[vestaviascott]

I've recently acquired my first zero turn mower. I have a residential lot totaling about 1.5 acres that is sloped from about 10-15 degrees. As you might imagine, cutting on a 15 degree slope can be a bit of a challenge with a zero turn mower.

So much so that as a test, I decided to see if I could place my foot against the outside edge of the uphill caster fork to keep it from turning towards the downhill slope. This is actually quite effective, but also quite dangerous and not a long term solution by any means. But it does prove that the idea of momentarily or on-demand locking one or both casters in place can be effective for slope control.

I began thinking of ways in which to mechanically hold or lock the caster assembly in place during the long stretches across the yard. The means of hold would have to be easily swapped from free swivel to rigid caster travel (to allow for turns and manuevering around obstacles of course.

In my research, I have come across two examples: one commercial solution and one DIY solution.

First, here is commercial solution:

Second, here is a DIY solution:

Both of these solutions are similar in that they both address the problem of improving slope control and wheel traction for zero turn machinery.

However, both solutions appear to be fairly finely tuned for the platform in which they are attached to.

My idea is to discuss an approach to the problem in a simpler manner that would have the potential to be applied to a wide range of existing zero turn mowers and machines using the simple idea of a swivel caster locking mechanism paired to a .5 inch square slot cut out on the caster fork.

Here is a video in which the general technique is described:

As you can see from the video, a simple latch mechanism, paired with a slot cutout, can act as a key/lock mechanism to regulate the caster's motion between rigid and swivel.

What are your thoughts on this idea?

I'm thinking that an ideal solution would be a universal add-on device consisting of a movable spring loaded bolt/latch designed to interlock with the caster fork cutout.

The utility of the device would be greatly enhanced if it could be actuated with a mechanical lever. Either foot control toggle or cable actuated with a mechanical switch lever that could be mounted close to the operator seat position.

 

[vestaviascott]

Here is a quick sketch to better illustrate the general approach of a simplified, on-demand, spring loaded, foot activated caster lock system:

The red area represents the rectangular/square cutout on the caster fork. The green drawing is a very crude depiction of the latch mechanism that would be affixed to the spindle assembly.

It would consist of a movable latch/bolt of thick steel, perhaps 7/16" square made to fit snugly into the 1/2" spindle cutout to lock the caster wheel in place when engaged.

Perhaps a small spring loaded foot control actuator could be attached to the top of the caster spindle (or to the footwell area near the caster) to lock and unlock the caster in place.

Something like a parking brake lever that stays on when depressed and can be reset by pressing past the last detent would be ideal and allow the operator to keep both hands on the zero turn lap bars but lock the casters in place for longer cross slope travel passes.

 

[Breezmeister]

For some one like me, I would buy that for my service cart, it has 4 swivel casters and moving it around the shop, there are times the cart will be caddywhompus...

But I think for the yokes on a rider, you might look into trailer gate latchs. Something that would be spring loaded. Something heavier/stronger that would have 2 positions....

Amazon.com: Large Trailer Truck Spring Gate Latch, Weld on, Heavy Duty- 27005 : Tools & Home Improvement

Buy Large Trailer Truck Spring Gate Latch, Weld on, Heavy Duty- 27005: Gate Hardware - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Amazon.com: Buyers Products B2598LP Spring Latch Assembly : Automotive

Buy Buyers Products B2598LP Spring Latch Assembly: Springs - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Let us know what you come up with.....
.

 

[vestaviascott]

Let us know what you come up with.....

Thanks for the feedback!

I believe a 3/8" shaft should be about the right size to hold the caster in place. Something that's about the same size as the pins used to hold deck lift positions in place.

It just needs to be a design that's compact and can be actuated with a cable. Perhaps spring loaded but easily releasable. Perhaps via a foot pedal attached to a cable that depresses and releases the locking shaft.

It would necessarily need to be very easy to engage and disengage the caster lock (foot control without having to move hands from the lap bars).

