Goodbye Kubota, hello EarthForce

[MChalkley]

Re: EarthForce EF-5 usage report

Today, while I was out taking pictures of lights with the sun shining on them for Harv /w3tcompact/icons/wink.gif, I decided to see how grading works with the Rexroth "automotive" speed control system the EF-5 uses.

The reason I was curious is that it's not at all like the control mechanism a typical CUT uses, and therefore isn't a system I'm very familiar with - yet. With a HST-equipped CUT, you set the throttle, then control the transmission via the foot pedal. When you depress the foot pedal, you're increasing the flow put out by the HST pump.

With the EF-5, the "accelerator pedal" controls engine speed, and the HST pump, if the shuttle shift lever isn't in neutral, starts stepping up hydraulic fluid flow based on a combination of the engine speed and the amount of back pressure from the motor (in other words, the amount of work the motor is doing). To be honest, I had been thinking that I wouldn't really like this approach as well as the way it's done on a CUT, but I figured that there has to be some reason it's done differently - and I knew it was going to take me a while to get used to it.

So, today, I took the 4-in-1 and went out to an area that needed a little grading. I opened the 4-in-1 enough to use the front half of the bucket as a skid shoe for the bulldozer blade part, letting the blade cut about 2-3" of dirt. I pushed down about halfway on the accelerator pedal and almost nothing happened - it crept forward just enough to let the blade bite all the way into the soil, then stopped. I pressed the accelerator down almost all the way and it started forward, then began cutting pretty easily. I was mildly surprised, even.

The really interesting part is that the EF-5 really did do a pretty good job of adjusting its own speed based on the conditions. If it hit a root, it would slow down until the torque built up enough to cut it off, then speed back up again. All in all, it worked better than I expected it to, and I don't think it'll take as much getting used to as I originally figured. I'm not sure, but since I feel like everything just has to be tweaked, I think it would work a little better if the input curve on the pump was biased toward slower engine speeds a bit. I think it's favoring rpms that are high enough that it puts the engine a bit out of its peak torque band. I talked to a Rexroth rep and he gave me good news: he said that parameter is very easily adjustable, just a screw under a cap, and is sending me info by e-mail on how to do it. Something else to play with. Cool! /w3tcompact/icons/cool.gif

 

[MChalkley]

Re: EarthForce EF-5 usage report

I spent a few hours this week reshaping 2 miles of gravel road, and have another few more hours to go yet. It's been interesting making the transition from pulling a blade to pushing one. In my case, I'm using the 7' York rake with a drop-down blade. There's definitely more of a tendency for the blade to try to roll forward, pushing the front of the tractor up, especially when you try to use the blade with the FEL in float position, so it's taking some getting used to.

As with most things, though, there's a trade-off. I've noticed that it's a lot easier to move larger amounts of material, as when re-shaping the road, like I'm doing now. When that's done, and I just need to smooth, it may not be as easy as it was with my L4310 and 8' Landpride blade with trailing hydraulic gauge wheel. That combo is pretty stiff competition.

I noticed yesterday that, at one point, when I'd been cutting up to 3" of material at a time for about two miles, I had gotten the hydraulic oil temp up to 120 degrees, as measured in the 25-gal tank. The hydraulic pump and motor were hot enough that I could smell the paint cooking on them for the first time. I'm very impressed with the machine's power and dirt-moving ability.

I also double-checked the lifting capacity of the EF-5 using the 1.5 yd (struck) bucket on the FEL by filling it heaping full of crusher run. According to one of my books, crusher run weighs over 3000 pounds per cu. yd. dry, and this stuff was quite damp, so it weighs even more. But figuring it at 3000 pounds, and excluding the heaped quantity of material, plus well over 1400 pounds for the bucket, it was easily hefting 5900 pounds. Just the additional 1/4 yd of crusher run is another 700 pounds, plus the weight of the water, so we're looking at over 6,600 pounds. Let's just say that I'm not planning on putting bigger lift cylinders on the EF-5. /w3tcompact/icons/smile.gif

 

[Thomas]

Re: EarthForce EF-5 usage report

Interesting..I've seen a road rake attach to 4WD pick up plow frame and used that way,but not on a tractor fel.
Pulling compare to pushing the rake did you adjust rake or the fel so the blade wouldn't arch upwards and tines?
Hope you got some photos. [winks]

 

[Woodbeef]

Re: EarthForce EF-5 usage report

Hey Mark,

On the smoothing part. With your bucket on,how far does it curl under? What I'm getting at, like on certain TLBs you can grade with the bucket curled under and boom in float going backwards,and just back dragging. This works on JCB,Ford and others,but not on all Case ones.

