Useful attachments adapted to PT ?

[2manyrocks]

The parts from McMaster Carr arrived. The bushing looks to be of a higher quality than the OEM, but it's 1/2" long where the OEM appears to be 3/8. Is your blade 1/2 thick where mine is only 3/8? Or is the 1/2" length supposed to work?

The diameter is also tight to the mounting hole in the blade which I assume is a good thing indicating that my blade mount isn't wallowed?

Many of my issues with the PT cutting deck would be resolved if I could just raise it another few inches. It's already at the maximum cutting height, but just 2-3" more would help keep the blades from getting so beat up.

 

[MossRoad]

I went through a few bushing on my 48" brush cutter on our PT425. I ended up measuring the ID of the hole in the blade and the OD of the bolt, then ordered a piece of DOM tubing with the correct dimensions, a few thousands bigger for the bolt. Then I used my band saw to cut a couple dozen bushings the correct length. That was probably 15 or more years ago. I think I'm down to just a few left, so maybe time to do it again.

 

[2manyrocks]

These are oil impregnated high load bushings which would be great to use provided I can understand how they fit. Maybe I could use a couple of washers as spacers, IDK?

McMaster Carr's on line catalog does not show a 3/8 length for these 5/8 ID x 1" OD type of bushings.

 

[ponytug]

The parts from McMaster Carr arrived. The bushing looks to be of a higher quality than the OEM, but it's 1/2" long where the OEM appears to be 3/8. Is your blade 1/2 thick where mine is only 3/8? Or is the 1/2" length supposed to work?

The diameter is also tight to the mounting hole in the blade which I assume is a good thing indicating that my blade mount isn't wallowed?

Many of my issues with the PT cutting deck would be resolved if I could just raise it another few inches. It's already at the maximum cutting height, but just 2-3" more would help keep the blades from getting so beat up.

View attachment 870778

I will have to go get a micrometer on the parts that I have, but what I previously posted is what I'm using. McMaster is not one to change part numbers.

I have an old blade in my metal stock that I will check for thickness. That said, having the bushing a little taller than the blade enables the blade to swing freely while the bolt is tight. Washers just spread the force from the bolt uniformly across the bushing.

All the best,

Peter

 

[2manyrocks]

Adding a few pictures to help clarify where I seem to be on this at the moment.


If I add a 1"ID washer to take up the slack, the blade no longer wobbles up or down, but the washer seems to be locking the blade in place so it can't freely pivot. My concern is whether the blade attempting to pivot on its axis will work the bolt loose?

If I remove the washer, then there is enough free play that the blade can then wobble up and down again, which seems worse than the original problem.

The original problem was the OEM bushings wallowed out and this allowed the blade to strike the edges of the mower deck housing.

edit: Wondering if I can use blue locktite to lock the bolt in place using the 1" ID washer to make up for the bushing being 1/2" long instead of 3/8" OEM?

One alternative is to get rid of the 5/8 nut and bolt, and replace them with 3/4 diameter fasteners since McMaster Carr stocks a 3/4ID x 1OD x 3/8T oil impregnated bushing part no. 2868T178.

 

[m5040]

I use my PT rotary for just cutting grass and with sharp blades it does well. For large brush I picked up a Rut Mfg for the 1460 and it takes down 4" Mountain Laurel (I raise it over and lower it down mulching it better then just cutting at ground level and driving over it). I have always been intrigued about the use of chains like a heavy duty string trimmer. I assume you take a cut off old blade and weld chain to it. Then hit rocks with immunity.
I would worry about adding heavier blades to a PT cutter. If anything fails it could potentially be fatal.
After all, a set of PT blades for my 1430 cost $50 last I bought. One blade for the Rut cost $50.

 

[2manyrocks]

Things that make me uncomfortable with my PT brush mower: 1) in the raised position, the discharge is pitched back at the operator station; 2) in the down position, the deck discharge builds up in the PT frame and between the left front tire and the frame; 3) there are no chain guards at the rear of the deck; 4) the space to install chain guards is limited considering the space available with the deck is raised; 5) at maximum height of the wheels, there's not that much ground clearance; 6) the OEM blade mounting seems to depend on locktite holding the 5/8 bolts in place???? (is this right?) rather than using a large diameter shoulder bolt and captive nut like a bush hog; 7) the blade mount bushings are in my personal opinion, garbage, plus they were dry from the factory and the greasable spindles on the front caster arms weren't greased from the factory, either; 8) as for the OEM blades, they don't impress me much either.

I have some 15" laminated wheels on order to see if I can salvage this mess by increasing the cutting height.

 

[m5040]

You could add the oil lube option, where the motor shaft seal leaks enough to lube the blade bushings.

