Kubota servo-controlled mechanical HST vs full mechanical HST

[troverman]

So I noticed my new MX has "hydraulic servo controlled" HST pedals while my 2013 B series does not. I guess on the MX, when you push the pedals, you are operating a small hydraulic valve that itself operates the full HST valving. On the B series, you are operating the valving directly. The idea is apparently to make pushing the pedal easier. It does do that, but you lose your "feel" for the transmission and how hard you are working the tractor. Frankly, I prefer the old method better.

Anyone else have experience with this?

 

[Holleyman]

I agree with you. I prefer the "feel" of what the unit is doing, instant feedback.
We are an old breed. Most new equipment go with smaller pilot controlled or even EH (electro-hydraulic) controlled circuits for operator comfort. If you think pilot control has little feedback, EH has zero.
New D11s are almost as plush and comfortable as cars these days, you operate these 110 ton machines with as much physical effort as playing a PS4.

 

[SDT]

So I noticed my new MX has "hydraulic servo controlled" HST pedals while my 2013 B series does not. I guess on the MX, when you push the pedals, you are operating a small hydraulic valve that itself operates the full HST valving. On the B series, you are operating the valving directly. The idea is apparently to make pushing the pedal easier. It does do that, but you lose your "feel" for the transmission and how hard you are working the tractor. Frankly, I prefer the old method better.

Anyone else have experience with this?

I have both, B1750HSDT, B3350 and L6060.

I expect that Kubota uses the same basic HST transmission without some of the bells and whistles in the MX as is used in the L6060. The servo control is necessary on the GL tractors to allow computer control of the HST+ features. Response is operator programmable in the GL tractors.

I find the servo control system less tiring but do not like the design of the pedal.

I determine load by sound, although that is more difficult to do with the L6060 because it sounds more like a zero turn mower than a tractor.

SDT

 

[NoBiffBetter]

So I noticed my new MX has "hydraulic servo controlled" HST pedals while my 2013 B series does not. I guess on the MX, when you push the pedals, you are operating a small hydraulic valve that itself operates the full HST valving. On the B series, you are operating the valving directly. The idea is apparently to make pushing the pedal easier. It does do that, but you lose your "feel" for the transmission and how hard you are working the tractor. Frankly, I prefer the old method better.



Anyone else have experience with this?

I don’t have experience with this but I completely see where you are coming from and how it could totally kill your feel of the petal and how hard the transmission is being worked..

I was a vehicle mechanic for years and always loved throttle by cable.. now everything is throttle by wire which means there is a sensor that is controlled by the foot pedal which then communicates with another sensor at the throttle body which then opens the throttle plate.. even tho you wouldn’t ever get a “feel” for how hard a vehicle is working I still can’t stand throttle by wire.. one good reason is that throttle by wire has a horrible lag IMO, the lag is totally noticeable especially in lower end cars and trucks.. throttle by cable was always instant, if you wanted to floor it you punched the petal to the floor and felt the instant power.. now all you feel is hesitation and lag lol

Like I always said.. if it ain’t broke don’t fix it! This goes for you too Kubota!


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[mikester]

I prefer the servo controls over mechanical valves as it feels smoother, is less fatiguing, and is easier to control, especially over bumpy ground. The adjustable servo response is handy and in general servo HST is less herky-jerky for me.

I never liked the old Kubota manual HST valve controls.

I find that the HST servo control and auto-throttle on the M59 works very well and it never seems to run out of power. Considering the price of the machine I wish the loader and backhoe controls were servo as well.

I've had a chance to run many different brands over the years and I found the JD servo HST control is the nicest and smoothest I've had a chance to operate.