The operator would most likely only use it while traversing a slope and would need to be able to quickly disengage it to turn or steer around an obstacle, tree, etc. Similar to how the Z-Spray mechanism is controlled.

I think ultimately it will take several prototypes to refine the design and also figure out if its possible to make it work with a single caster. I'm not sure I'll have time or resources to make a prototype but putting it out there if someone has time and tools can take it and run with it.

In essence, as long as both casters are on the ground, they should turn in sync, so it should be possible to lock one caster and the other one should stay straight. But the ability to lock both casters is probably needed.

 

[tobylou8]

I seem to remember Dixie Chopper and maybe Walker having locking casters for hills. ANY mower must have ROPS and a seatbelt. That can be a dangerous and deadly situation even for a seasoned LCO. If one caster turns, it will pull the mower against the locked caster towards it.

 

[Jashley73]

Eh, I don't know about it. I want full control over the mower at all times. I understand the appeal, but I don't think it's wise.

If I'm on a hill, and things start to go wonky - I want full control to be able - to mash the stick for the downhill drive wheel forward - to steer the machine back up-hill. I don't want the front tires impeding that in any way.

One answer to this - better drive tires.

 

[tobylou8]

Eh, I don't know about it. I want full control over the mower at all times. I understand the appeal, but I don't think it's wise.

If I'm on a hill, and things start to go wonky - I want full control to be able - to mash the stick for the downhill drive wheel forward - to steer the machine back up-hill. I don't want the front tires impeding that in any way.

One answer to this - better drive tires.

And a wider stance! I have and old Lazer Z that is awesome on hills.

 

[vestaviascott]

I seem to remember Dixie Chopper and maybe Walker having locking casters for hills. ANY mower must have ROPS and a seatbelt. That can be a dangerous and deadly situation even for a seasoned LCO. If one caster turns, it will pull the mower against the locked caster towards it.

I did a bit of searching but couldn't find anything on the DC's locking casters. DC looks like it was a very well built product though. I would be interesting to see their approach as well as Walker's.

For such a fundamental issue, I'm surprised that there hasn't been more innovation in this area. For flat surfaces, the current ZT design is pretty much unbeatable in my opinion. However, one you introduce 15-20 degree slopes into the mix...

There is another design I hadn't seen before now. Bad Boy Mowers has a disc brake add on for their caster wheels that is sold as a $500 dealer installed option. It allows you to temporarily lock the casters into any current position using a handbrake on the lap bar.

 

[vestaviascott]

Eh, I don't know about it. I want full control over the mower at all times. I understand the appeal, but I don't think it's wise.

If I'm on a hill, and things start to go wonky - I want full control to be able - to mash the stick for the downhill drive wheel forward - to steer the machine back up-hill. I don't want the front tires impeding that in any way.

One answer to this - better drive tires.

Agree totally on the control issue. The Cub Cadet "synchro steer" design is best in that regard in my opinion from what I've seen of it - I've never tried it but demo's look great. The only issue I have with that design is it takes away the lap bars as a control mechanism in favor of a steering wheel and foot pedals for forward/reverse.

A fully electrified zero turn should be able to use a logic board along with small motors or servos on the casters to sync the steering of the fronts with the rears. That would be the ultimate zero turn in my opinion. As long as they keep the lap bar control for steering and forward/reverse.

 

[vestaviascott]

Something like this, but with lap bars instead of the steering wheel and fwd/reverse foot pedals:

 

[tobylou8]

Dixie Chopper is still made, but the caster lock was probably offered over 20yrs ago. I don't work in a particularly hilly area, so I've never seen that setup on any brand mower. Around here, steep hills are done with lots of H2B workers and weed eaters.

 

[vestaviascott]

Something like this, but with lap bars instead of the steering wheel and fwd/reverse foot pedals:

After a closer rewatch I'm seeing some obvious turf damage from the rear wheels that isn't really addressed in the video commentary. Stanley is usually a straight shooter though so I don't think the oversight is intentional.