 

[MossRoad]

Things that make me uncomfortable with my PT brush mower: 1) in the raised position, the discharge is pitched back at the operator station; 2) in the down position, the deck discharge builds up in the PT frame and between the left front tire and the frame; 3) there are no chain guards at the rear of the deck; 4) the space to install chain guards is limited considering the space available with the deck is raised; 5) at maximum height of the wheels, there's not that much ground clearance; 6) the OEM blade mounting seems to depend on locktite holding the 5/8 bolts in place???? (is this right?) rather than using a large diameter shoulder bolt and captive nut like a bush hog; 7) the blade mount bushings are in my personal opinion, garbage, plus they were dry from the factory and the greasable spindles on the front caster arms weren't greased from the factory, either; 8) as for the OEM blades, they don't impress me much either.

I have some 15" laminated wheels on order to see if I can salvage this mess by increasing the cutting height.

I'm pretty sure there's a lock nut welded inside the hub that the blade bolt goes through. I've never had a bolt work its way out. I have had the bolt heads snap on rocks.

 

[MossRoad]

I'm pretty sure there's a lock nut welded inside the hub that the blade bolt goes through. I've never had a bolt work its way out. I have had the bolt heads snap on rocks.

And that's a treat, because you have to drop the hub to get to the back side of the broken bolt. I have two thin nuts that I thread onto the back of the broken bolt and jam them together, then use them to back the bolt out.

 

[2manyrocks]

The OEM bolts were hard to remove on mine, but the new ones threaded right in. I don't know if that means there is a locknut that is now shot or if they used thread locker. I put thread lock on the new bolts a couple of days ago, but haven't checked to see if they are now set in place.

If I could source the right kind of blades and bolts, I'd be very tempted to change them out.

 

[MossRoad]

I think I've mentioned that I'm tempted to cut my hub down in height and use gull-wing blades. Some day I may give that a try.

 

[2manyrocks]

The wheels were delivered today and had only a brief moment before it started pouring rain.

I bought one set of wheels with a 1 1/4 yoke. No joy. The PT tube is maybe 1mm or so too small in diameter. Rain was starting so didn't get the exact measurement.

Also bought pair of wheels without the yoke. The hub on them doesn't fit in the PT fork, either.

In meantime, saw that there doesn't seem to be a spec of grease on the front wheel bearings.

So here we ago again with nothing being easy.

 

[SpringHollow]

You could always bore out the tube if you were sure you wanted to go this route. If the shaft of the yoke is removable, you might be able to replace it or possibly turn it down if you have a lathe or know someone who does.

 

[2manyrocks]

The shaft on the replacement laminated wheel is welded in place. The OD is 1.255" where the PT shaft OD is 1.245". For comparison, the shaft on my 5' Jbar tail wheel assembly is 1.248".

I suspect the least cash outlay would be to buy some 1.25" steel rod to replace the shaft, but looks like a pain to grind out these welds.

Maybe I can find a shaft/yoke assembly that isn't oversized and return these.

 

[SpringHollow]

A hone might take care of that ID

 

[2manyrocks]

I'm reluctant to enlarge the mount because if it turns out that a 15" tire is just too big to use with the factory caster mount, I'd like to be able to reinstall the OEM fork/yoke/wheel.

Local machine shop sold me a 22" piece of 1 1/4 rod that fits inside the PT mount for $15. Right now, I'm wondering if it would be less work just to build my own fork instead of trying to cut out the oversized shaft from the replacement yoke and replace it with the rod from the machine shop.

I called the manufacturer that made the replacement yoke to ask if they have any other yokes with a shaft that will fit. The guy I spoke with thought they'd all be the same OD. Was told I needed to speak with the owner when he returns after Memorial Day weekend to see if he could suggest any other options.

 

[SpringHollow]

I do not think it would be that hard to replace the shaft on the new fork with the 1 1/4 stock you got or sand off the 0.01" to downsize the shaft that is already attached.

 

[2manyrocks]

I do not think it would be that hard to replace the shaft on the new fork with the 1 1/4 stock you got or sand off the 0.01" to downsize the shaft that is already attached.

The shaft fits after removing the powder coating with a wire brush in an angle grinder.

The entire assembly is free to rotate without striking the cutting deck at least with the deck in the highest position. Cut a test section of field, and I think the cutting deck is now sufficiently high to clear most of the debris left from mulching.

These are the wheels/yoke assemblies I bought. https://www.amazon.com/Laminated-Wh...16860150&sprefix=laminated wheel 1 1/,aps,641

I still have to figure out how to mount larger wheels at the rear of the deck.

 

[2manyrocks]

I think I've mentioned that I'm tempted to cut my hub down in height and use gull-wing blades. Some day I may give that a try.

If you could raise your deck by using larger wheels, you might gain enough clearance to mount gull wing blades without having to cut your hub down.