880 mill setup questions

[Valandscaper]

His guys, iv been looking at a chainsaw mill for my 880. This saw is pretty much useless where I live (eastern va) very few trees around here need a saw that large. Iv got a couple ?'s. I currently run 404 chain. Should I switch to 3/8? And I have a 42" bar now so I'm looking at the 36"rail mill. Also I need an oiler on this right? Iv also seen where guys adapt a winch to the mill such as a logosol, is this helpful with a grandberg?

 

[BobL]

I currently run 404 chain. Should I switch to 3/8?

Yes

And I have a 42" bar now so I'm looking at the 36"rail mill.

Sounds OK.

Also I need an oiler on this right?

Yes

Iv also seen where guys adapt a winch to the mill such as a logosol, is this helpful with a grandberg?

You be better off spending the money on a decent jack to lift one end of the log off the ground. Then you won't need a winch as the mill will "fall" down the sloped log under its own weight.

 

[VA-Sawyer]

I have a 48" Grandberg mill that I use an 880 on. I have an aux oiler for it as well. My bar has a helper handle and it cuts well enough that I don't see a need for a winch. Of course, I have a WoodMizer for most milling.
I used to live in Williamsburg. There are a few trees in the area that need the big saw. There was a Pecan in Toano that exceeded 50 " for over 20'. Also did a Red Oak that was almost as big.

 

[Valandscaper]

This will be my only mill for now. Iv been wanting a band mill but that is just not in the budget right now. I have a small tree service and absolutely hate taking wood to the landfill. It's not only a extra expense, but a waste of a resource that can be used by someone else or myself.

 

[VA-Sawyer]

I don't know that I would get a new bar and chain just to go to 3/8". I use .404 on my mill with no problems. In fact I would suggest it on a mill larger than 36" to avoid sagging.

 

[BobL]

. . . . I use .404 on my mill with no problems. In fact I would suggest it on a mill larger than 36" to avoid sagging.

I can't see how a 3/8 chain will sag any more than 404. The chain is held horizontal by the bar groove so any sagging is determined by the bar rather than the chain. Bar sag for naked ranges from about 0.04" on a 42" bar up to 0.09" for a 60" bar. On mills that use two bar clamps (inboard and outboard) the weight of the powerhead will counter balance the small amounts of bar sag on shorter bars.
On longer bars, sag can be "controlled" with some care using an anti bar sagging device.
This device uses a strong magnet on the end of an ally rod to hold the bar straight and enables the saw to start the cut straight bar and with a bit of luck the b&c will continue to cut straight.
It does not need to be this fancy - even some sort of wooden hook is sufficient

What I think happens is that on wide cuts the sawdust is not adequately cleared by the chain so some of it packs in behind and underneath the bar in the kerf thus holding the bar up inside the kerf. This means on wide cuts it is important not to pull the mill back or seesaw the mill sideways otherwise that will clear the sawdust in the kerf and this allow the bar to sag. Just keep constant pressure on the bar and keep cutting. If I do this I usually get a sag free cut. The one time I had to back a mill out of a cut to do some adjustments on reinserting the milling into the cut, within a foot or so of cutting I had a sag problem.

 

[mdavlee]

I don't know that I would get a new bar and chain just to go to 3/8". I use .404 on my mill with no problems. In fact I would suggest it on a mill larger than 36" to avoid sagging.

Just buy a new tip for $20 and then the chain to fit. I'm changing my 41" and 48" bars to 3/8" soon.

 

[VA-Sawyer]

With my .404 bar on the mill, if one guy picks up on the helper handle, and another guy picks up on the saw, there is a lot of flex in the bar. Any up or down force applied to either during the cut will also tend to flex the bar. It takes an lot of concentration to apply the push force along the cut without any up or down force also being applied. Maybe I should had said flexing instead of sagging in my earlier post.

 

[JakeG]

With my .404 bar on the mill, if one guy picks up on the helper handle, and another guy picks up on the saw, there is a lot of flex in the bar. Any up or down force applied to either during the cut will also tend to flex the bar. It takes an lot of concentration to apply the push force along the cut without any up or down force also being applied. Maybe I should had said flexing instead of sagging in my earlier post.

Which bar are you using? I imagine the Cannon bars would sag less than most by looking at how much they weigh. All speculation of course.

I know what you mean by maintaining forward progress without lifting or drooping the power head!

 

[steve easy]

If you have to push an akaskan mill somethings up, id go with bobl get one end of log up and let gravity give you forward momentum, work the throttle by hand if you have chain set up right theres no pushing needed saw should feed itself through. You can put tension up or down on a bar to counter the flex by loosening one end of mill while pushing/pulling on bar and retighten to where ever you want it. I have a 48" gb titanium i mainly mill with and has very little to no flex, and i have another standard gb bar about a 72" that wiggles like a snake when you give the saw a rev. I keep my chain tensioned pretty tight when milling , using plenty of oil through aux oiler for bar tip end makes a big difference.

