large scale RC

[pugs]

Stumbled on this awhile back, finally found it again. This is on the same lines of the stuff I want to build, RC controlled but quite useful as well.

http://video.google.com/videoplay?do...6840241254192#

[Lil Giants]

Ken Knolman from Winnipeg, Manitoba built that 1/2 scale New Holland skid steer. He had it listed on ebay couple yrs ago with a starting bid of $7000cdn... I was tempted, what handy lil toy to have around the farm... clean out the barn, clean up grain piles off the ground, snow removal... I wonder if he sold it yet, nobody bid on it then.

Ken also built a 1/4 scale Caterpillar 980 before the skid steer. Both machines ran on hyd orbit motors with 9hp Honda engines.

[pugs]

Are there any pics of the 980 on the web someplace?? Would like to see how it was done.

[Lil Giants]

I looked up his www that I had bookmarked when I saw your posting, but it has since been removed.

His 1/4 980 was nothing fancy, it was just similar in shape that had turf tires on it, like the skid steer.

[pugs]

I'm starting to think I'm going have to start drawing up plans for a haul truck or wheel loader now. Starting to get the itch........may take a few years to complete but thinking I should probably start.

[Thorsteenster]

I wouldn't mind trying something in 6th scale, I have a couple other 6th scale projects in the works, and 12" action figures work great for drivers etc.
Not knowing much about hydraulics though, I don't know if there are appropriatley sized components.

[dirtpusher9]

Originally Posted by pugs

I'm starting to think I'm going have to start drawing up plans for a haul truck or wheel loader now. Starting to get the itch........may take a few years to complete but thinking I should probably start.

Get after it Jeff, we need more builds in the construction department, more inspiration. Oh and btw welcome to the forum.

[pugs]

Thanks for the welcome,

I figure my pocketbook can't handle the build right now, but that doesn't mean I shouldn't do some CAD work in my spare time and get the thing figured out.

Right now I'm leaning towards a 1:5 scale Cat 797F haul truck with a diesel engine and hydrostatic drive. which would put the model at about 6.4' wide. Sounds big, and ambitious but I figure why not make something I can really use. Thinking I'll stick a hidden panel in somewhere with manual throttle control and maybe a 2 section auxilary hydraulic hookup, that way I can use it on the farm as a mobile hydraulic powersource for things like augers, logsplitter etc, as well as be a small dump truck for working on ATV trails down in the woods. Will try to build as scale looking as possible, but may change a few small things here and there to add to it's versatility.

Any other suggestions from the pros?? Eventually I would like to build a Letourneau wheel loader and a Liebherr excavator to go with it, and maybe a D11, but it will take lots of time just to get the first one built.

[dirtpusher9]

I've thought about the 2350B Letourneau loader as well for a while now, They build them about 50 miles up the road from me. It would be a moster in 1/10 scale though.

[Thorsteenster]

If you wanted to keep it electric, probably use one of these to power the pump.
http://www.hobbyking.com/hobbyking/s...ner_(eq:_70-55)
http://www.hobbyking.com/hobbyking/s...ner__(100cc_eq)
Eh, yeah, okay probably not for space to hold all the cells to power it, but they are some bubba sized outrunners.

[pugs]

Holy cow, them some biguns.

I much prefer hydraulic power, seeing as it's needed for the dump and such, doesn't take much more to make it drive as well. I could do electric drive and put a big ac generator on the engine...........maybe the L2350 wheel loader could be that way to stay with how the real ones are.

I'm already thinking I may end up putting a PLC inside the haul truck version and then I can put a larger industrial scale actual servo motor with encoder feedback on a hyd steering valve for the steering system. Maybe PSI sensors in the 4 nitrogen over hyd shocks and have a load weight readout like the real ones have off the PLC as well

[D8R]

If you go big like the 797 you can use eaton hydrostatic trans like:

http://hydraulics.eaton.com/products/pdfs/07-403.pdf

or maybee go for a rear axle ready like:

http://hydraulics.eaton.com/products...LD-MC002-E.pdf

I was concider this trans for my D8R but it was to big to be built into the model. Best part with the eaton trans is that you have speed control, reverse and braking built in. It "only " to connect the engine to input shaft. Then of course some small metal fabrication.
Check video on other tread about 988, there´s the A35D dumper project in the end. This dumper is built with mecanical driveline (incl gearbox, 2 speed and reverse). Power to cylinders can easily be done with a small gearpump, then you don´t need big oil tank for the transmission
Keep up modeling!
Dan

[pugs]

I was thinking about a variable displacement pump and a motor on a custom rear end with like ford 9" differential guts in it. The pump would be just like the ones in a skid steer, only one section, this would give fwd, rev, braking in a closed loop system and a cushion valve in the motor lines would give emergency braking

Then it's just a small hyd pump for the bed dump, steering motor, and shock adjustment.

I'm thinking the drive motor would be a 2 speed motor for speed range, but the pump has the control for actual speed adjusted by a servo. Thus I would have 2 speed ranges fwd and rev but still infinatly variable in those ranges by stroking the pump in or out, plus have engine throttle adjustments on top of that yet too. Thinking a 3 pos switch on the radio could easily be rigged to run the engine at idle, mid idle, or high speed.

[grumpygrady]

at 6' 4" wide you would have room to put a 12 volt motorpump unit in it like this
http://www.splitez.com/hydraulic_DC_Pump.html
or this

http://www.northerntool.com/shop/too...mp%2B12%2Bvolt

[pugs]

Could do electric, but I was thinking a 20-40 hp Kubota diesel depending on what fits and what I can find

[JAMMER]

I must say after buying that 1/12 scale excavator and the size that these models are getting you could almost get the real thing used for the money that is being spent. Ed

[pugs]

What would be the fun in that?

[JAMMER]

Well then you wouldn't have to dig up the flower bed and get the old lady mad you could dig up the hole yard. Ed

[Lil Giants]

Have you ever seen this site?

http://www.wessels-modellbau.de/

This guy is 1/2.5 scale and uses his models in his earthmoving business. I seen a vid where he was digging a grave site.

[pugs]

No I hadn't seen that one before, thanks for the link