Improvements You Need on PT

[BobRip]

Another can of worms. What improvements would you like on the PT that have not been discussed extensively on this site? Yes, new needs.

 

[Baby Grand]

I sense a think tank.

 

[Clumber]

I would like to see some sort of govening device on the joystick and treadle controls to prevent jerky movements. Sometimes these controls react like a hair-triger. When working with the very heavy attachment such as the snow blower I realy have to concentrate to achieve a slow movement of the FEL arm. A lot of times the heavy weight moves and stops too fast causing the heavy attachment to bounce which causes the whole tractor to begin bouncing. This is a scary situation. Also, sometimes I would like to have very fine movements similar to the inching capability on the Kubotas.

 

[J_J]

You could install a thumb controlled solenoid diverter valve and divert the fluid through a restrictor for those slow operations you need. Switch off, hyd work normally. Switch on, the hyd operate in the slow mode.

You can also reduce engine rpm which will reduce flow. Will still have good pressure.

To slow the hyd manually, a pair of gate valve would route the fluid through a restrictor for slow operation, or one of these.

https://www.surpluscenter.com/item.asp?item=9-6133&catname=hydraulic

 

[KentT]

Doubt you'll hear too many "new needs' since these machines have been discussed in depth...

Some things I'd like to see:

1. A float position on the lift arms that doesn't "bounce out of float" on rough terrain.... It needs to be "set and forget" similar to putting the 3-PT hitch down on a normal tractor. Doesn't need to be as complex and expensive as true draft control on the larger machines ...

2. Aux PTO controls up beside the steering wheel, rather than needing to do shadetree engineering to do that. A cable-operated control lever would probably cost less than $50 in additional parts, if installed when these things were built, and would require only VERY MINOR changes to the current design. The hydraulic circuits and control valves could remain where they are...

3. A stronger pivot joint between the two halves of the tractor. IMO this is the most stressed and potentially weakest link in the entire PT design...

4. Increased lift height on the smaller models -- even the "improved" 60" on the newer 425s is not enough. It needs to be 72" IMO.

5. Adaptor plates that would let you use mini-skid attachments on the smaller machines and skidsteer attachments on the larger ones -- while maintaining the PT advantage of hydraulic control over them, rather than manual pins/latches... (Never will happen from Tazewell, IMO, because they want to sell their proprietary designed attachments that are sized for only one class of machine).

6. True emergency/parking brake systems that activate automatically on the loss of hydraulic pressure... some wheel motors have this built-in, at an additional cost of less than $100 per wheel motor.

7. Wheel motors that are designed strong enough that reversing wheels or adding wheel weights or dual tires won't compromise the reliability...

8. Finish mower decks with a provision for adding a vacuum collector and bagging wagon...

9. Heavier duty rough-cut mowers...

10. Easy way to plumb in a control a rear hydraulic circuit for dump carts/wagons, etc.

11. Rear connectors for the main PTO circuit so you could power attachments off the rear of the machine, such as towed brush chippers, etc.

12. Published specs for hydraulic motors and pumps so it would be easier to size the motors required for custom attachments...

13. Factory provisions for ball hitch on the rear -- the current design only complicates things and serves little practical value. A plate that would support a 2" ball would likely cost less that what they currently use...

14. Adjustable forklifts for the smaller machines.

15. Post hole diggers that used common aftermarket augers instead of their proprietary design.

16. Male and female connectors on the AUX PTO circuit (similar to main PTO circuit) that prevents you from accidentally crossing the circuit for attachments. This wouldn't cost them anything extra, in the big scheme of things...

17. SAE-standard hydraulic quick connect fittings instead of these strange Italian connectors...

That's a quick brain-dump... I'm sure I could come up with quite a few more....

 

[MossRoad]

Only 17 items. Is that all you got? :laughing:

Good list! :thumbsup:

 

[Phils]

I would like to see some sort of govening device on the joystick and treadle controls to prevent jerky movements. Sometimes these controls react like a hair-triger. When working with the very heavy attachment such as the snow blower I realy have to concentrate to achieve a slow movement of the FEL arm. A lot of times the heavy weight moves and stops too fast causing the heavy attachment to bounce which causes the whole tractor to begin bouncing. This is a scary situation. Also, sometimes I would like to have very fine movements similar to the inching capability on the Kubotas.

I installed some restriction valves that have worked great and are easy to adjust. I only installed two for the FEL arms, but it's easy enough to do for the other circuits too.

http://www.tractorbynet.com/forums/power-trac/49694-hydraulic-flow-restrictors.html

Phil

[on edit] in looking at that old thread, maybe I put the restrictors on the curl circuit. It's been SOOOO long and my memory isn't as good as it used to be, and it used to be pretty crappy. I put them in so I'd have better control of the stump grinder. I don't think I've messed with the restrictors since, things just work as I expect them to.

