Multiple power heads

[betterbuilt]

That was kind of my point - lots of armchair experts around.

Then again - maybe the guy who says it's inefficient was running one saw backwards. In that case, I guess he's right.... 090 Contra - 076AVE = 029?

I figure if its even 10% faster it might be worth it.

 

[PhilB]

I've been thinking about the speed advantage of a two power head CSM. It seems to me if you had a big CC power head on a single head CSM, adding a second head wouldn't get you much of a speed increase unless it was a very large cut. But if you had a medium CC power head, adding a second meduim CC power head would get you to the required horse power, increasing the speed. It's a matter of having enough HP for the job.

 

[Daninvan]

I recently acquired a 4' long double headed bar. I will report back on how it works shortly. (Like a week or two)

Glad that I don't have to run one of the saws upside down though! I guess one will be the 'lead' saw and will get pulled into the log?

Dan

 

[betterbuilt]

I recently acquired a 4' long double headed bar. I will report back on how it works shortly. (Like a week or two)

Glad that I don't have to run one of the saws upside down though! I guess one will be the 'lead' saw and will get pulled into the log?

Dan

I'd be interested to hear how it goes. Your right on the lead saw. The first time I saw it, confused me.

 

[john taliaferro]

Phill B , I MILL WITH 88 MEANER heck in maple but in 48" white oak it could use a 460 or 660 pulling some slack . Iam just not patient enough i guess

 

[olyman]

This is something that was recently posted in the Aussie milling forum in a discussion of the engineering and Physics of twin powerhead setups.
I think it's an interesting post especially for those besotted with twin power heads to think about.

which is about what 820wards did--ex smaller power--

 

[BobL]

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The problem I see with two power heads is your chain still has the same size teeth and you still operate at a max RPM, so you will only cut so fast.
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Granted, the extra power head should help you maintain your max RPM under load. They make bars for twin heads, and if they didn't work at least half way well, people wouldn't buy them and they'd quit making them.
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I've been thinking about the speed advantage of a two power head CSM. It seems to me if you had a big CC power head on a single head CSM, adding a second head wouldn't get you much of a speed increase unless it was a very large cut. But if you had a medium CC power head, adding a second meduim CC power head would get you to the required horse power, increasing the speed. It's a matter of having enough HP for the job.

Cutting speed could be improved significantly by driving bigger sprockets and running much lower rakers - I've heard about rakers as low as 0.06 being used on 4 stroke slabbers

 

[john taliaferro]

Bob .06 what , how many degrees is that and what is a 4 stroke slabber ?

 

[BobL]

Bob .06 what , how many degrees is that and what is a 4 stroke slabber ?

Sorry, 0.06" for raker depths.
A 4 stroke slabber is ~20 HP four stroke engine and a 60" + bar all mounted on a carriage that runs on rails alongside the log. This is the Lucas Mill version.

 

[Bambi]

I haven't milled in a couple of years, too many other duties. Years ago 70's milled with a dual setup. It was big, cumbersome, noisey of course and very heavy. I thought it was the cats ass. It was easy gettin someone to run the other saw, but you had to pay attention to them. Getting someone regularly that had some experience, that would pay attention to you and things in general was a problem. There were some friends that, I would never let on a sawmill let alone a chainsaw ever again.
If we fast forward a few years, people knew that I milled back then and life moved on. One day someone put the bug back in me and I had 4' ash, maple and poplar to contend with. New saw, 3120, 54" Woodsman Pro bar (Canon) with the stinger handle. This gave me the option of goin dual. As for chain, I stuck with the Baileys chain as well as Granbergs. With two of us on the mill, we cut a 48" wide slab 17' long in around 15 minutes on fresh white ash. I didn't time this, someone else did.
Technology has changed. I have tried other chains, some cut leaving an coarser finish. I have also run this setup by myself. Most of the time I would be milling by myself. Not gonna happen with a dually.
I have also used regular new, not used motor oil as a oil in the auxilliary oiler and winter bar oil in the saw. Bar does run a lot cooler.
The issue that I am reading is how much faster can we go if we run a dually? 10%, 20%, 30%. Fuel is a minor part of the issue. The question is do you have a competent helper all of the time? Weight, this is gonna weight a ton. Cost, double end bars are bit more expensive and the cost of another saw, them big saws bring big money. For the amount of money it costs for so little a gain, it doesn't add up in my opinion.
I would opt for maybe a ported saw with improved muffler. Chain sharpening well my opinion BobL is the man. I like the Canon bars. I would put my money in the details getting more bang for my buck.
Many guys like Aggie and BobL have been milling giant wood with singles very successfully. I don't think I will ever see some of the giant stuff they mill, but if I do, I'll either buy a bigger bar or deal with it another way.
Though I would like to have another 090 or two, just to hear them bark once in awhile. I would rather work with the 3120 or an 088. Work smarter and not harder.
I would like to thank guys like Aggie, BobL, Woodshop where ever he is and many others. I enjoy their comments and the info they share, I have learned some tricks and many shortcuts. I appreciate all that everyone contributes.
Just my two cents.

