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Another build thread... JoshNZ

Started by JoshNZ, August 04, 2019, 08:52:44 PM

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JoshNZ

@YellowHammer I was playing around with feeds in this log too, getting a little bit of mixed results. I remembered your post on my blade thread a while back and tried a cut pushing to the point where the engine just barely started to bog, which felt wrecklessly fast to me. But it was by far the best surface finish I got all afternoon.

I did notice however there was a knot in the end of the log and I was getting a faint wave as I hit this, with the high feed speeds. Should I be lowering rake if I see this, or slowing feed down for knots or is it just unavoidable?

YellowHammer

Nice on the cut speed, before long you'll get used to sawing fast and getting the maximum power out of your mill while getting a good clean cut.  There is a bit of driving involved, like a car slowing down for the turns, then accelerating out of them.  Same thing with knots, if it's a little one, just power on through, if it's a big knot, take your foot off the gas, get through, and them power back up.

It's critical to watch the rooster tail of the sawdust coming out of the kerf, as it's the best way to tell real time what's happening in the cut.  If the rooster tail jerks, twitches, or angles upon or down like the needle on a gauge, then that indicates that the band is waving up or down.  If the rooster tail settles in line with the band then the band is cutting straight.  If the sawdust looks like a spray but is inline with the band, then that is what actual gullet spillage looks like. If the sawdust is in line with the band but spraying, then the band is cutting straight, but is getting dull, or is overset, because the sawdust isn't staying trapped in the gullet of the band.

The absolute best look when the band exits the cut and there is no gullet spillage.  This is when you almost can't see the sawdust, and it looks like the band is simply cutting through the log like a knife.  This is the epidimy of sawing fast and straight, and when you see it, you won't forget it.  You'll also feel it with the way the engine sounds and feels, and the way there will be almost no sawdust on the board after the cut because its all being ejected.  

The cool thing about watching the sawdust roostertail is that you'll know the condition of the band, at all times, as you saw.  You can actually see it starting to dull, and you'll know when you are starting to lose a straight cut, with instant feedback so you can make an immediate correction, and not after you stack the board sometime later.


     
YellowHammerisms:

Take steps to save steps.

If it won't roll, its not a log; it's still a tree.  Sawmills cut logs, not trees.

Kiln drying wood: When the cookies are burned, they're burned, and you can't fix them.

Sawing is fun for the first couple million boards.

Be smarter than the sawdust

JSHogue

Quote from: JoshNZ on October 04, 2020, 03:47:42 AM
Had the first big blowout today with a main bearing on the idle wheel failing. Let go with a bang, blade flew off etc.

I can't find any info about the rating of this bearing here. It's got written on it FAG UC208-24 and M1216-08.

Is a 1.5" bearing enough, can I find a high load one or do I need to go up in shaft size? Or turn collars for my current shaft and go up in bearing size? They were quite a tight fit, it may be that I damaged them while pressing.




How many board feet or hours do you think you've sawn before this bearing failed? Did it give you much warning? How do the others feel? 

JoshNZ

It did give plenty of warning and I ignored all of it, in hindsight. I remember quite a while ago I started getting a rumble and the blade guard door was vibrating, I just thought it was a new harmonic. A few sessions later I ran it up in the shed and it didn't quite sound right, and lots of vibration in the blade. Ive finished looking for teething problems and now was just too keen to get sawing to pay it any attention. Need to get into a habit of pre-checks and general maintenance observance now.

The others are fine, I replaced both on the failed side after polishing the shaft down to a tap fit. I remember the bearings being really hard to get on I think I probably damaged them during installation, and overdid the interference fit.

YH I've definitely noticed the rooster tail change consistency with a dull blade, not sure I've noticed it twitch or jerk or move, I'll keep and eye on it and see if I can make some sense of it.

Crusarius

Thanks for that info yellowhammer, My mill should be back together and running by sunday. I will pay attention to that.

JoshNZ

I paid particular attention to the rooster tail today, I can't say it was ever dead straight, usually twitching up and down even when I did get well finished flat boards.

Pulled a couple more logs off the stack, im still trying to establish a routine in my head for where things go and the order they happen in etc. Everything begs more questions.

Pretty happy with the timber I'm pulling off the mill anyway, I'm wasting a lot of sap wood but fine with that, the heart is awesome, and staying straight. I'm excited to get into my flooring run!



 

 

One question/s I have, when you guys are chewing through a whack of logs, how many piles/packets are you working on at any one time?
Do you saw everything to specific thicknesses, and build a packet out of each thickness?

I plan to do that but after turning to accommodate board quality or tension, I usually end up with one or two odd balls, and usually an odd dimension box around the heart. What do you do with your odd sized lengths?

