Firewood processor design trouble

hedgerow · May 27, 2020, 09:58:58 AM

Quote from: Demetrio on May 26, 2020, 01:05:57 PM

Hi @hedgerow , I'll throw a look around to see if I can be as lucky as you and find a surplus/second hand cylinder. I had a quote for a new one (anterior flange, 100mm bore, 600mm stroke, 60mm rod, 1/2 inch ports) and it would cost something around 400$.

I wouldn't think that was a bad price but I would have it built with 3/4 ports also. I did get lucky and bought this cylinder cheap. It was new but had been setting for years so it went to the hyd shop and was honed and had heavier seals and glad rings installed before it went on the processor. Its a six and half inch cylinder with a four and half inch rod it has a 36 inch stroke but I only use 24 inch most of the time. It actually has two one inch ports and I feed it with two pumps and engines to get the speed up.

Demetrio · May 29, 2020, 05:49:46 AM

Hi wiam, I'll look if I can have bigger ports. Yeah, I think that 400$ is not that bad, especially considering that you have something brand new.

Hi jmur1, that's clever, even if I do not have the necessity of cutting different lengths (I would cut 18-20 inches). I totally agree with you, it's better to spent time in the design phase and then start the build. I'm considering 600mm rollers (maybe slightly less/more). I'll keep an eye on the tank design as soon as I start to sketch the hydraulic circuit. Thanks for all the valuable infos! I've seen your firewood processor; that's a hell of a job! Really nice design! I'm still considering the benefits of using a circular saw, even if it feel less safe to me (but that's only a feeling).

Hi hedgerow, changing the seals wouldn't be a problem for me, I've already done it and it's a cheap operation. I'm more afraid of finding rust/corrosion inside the cylinder which would be a serious issue.

Thanks for the help guys!

Demetrio

hedgerow · May 29, 2020, 11:06:04 AM

Demetrio
I was a little worried about rust and corrosion but the cylinder was within driving distance 200 miles and still had pipe plugs in it been stored inside. So when I got there we pulled two of the plugs and hung the cylinder on a fork lift so it could be extended and the rod could be inspected. Rod looked like the day it came out of the factory. I to would be worried on buying a surplus cylinder spending the money and freight and it shows up full of rust. I wanted a six inch plus cylinder with a over size rod and getting one built wasn't in budget. If your not going to be cutting huge dia wood I sure would look real hard at using a circular saw. The cost of a making hyd chain saw adds up quick.

Hilltop366 · May 29, 2020, 12:36:02 PM

Or the rarely spoken about option 3, bandsaw. I wonder how it holds up?

Malkas skaldÄ«tÄjs - procesors Mottimaster XL - YouTube

Demetrio · May 30, 2020, 05:11:15 AM

Hi hedgerow,

my main fear with a used hydraulic cylinder would be rust inside the cylinder. I had (still have) a cylinder from an excavator which looked pretty rigth from the rod, but had serious corrosion inside the cylinder. That would be hard to inspect before buying, unless you have the opportunity to disassemble it. But I guess it is not worth, unless it comes very cheap and close to home. Another practical way to test a cylinder would be to put pressure in it and close a port (close the lower port). If there's any leakage the rod will extend. But then you don't know if it is due to the seals or to some corrosion inside. I was considering a circular saw mainly because I find it easier to design/build; but it's limiting, since you need a diameter which is at least twice and a half the size of the average log. Yeah, I'm experiencing the hyd chain costs ramping up quickly :D

Hi Hilltop366,

I was also wondering why almost no one is using bandsaws. I have one vertical bandsaw and the main issue is to keep the piece of wood straigth during the cut (no torsion on the saw blade), otherwise you'll break the blade/stop the blade. I think that's the main reason. It would be hard to keep the log perfectly still while cutting, especially if it is crooked (indeed in the video they're cutting a pole basically). I see no other cons. Anyway it's an interesting solution, far more efficient than the most common ones, and safer I'd say. I've seen also guillottine systems, but they're pointless in my opinion.

Demetrio

thecfarm · May 30, 2020, 05:45:43 AM

Bandsaw? Never seen that before.

wiam · May 30, 2020, 08:13:34 AM

I have been happy with my belt driven chainsaw on mine.

jmur1 · May 30, 2020, 08:50:58 AM

I was impressed by the bandsaw video. I had thrown around that idea when I got started my build, but I knew how it fails on dirt and bark (from my woodmizer exposure) so I didn't pursue it far! It would need sharpening every 2 hours or so. 50 ways to skin a....

The guillotine option also grabbed my attention but the hp and cylinder size show a built in slowness for any large logs. I am pretty sure the two main (efficient) options are circular or chain.

I wonder if there is a water jet version yet?