 

[Bambi]

I think the guy is Edwards that built a mill with and old McCullough? motor, did a really nice job, sorta like BobL and his rigs. BobL just mentioned the 20hp 4cycle slabbers. I have a friend that runs motocross. He runs Kawasaki 125's. They sell basically the same motor for shifter karts.
If I was think of buildin a chainsawmill, like an Alaskan and had the money I would use one of them motors. Watercooled. If my memory serves me right they were gettin about 43 horsepower out of them and they spun 15,000 rpms. They are not all that heavy. With the prices of saws goin up, one of those might compare in price, but then you have to make it work. I could see BobL buildin the better mousetrap.
Just some food for thought.

 

[mtngun]

New saw, 3120, 54" Woodsman Pro bar (Canon) with the stinger handle. This gave me the option of goin dual. As for chain, I stuck with the Baileys chain as well as Granbergs. With two of us on the mill, we cut a 48" wide slab 17' long in around 15 minutes on fresh white ash. I didn't time this, someone else did.

0.227 inch/sec, thanks for the data point. That's believable, and it's not bad for a 48" wide cut.

 

[820wards]

Cutting speed could be improved significantly by driving bigger sprockets and running much lower rakers - I've heard about rakers as low as 0.06 being used on 4 stroke slabbers

Bob,

I changed out the sprocket on my mill that was running an 7 x .404 sprocket to a 8 x .404 and with BobL's calculations it increased the speed of the chain by 14%. Now my 134cc 820 PowerBee motor doesn't operate at 10K+ RPM, but the torque makes up for less RPM. With the additional torque the motor has I have also been able to set my rakers at .042" allowing me to make a deeper cut. I'm of the opinion that one good motor is less expensive to operate than two motors trying to ballet together.
jerry-

My mill with it's 134cc 820 PowerBee motor.

 

[john taliaferro]

Jerry what was the weight , my 88 , 60 cannon ,grand berg is 58 lb .

 

[820wards]

Jerry what was the weight , my 88 , 60 cannon ,grand berg is 58 lb .

My mill has a 38" bar and with the gas tank and two oil tanks full it weighs 62 pounds.

jerry-

 

[BobL]

You know the more I think about the dual head thing one thing does come clear. The guy who thinks that one saws gas tank has to be down obviously hasn't tried it.

Actually we (the Aussie) just worked out what he meant, he's not talking about the saw being upside down on the mill, he's referring to when a double ended mill using saws like 090s or 076s need to be fueled. On these saws the gas cap is on the top of the saw. That means to fuel up one saw the mill has to laid over on its side, then the other saw is upside down and to fill this one the mill has to be laid over the other. Still not that big deal I reckon.

 

[gemniii]

We visit this topic from time to time, and it is worthy of discussion for the new folks. The search engine isn't always the best for finding the information,

"The search engine" here is BROKE.
Google:
dual powerheads site:arboristsite.com.

I started a thread back in November, http://www.arboristsite.com/milling-saw-mills/151749.htm. Some good pics of woodrunner w/ a dually.

However most people just said buy a bigger power head. Then the thread degenerated into a beer thread.

People that hadn't tried it knew all the problems and why it wouldn't work.

Bumblebees can't fly, the earth is flat and the center of the universe.

Well it seems like always, I didn't express myself well enough.

I've got one 660 and just bought another from redlinefever, both about the same HP, same CC. Woodsrunner had a 395 and a 385, slightly different but the setup worked well for him.

When I need it I've got 2 strappin' helpers (bred them myself) handy and two more of the same family and age group on call.

I've got occasional LARGE wood. (I could get a steady supply, but it's not in my game plan). I want to prepare for the possibility to mill it.

Before I found woodsrunner's post I wasn't to sure about the viability of a twin powerhead setup. Virtually all the posts I found here and elsewhere were along the lines "don't do it", "buy one big saw", "requires a helper" "won't work", accompanied by "but I never tried it". The earth used to be the center of the universe, the world used to be flat.

I think one of the best comments from someone who purported to have done it was from Procutsaws Alaskan Sawmill and Procut Sawmill using Double Ended Sawbars from Procut Portable Sawmills .

Heck my little single 660 setup

can probably handle 36". And I didn't think 36" qualified as "very large".

So I'll be in the market for a good 72" double ended bar. I've got the saws, I've got the helpers.

Bottom line is it seems to work for some.

 

[betterbuilt]

Actually we (the Aussie) just worked out what he meant, he's not talking about the saw being upside down on the mill, he's referring to when a double ended mill using saws like 090s or 076s need to be fueled. On these saws the gas cap is on the top of the saw. That means to fuel up one saw the mill has to laid over on its side, then the other saw is upside down and to fill this one the mill has to be laid over the other. Still not that big deal I reckon.

That makes more sense.

 

[PhilB]

Am I missing something? (one power head having to be upside down).

I guess I did miss something. Thanks Bob for clearing this up.

Well it at least it got some of us thinking about how this all works.

Phil