Mesquite cutter

How is the single axle holding up?  
Backyard woodworker. 
DIY sawmill
Youtube:  Retired DIY Guy

JoshNZ

Sorry I remember reading that in your thread, I didn't know if it was directed at me and never came back to it.

Fine, anyway. But my mill is way under its rated weight, it was a 1500kg axle and I think I've arrived at about 800kg. There was def no reason for me to go to a tandem and I think unless you could get the wheels under the bed and clear of your working space, it'd be a pain. One is enough of a pain but I can step over it.

Mesquite cutter

I am going to try a conversion kit to get the axle under the springs and use shorter trailer jacks.  That should do the trick.  
Backyard woodworker. 
DIY sawmill
Youtube:  Retired DIY Guy

RAYAR

Quote from: Mesquite cutter on October 14, 2020, 09:05:54 AM
I am going to try a conversion kit to get the axle under the springs and use shorter trailer jacks.  That should do the trick.  
Just be aware that your wheels may end up too high for your carriage to pass over at minimum sawing height. You just may end up sawing the tops of your tires off if you don't remove the wheels. ;)
mobile manual mill (custom build) (mods & additions on-going)
Custom built auto band sharpener (currently under mods)
Husqvarna 50, 61, 254XP (and others)
96 Polaris Sportsman 500
2006 Ranger 4X2 w/cap, manual trans (430,000 Km)

Crusarius

that is a major design flaw on my mill. so when I built the guards they hit the tires first :) otherwise without them its quite possible to rapidly deflate my tires.

JoshNZ

Was a problem on mine too, I went and bought the lowest profile tires I could find, and smallest rims and had to run the axle under the spring. You get a bit back with your bunks and have some flexibility as to how thick these are.

Crusarius

I have torsion axle. I just use the jacks to lift the bed up and the tires hang under the rails.

JoshNZ

I can't remember if I mentioned it yet but I added these little lugs I guess, to the sides of the log clamps. Little turned conical cylinders with a clearance for a bolt and threaded into the side of the dog to spare the plating finish. They have been great, they bite into the bottom 1/4" of the cant and have made life a lot easier during the last cut.



 

On that note, I have one clamp that is a total dud and won't bind when torque comes on the tube. Universities should come and study it I think it holds the secret to product free perpetual lubrication  >:( >:( >:(

It worked fine unpainted, so I tried cleaning the paint off, no good, tried primer only, tried epoxy paint and orange peeling so it finished dusty, tried putting it on the lathe and cutting a shallow thread down the length of it, tried beating the tube ends in so it barely slides along on it, tried ovaling them both ways... I'm beaten and thinking about starting again but I don't really know what design feature it has that I'm trying to avoid haha, any time pressure comes on the dog the tube greasily slides. The other two are identical, all made with same dimensions and they work perfectly, never slipped. Anyone using this design discovered the secret?



 

Crusarius

your sleeve looks to long to me. Not allowing it to twist enough to lock on both ends.

Vautour

 I would say that the length of those tubes are way too long and not causing a binding effect.... 1''long and a bigger diameter should work... i've built a machine with 20,000 pull to remove tubes out of boilers using this simple idea.. like that little "washer type device" that keeps a aluminum door open it has to bind... that's were i got my idea.      
the Gospel is WANTED by the people in 52 Countries but made illegal by their Government

nativewolf

Liking Walnut

RAYAR

I would cut that sliding tube to about half that length. Too short and it'll want to bind up too easily while you're trying to adjust it. A little more clearance around the rod would also help it bind.
mobile manual mill (custom build) (mods & additions on-going)
Custom built auto band sharpener (currently under mods)
Husqvarna 50, 61, 254XP (and others)
96 Polaris Sportsman 500
2006 Ranger 4X2 w/cap, manual trans (430,000 Km)

JoshNZ

Yuuuup you guys are right of course, why couldn't I think of that. I'll trim the dud one down and get to the others when I can.

Walnut is going good thanks @nativewolf I'm selling it as fast as I'm cutting it believe it or not, which isn't that fast admittedly - I'm reluctant to pole into it with no particular market in mind, I try to saw a bit then sell a bit gauge interest etc. I've gotten tied up with a guy who has a few kilns in the next city over, so with the mention of dry stuff being available shortly, I'm getting offers for the entire stacks pretty well as soon as it is listed, and enough wanting individual slabs that I'm cleaned out twice over, just as quickly. I've only really been doing slabs so far as it's so easy to sell to the local market, but hard to feel like you're getting anywhere selling 1-2 here and there, I'll be looking forward to seeing if these guys wanting the whole stacks work out.
Also got a few guys wanting me to keep an eye out for fiddleback/burl grained pieces who are paying pretty well, the contractor has left the crotches on most logs and most of them have this here which is nice.

