I've got a small setup with a skidsteer and forwarding trailer. Any chance there's a way to power the trailer wheels off the skidsteer? Maybe with a motor driving each wheel? Running off the auxillarys? Probably be hard to keep same speeds in sync? I know a single bunk forwarder is made for the job, but this setup sure is handy for small jobs. Very nimble in the woods too :)
(https://forestryforum.com/gallery/albums/userpics/42544/KIMG0268~0.JPG?easyrotate_cache=1515779823)
Sure, but it isn't going to be cheap. You can buy a hydraulic motor, wheel drive assembly (with a brake if you want it) for around $2500 a pop. Weld them on, slap on your tires and wheels and hook them to your aux hydraulics. If you want independent motor control wire in a 12VDC diverter or flow control that you can trigger with one of your toggle switches to send the flow to one wheel or both.
In Nova Scotia lots of guy's used to have power trailers behind there farm tractors. They ran the differential on the trailer off of the power take off of the tractor and only used it to get unstuck. May work for you if you have a farm tractor.
many power carts here in nova scotia were built using the back end of an old truck with a 2 speed rear axle and the transmission. with ground speed pto on the tractor if you could match the ratios and gearing properly, it was an almost unstoppable combo.
when travelling between jobs, the operator would shift the axle between hi an low into "mexican neutral", to save wear and abuse on components.
this same setup could be used with a hi torque hydraulic motor on your skid steer, but, as stated earlier, it may not be cheap.
Yes, with a truck axle and a differential you probably get away for a lot less money.
Here is just another idea, years ago I ran a old forklift on top of a old barn to stack big square bales. I got it cheap without a motor, pulled the tranny and coupled the original crank driven hydraulic pump with a five horse electric motor I had. Then I went and bought a high speed hydraulic motor and mounted it direct on the diff. A food pedal and a old loader valve with a linkage was doing the forward and reverse. Just remember the faster a motor spins the less torque it has and the same thing the other way around. You find pretty rugged ones on old sander boxes.
Put a large BIG 80 roller sprocket on each wheel and run one motor . you would need a case drain hose and a over riding clutch . Or just chance out the axel for a rear end and run a HYD.motor on it. You will have to limit the speed to your hydraulic flow or use a over riding clutch .
Does the Bobcat have any trackgrips on the tracks to aid traction in the snow? Pretty hard on the tracks though in hard ice?. or go to a modern track on the bobcat with plenty steel in the track and a big 'rubber grouser bar'.
https://youtu.be/5rukCSDmKB8?t=3m19s
Would a tandem axle trailer spread the weight better.?
Do you have more pics and details on that trailer? It looks sweet!
All good ideas guys! Glad to know it's possible. I'd like to stick with the skidsteer rather than the tractor. It works much better to [short skid] to the trails than a tractor. And much easier to transport it and the trailer.
Quote from: krusty on January 12, 2018, 08:15:50 PM
Do you have more pics and details on that trailer? It looks sweet!
I bought it from a guy off craigslist a few years ago. It's got a long cylinder on the front that hooks up to auxillarys to dump. I don't use the dump with the bobcat. Just lift the loader up and "shake it off". I've used it with the tractor, but you've gotta have pretty nice wood so the logs slide off. Crooked stuff gets jammed up sometimes.
Quote from: Riwaka on January 12, 2018, 07:22:33 PM
Does the Bobcat have any trackgrips on the tracks to aid traction in the snow? Pretty hard on the tracks though in hard ice?. or go to a modern track on the bobcat with plenty steel in the track and a big 'rubber grouser bar'.
https://youtu.be/5rukCSDmKB8?t=3m19s
Would a tandem axle trailer spread the weight better.?
I stuck a few 3/8 grade 8 bolts through the underside. Might try longer and more of them. I think those trackgrips would be rough on frozen ground. I used to have a wheeled bobcat with steel loegerings, and welded some short snow chain links across the bars, and it was very rough. Also, the snow didn't clean out and stuck to them alot making it worse
The challenge is you have variable displacement drive pumps feeding the track finals, and a fixed displacement auxilliary flow out of the work ports on the loader couplers, which is fed off the charge pump. The charge pump really is to feed the drive pumps first and is meant to be run at rated rpm. Idling down to vary flow will result in lowered charge pressure which os detrimental to the high pressure drive pumps that make up the hydrostatic system.
So basically, its easy to use the remote hydraulics to feed a hyd motor coupled to a truck differential, but you cant modulate speed and it might be pretty challenging to operate where you arent fighting the two different speeds. Freewheeling could also be a challenge.
I can think of a hundred rub goldberg ways to try this however i think the most straightforward is a truck axle and driveshaft in the trailer. The driveshaft would go to a carrier bearing with a belt sheave on it. Next to that, mount a variable displacement piston style (swash plate) drive motor also with a sheave and belts. Use an idler to tension the belts when drive is needed. When you want to freewheel down the road, pop the belts off. The driveshaft allows the motor to be placed up near the tongue with the motor up out of harms way, no crawling under, snagged hoses or hooking it on a stump or submerged in mud.
The sheaves give a coarse speed adjustment incase you get things way off, and the variable swash plate kinda gives you a high/low range. This is exactly how the transport speed and work speed is achieved in burkeen trenchers and tennant sweepers. You get power in forward and reverse, with a neutral and two modes with a fairly easy/light and possibly affordable setup if youre good at scavenging.