 

[Mad Professor]

You only need the real long bars for real fat logs. I would go with 3/8 for less kerf, more lumber.

I have a logosol and made a take down ramp with steps from lumber I milled. I can roll on the biggest log the mill will handle using a peavy/cant hook by myself.

 

[BobL]

With my .404 bar on the mill, if one guy picks up on the helper handle, and another guy picks up on the saw, there is a lot of flex in the bar. Any up or down force applied to either during the cut will also tend to flex the bar. It takes an lot of concentration to apply the push force along the cut without any up or down force also being applied. Maybe I should had said flexing instead of sagging in my earlier post.

Yet another reason to work solo.
Steve has the right idea, get the log up on a slope and if everything is on song you can do this.
Thats a 60" bar cutting by itself on that little slope.
The mill rails do have 1/4" thick HMWPE runners underneath and the log rails are worn smooth from use.

 

[Dave Boyt]

Bob, looks like you're working way too hard!. I'm assuming that's a cable across the top that uses tension to help keep the bar straight, and that's attached to the magnet on the bar? A good source for a magnet is from the inside of a discarded computer hard drive. Those things are amazing!

 

[cityslicker]

One thing that I have been thinking of but have not yet tried on my granberg is to grind the four steel bar mount clamp pads (the actual piece of steel that literally touches the bar) with a slight up ward angle so when they clamp down on the bar it wil actually slightly flex the bar back upwards back close to flat. With my alaskan modified to fit a 69" titanium GB bar I have 1/4" or more sag in each slab which is ugly! Either that or completely redesign the alaskan mill so that it is boxed in better (kind of like an old wooden bridge) to stiffen the frame and the make the bar a bolt on type like bob's. Then make the actual mount stiffer and the metal that contacts the bar a bigger foot print thus forcing the bar to lay flatter, through better leverage. Also I still use .404 .063 skip tooth full chisel chain but I just round file it sharp. I have been wodering how well lucas mill super skip chain would work on an alaskan mill. I may try it soon as I have broke a few chains with the lucas lately and could shorten them to CSM length.

 

[BobL]

Bob, looks like you're working way too hard!. I'm assuming that's a cable across the top that uses tension to help keep the bar straight, and that's attached to the magnet on the bar? A good source for a magnet is from the inside of a discarded computer hard drive. Those things are amazing!

The thing that looks like a cable is just an "occy strap" to dampen the mill rattle and vibe. I did use the magnet from the inside of a hard drive in the first iteration of the anti-sag device but then one of the techos at work gave me a big fat Rare Earth Magnet (same as the hard drive type but 1" thick). Because my anti-sag device rides on the mill over time the saw/mill vibe actually reduced the magnetism in the magnet so I now don't leave it on the mill.

One thing that I have been thinking of but have not yet tried on my granberg is to grind the four steel bar mount clamp pads (the actual piece of steel that literally touches the bar) with a slight up ward angle so when they clamp down on the bar it wil actually slightly flex the bar back upwards back close to flat. With my alaskan modified to fit a 69" titanium GB bar I have 1/4" or more sag in each slab which is ugly! Either that or completely redesign the alaskan mill so that it is boxed in better (kind of like an old wooden bridge) to stiffen the frame and the make the bar a bolt on type like bob's. Then make the actual mount stiffer and the metal that contacts the bar a bigger foot print thus forcing the bar to lay flatter, through better leverage..

A while back I worked out what sort of tension would be needed between the tops of the uprights of an alaskan mill to take the anti sag out of the bar (i.e. a occy strap is not going to do much) It turned out that it would need something like 13 tones of force to remove 90% of the sag which would tear the mill apart so your idea of using angled clamps would be better. Somewhere I saw a photo of some metal wedges that just sat over the bar clamps that apparently helped but did not eliminate the problem. To get this to work you might need stronger bar bolts

.

 

[cityslicker]

Bob that is exactly what I had in mind except I was just going to grind the pad itself. Great drawing!

 

[BobL]

Bob that is exactly what I had in mind except I was just going to grind the pad itself. Great drawing!

The reason he used the pads was that they could be changed for different length bars. If you grind the pad then you are stuck with that bar length.

I have an idea of using an adjustable pad, one with a large bolt attached to the pad that pushed down on the bar on one side of the pad, and another bolt other side of the pad that pushes up. The drawback with that is loss of cutting width.

 

[cityslicker]

Tonight I have been setting up my CSM with the 69" GB bar on it. I cut some 1/8" wide strips of cheap hacksaw blade steel the length of the mounting pad and snuck them in between the pad and the bar while mounting the bar. with the nose side tight I noticed no difference, but once both sides were really tight the bar actually bows upward a bit! So I barley loosened the bolts till the bar is flat and it seems like it works! Will try tomorrow.