New member. Building D8

[Lil Giants]

A bare stock will pull it ok, but at least 3:1 additional gear reduction would be better control. Lock the rearmost axle.

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How do you lock the rear axle the gear reduction is that from rc4x4 ?

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I am building this project as cheap as I can here's the first axle. Using threaded rod with long nut on each end passing through 1/2 by 1/2 square tubing

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Here's anther view of axel. Like I said building this as cheap as I can I am make the wheels out of hockey pucks turning them on my lath. Still thinking of how to build the goose neck.

[Lil Giants]

Take the axle off the trk, split the plastic case, take the diff apart & there you will see the 3 small bevel gears on the cross. Slide one spider gear off the cross & drop it between the other 2. Reassemble the axle.

Locking the rearmost axle doesn't seem to hamper the steering too much, but does help immensely in pulling in the dirt. Of course 6wd is even better yet & adding Shoe Goo to front 2 diffs is the best for limited slip & great steering control.

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Great thanks will look in to it. Here is a few pics of axles installed

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Pic of axle pieces.

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I am going to put a new duel speed control in my king haule and was wondering if I could use a 12amp in it or should I go with the 25amp. Any suggestion
Thanks

[RCP57]

12amp should be fine. I use a Sabertooth 2x12 in my 850 Kenworth and it only overloads it while in high gear towing a load. The truck is around 100 pounds at that point.

[Lil Giants]

Here's Fumotec's PDF of his track hoe, scroll down to pg17 for the hyd system installation. It's the same system that Premacon assembles to sell as a kit.

http://www.fumotec.de/downloads/koma...tung-klein.pdf

Your pressure line on one side of the valve & the pressure relief valve on the direct opposite side. The other two ports should be plumbed back to the oil tank with inline filters. The one returning oil line will be Y'd to the prv.

Fumotec uses fuel tanks from helicopters (he is afterall an employee of Vario Helicopters) for oil reservoirs. Your dozer wouldn't need a tank capacity of any more than 250ml or so.

That Jung pump is capable of putting out 100bar (1400psi), so when you deadend the cyl stroke & the oil has no where else to go, the pressure line will explode in an instant! I hope you're wearing eye protection when you're messing this stuff?!

[Lil Giants]

Here's a couple of pics of my Norwegian friend Ole Iverson Vario hoe.




You can see in this pic at the left that the straight fitting is connected to the yellow return line, and the right angle fitting goes to the bottom of the prv. Then the side of the prv has a yellow return line Y'd with the above mentioned return line.

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Ok that helps a lot. Thank you very much. The pump I ordered was supposed to have a prv included but it's not with it. I emailed them yesterday but haven't heard anything back yet. It looks in the pics that there using rubber fuel line? In the PDF it looks like a line from one of the valve is returning with a filter on it. Not from the end of valve but from side.hope you know what I mean.

Just to be clear.
1-I will have a line from my tank to my pump
2 from pump to valve
3- from valve to tank with filter on one side of valve
4- directly accross from inlet from pump to valve I will put pressure relief valve with pressure gage then back to tank.
Why is prv y into return line from valve bank. Does that not back feed?

From control vales two lines to cylinders.

Sorry for being stupid trying to get it all straight.
Thanks again for your help. I am glade I went hydrulic works good. So once I get everything right it should work nicely.

[Lil Giants]

The CAD drawing is a little misleading, that return line is from the end of valve.

tank - pump - tee in pressure gauge - valve - prv - tank
the other port on each end are returning to the tank & each line has an inline filter.

The prv is Y'd to other returning line b/c where's the oil gonna go when it enters the prv? There's an in port & an out port on the prv. You understand how a prv works, right? A steel ball covers the inlet port, a heavy coil spring applies pressure to steel ball & an adjustable screw tensions up the spring so it takes a certain amount of oil pressure to compress the spring & allow oil past the steel ball. The oil entering the prv goes out a different free flow port.

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Yes I understand how the prv works just not clear on piping it. I really appreciate your help you are very knowledgeable. Now to get Prv that I didn't receive. I haven't received a reply yet. This forum rocks.
Thanks again.

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Now that I am back waiting for a prv I did some painting

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Ready for primer and paint

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Cab painted.

[Lil Giants]

Pretty good speed up/down, higher pressure might increase it somewhat, but it looks to be close for acting quick enough while pushing. Good work!

Is that a 3s or 4s lipo in the 1st vid? What's the brand name?

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This is what I was running pump with I bought it to run track motors I might use the same for pump. Or go to an 18v like Greg uses in his. The speed was good and that was with pump not running at full speed. At around 20 bar like you suggested. I need to look at sizes of 18 v battery as it's very tight for space. Is it ok to run pump at slower speeds? Or should it run at faster speeds when pump is working.

I have striped the dozer down and started to paint it. I have a few things that I need to make for it like the track bed. Windows and some other small details.
But it's coming along nicely.
Thks for looking and all the help.
Patrick

[Lil Giants]

I guess you look online to see what the rated voltage is for the track & pump motors you're powering & don't exceed that.
The Jung pump in my Vario is running about 4000rpm (4s 16,8v @600kv, motor is 10,800rpm with a 2,5:1 belt reduction), and I only rev it to the max (or near it) on boom lift. Stick, bucket & boom down is 1/2 to 2/3's of that
Other guys are running their Vario hoes with 3s... that's a bit slow for me.

Thanx for the pic... what's the LxWxH, plz?