a control panel on the carriage wall with cut height and another control panel on the saw beam with throttle/choke/ignition. Rather than flexing all those wires/cables all day to the fixed control box.

I've got a bunch of spare Atmel processors too I could implement functions like double tap for continuous lift and speed adjustments etc taking the pith? What will I wish I had haha

[Crusarius]

When I did my raise lower setup I wanted to make an arduino controlled setup to give me a pseudo setworks. My thought was being able to punch in board size and hit go. Then hit repeat to continue making that size cut. Or type a new size and let it go.

I also wanted a home button so I can just hit it and go load the next log. When I get back the head would be high enough to start my cut. another variation of that was limit switch mounted to a magnet. Hit the up key and let it shutoff when it hits the switch wherever I place it. The limit switch would be better than always having a constant home. So that would minimize excess head movement.

Right now I have momentary up and down switch that works well with my log scale. My biggest issue I have is only 1 pointer on the log scale means I cannot change board thickness without doing alot of math.

I like what I have but the home or limit switch would be great when fetching the next log.

[luap]

Your engine size will also depend on the band you are pulling.  Will it be 1¼" or 1½"?  The bigger, the more tension and the more HP you will need.  I'm pulling a 1¼" and "upgraded" to a twin 18hp.  I'd like 20 or 22 hp after using it a couple years now cutting up to 28".

Tracking like that should work.  You WILL need tracking adjustments on both the powered and the idle wheels.

Using a bottle jack would work great, IF it will work in that position.  Might not.

Bottle jacks will work horizontal if the pump is positioned on the bottom.

[JoshNZ]

Cool idea Crusarius I hadn't thought of using it like that. Would need an encoder of some sort on the saw head. I'll get it sawing with buttons first think I'm getting ahead of myself.

I added the second rod and strut today, thought I'd have a short day and finish early but it was a real pain getting everything aligned. Still it seems to work pretty good.



 


 

It's got a slight bit of flex forward and back as there is nothing stabilising it in that direction but, in/out and up/down (the one that counts I guess) it is rock solid.

I added gussets to the static guide to stiffen it up as well.



 

I do have one thing bugging me, is it normal for the tracking to change quite significantly as tension is changed? I've got it riding maybe 1mm off the back of the wheel at what I think is about the right tension, if I let it all go and turn the wheels I think the blade would literally walk right off the wheel.
Which I guess means something is flexing, but the belts are flexible, is this just normal flex? If it's the structure flexing - does it matter, if it's stable?

The flipn jack is playing up again too. I'll clean it out when I tap it for the gauge and if it doesn't come right it'll have to go in the bin. To dump tension while sawing would be pretty dangerous.

I found some dirt cheap isolation mounts too! On a local auction site, I called the guy when I saw the price and said what's going on here he said yep you're right, they're end of line stock for us we're getting rid of them in packs of 10. Big 75mm M12 mounts worth $50 for $2.70 each  8). So I have 6 spare if anyone wants to try them 

[Crusarius]

Looks good. if your using a stepper motor for raise and lower you would not need an encoder. But if you want an encoder my thought was to cannibalize a scroll wheel off an old mouse and place it in a spot that would be relatively dust free.

My hardest issue I am having is just wiring. since my head moves up and down 36" I have the electric switch and motor for raise and lower mounted on the fixed part of the frame, the engine and battery are mounted on the moving part. So I have long wires just dangling in space.

Really need to see about cleaning them up. I hate having wires in the way.

[JoshNZ]

You can't wrap them all in loom and have one loop that rolls back and forth? I'm not planning on carrying my fuel on the saw head either so will have that line to deal with as well.

[Crusarius]

I have some in a loom but with the locations of everything it would be 3 looms. I may figure it out one day.

[charles mann]

@JoshNZ could yo pm me the site link with those isolator mounts? id like to do some research and see their capacity and figure how many i would need, IF, that is even an option for my power plant. 
as with ya'll's wiring and fuel line debacle, i too am thinking of where to put my control panel. i would like an all in 1, or maybe a double decker similar to the setworks/accuset boxes, definitely with easy arms/hands reach, with an emergency stop button. with all the engine gauges, plus carriage/head control switches and emerg stop, 1 box may be a bit big and cumbersome, so the 2 box stack method may be a better solution. but then there are all the wires and possibly the fuel line constantly in motion during operations. i think eventually, wire bending will take its toll. ill look in the docs for wiring and see if there is something that says how much loop there needs to be for movable control surfaces. a doc that may have some of the wire flexing info for ya'll is the FAA AC 43.13-1B of the army TM 1-1500-204-23-4, which both can be found using a google search. ill do some digging and see what i find out and pass it on, unless 1 of ya'll find it first.  

[JoshNZ]

Done. International postage is a bit of a killer but I bet it'll still work in your favour at that price!

I'll let you know how I go with the ones I got, I can do a before and after vid maybe. I got it tensioned and leveled today and put it through a small native ring screwed to a plank. Heavy/hard as hell and it ate it piece of cake so that's encouraging. Definitely need to get onto the log clamps.

Still a lot of vibration, I'm hanging pretty high hopes on these mounts. But nothing to scoff at for the first cut I guess.



 

[JoshNZ]

The mounts showed up today, there were two styles but I don't have bolts for the taller type. I suspect they'd work better. Pretty disappointed anyway a bit of the harshness is gone from the frame rattle but no noticeable difference to blade vibration. They are hard as rocks.



 

I got the backstops welded up. Bailed on the all joined one lever idea when I started piecing together a plan and steel requirements.



