I am doing a little more milling right now with the bandmill, and it is more of a "production" type of sawing with the same dimensional boards coming off of the saw all of the time.
I "have a dream" of being able to cut a slab with the right dimensions, take it off of the mill and have that slab cut into 4 or 5 pieces, all the same size.
Do I want an edger or do I want a gang saw? What are the advantages or disadvantages of each?
With either one, is it necessary to have a straight edge on one side of the slab first or could I just cut the slabs with a live edge and have the gang saw (or edger) do all of the further processing?
Edgers are meant for boards. They usually have 2 or 3 saws. One is stationary, the others are movable. Gang saws have a series of saws that are a set distance apart. These are stationary.
Power requirements. Rule of thumb - 5 hp/blade/inch of wood. For a 1" board being edges with 2 saws, you would be able to get away with 10 hp. I would opt for more, since most boards are thicker. For a gangsaw cutting 6" boards, you would need 30 hp per blade. You can bend the hp rule somewhat by slowing down feed rates and use a fewer number of teeth in your saws.
You could go over to a resaw, but then you defeat the purpose of your saw. All you're doing is adding another headrig.
I have both in one machine. I have a 642 cornell edger with one stationary and two movable blades on one side and a gang bank set up for ripping battons on the other side of the machine. I run the machine with a 353 detroit. It's a bit under power for 2" lumber so I will be up grading soon to 471.
I bought a 3 saw edger thinking it would save me time on a similar sounding job, but it didn't. I thought I could take my 2" flitches and run it through the edger to get my 4" width rather than edging on the mill as I usually do. It ends up saving me very little time, as handling a large slab takes time and muscle (these are hardwood 2X's), and playing both pitcher and catcher doesn't make for effective use of time. If you have someone on the other end, it definitely speeds things up but I'm a one man operation.
Would a resaw with a return be a consideration?
Would a resaw with a return be a consideration?
This is what I'm asking... I dont know a thing about gang saws and edgers, so I'm looking for some answers. The only thing I know is that I could use some speeded up production and this is one way that it can be done.
I was actually looking at something like a dragback on the mill to push off the slabs onto a "live" deck that feeds the gang saw.
I'm also looking at something like 9 blades to get the desired results for what I need. Using the figures above, this would mean 350 HP (roughly) :o
I was also looking at using a thin kerf blade... probably around 12" in diameter. The blades I have looked at are 6 to 10 teeth per blade. This doesnt need to be finish grade cuts, just rough sawn is fine.
I was also thinking that 5 ft/min would be plenty. Is that slow?
Perhaps something like a resaw with an automatic return would be the answer also. When I think about this, I'm picturing in my mind something on the likes of a deli meat slicer... is that what you are talking about?
One other thing I have found is a gang saw that uses a blade that looks like the old fashioned cross cut saws THIS LINK (http://www.sharptool.com/Products/BandSaws5.htm#SashInfo) has some info on them, but on on the actual machine it is used on. I just wonder if the HP requirements for this type of saw is lower than a circle blade?
Ken,
Google up Sash Saw and see if that matches what is in your head.
Are you planning to add another person to run a resaw? If not, then you aren't doing anything except unloading one machine and putting it onto another machine. Resaws work OK in certain situations. As I said, a resaw is another headrig.
In commercial hardwood mills, circle saws are often used to break down a log into a large resaw cant. That cant is moved to a resaw to be taken down into lumber, which frees up the circle saw to saw more cants. But, these cants are all moved through automation. The production line is in-line.
For a board resaw, I've seen them work well in pallet plants. You buy ready made cants and produce pallet boards all day long.
I've only ever seen one sash gang saw. Very noisy and dusty.
Edgers do just what they are named they cut the edges off a slab making it a board. Gang saws are a little diferant they can be set up the rip a slab into many boards at once or set up to rip a cant into boards. A resaw is made to resaw cants into boards. I have a morgan resaw that I saw the dog boards off my circle saw with. If i'm sawing 1x6 instead of ending up with a 2x6 dog board I leave it a little heavy kick it over to the resaw and make 2 1x6 then it goes out with the order instead of becomming inventory.