I've sawn a few 2" thick packets for myself, which I'll just leave air drying. I may kiln dry the first one and see if there's interest, would be easy enough to do a dozen cubes and leave them air drying for a nest egg down the road. I'm working out the logs slowly, negotiating the tension, wasting a lot admittedly, lots of planning cuts wasting tapers and bows. Sometimes I think I've got it figured out, the blade exits the cant and nothing moves, like the blade never went through it and I drag a dead straight board off onto the trailer. Then the next one I do exactly the same and get a banana  ???.

Another guy with some machining equipment seems to think he will be able to sell flooring as fast as I can send blanks his way, so I might pursue that avenue as well. Flooring seems like a great sell - being that if you get someone on the hook you're up for a decent sale all at once. The main reason I bought the logs was for my own floor so, the first round at least will be pretty risk free.

I am thoroughly enjoying showing up to my shack, putting a log on the bed and starting, and just leaving when I'm finished. I've come to really hate unpacking and packing the thing for some reason. Numbers aside anyway - I'm having fun, I guess that's what it's all about.

This was the last load I took to the kiln, one of a few more hopefully (logs as payment), bit hard on the poor old ute it's only a diesel 2.8L 4.. Pity the kilns are over the ranges, I'd definitely set one up myself if this was going to be a long term thing.



 





 


JoshNZ

You guys hit the nail on the head with that one. Have halved the base of all three clamps, haven't had one slip since - thanks a bunch.

I'm into the flooring run now, cutting 150x25 blanks, for machining down to 130x19 I think is the plan. I am super excited to get it on the floor, I think it'll be a pretty unique looking place, especially for this little town in this country. I've found pressure washing (from a distance) is best way to clean/remove sawdust, and Ive got some 3 phase fans blowing across the stack which is working great. 2 hours after stacking I've got clean, purple coloured touch dry boards. Any walnut boards I've left damp have stained from mould but I think it will avoid this.

I was having a crap morning last week, got the tractor stuck had logs splitting bla bla wondered why the heck I'm doing this haha. I got my partner to call a flooring company and get a quote to have done what I'm attempting to do, just for kicks. Holy crap.. makes it all worthwhile.



 

 

 

Vautour

Woah that's some nice looking boards.....hard work always pays off in the end... good job Josh 8)
the Gospel is WANTED by the people in 52 Countries but made illegal by their Government

Crusarius

that floor is going to be amazing!!!!

JoshNZ

I thought I'd come back here and probe the knowledge base again. I need to stiffen my carriage to stop it racking side to side while cutting up high, it's driving me nuts.

The saw runs pretty flawlessly up to about 400mm cutting height and below. For opening cuts and first few flitch cuts on descent sized logs above this, the cutting force has a decent lever to torque the whole carriage around its feet if that makes sense. This causes the carriage to flex away from the cut and then eventually gets into a rocking harmonic.

What it needs is an angle brace from corner to corner to restrain this movement but obviously that runs right through where your log is sitting. Any ideas..? I have braced the carriage legs at the corners but I assume the problem is the thin 3mm wall 50x50box flexing below this brace point.

Is welding on doublers a waste of time?

mike_belben

Add in round tube torsion bars.  Big diameter, thin wall.  Exhaust pipe and emt are my go to for light duty stiffness increasers.
Praise The Lord

RAYAR

Quote from: JoshNZ on May 19, 2021, 06:29:57 PM
I thought I'd come back here and probe the knowledge base again. I need to stiffen my carriage to stop it racking side to side while cutting up high, it's driving me nuts.

The saw runs pretty flawlessly up to about 400mm cutting height and below. For opening cuts and first few flitch cuts on descent sized logs above this, the cutting force has a decent lever to torque the whole carriage around its feet if that makes sense. This causes the carriage to flex away from the cut and then eventually gets into a rocking harmonic.

What it needs is an angle brace from corner to corner to restrain this movement but obviously that runs right through where your log is sitting. Any ideas..? I have braced the carriage legs at the corners but I assume the problem is the thin 3mm wall 50x50box flexing below this brace point.

Is welding on doublers a waste of time?
Crank the head up quite high and try pushing on it to see if you can cause it to sway. If so, weld some cross pieces just above the largest diameter log your mill can handle. Maybe first try clamping some pieces across to see if the sway goes away. Mine uses 38 X 38 X 5mm tubing and it is rock steady.
mobile manual mill (custom build) (mods & additions on-going)
Custom built auto band sharpener (currently under mods)
Husqvarna 50, 61, 254XP (and others)
96 Polaris Sportsman 500
2006 Ranger 4X2 w/cap, manual trans (430,000 Km)

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