 

[StuartR]

Our two large zero turns have no issues holding sidehills. One is a Hustler and the other a Deere, they both track great right of to the point you think you are getting close to tipping over and test the ROPS.

 

[vestaviascott]

Apparently EGO is scheduled to exhibit at Equip Expo in a few days. Perhaps we may get more details on their new zero turn with "E-Steer" technology. Apparently this tech offers 4 wheel steering that handles up to 20 degree slopes. Unfortunately, the concept photos show a steering wheel zero turn (looks goofy as hell). Hopefully they bring this same 4 wheel steering tech to their Z6 lap bar zero turn.

 

[vestaviascott]

From that photo, it does not appear that the front wheel assemblies look any different than their current 2 wheel drive zero turn. Perhaps they have modified the spindle shafts with DC motors inside the existing spindle housings?

We should find out soon! Equip Expo (Louisville, Ky) starts this weekend.

 

[Dawson]

Eh, I don't know about it. I want full control over the mower at all times. I understand the appeal, but I don't think it's wise.

If I'm on a hill, and things start to go wonky - I want full control to be able - to mash the stick for the downhill drive wheel forward - to steer the machine back up-hill. I don't want the front tires impeding that in any way.

One answer to this - better drive tires.

That's exactly the opposite of what you want to do if you start to lose control on side of a hill, you have to slow down and stop and then slowly maneuver yourself back up the hill. If you're starting to go down downhill when you're going along the side of the incline and you mash the lever forward you're just going to go downhill faster you're not going to start going back uphill. Once those casters are aiming downhill ,unless you're going real slow ,you're going down the hill pretty much no matter how much traction you have on your rear tires.

I learned that the hard way back when I was 15 the first day I was using a ZTR and ended up with a mower upside down at the bottom of a slope. Thank goodness that was before the days when they had seat belts and roll bars on big ztrs, I was able to jump clear does it started going over, if I had been strapped in or had a roll bar I had to get around I probably gotten hurt pretty bad... As it is the only thing that was hurt was my pride, the mower was even okay, rolled it back over and it was no worse for the wear.... Fortunately the swamp I rolled down into was dry at the time.

 

[Jashley73]

That's exactly the opposite of what you want to do if you start to lose control on side of a hill, you have to slow down and stop and then slowly maneuver yourself back up the hill. If you're starting to go down downhill when you're going along the side of the incline and you mash the lever forward you're just going to go downhill faster you're not going to start going back uphill. Once those casters are aiming downhill ,unless you're going real slow ,you're going down the hill pretty much no matter how much traction you have on your rear tires.

I learned that the hard way back when I was 15 the first day I was using a ZTR and ended up with a mower upside down at the bottom of a slope. Thank goodness that was before the days when they had seat belts and roll bars on big ztrs, I was able to jump clear does it started going over, if I had been strapped in or had a roll bar I had to get around I probably gotten hurt pretty bad... As it is the only thing that was hurt was my pride, the mower was even okay, rolled it back over and it was no worse for the wear.... Fortunately the swamp I rolled down into was dry at the time.

I guess I should have been a little more clear. When mowing sideways on a hill - the way you're supposed to on just about any lawnmowing equipment - when the mower wants to starts to "go" downhill, there is no stopping it. The only way out is UP! - meaning, you have to use the downhill drive tire (the one with the weight on it) to accelerate, which turns the machine uphill. Once you're pointing uphill, you get more control, and can stop, turn, backup, climb up, etc...

Afterall, that is the whole point of this thread - having locking casters on a ZTR would help with hillside stability - that is, mowing sideways on the hill.

Driving downhill on any ZTR or lawn tractor is about the most dangerous thing you can do, as with no front brakes, there is almost nothing to stop a downhill slide once it happens.