The speed you mention of an edger of 5 ft per min is extreamly slow to me. My edger will take a 10' board through in just a couple seconds. I don't think you are in need of a resaw by the way your talking. I think an edger or gang saw is what your in need of. If you look around you can probably find a big edger that can be set up as a gang or used as an edger. As I said in my last post i'm doing both at the same time with one machine. But you got to have power as Ron said. I don't know how much your looking to spend on a setup like this but I can tell you my edger cost about ten grand used and I had to replace some sprockets and bearings and then I needed a power unit to run it yet.
We run our thick slabs as well as small logs through a scragg mill and then a resaw, but like Ron said, it all goes into pallet boards.
I am planning on adding a second person ( a helper) to help pull the slabs off of the mill and also pull the finished boards off of what ever kind of machine I get to cut the slabs into boards. If I have a dragback to push the slabs onto a live belt feed deck, this may even eliminate this portion of the job.
I may even automate the portion of the job to rough stack the finished boards into a pile that can be stacked and banded in bundles later.
I'll google resaw and see what I come up with. Thanks for all of the good advice !
GOI, you never said what size the boards are gonna be. I have a jig for the band mill where I can cut 60 stakes at a time...spend more time picking up stakes than sawing. Sawed out custom crates for a while...for that I just laid 5 cants on the mill bed and sawed 5 boards at a time. Just throwing out idea's for you to conjugate on.
I'm sawing 2 1/2 inch square blocks - 8 to 12 ft long
Ken, you can buy or build a portable resaw conveyor to mount on your bandsaw bed and a return to bring the cants back for a rerun.
Quote from: Larry on June 03, 2006, 02:41:44 PM
I have a jig for the band mill where I can cut 60 stakes at a time...spend more time picking up stakes than sawing.
Larry, how does that jig operate?
Well ok GOI, how bout sawing em out like this? Make a 3 sided cant then 2 1/2" drops saw straight to the bed. Rotate all your slabs at once 90 degrees and saw straight to the bed again with 2 1/2" drops. Might have to put a strap around them to turn. Power up and down is gonna help a lot. Being a one man band here, I would do anything to avoid picking up or moving 2 1/2" slabs by myself. I do something quite similar when sawing dimension lumber out of power poles.
woodbowl, the jig is up in the top of my barn or I would take a pic for ya. I'll try to explain. Two 2" X 1/4" bars 16' long. Every 3' there is a 5/8" all thread. Lay the jig flat down on my bunks. Between the all threads I put twelve 1 1/2" slabs 30" long. Tighten with a cordless drill. Total of 60 slabs. Saw in 1/2" drops to the 2" bar. Now that I read it sorta sounds Rube Goldberg but works with little investment and doesn't take long to spit out 1,000 survey stakes.
Larry, that is what I am doing now.... I'm looking for more speed :)
GOI,
I sent you a PM. Your welcome to come down and look at my big mill that has a gang set-up. I'm a bit over two hours from you.
Mark
If you're looking at cutting 2 1/2" squares, I think I would opt for an edger. It would be more useful to you since you could also edge your outside boards. For a 2 saw edger, you could get away with about 25 hp, if you only use 2 blades.
I don't know what type of setup you're trying to have or how much you have to spend. A green chain works pretty good for moving material from point A to point B, as long as you have the chains spaced to handle your wood. You can build these fairly cheaply and use regular chain. It takes about 5 hp to run one. Green chains give you plenty of surge area, if your mill is layed out right.
On the edger, I have seen one guy that put a set of spiral rolls on the end of the edger and ran the edged boards to a conveyor. That brought the board and edgings back to his green chain. The edger man also stacked all the lumber.
Sounds like you should have gone with the Automatic Swingblade Mill with a drag back. It would work like a charm.
