Vertical band mill

[longtime lurker]

60" optimised twin edger in action...

carriage can take logs from 10 - 18', cant goes to a multisaw with chipper reducers and stuff, slabs go to a resaw and then everything to an edger..... all of it with scanners and positioners and all that technical gear that replaces sweat and dirty hands.

Optimising Twin Edger 60" - YouTube

Scary isn't it?

[moodnacreek]

You guys are always thinking, keep posting. Lurker mentions the resource and so many forget or don't realize that the size and shape of the raw material means everything. A softwood, low grade mill a few hours from me runs 2 circle mills, r/h and l/h side by side delivering cants to a horz. band [small like W.M.] run around re saw system. This of course ups production and the wide kerf of the circle mills means nothing here. The Brewco band conversion shown is cutting boards on the mill, this is being done less than ever and if a mill put in a band re saw they might keep the circle head rig. There are so many ways to do it, always interesting.

[moodnacreek]

That Brewco is exactly what I was thinking.

Doug, you wouldn't have to have a debarker, but it would significantly extend blade run time, maybe enough to justify a debarker alone, without figuring in chipping the slabs. But as you probably already know, a debarker and chipper will replace one warm body that would have to stack slabs.
Mostly I'am just runin my mouth. Don't have much land and not young. have to build a pantograph and get hydraulics on the carriage now.

[JB Griffin]

Double L, that looks basically like a big end doggin scragg mill, I couldn't get enough logs to feed that thing.

Doug, ain't nothing wrong with old school,  a lotta times its better or at least easier to troubleshoot and fix. Are you gonna run hyd dogs, tapers, and setworks?  Or just dogs and tapers?

[Ron Wenrich]

The whole scope of things is that in any mill situation, the bottleneck is supposed to be the primary breakdown saw.  That has to be matched to the resource and markets.  Efficiency comes about by keeping the saw in wood and cutting as fast as conditions allow.  

The Brewco looks like you can get a board or two on occasion, but the speed slows down because the blade can't take the dust away as efficiently as a circle saw.  The band will not take a feed as aggressive as a circle mill.  That means the increase in fiber use efficiency comes at a cost of time.  Time has value, and can be figured out.

The debarker increases efficiency at the headsaw by allowing longer cutting before there needs to be a sharpening.  We don't know how long you can run a Brewco blade before it needs to be sharpened.  On most normal days, I would sharpen my saw after lunch and after work.  The rest of the time I was sawing, unless I hit junk in the log.  A good debarker operator goes a long way to that.  

A double cut band mill increases efficiency and yield.  But, the efficiency is the big factor.  The carriage is productive on both cuts.  The lead in circle saws prevents them from being efficient double cuts.  You'll heat the saws.  The double cut efficiency has to pay for the millwright to take care of the blades.

Resaws are the same as adding in another headrig.  Material handling is increased, as is labor.  Cost evaluation is whether that is profitable enough for the capital investment.  There is some fiber saving, and you'll get an extra board here and there.  But, the savings comes from being able to breakdown logs on the headrig quicker.  You bypass the debarker on the added resaw as compared to adding another headrig.

The biggest efficiencies can be had in material handling.  You must get material away from the headrig as quickly as possible.  A belted takeaway is the easiest method.  It eliminates a man.  Drop conveyors for slabs also eliminates handling.  You want to handle your waste product the least.  Shutting down to shovel sawdust takes away from sawing.  Efficient handling will get rid of a lot of labor.  I had one good hand that could trim and stack 15 Mbf a day.  Usually we used 2 guys for trimming and stacking.

Another production hog is downtime.  Poor maintenance or waiting for something to fail before replacement costs a lot of production time.  We had minimal daily maintenance, but had repairs and major maintenance handled when the crew wasn't there.  I was pretty good at finding things that were failing and we repaired at opportune times.

I ran a mill with a vertical edger.  The lure of these machines is to do away with an edgerman.  The theory is better than the practice.  It slows down the sawyer.  Instead of having 1 saw to watch, I had 3.  I had to move the carriage further back to accommodate the added 3 feet for the saw.  That's an extra 6' per cut for a board.  It doesn't sound like much until you figure thousands of cuts in a day.  Add in the extra time to set the blades, and how often you might miss the mark.  You do lose some volume in order to keep production up.  Deep cuts also caused you to slow down.  You can't upgarde boards, which has to be done on a horizontal edger.  The upside was that slabs were cut better so there wasn't a chipper problem.  

[moodnacreek]

J.B., This is what I got; live log deck w/ stop and load, old crow foot log turner, manual carriage, off bearer over husk, spiral roll case w/ 2 flags dropping flitch boards on [floor] trap door/ scissors lift , accumulate for edger, then flat belt to flip table, l/h to green chain, r/h to slab drag accumulate for slab wood saw. This set up is so 1 man can run mill and it works with low production of course. When I have help and nice logs the manual carriage is the bottleneck. To start I think powered set works would be the thing, help turn faster. Thanks for your interest.