The really complicated expensive way is to find a burnt matching bobcat undercarriage and build a bunk ontop. Your pumps could be run to the other drive motors in series or parallel. Series will run normal speed, parallel will run half. Thats the other way to get a hydraulic rabbit/turtle speed. A switching valve that goes from series to parallel.
Quote from: krusty on January 12, 2018, 08:15:50 PM
Do you have more pics and details on that trailer? It looks sweet!
(https://forestryforum.com/gallery/albums/userpics/42544/KIMG0243.JPG?easyrotate_cache=1515808945)
(https://forestryforum.com/gallery/albums/userpics/42544/KIMG0205.JPG?easyrotate_cache=1515808912)
(https://forestryforum.com/gallery/albums/userpics/42544/KIMG0242.JPG?easyrotate_cache=1515808900)
Might look around for a tractor wrecking yard and see if you can find any older tractors that had hydraulic front wheel assist on them that you could swap out. There were a bunch around in the late 70s/early 80s, bigger JD 30 and 40 series tractors come to mind
Or rear wheel drive off a wrecked combine would work too
Did you put a hitchball in the stump bucket?
I jockey around and dump a small trailer with my stump bucket as well, but it has a pintle and i capture it with a grapple tine. This way i can pick it up and put it down without getting out of the machine.
I torched a hole in the middle tooth of the bucket. Just a hitch pin. I should add some metal to the stump bucket to close tighter. Right now it doesn't close tight enough to grab a pintle. Good idea Mike!
I think what you are looking for is some help in the tough spots and corners not full time assist .
Maybe move the axle back a foot or two. That will put more weight on the skid steer.
Maybe a walking beam axle would go over rough ground easier but maybe turn a bit harder.
Nice rig ! ! ! 8)
If you had the dollars another machine - a Morooka (track dumper) with a log deck that is interchangeable with a tipper deck or a small JD or like bulldozer (dozer track loader?) that the trailer can be kept hooked to. There are a few accidents when the trailer is unsecured or is reattached etc sometimes. Probably find a dozer that is not as worn out as what the old forwarders are.
e.g https://www.machinerytrader.com/listings/construction-equipment/for-sale/22720515/1985-deere-450d
Quote from: Gearbox on January 13, 2018, 10:47:40 AM
I think what you are looking for is some help in the tough spots and corners not full time assist .
Exactly. Flat ground is a breeze. Hilly and rough terrain not so much
For the hydraulic control, a variation on a surge brake might work. If you need traction in one direction a brake controller might work. The master cylinder would control a slave cylinder connected to the valve that controls the drive. If traction is needed in both directions, you would need to build a dual directional surge controller. If the skid steer can not move; your stuck!
A heavy duty front axle with locking hubs would be nice for easy going. Also, this type of axle could be steered.
You could have a deck engine used to run the hydraulic drive, at the expense of adding weight and taking up room.
If a power assist is run by the aux hyd I'm thinking it would need over spin clutch and a valve that returns to open when let go, otherwise you run the risk of the cart pushing the skid steer over or at least mangling up the hitch.
Hilltop I was thinking of a PTO over riding clutch . You would have to figure how to back up . I guess you could engage the hyd. to back up limited speed .
I guess it would need a forward/reverse transmission after the over ride clutch, probably not that convenient in this situation.
Twist hubs is a great idea. But you wont find them in a junkyard off a rear end. An electric PTO clutch could be useful but its not gonna do anything special or as cheap as a belt idler. Look at your mower deck, belt idler has worked to turn that on and off for near a century. Much more reliable than a DC pto clutch also. Fwiw, the ones on york AC compressors are the strongest ive seen at throw away pricing.
An over running clutch is gonna help you get down in a hole you think u can make, get stuck and have no reverse to get out
Maybe one made like a 4x4 front hub will lock after 1 or 2 turns each way .
I appreciate all the feedback and ideas guys! Now I just need to figure out what will work the best for me. [ And find enough ambition to tackle such a project :)] I've kicked the idea around of getting a small cable skidder again, but people sure seem to like the idea of their wood carried not skidded.
I have a 742b bobcat in "farm condition" and a spare parts rolling chassis 743 that ive told myself will one day be grafted into a micro forwarder by putting OTT tracks on the power unit and cutting the spindles and chainbox/motor parts into a hydrostatic walking beam. I have a mercedes OM617 turbo diesel set aside for it.
My perception is that stave and veener tracts are being depleted and subdivided out of existence, hopefully im mistaken. But if not, and If i want my kid to ever cut veneer, it looks like im gonna have to go manage some stands 50yrs in advance for him.
Look at wheel motors in surplus center catalog or chain up a hyd. motor to a light truck rear axel as stated by others. Sizing the motor is tricky [ for me] but it could be a little to fast because you will need a flow control valve anyhow. Surplus has all this stuff and not that expensive.
How are loading that trailer? Looks like a couple cords?
Ya load with the stump grapple. In small wood like that his pile will stack out id say around 3/4 cord. I have a very similar setup that makes a half cord every time.
Yes, load with stump grapple. Trailer holds an easy cord. A big bypass grapple is on the wish list. I think I'd be able to 'short skid' much more to the trail each trip
For the amount of time and money you'll spend, I'd opt to put that towards a small tractor with front wheel assist and use that to pull the load, the skid steer to load it and use the hydraulics off the tractor to dump the load and I think you'll be much happier all around.
I'm not so sure a 4wd tractor would give me much more traction. The ctl grips & pulls well.