I'm beginning to think that there is going to be a Peterson ASM in my future really soon.
I don't know how most edgers are, but on my Morgan Little Champ, the closest I can set the blades is 4" apart. The collar hubs for the split blades won't let them get closer and still be adjustable.
GOI,
If you are sawing a stack of 21/4 slabs on your bandmill,then rotating 90 degrees,that's probably the fasrest method without major equipment changes. Your next best option might be an edger with several fixed blades.This will work,and work well,problem is time,and handeling. You still have to cut your flitches,move them to a staging area by the edger ,then feed them through. Even with additional manpower,the time and effort involved is the same.If your flitches are wider than the setup on the edger,then they have to be returned,more time ,and handeling.
It could be done,probably quite well with a coupla turnarounds,your 21/4 cuts going one way,and the flitch returning another,that way ,you could have several in motion at one time.Still it will take some mechanicals, and labor. Don't know what kind of volume,or how long you plan to do this. Would it justify the investment ,and effort.
Depending on how your bandmill is set up ,a rack on the back side to push the strips into once the second cut was made seems like the fastest way to me,but I'm probably missing something important.
Brad
Most edgers have a set blade and an adjustable fence that should give you 1/2" increments. That's how we do 2x2 for stakes.
It is looking like this will be a long term project and worth the investment. I just dont want to get carried away and go into debt to get started and then work the rest of my days trying to pay for the investment.
I have produced a bunch of these with the Peterson ATS sawmill, but tailing the boards and having some way to automate the log feed to the mill slows me down considerably.
Loading logs and turning them after being cut into slabs is a slow process on the bandmill also, especially turning the logs.
I am looking for solutions to increase the production rates so that I can make some money at this. It seems to me like cutting the logs into slabs and then feeding the slabs into a gang saw while cutting another slab with the bandmill would be the best way to produce a large amount of these in a hurry.
If you have no way of moving the slabs other than the Armstrong method, you won't get much more done. Wouldn't a double cut or a dimension mill be a better solution than a big gang saw?
It seems to me that a dimension mill would be able to cut one on each pass, for the most part. Feed rates are better than the band mill and while the mill is cutting one, you are stacking a cut one.
Quote from: Ron Wenrich on June 05, 2006, 05:43:50 AM
Wouldn't a double cut or a dimension mill be a better solution than a big gang saw?
It seems to me that a dimension mill would be able to cut one on each pass, for the most part.
I looked at my mill this morning with that question in mind.There are normally two 4" horizontal edgers on the dimension mills with a third edger blade that can be added in about 15 minutes.If set up this way,a person could saw out three 2 1/2" squares in every pass.(or three 2x4" or 4x4 etc )
Some very good info on edgers
Nice gravedig Red
Seems like yesterday
Since this has been brought back from the dead. What would a twin saw like a mobile dimension followed by a sash gang look like. Use the big edger blade and the drag back would do most of the moving. Push it straight into the sash and mill up the next can't while that one is going through
I think it'd look pretty silly..I dont think Mobile Dimensions are really cut out for cutting big cants and dragging them back but thats just
me
Like Doug says the dragback is going to be your weak link. You need a variable height belt offbear so that as soon as the flitch is off the log the belt is taking load off the dragback... and y'know its just easier to feed the same resaw with a carriage headrig.
I've looked for years at that kinda combination and I can definitely see the potential there if you had the right logs for it (because lets face it - thats a big log system if ever there was). I'd suggest that rather than a MD you need to be looking at a Duncan Beam Saw though... MD's bigger uglier brother with a steroid abuse issue . You start playing with big flitches all day and believe me you're going to want it built heavy so things dont break. The biggest of the Turbosaws is another one that offers potential but same issue... you got a ½ ton mill dragging around ¼ton flitches all day and it wont hold together for long.
Yanno I hate the idea of band headrigs but if you dont want a conventional carriage type headrig for primary breakdown - say if you wanted to be more transportable - one of those Sanborn slant rigs might fix the problem.