 

[Clumber]

You could install a thumb controlled solenoid diverter valve and divert the fluid through a restrictor for those slow operations you need. Switch off, hyd work normally. Switch on, the hyd operate in the slow mode.

You can also reduce engine rpm which will reduce flow. Will still have good pressure.

To slow the hyd manually, a pair of gate valve would route the fluid through a restrictor for slow operation, or one of these.

https://www.surpluscenter.com/item.asp?item=9-6133&catname=hydraulic

I am assuming that reducing RPMs means easing back on the throttle? Also, is lift capacity and height affected by restricting flow or reducing RPMs?

 

[J_J]

I am assuming that reducing RPM's means easing back on the throttle? Also, is lift capacity and height affected by restricting flow or reducing RPMs?

Yes on the throttle. Height and lift capacity is not affected.

Engine and pump speed affect the speed of operation.

 

[Clumber]

Yes on the throttle. Height and lift capacity is not affected.

Engine and pump speed affect the speed of operation.

Thanks JJ, great suggestions.

 

[Clumber]

I installed some restriction valves that have worked great and are easy to adjust. I only installed two for the FEL arms, but it's easy enough to do for the other circuits too.

http://www.tractorbynet.com/forums/power-trac/49694-hydraulic-flow-restrictors.html

Phil

[on edit] in looking at that old thread, maybe I put the restrictors on the curl circuit. It's been SOOOO long and my memory isn't as good as it used to be, and it used to be pretty crappy. I put them in so I'd have better control of the stump grinder. I don't think I've messed with the restrictors since, things just work as I expect them to.

Thanks, would you have any photos or videos?

Patrick

 

[MossRoad]

I am assuming that reducing RPMs means easing back on the throttle? Also, is lift capacity and height affected by restricting flow or reducing RPMs?

If the torque of the load exceeds the torque of the engine, the engine will stall.

You can prove this by putting your FEL bucket under the bumper of your truck and trying to lift it at idle, medium throttle and high throttle.

At idle and probably at medium throttle, you will stall the engine, while at high throttle, you will pick the back of the PT off of the ground (or pick your truck up, whichever comes first).

 

[MossRoad]

Also, on a gas engine like in our PT400 series tractors, the engines are meant to run at a constant 3600 RPM for cooling purposes. While there is little to no chance of overheating the engine by running it at low RPM for precise control in tight situations, you should be aware that running the engine under 3600 RPM for long durations with a heavy load on it could overheat the engine.

 

[J_J]

Just curious what the 425 can lift with extra weight on the back. Have any of you checked your relief pressure?

 

[BobRip]

Just curious what the 425 can lift with extra weight on the back. Have any of you checked your relief pressure?

On the 422 I lifted an 819 lb rock with the fork. I had a weight of 110 lbs and my neighbor (about 170) on the back. I doubt if it could lift more. I could not steer very sharp or the tail would lift.

 

[Clumber]

Also, on a gas engine like in our PT400 series tractors, the engines are meant to run at a constant 3600 RPM for cooling purposes. While there is little to no chance of overheating the engine by running it at low RPM for precise control in tight situations, you should be aware that running the engine under 3600 RPM for long durations with a heavy load on it could overheat the engine.

Interesting discussion. Lots of questions come to mind. Without a Tac, how does one estimate the engine RPMs. How much throttle should be used for different tasks and attachments. For example, should your run full throttle when mowing or brush hogging -- will that overheat the engine. Is half throttle about 3600 RPMs???

 

[Phils]

Thanks, would you have any photos or videos?

Patrick

If you read far enough in that thread you'll find a pic of the two valves installed.

Phil

 

[BobRip]

Interesting discussion. Lots of questions come to mind. Without a Tac, how does one estimate the engine RPMs. How much throttle should be used for different tasks and attachments. For example, should your run full throttle when mowing or brush hogging -- will that overheat the engine. Is half throttle about 3600 RPMs???

Wide open is 3600 rpm. Mowing is one of the toughest loads, always mow at full throttle For intermittent loads you can cut back, but never lug an engine. Going down hill I wil throttle back and then raise speed going up hill. Sounds too complex, wide open all the time.

Lots of good ideas here. Thanks.

 

[J_J]

Hyd pump GPM's is determined by engine rpm. High engine rpm equals faster cylinder speed, and a faster hyd motor as on attachments. .

 

[KentT]

Unless I'm using a mower deck or the stump grinder (i.e. a powered attachment), I usually operate at about 3/4 throttle all the time --then speed up/slow down if tramming a long distance. It slows down the hydraulic actions enough to where you can control them. It's almost impossible, IMO, to use the mini-hoe with any accuracy when running full throttle. The lift/curl circuits are just TOO jerky -- I'm slamming and banging all the time, unless I slow the engine down. I may have to think more about putting restrictors in that curl circuit. But, as Bob cautions, I also make sure not to lug the engine.

I'm surprised there haven't been more suggested improvements...