[etroup10]

What i want to do is build/buy a slant mill like a sonborn running 2" bands, with a roll case as an outfeed sending cants to a verical band resaw(2") with run around, all feeding the same greenchain with the edger located after the resaw outfeed to allow upgrading any lumber off the resaw and headrig. And a "grading station" located on the greenchain just below the resaw outfeed.

[Ron Wenrich]

What type of production are you aiming for, and how well can you buy that volume of logs in your area?  There was a mill up around Shinglehouse that had 2 Woodmizers feeding a resaw and had 13 employees to run things.  Their production was less than my circle mill without a resaw and 5 employees.  Shut down by fire.

[longtime lurker]

Much depends on logs ... types sizes and volumes.

And markets. A whole lot depends on markets. I've got a want verging on a need for a band resaw. The reason its still just a want is market driven... we're running a fair bit of flooring and panelling feedstock. But as a percentage of my overall volume its maybe 15%(though growing) the balance is still 8/4 and 12/4 structural, and we do maybe 10% of our output as bridge and wharf timbers at 16/4.

Aint much point saving on kerf when you've got a market for ties. The kerf equation tilts to circular saws cutting 8/4 or thicker in average logs, because you can't save that 1/8" enough times to get an extra board between heart and bark.

And you got to price your fibre too: thin bands cost time due to slower cut speeds, and time is money. Wide bands cost money in maintenance. Circles are cheap to run - they're faster then thin bands by a mile and cheaper to maintain than wide bands. Sometimes the most profitable thing to do is save the money you were going to spend on either slow cutting time or band maintenance and put it to more logs and make more sawdust but sell more lumber.

Every one of us that saws to eat has to find a place in the equation that works for us, and it might not look like anyone elses but it doesn't have to so long as there is black ink on the balance sheet.

[JB Griffin]

Ron, glad you dropped by with valuable insight. Labor is a big problem here and many of the circle mills have went to a vert edger because of that.  Assuming that brewco blade is  20-24ft long and 2in wide, a good blade in clean logs would last about 2hrs and coat approximately $50- $55 or about $12-$16 to resharpen if farmed out. 

Doug, hyd dogs, setworks, and a bar or chain turner would make life easier on ya anyway.  Hyd setworks might not be as easy to set on the money as quick but saves pullin the handle. I have shy'd away from circle mills because Im a one man show and couldn't figure a way to make it work.

LL, spot on again. Logs down here usually don't grade real good and it drops fast when sawing. Sawin decent 14in and up logs into 7x9s and 4/4 I will always get more out of those logs, always. Sawin 5/4 the difference is significantly less, but still there, but not nearly as much at all.

[Ron Wenrich]

The circle costs would be about $60-70 for a change of teeth.  I could get 60-75 Mbf out of a set of teeth, since I didn't take them down to nubs.  Resharp costs about $10.  How many resharps on a band until it has to be replaced?  Hitting a nail is usually replacing a few teeth at worst.  Saw costs are much less on the circle than a band.  

I had a portable Jackson automatic that had a simple hydraulic setworks that was dead on.  It had mechanical stops, just like the manual setworks has.  It had 4 sets of 4/4, 5/4, 6/4, & 8/4.  They moved on a bar that had a hydraulic cylinder on it.  

Those Jackson's were a pretty cool setup and you could saw by yourself if you had a green chain to use as a surge deck.  Load your deck up and then sort it out.  You could use either a vertical edger or a horizontal edger, depending on your setup.  Production capacity on that mill was about 1 Mbf/hr.  If sawing by yourself, figure half of your will be spent sawing and the other half sorting and loading logs.  And, you wouldn't have to carry lumber or slabs around. 

[JB Griffin]

No doubt saw costs are less with a circle mill, it blows my mind that mill that costs 3-4 times as much is actually cheaper to run, but it is true.

A good quality band that is well taken care of would last approximately 6-7 resharps before the hardened tip would be mostly used up. I think (I know, thats dangerous) in good logs 14"-20" that 1mbf/hr is entirely possible sawing 4/4 and 7x9s
So, 2hr run, 2mbf per run= 12-14mbf per blade. So blade costs would be just over a penny a foot, something like 1.2 cents. It would be much more if you hit trash in the logs regularly. 

The only circle mills I have been around had computer setworks, I was unaware that there was such as you described on that Jackson. I literally was thinking Doug would have to set off a dial, instead of the ratchet.

[longtime lurker]

 

 

 

Cutting ¾ feedstock again today... My circle resaw runs a ¼ kerf... cut 3 boards and turn the 4th one into sawdust...This is hurting just watching the sawdust pile grow.