Finishing mower gearing

[xtruckerbob]

I rebuilt my Bush Hog "RM48" Brand finishing mower. It was a 48 inch and I made it a 60 inch. I used the same gear box and 9 inch pulley. I put 2 - 30 inch blades instead of the 2 - 24 inch blades. Now as soon as you get in any grass even only a 1/4" high the blades will stall and burn the belt. I am wondering what size pulley should I use under the gear box or should I add another rotor?

 

[JCByrd24]

Hmm, most 48" have three blades, and 60" for sure, 30" blades are large. A 7.2" pulley will give you the same tip speed as you had previously and more torque, however that might not help your belt situation. Do your belts have sufficient wrap around the drive and blade pulleys and sufficient tension?

Do you have a thread on the rebuild? I'm pondering going from 48" to 60" myself as I haven't had good luck in the used 60" market here in Maine.

 

[aczlan]

How is the belt tensioned? Sounds more like the belt isnt tight enough to prevent slippage.

Aaron Z

 

[Agent Blue]

I would check the tension and try a good year cog belt. They seem to have more bite for pulley traction and run cooler. They are only a couple bucks more than an average belt.

 

[xtruckerbob]

I had a new belt (just a plain smooth belt), and belts have sufficient wrap around the drive and blade pulleys and sufficient tension? I'll have to check but I think I have a 7 inch pulley already.


I built this several years ago and decided to try 1 more time to make it work,..... or else, at least I will have some gauge wheels and 3pt to buld something else

 

[xtruckerbob]

I redid the top mounting on 60" deck so that I have nearly twice the surface area with belt against the pulley. When I go back to town I'll get the belt and let everyone know

 

[xtruckerbob]

I loaded my tractor and mower up and went to Tractor Supply so I could get a belt that fit first time. With the new belt I could not wait to try it out, but again it did not work, as soon as I hit the grass which was a little over 2 inches high the blades stop and the belt started smoking. I guess I'll start looking or a 5" pulley and try it again. This makes me think I need a motor cycle style chain instead of a belt. At least it would not slip.....would it?