 


 

Vertical up welding is a bit shoddy but I don't think it's going anywhere.
Added cap bolts to the tops to stop them landing on the road if the clamps work loose too.





I'll get started on the sliding clamps tomorrow. I've got some tube I'm thinking I'll run a cutter along on the lathe in a high gear to give it some 'teeth' and then have a cam lock spike sliding on it.

[Crusarius]

Thats looking great. I like the points on the top of the tube. I may have to steal that idea when I redo my backstops.

[btulloh]

Points on the backstops are good. Bearings even better. Look at the Woodmizer stops. Not a priority though. Mine still have the angle and waiting for the round tuit to change to bearings.  Something to keep in mind though. 

[Crusarius]

I was talking about the small points on the sleeve for holding the cant.

[btulloh]

I see now. That is a goood idea. Another round tuit. I need a lot tuits  :D 

[JoshNZ]

Yesterday ended up going a different way. I've been kicking this battery tray around on the floor for the last few days so figured it was time to go on and put the electronics together.

The control box is just an electronic enclosure with holes drilled for the buttons. Emergency stop button taps into the engines oil level sensor and just drags it to ground. I found a little ATV winch contactor relay for $25, will see how it goes. Heavy leads in its own loom and the signal wiring in a tidy braid tube. I'm not sure whether running the battery leads in a loom with fuel line is sensible, so there may be two looms when I get around to fitting fuel tank.

One thing I have noticed, now that it's easily thrown back and forth is the helical gears in the lift drive may cause an issue. There is quite a bit of slack in the motor armature and of course when you change directions the axial force is in the opposite direction and hammers it with quite a crack. I have another two gears with spur teeth out of the same diff, I may count the teeth and see if that will work. Deeper teeth also which has to be good.



 

 

 

Still a bit of a birds nest but I have more wiring to add yet so won't cut and finish just yet.

[charles mann]

Ill be using a winch control relay for my raise/lower motor too. Gotta figure out how many ft lbs its gonna take for the raising action before i can buy a motor and rgb. I might end up using a 24v motor and change from a 12 to 24 vdc alternator to ensure i have plenty of tq going to the rgb. The biggest 12 vdc motor i can find is 1hp, which may be a few ft lbs low are right at the limit, meaning it'll be running 98-100% everytime i make a lift. 

[JoshNZ]

An alternator with no battery? Or two seperate batteries and circuits on your saw? I'd be surprised if 1hp reduced wasn't enough. Reduce it enough to make it work I'd say.

[Crusarius]

24 volt will draw more current than 12v. not sure how, but thats what my electronics wizard told me. I trust him he has not been wrong yet.

[charles mann]

An alternator with no battery? Or two seperate batteries and circuits on your saw? I'd be surprised if 1hp reduced wasn't enough. Reduce it enough to make it work I'd say.

Feed in to 2 batts, then a 24 to 12 step down. 
I can get a rgb that would work, but the final output would be to slow. 
@Crusarius i could see it drawing more, but if it runs at 75-80% rating compared to 95+% on the 12 vdc, im thinking it should prolong the motor life. It depends on cost difference and if 2 12v motors would cost the same or more than 1 24v but burn out 2x faster. 
I was thinking of a 20:1 rgb, which would put my output tq at around 60 ftlbs. I wont know tq requirement for another month, depending how much i get on my next tour hm. But iv got surgery on oct 28, so ill be out for a wk or so before i attempt to work while on crutches or hobble on 1 foot. 

[JoshNZ]

V=IR, R is constant, your motors winding say .5ohm.

So I = V/R, 12V/.5 is 24amp
or 24V/.5 is 48amp.

R isn't quite constant as a motor starts/runs but that's the gist of why it draws more.

These are the two other gears I have. Haven't had time to count all 4s teeth and do the math but I've got a good feeling about it just looking at it. Might be slower which is fine I think.



 
Haven't done anything whatsoever today. Got a call from a friend with a fallen walnut and native log so off we go. Funny how the news of it gets around I must have a weeks work+ for it already!


 

[Ljohnsaw]

V=IR

I can't argue with that formula and your math, but...

Looking at a normal ac motor that has switchable voltage, I see amps for each voltage.  When you go from 120v to 240v, the amps are cut in half - in apparent defiance of Ohm's law.  I never thought about it before - now my brain hurts :-\

[JoshNZ]

When you rewire for voltage on an AC motor you are usually also switching between star wiring and delta wiring, I think. Meaning length of windings current has to flow through is different so R/ohms changes. Def not the same rules as DC motors.

Jeez my buddy was shredding the place. Putting logs on mine or his trailer as quick as I could point to them. Thought I was showing up to help out but there's just no point with a slick digger operator on the scene haha I mostly just kept out of the way. Everyone needs a digger 

Got some good logs to get some setup/practice with and some really nice logs that will produce some decent timber I'd say! Made two trips with full trailers, this one was the walnut.



 



 

[btulloh]

Ohm's law is ohm's law and a constant R will draw higher current at higher voltage as stated.  When you change a motor from 120V to 240V it is using different windings, which doubles R, so current is cut in half.  

If you run the very same 12V motor on 24V, it is using the same winding so R stays the same and current doubles.  The benefit would occur if you used a 24V motor which would have a higher R to produce the same power.

(In AC motors, we're actually dealing with impedance instead of simple resistance, but that's another story.)

Sorry for the eye-glazing details.  

[Ljohnsaw]

When you change a motor from 120V to 240V it is using different windings, which doubles R, so current is cut in half.

I think that the R value goes up by 4.  If it only doubled, the same as the voltage, then the current would remain the same.  But I get what you mean.

[Crusarius]

So my friend is not cooky dukes