Mowing Brush mower maintenance

[ponytug]

Dear Folks,

I have a couple of maintenance related questions:

1. Are you using the PT blades or something heavier?
2. How long do your mower blades last?
   • And how do you decide when to replace them?
   • Wear?
   • Weight difference?
3. How often do you sharpen them? (mowing hours? per month?)
4. How often do you replace the oiled bronze bearing sleeves?
5. How often do you oil/grease them?
6. How often do you replace the bolts on the blades?
7. How often do you replace the bolts 90 degrees away?

I'm finding that the sleeves can look fine, and then three hours later, the bolts have worn into the blades, giving me a halfmoon bite out of the bolt hole in the blade.

I know Woodlandfarms went to 1/2" blades (Brush Cutter brand? Hand made?). Did anyone else modify their blades/spindles, if so how? I think we have a few people who have reinforced the metal deck itself.

Finally, am I the only one having trouble with the bolts that limit the travel on the main swivel connector for the mower deck itself? I keep changing mowing angles and shear them off because I don't have the fore/aft tilt set correctly for the ground motion.

Thanks!

All the best,

Peter

 

[MossRoad]

I have the 48" brush cutter.
I have two sets of PT blades (4 blades total). Two of the four blades are bent beyond use.

How long they last? Well, now that I've hit about every rock on our place, they last a lot longer! It really depends on if I hit anything or not. The only reason I replaced them was on the first set I bent one badly. The 2nd set I wore out the hole in the middle. Between the 4 blades, I now have two good one.

I check them after each use. If there is any wear in the little bushing inside the blade bolt hole, I change out the bushing. I also change out the blade bolts at that point. Seems if I ever re-use blade bolts, I shortly thereafter break one and then its a pain in the neck to get it out. So, changing the blade bolts often is a couple bucks well spent.

I sharpen them as needed. I don't make them razor sharp, just kinda sharp and take out any huge nicks. I use a hand grinder.

I grease the zerks before each use, no matter how many hours, so it never goes more than 5-6 hours between greasings.

I've never replaced any bearings on it yet. Probably only a 120-150 hours on that attachment, based on 10-15 hours per year.

 

[woodlandfarms]

[*]Are you using the PT blades or something heavier?

Heavier. 1/2" hardened steel
[*]How long do your mower blades last?
Unanswerable. they tend to break off and disapear in the brush. I do not sharpen, but will try this year.

• And how do you decide when to replace them?
• Wear?
• Weight difference?
  I do have an issue with weight differences and noticing. I now use a food scale to match my blades

[*]How often do you sharpen them? (mowing hours? per month?)
never
[*]How often do you replace the oiled bronze bearing sleeves?
Huh?
[*]How often do you oil/grease them?
I grease the rotor hubs maybe once ever twenty hours or so.
[*]How often do you replace the bolts on the blades?
If I notice them bent, but usually they break before I get that chance
[*]How often do you replace the bolts 90 degrees away?
I assume you mean the plugs? I removed those bolts a long time ago and put hex caps in place. Keeps the hole a bit cleaner. When I am mowing, and I have a break, I do take advantange of the spare holes. When Usually I can get a season done and then I flip the mower over, get my welder and remove all the broken bolts.

I am wondering about your sleeves and I am thinking that they should not be brass but steel pipe. Mine get grooved up pretty quick so I am now making my own. PITA.

 

[MossRoad]

Here's a link to a thread I made last fall regarding how to deal with the problem of broken blade bolts before it happens so its easier to extract the stubs when it does happen.... and it will. :laughing:

http://www.tractorbynet.com/forums/power-trac/256362-pt425-48-brush-hog-broken.html#post2987128

 

[ponytug]

Dear Carl,

Yes, I did mean "the plugs". Mine sheared off, and I have just left them with the old stud in place. I should probably put in the cap screws as you have done.

I notice that DN and BH don't seem to lubricate their bolt assemblies. Perhaps you are onto something with the use of hardened steel.

Did you upgrade your bolts to something like these?

All the best,

Peter

 

[woodlandfarms]

I went to grade 8 but when they broke, and they did(but they never really bent) it was a major pita to extract. Now that I am welding nuts on to extract it may go easier.

I love the idea of getting in from the top to extract but I haven't found a spot I feel comfortable in cuttin a hole to access.

I love those bolts you found. Where did you get them? I will swing by fasten all to see if they have a source.

 

[ponytug]

Dear Carl,

They are the bolts used by "Brush Hog" and several other vendors. Try your local farm supply place. I like the beveled edges of the more modern version. I have a feeling that it would be a certain amount of welding/engineering to switch over, as the bolts appear to have two indexing grooves that provide the counter rotation resistance necessary to tighten the nuts. (from the top, which raises the issue of where is the best place to cut the hole, and how to reinforce the deck if you do.)

There's a discussion over on Yesterday's Tractors that implies you can use the older, non-indexed ones with some care just by using a big wrench. YMMV...

All the best,

Peter

I went to grade 8 but when they broke, and they did(but they never really bent) it was a major pita to extract. Now that I am welding nuts on to extract it may go easier.

I love the idea of getting in from the top to extract but I haven't found a spot I feel comfortable in cuttin a hole to access.

I love those bolts you found. Where did you get them? I will swing by fasten all to see if they have a source.

 

[KentT]

My 48" brush mower uses a wheel hub with the stump jumper head welded onto it. I unbolt the 5 lug bolts from the top, after removing the grease zerk (which won't go down through the hole), and the stump jumper will drop down far enough that I can get to the other end of the sheared bolts from underneath the mower's deck. It's a bit of a PITA, but still far simpler than trying to use EZ-outs or other means of removing the sheared bolt from the bottom. I use Grade 5 bolts instead of Grade 8, allowing them to shear, as they are designed to do, and put NeverSeize on the new bolts when I put them in...

 

[woodlandfarms]

I put silicone on the bolts when I install the blades

To drop mine you need to remove the 5 bolts, but then undo the belt pulley. It starts to get too complicated for me at that point.

 

[KentT]

I have the 48" brush cutter.

I check them after each use. If there is any wear in the little bushing inside the blade bolt hole, I change out the bushing.

Moss, have you found a local source for the little bushings. I've run out of stock from Tazewell, and don't need enough stuff for their minimum order...