Yet another mill build...but a band slabber

[bkaimwood]

Wheels are turning to build another mill...I need something to cut wide slabs...would be happy with a4 foot between the guides, but going bigger...but not all out...going to economically prove theory... I get alot of big logs that would make great slabs, and I'm tired of trimming them down to boards, losing 2/3 of their value...I've successfully built one already, and swore I'd never do it again, but here goes... Preliminary plans have me using a WM 196" blade .045" 1 1/2", cooks guides, 19" steel bandwheels with belts...preliminary calculations put my max width between the guides at close to 60"... As for power, we'll see, but it will be light, probably close to 20 hp...weak, I know, for something like this, but remember, its an economy build in search of precision and accuracy, not speed and production... It's to deal with and make something special of those 1 in 10 logs I get....I know lower hp, and wide cuts equals more blade heating, so a liberal lube system is in the plan, mostly in the form of blade flooding... Any past experiences or input would be appreciated... It may be awhile between updates, but hopefully, they will come...I'm hoping to make it lightweight enough to possiby be portable, maybe leveling independent tracks on site. Like a CSM, kind of...sounds sketchy, but I'm looking to slab these logs, don't need the precision to make stickers...but do need the precision to slab 12 foot logs FLAT, within 1/8"... Thanks for listening...!!!

[Ox]

Whew - you're a better man than me.  I'll never build another mill.  Ever.  I'd buy one before I'd build one.  Did I get satisfaction?  Sure!  Was it worth the 2.5 months of time and aggravation?  Nope.  I'm sure if you built the same style over and over again it would get easier every time.  I wish you luck.  I would offer this one suggestion:  it would be good for you to add a power feed on this slabber.  I'd go with a hand crank of some sort for control and cost effectiveness.  My widest cuts at around 30" had my mill shucking a little at the taller height settings because I couldn't finesse the feed by pushing by hand.

[Kingmt]

Sounds nice. I'm interested in watching & possibly coping. I do some slabbing because that is the only way I can handle them. Building it to be assembled on site sounds key for what your wanting to do. I'd consider something that would be easy to handle if you have to set it up to use going up & down hill. Power feed doesn't mean anything to me going on level ground but having to hold it back would be important.

[bkaimwood]

Thanks for the input fellas...not worried about power feed yet, but the hand crank idea is the way I would go...my main mental heardles right now are...first, can I get that wide of a spread between guides on 20" or so belted steel wheels, achieving the higher tension likely needed for this application, without the band going crazy? I'll get back to that...second, can it be done with a band only 1 1/4" wide, 1 1/2" max, hoping to stay .045" on either, not going to a .055"... Going to a .055" robs more juice, and likes bigger diameter wheels...now, back to the tension...my home made mill uses 26" car tires, and runs a 16', 1 1/2", .055 blade...28" between the guides...with alot of playing, moving the guides farther apart, I've gotten to 30-32"...it was hairy, and I got too much deflection over knots, creating unacceptable waves...I keep increasing the tension, knowing what will eventually happen... It will get mad, and track CRAZY, either blowing off the front, or jumping the guides and blowing off the back..I don't know if you can get that wide on tires, and still maintain your sanity, as tracking issues are always amplified the wider you go, due to the demand for more tension... Seems every home made band mill issue you read about hear, or close to it, are essentially tracking issues, whether it be wheels or guides...everything done so far has been done on paper...keep the input coming guys, I appreciate it!!!

[Den-Den]

I will be watching this thread, likely to be some good information in this one.
My home built mill uses tires and 1-1/2" blades; I have made a few 36" wide cuts but keeping those flat requires an almost new blade.  This is approaching the max on my mill, way short of what you are wanting to do.  Maintaining a steady feed rate at those widths is a problem for me (manual push).
If my math is right, using tires does not limit the band tension if the tires have a little crown and have enough pressure to keep the crown with the blade tight.  I know that a small amount of flex in the frame and axles will limit the tension regardless of what the wheels are made of.

[Ox]

I'm starting to think that you'll be needing the thicker, stiffer blades and larger, more solid band wheels.  I know this increases the cost quite a bit but I can see the tires and a thinner blade wandering all over the place at that kind of distance between the guides.  Have you considered a chainsaw type mill?  There would be no wandering cuts with this type of slabber.  It seems that everything in life has advantages and disadvantages and it's up to the individual to decide what he/she is willing to accept as trade offs.

[bkaimwood]

Yeah, thought about a CSM, but only briefly... I'm WAY too old for that... I may end up downsizing to 4 foot or so...

[Hilltop366]

Perhaps look at a Lucas dedicated slabber for ideas for using a bar and chain, vertical shaft engines can usually be had rather inexpensive from lawn tractors.

Good luck on the build!

[Ox]

I was thinking a bandmill type setup with the frame and carriage but with a slabber chain bar instead of a band.  Vertical shaft engine with a harvester sprocket and a long bar and off you go.  It'll be slower but somewhat smoother and no wavy cuts.  It wouldn't be hard to run with a hand crank system.  It may be the simplest and less aggravating way to go.