 

[Jashley73]

Now that I think about the idea of locking casters, I would give some thought to a "momentary" fixed caster. Meaning...

The "lock" is spring-loaded to the "unlocked" position. The castor lock would require you to HOLD the castors in a fixed position, and they would return to a free-rotating state automatically when you let go of the caster lock.



Let's redefine terms, as I think it would be helpful...

Castors can rotate 360* = Free
Castors held at 0* / straight ahead = Fixed

I'm thinking of a foot-pedal for each caster wheel, that must be held down to keep the castors fixed. When you let go of the foot-pedals, springs automatically unlock, and return the castors to a Free state

There is no way to lock the castors in the fixed position.



It would increase hillside stability ONLY when you need the castors fixed.

 

[Dawson]

Now that I think about the idea of locking casters, I would give some thought to a "momentary" fixed caster. Meaning...

The "lock" is spring-loaded to the "unlocked" position. The castor lock would require you to HOLD the castors in a fixed position, and they would return to a free-rotating state automatically when you let go of the caster lock.



Let's redefine terms, as I think it would be helpful...

Castors can rotate 360* = Free
Castors held at 0* / straight ahead = Fixed

I'm thinking of a foot-pedal for each caster wheel, that must be held down to keep the castors fixed. When you let go of the foot-pedals, springs automatically unlock, and return the castors to a Free state

There is no way to lock the castors in the fixed position.



It would increase hillside stability ONLY when you need the castors fixed.

I recall Dixie chopper tried a set up like that probably 20 years ago, it was a little bit janky looking (used a belt and pulley on top of the spindle castor if I'm not mistaken) and probably worked but it never caught on... Not even sure it ever actually went in to production.

Cub cadet has a commercial ZTR that operates with a steering wheel that turns the casters, it's full-time but you get the best of both worlds with that for hillside use, zero turn capability and a more traditional style steering. It would probably be a good option for somebody who does a lot of slopes

 

[J. Baker]

Some points:
* ZTR’s have an extremely low center of gravity. They’re hard to roll over and definitely won’t until probably around a 35-40% grade. 15-20% should be easy.

* I don’t know how much experience you have with spring loaded mechanisms like this but I promise that by the time you get a spring that is strong enough to unlock under pressure, you won’t be able to hold it locked with your foot without also building a complex leverage multiplier. What is likely to happen with your idea is you will remove your foot from the lever, but the wheels won’t unlock until you maneuver the machine to let the pressure off the pin. By the time you can make that happen, you’ll already be in worse shape. Trust me on that, I’ve got a lot of experience in this area.

* The point about jamming levers for quick correction being wrong is dead on. Once you break traction, your best bet is to stop and go slow to regain traction. Once traction is lost you’re riding a sled with no brakes. This is why ABS was developed.

* Better drive tires is the answer for hilly or slopes terrain. Yes, they’re a bit harder on turf that is flat when turning, but you have to make a judgement call. We run very aggressive drive tires on our Walker Mowers because of areas we mow and the hills/ditches. We have to turn around pretty slow and careful to avoid turf damage, but we had too many close calls and minor accidents (sliding down hills resulting in stuck machines) that we decided it was worth the trade off.

All in all, I’m kind of in the position that if locking the front casters was helpful, the manufacturers would already offer it. Most companies offer rear weight kits. Adding weight behind the rear axle works like a teeter totter reducing weight on the front casters and thus placing all the weight on the drive tires. The more weight you can place on the drives, the less the caster wheels will affect steering. Also, the better the turf will look after mowing because the drives are behind the deck. The less gras that gets driven flat by wheels prior to cutting the better cut quality you get. Yet another reason Walker Mowers have exceptional cut quality. Virtual no weight on the front casters. At least 80% of the machines weight is on the drive tires on non GHS models.

All in all I think you’re trying to solve a problem with a different approach that is best solved with solutions that already exist. Try adding rear weights before building something. Tell us if that doesn’t fix the problem.