Author Topic: Head raise system (Read 1825 times)

waynorthmountie · « **on:** February 08, 2018, 06:02:48 PM »

I recently bought a peice of land which contains a woodlot with a 5 year plan of making it the location of our home. The short term plan is to build an off grid cabin for when we visit. Would like to build the cabin out of 8×8 from the trees on the property.

I am a person who likes to tinker and build thinks and plan on building my mill using an old bus frame for the base. My biggest dilemma comes when deciding on how to move the head up and down. I personally would prefer to use an acme screw for accuracy but see that most commercial models use a cable system and it also appears to be the moat popular style on home. Also i habe seen several spring assisted chain systems that seem amazing. Hydraulics is not an option as i would like to keep they system as simple as possible.

From owners and builder's experience what system would they use on their dream mill for a muscle power option.

Thanks in advance for your assistance

Ga Mtn Man · « **Reply #1 on:** February 08, 2018, 06:07:01 PM »

I'd use a gearmotor with chain and sprockets.

SawyerTed · « **Reply #2 on:** February 08, 2018, 06:51:27 PM »

This sounds like an ambitious plan....wood lot, build a saw, build a cabin, build a house in 5 years. Maybe I'm missing something or didn't understand the time line?

waynorthmountie · « **Reply #3 on:** February 08, 2018, 07:04:09 PM »

The cabin would be first. I would hire out the construction of the house as i have a full time job.

Yes i know its a pipe dream but if you dont think big you have nothing to push for. Cabin is gonna be dead simple. Just a box with a loft

Kwill · « **Reply #4 on:** February 08, 2018, 08:24:09 PM »

Quote from: Ga Mtn Man on February 08, 2018, 06:07:01 PM

I'd use a gearmotor with chain and sprockets.

that's the system I'd like to go with if I could figure out a good way to do it.

Den-Den · « **Reply #5 on:** February 08, 2018, 08:33:57 PM »

For a fully manual system, the lift needs to be simple and efficient. Cable with spring assist would be good.

Wudman · « **Reply #6 on:** February 08, 2018, 08:49:38 PM »

I built mine with acme rod. I used 1" by 5 threads per inch. It is a four post type mill with a single acme rod on either side connected by #40 chain. I have a steering wheel on one side pirated off a lawnmower for small adjustments. I have a 3/4 inch bolt head on the other side that I power with a Milwaukee cordless drill for more movement.......works very well for me. I built mine to build a house as well.....built the mill around 2000......moved into the house 2 years ago. It was done by a contractor. I could have done it myself, but I got married in the interim. Wives don't have quite as much patience as I do.

Wudman

kelLOGg · « **Reply #7 on:** February 08, 2018, 09:01:13 PM »

There is an extensive thread on this subject.
Bob

http://forestryforum.com/board/index.php/topic,16775.0.html

Kwill · « **Reply #8 on:** February 08, 2018, 09:12:54 PM »

Quote from: kelLOGg on February 08, 2018, 09:01:13 PM

There is an extensive thread on this subject.
Bob

http://forestryforum.com/board/index.php/topic,16775.0.html

not real extensive

waynorthmountie · « **Reply #9 on:** February 08, 2018, 09:56:42 PM »

Another question came to mind about head raise systems.

I have not seen a system that is counterweighted. A counterweight would limit the force required to lift the head and thereby make a gear/chain system more effective.

Or is there some reason this is not done.

Kbeitz · « **Reply #10 on:** February 08, 2018, 10:26:06 PM »

Quote from: waynorthmountie on February 08, 2018, 09:56:42 PM

Another question came to mind about head raise systems.

I have not seen a system that is counterweighted. A counterweight would limit the force required to lift the head and thereby make a gear/chain system more effective.

Or is there some reason this is not done.

I would think if the head was floating that it would enhance wavy cuts.
Best to let the gravity do its work and hold things down.

waynorthmountie · « **Reply #11 on:** February 08, 2018, 10:27:28 PM »

Quote from: Kbeitz on February 08, 2018, 10:26:06 PM

Quote from: waynorthmountie on February 08, 2018, 09:56:42 PM
Another question came to mind about head raise systems.

I have not seen a system that is counterweighted. A counterweight would limit the force required to lift the head and thereby make a gear/chain system more effective.

Or is there some reason this is not done.

And now it becomes painfully obvious.

I would think if the head was floating that it would enhance wavy cuts.
Best to let the gravity do its work and hold things down.

ladylake · « **Reply #12 on:** February 09, 2018, 05:54:04 AM »

Nothing wrong with using a counter weight or garage door spring to relieve some of the weight , surely don't want it floating. Also if using a worm gearbox make sure it a heavy duty one with a high ratio like 80 to 1 so it holds the head when stopped. A 20 to 1 or 30 to 1 might not.. Steve

Kbeitz · « **Reply #13 on:** February 09, 2018, 08:01:06 AM »

Acme rod come in 1 cut 2 cut and 3 cut. One is slow and 3 is fast.

Ga Mtn Man · « **Reply #14 on:** February 09, 2018, 08:08:24 AM »

I did not know that. So it's like course and fine thread pitch?

Kbeitz · « **Reply #15 on:** February 09, 2018, 08:31:17 AM »

Quote from: Ga Mtn Man on February 09, 2018, 08:08:24 AM

I did not know that. So it's like course and fine thread pitch?

No... It will have 1-2 or more starting threads.

What does multiple start mean? Lead screws can have more than one thread cut into the diameter.
A 1 start has only a single thread cut. A 2 start has 2 threads and
the motion per revolution is doubled from .1 inch per rev to .2 inch per rev. Similarly the 5 start has
5 separate threads cut into the outside diameter of the rod. This results in motion of .5 inch
per revolution of the screw.

pineywoods · « **Reply #16 on:** February 09, 2018, 10:18:09 AM »

I added a couple of garage door springs to the head lift on my manual wm lt40. Just enough to help a head lift motor that's a bit on the small slow side. Pics in my gallery. I know of one local mill that uses a couple of big lead counterweights. He removed the gas engine and installed a 20 hp electric motor...too much weight for the lift mechanism..

bedway · « **Reply #17 on:** February 09, 2018, 10:25:25 AM »

If you go to my photos you will see my process of adding a spring to my saw head. It has worked out great.

waynorthmountie · « **Reply #18 on:** February 09, 2018, 03:38:45 PM »

Bedway. Do you have a link to your complete build.

Also curious as to why you added the spring assist to the acme screw system.

Crusarius · « **Reply #19 on:** February 09, 2018, 04:08:58 PM »

I was thinking of adding a spring assist as well. It will be less stress on the motor and maybe less wear on the bronze bushings. The spring assist should never cause the head to float just make it lighter. Right now my motor is working well without the spring assist so that may be a future mod.

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Author Topic: Head raise system (Read 1825 times)

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