[bkaimwood]

Thanks fellas...ox, my first consideration was such a setup...I was slight turned off from it for 2 reasons...first, nearly any 4 stroke or diesel engine would need to be run through a differential of some sort, two multiply speed by a minimum of 3-4 times to get close to a chainsaws speed...second, I've read quite a bit about how long chains last between sharpening on wide slab cuts (not long at all), so frequent down time, sharpening, chains in stock, changing chains, etc...not to mention kerf loss... ??

[Kingmt]

If your band can drift then that would be worse than kerf lose.

[Hilltop366]

Not much if any shaft speed increase required so no gear box needed, just belts to transfer from engine to sprocket shaft, using a harvester drive sprocket (much larger than a chainsaw sprocket) will increase your chain speed. Built right chain swaps could be pretty quick.

[customsawyer]

Back when I had a LT40 with 19" wheels I ran the .055 blades all the time and didn't have much problem with blades breaking. I would plan on the 60" cut and use .055 blades.

[bkaimwood]

Hilltop366...interesting... Any idea how much rpm is ideal on a harvester sprocket? Or does anyone know? My stihl dealer said that due to the high rpm a chainsaw runs, this multiplication would be needed...maybe not as much as thought...and it could be done with pulleys, I suppose...I think it would be a good idea to used a double belt system to handle load of such a cut and avoid slippage...

[Hilltop366]

It all comes down to chain speed (feet per minute) determined by power available, width of cut, number of teeth in the cut i.e. type of chain (full comp, skip tooth etc.).

Not trying to persuade you to make one vrs. a band mill just throwing out some ideas.

One thing that tripped me up when building a vertical shaft CSM (16 hp with a 30" bar) years ago was thinking I needed chainsaw chain speed but I was not using chainsaw chain I was using harvester chain with a 50 thousand" on the rakers, I started no where near chainsaw chain speed but still ended up swapping out the driven sprocket to slow it down some more, full comp chain was too much for the single belt but skip tooth worked pretty good.

Take a look at some Lucas Mill dedicated slabber videos on youtube most look to be around 23 hp.

@Ianab might be able to tell you more about power requirements and chain speed. 

[bkaimwood]

Thanks, hilltop366... No persuasion needed, if I'm going to decide one way or another, the time is now...I've looked at the grandburg MK-III C-2, and although it's not cheap, and is labor intensive, I figure...buying a bar, chain, and some metal to start fabbing, and I'm already half way to one of those...maybe try one out...and use it to build on? Started looking at panther, but ran out of time...

[Kingmt]

I bought some aluminum the other day to build mine. I'm waiting on my bar & chain now. I had no idea there was patterns out there.

Do you have links to any that you liked?

[Hilltop366]

Your welcome, I'll include a link to a video of a diy mill that someone built that gives the general idea of what I am talking about.

Kind of like this only bigger with more power etc.

https://www.youtube.com/watch?v=iJUoER2xJYA

[jimdad07]

Yeah, thought about a CSM, but only briefly... I'm WAY too old for that... I may end up downsizing to 4 foot or so...

An Alaskan mill is pretty heavy with a big rig on it but what if you were to build a carriage style mill using a chainsaw?  There would be no tracking issues, power head is easy to take on and off, ripping chain isn't too bad on the wallet, much less figuring in the design and build aspect, much less to go wrong as far as setup goes and you can get very accurate cuts out of a chainsaw.  As far as the power head you would have to go with something like a Squeel 880 or a Hooskie 3120.

[fishpharmer]

Bkaimwood, here is a pic of the bandmill I built that is 48" max between the adjustable blade guide rollers.  Hudson builds a bandmill that cuts wider than mine.  And Woodmizer has the WM1000, wide bandmill.  Slabbing with a bandmill can be done. 

[Magicman]

It also can make bobtail log dogs.   ;D

[bkaimwood]

Cute pup...not a bad looking slab either!!! May I ask the dimensions of the blade you r running?

[4x4American]

Subscribed.  Maybe larger bandwheels than 19" might help your 20hp engine, but what do I know I'm not an engineer!

[fishpharmer]

Cute pup...not a bad looking slab either!!! May I ask the dimensions of the blade you r running?

Thanks fellas, my golden retriever was always too smart to get bobbed.  :D. Blade length I cannot remember exactly, 21 feet sounds right.  I know the mill is ten feet wide outside the guards.  The tires are in the 30" range.  If you care to look back, most my early posts are about this mill and how ffer's helped me get her cutting right.  I think a CSM would be far easier to build.   ;D

[bkaimwood]

Thanks fishpharmer... I was curious as to thickness and width, too. I assume you are running .055" x 1 1/2"? As for links to my interests? Sorry, but I just Google stuff and see where it takes me...Google Peterson, panther, Lucas, or whatever, or just CSM, and prepare to be overwhelmed...I took a second look at my current home made I previously mentioned, looking to possibly modify for this purpose... It only has 46" between the uprights, so I'm limited to that, but it may be great for experimenting... I'm looking at some trailer tires to go down in wheel diameter to early 20's, from current 26"... Seems counterproductive, but it give me more clearance, and the ability to play with the guides a bit more...may have to shim the center hub to get true center though, so there's no wobble...still investigating...I have a 45" maple log I want to make nervous...