 

[MChalkley]

Re: EarthForce EF-5 usage report

Woodbeef - Here's a picture of the bucket <A target="_blank" HREF=http://www.tractorbynet.com/forumfiles/19-93271-PC220025b.jpg>fully dumped</A>.

It dumps far enough to be just a bit past vertical, which is fine for grading, from my experience. Most of the time, if I'm grading while backdragging, I prefer to use the front half of the 4-in-1, opened just enough to allow the rear half to provide the right amount of depth gauge. That makes it easy to haul the dirt somewhere else, too. But if you're trying to use the dirt in the same place, filling in holes, etc., it's easiest to use the front edge, as you said.

 

[MChalkley]

Re: EarthForce EF-5 usage report

Thomas - I'm not quite sure what you're asking when you refer to adjusting the rake or FEL so the "blade wouldn't arch upwards and tines" - can you elaborate?

No photos yet - I was too busy learning to use it /w3tcompact/icons/smile.gif - but soon, I hope.

 

[Thomas]

Re: EarthForce EF-5 usage report

Just wondering what adjustment are made to the rake or the setting on the fel,so the tines and blade are level w/out digging in.

 

[MChalkley]

Re: EarthForce EF-5 usage report

Thomas - There was a major tendency for it to want to dig in when the wheels were out in front, unless I kept it up with the FEL. Now, with the wheels running behind the rake/blade, it doesn't seem to be as bad, but I haven't used it as much yet, so I can't say for sure. The FEL on the EF-5 is too heavy to be supported by the tires on the York blade by putting it into the float position, but it's not really designed to be operated that way, anyway. There's a separate "float" mode on the rake that allows you to lower the FEL below the point where it's holding the rake up, and it will then be supported by the gauge wheels, with the FEL just used to push it. This works pretty well, I think, but I don't quite completely have the hang of it yet.

But, basically, so far, I just set the gauge wheels to where they'll help hold the rake/blade where I want it (especially tilt-wise, i.e. side-to-side), then finish regulating the height, or depth of cut, with the loader lift control. Operated this way, there's very little tendency for it to dig in. It may reguire a little more attention than the rear mounted blade with trailing gauge wheel did, but I think I'll be able to produce about the same results once I get a little practice, and I definitely don't get the crick in my neck and back that I used to from looking over my shoulder all day while grading... /w3tcompact/icons/crazy.gif

 

[Thomas]

Re: EarthForce EF-5 usage report

Thanks Mark for the reply.

 

[MChalkley]

Re: EarthForce EF-5 usage report

As some may remember, arrival of my EF-5 was delayed a couple of months primarily because I wanted a hydraulic quick-attach for the FEL instead of the standard mechanical one. Development of it took longer than it was supposed to. Eventually, it was decided that I would just get the machine with the mechanical quick-attach instead, and the parts to adapt it to the hydraulic version would be sent to me when they were available. I received it a couple weeks ago, but I didn't like the the switch design they used (a rocker switch on the dashboard) to actuate it, so I waited until we could come up with the parts to do it the way I wanted it (a pushbutton on the 4-in-1 bucket lever, for reasons that will become clear in a moment).

Anyway, after talking it over with the powers that be here in the States, and even in a conference call with a couple of the EarthForce engineers in Prague, they decided that it belonged on the 4-in-1 lever, too, so they sent me the parts to do it that way.

So, today, a friend of mine and I installed the new hydraulic quick-attach kit, which makes my EF-5 the only machine in the world to have one. Surprised, aren't ya? /w3tcompact/icons/smile.gif

Anyway, I liked the mechanical quick-attach, but the hydraulic one is awesome. You just pull up to an implement, slip the FEL plate under the lip on the implement, lift the implement and roll it back, then hold the hydraulic quick-attach actuator button down and move the 4-in-1 control lever forward (as though you were opening the bucket). A solenoid diverts flow from the 4-in-1 circuit to pressurize the hydraulic quick-attach cylinder, which then locks the attachment on the FEL. Removal is just the reverse of the process. I don't know how relevant this is to others here on TBN, but I can post some pics if anyone is interested.