RC4WD Excavator

[Papy]

I know Leimbach recommanded to run new pumps without pressure and on low RPM for some hours, increasing step by step up to the nominal, and then change oil before using them at full power.

The purpose was to allow the gears and casing to self-adjust together gently (sorry, can't find the english translation of the exact word we use in french for that operation...).....

[Lil Giants]

Yeah well, I was curious too to see what this new model on the market was like and an excavator is my favorite model to operate.

In the basement vid I had a 4amp NiMH pack in it. It was fully charged when I started and after loading that trk twice it was dead! The vid is the 2nd load. Much too fast of a kill rate. The 850, that pack will last about 25 mins of tough digging.

Outside vid, it was really cool temp this morning, model sat out there about twenty minutes before I started using it... can't see the oil thicking up that much in that short of time. The cord hanging out the back goes to a car battery, it's 18guage wire, I've used this small guage wire for yrs with the stahl hoe & it worked fine for the 850 as well. I checked the batt voltage, it was about 12.3v, a little low.

Tonite however, I made a new power cord from 14guage wire and that has seem to help, but the wire still getting warm after ten minutes or so of the pump running continuous thru the relief valve.

This brushless motor is about the same size as my 850, but the plumbing is the same size as the Stahl... might be too much motor for this hyd system.

I see in the radio settings that the EPA for the pump is set @23%. I tried turning it up and the motor stops increasing in rpm @35%, the 18ga power cord would get almost too hot to the touch within mins! Even now with the 14ga power cord, the wires get quite warm, but not hot.

I've left the EPA setting at 24%. and the 14ga has only a little bit of warmth to it.

Neil, I've been monkeying with the P-Mix settings in the tx, but I can't get it to work... don't know what's wrong there. It's a bit different than the DX8, as in a couple extra settings: offset, uprate, downrate. I've tried changing these values one way and the other to no avail. And the manual (translated from chinese) doesn't offer any insight as to what these values will do.

I guess if oil were a bad thing, something would blown up by now, eh Willy? Thanx for the insight.

Although, I've had leaky Leimbach pumps seeping oil into the electric brushed motor which causes it to labor for a short time till the oil burns out of it.

Papy, I did not know Leimbach had this recommendation for "break-in" (probably the word you're looking for?). But I did use a 7.2v batt during 1st time start up to fill the Leimbach hyd system to keep the oil foaming/air bubbles to a minimum while cycling the cylinders.

As I sit here typing/thinking about my pump motor problems, I'm thinking maybe this brushless motor is just a little too big for this hyd system. Back off the EPA to 22%, maybe decrease the relief psi a bit... more experimenting to do to get it to run efficeintly without killing packs so fast or cooking the power cord from a car battery.

[SmallHaul]

Joe, I applaud you for taking a chance on this purchase! You have so much experience with hydraulic construction equipment that I believe you made an educated guess from the photos and info that the gamble wasn't too big.
It seems to run quite well. The very high pitched sound to the motor/pump concerns me the most. It could either be a bad bearing or the magnets in the brushless motor are touching the armature.

[Papy]

Originally Posted by Lil Giants

.....Papy, I did not know Leimbach had this recommendation for "break-in" (probably the word you're looking for?). But I did use a 7.2v batt during 1st time start up to fill the Leimbach hyd system to keep the oil foaming/air bubbles to a minimum while cycling the cylinders.....

Break-in....yes ! Thanks ! could not remember at the time I wrote my message

This recommendation was not written in any operating manual. I read something about that on a german forum and then asked directly to Leimbach about this process.
Doing that, I have been able to operate [intensively ] a Leimbach pump at 18 bars (260 psi) for ten years before it breaks.

Using a 7.2 V battery for a while may produce the same effect.........