Demetrio · May 30, 2020, 01:24:39 PM

jmur1,

I don't think that wj would work easily, unless you keep the nozzle fixed and you rotate the log around its axis (the nozzle has to be very near to the surface to be cut, otherwise you'll loose too much energy due to the interaction with the air). Also it would be quite overkill for the job :D. And it's extremely costly to operate. It works fine when you have planar pieces to cut, and not extremely thick. Plus it does not heat up the piece, spoiling mechanical properties as laser cut would do. Would be funny to try though ;D. Anyway I found a crazy video:

ULTRA HIGH-PRESSURE WATER CUTS THROUGH LOG www.TrashBinCleanersDirect.com - YouTube

hedgerow · June 02, 2020, 04:01:01 PM

Quote from: wiam on May 30, 2020, 08:13:34 AM
I have been happy with my belt driven chainsaw on mine.

If I were building mine again today I would go belt drive using a AC clutch off a york compressor. Save a ton of money over building a hyd saw.Now that I am done with a lot of the larger locust wood I had to process I wish mine was a circle saw. I just get tired of dealing with chains and the oily mess saw dust. Processors are like most pieces of equipment one size doesn't fit all. If I knew what I know now I probably wouldn't have built a processor. With my operation were I come off the processor and stack in trailers that hold around three cord working wood by myself just doesn't work that well. I have to stop the processor and conveyor and stack wood in the trailer if I just conveyor pile in the trailer the load is too small. Honestly the best way for me is if one of my two helpers come out after work and I hold logs up with the skid loader and it just bucks the wood to get around two or three cord and then an a Saturday he and another buddy of mine show up and we split and load and stack in the trailer. Having the blocks ready really makes doing three cord split and stack a nice day for three older guys.

Demetrio · June 04, 2020, 03:58:03 PM

Hi hedgerow, how would you eventually power the belt driven chainsaw? I might need to add a belt transmission between the hydraulic motor and the chain sprocket in order to reach the proper cutting speed. But then I would also need a system to tension the belts, and I don't really like the idea. I've red that the ideal chain cutting speed is somewhere around 80 feet/s, which is hard to hit using a hyd gear motor directly driving the sprocket (even considering the biggest sprocket).

hedgerow · June 04, 2020, 06:04:00 PM

Demetrio I didn't explain very well. If I was building one today I would belt drive it direct from a gas engine and cut the hyd motor out to save a bunch of money on hyd's. I used a surplus bent axis fixed displacement piston motor I found to run mine so I have a lot of speed and power but it takes a lot of hyd power to make it happen. It makes a 40 HP motor get down and pull. Look up Danzco saw on the internet he builds hyd saws using gear motors and he gets enough speed out of them to direct drive them. He won't sell you just a motor but he is a good source for chain sprockets and I did buy mine from him. Nice people but they aren't going to give away all there secrets. It complete saws were out of my budget. Search on this forum there are a couple of firewood processor builds that used gear motors and there saws work.

Demetrio · June 05, 2020, 06:31:33 AM

hedgerow, I couldn't agree more, Parker has some hyd motors specifically meant for firewood processors (f series, bent axis fixed displacement piston motor, high speed), but they are over 1000$, which is a lot of money. That's the reason why I decided to switch to gear motors. Only problem is the max rotating speed. So I was considering: 1) a transmission drive to increase cutting speed; 2) direct drive with sub optimal cutting speed. Rigth now I'm leaning toward the latter, since it wouldn't be a big deal. Thanks for the advices, I'll throw a look at Danzco systems.

wiam · June 05, 2020, 11:21:13 AM

This thread shows my belt drive https://forestryforum.com/board/index.php?topic=104672.0
Single 5/8 belt was not enough. My motor is fixed, which is why I went with link. Still slipped so I added an idler/tightened.
I can still slip the double belts if I push it too fast.

Demetrio · June 06, 2020, 01:30:38 PM

Thanks wiam, you've done a great job with your processor! My idea is still to use the hyd motor to power the saw. Almost surely I'll have to add a belt drive (double belt) to increase the sprocket rpm, but I was thinking of a more compact design. I'll post progresses soon!

wiam · June 06, 2020, 06:31:30 PM

You can vary your chain speed quite considerably with different tooth count drive sprockets.

Demetrio · June 07, 2020, 05:23:08 AM

Hi wiam, I agree, but even with the biggest sprocket (18 teeth is the biggest I found) I'm still pretty under the desired speed. Also, a big sprocket would require a proper bar. I just need to find the best compromise between perfomance and costs.

Hilltop366 · June 07, 2020, 08:06:28 AM

Don't forget to add raker depth in to the equation, a .404 harvester chain has a tall tooth with a 50 thousand inch raker depth and well take a big bite compared to a regular saw chain that would be 25 to 30 thousands. The cutting speed may surprise you even at a slower chain speed.