Cutting deck belts

[Harry Bloomfield]

The cutting deck of my tractor (Lawnflite 703) seems to have two differing belts specified for it, depending upon the year of manufacture, as near as I can tell, both years use the identical deck. My belt hasn't quite snapped yet, but it does need replacing soon.

The one specified for my older year, is a (shallow, wide) V belt.

The one specified for the later year is called an (equally shallow and wide) hexagonal belt. This being shaped like two back to back V belts.

The pulley is driven from the engine PTO pulley, to a cutter pulley, a sprung idler pulley, a 180 twist (in cross-section) then to the second cutter pulley, a second idler pulley, another reversed 180 twist and back to the engine. The 180 twist, allows the belt to present its flatter face to the idler and the v to the cutter pulley.

I cannot find a belt layout for the second version, but seems to me, with that version of belt installed, it would obviate the need for any twists in the belt at all, as it can drive the cutter pulleys from either side. I am wondering whether to risk order the later belt, or not?

 

[conny]

Cost may be a deciding factor. If they are cheap enough, get one of each and try them out.
Or play safe and stick with the older year type.

 

[Burnerman]

The back to back vee belts are for those machines with counter rotating blades so the belt can drive on pulleys with that arrangement.
Go for kevlar reinforced belts if you can - often blue in colour.
John

 

[Harry Bloomfield]

The back to back vee belts are for those machines with counter rotating blades so the belt can drive on pulleys with that arrangement.
Go for kevlar reinforced belts if you can - often blue in colour.

These blades are counter rotating, which is why there has to be the 180 twist and untwist in the belt, so the V engages correctly in the cutter pulleys. It seems I could avoid the need to twist, if I could simply use the later belt type. Strangely, the later belt seems to be the cheaper of the two. Maybe try to find out the length of each, and see if they match?

Thanks, I did wonder why the back to back V design.

Cost may be a deciding factor. If they are cheap enough, get one of each and try them out.
Or play safe and stick with the older year type.

They are quite expensive, at around £60 each.

 

[lostinthelight]

Idlers and tension pulleys for hex belt decks are “v“eed so if your v. belt one presses on the flat back it may not be suitable with hex belt , thats if Ive understood correctly what your contemplating

 

[Harry Bloomfield]

Idlers and tension pulleys for hex belt decks are “v“eed so if your v. belt one presses on the flat back it may not be suitable with hex belt , thats if Ive understood correctly what your contemplating

Good point - I will see if I can compare the part numbers for the idle/tension pulleys.

 

[lostinthelight]

Good point - I will see if I can compare the part numbers for the idle/tension pulleys.

I’m sure you've considered it but some v belted decks are B section where hex can be AA

 

[Harry Bloomfield]

I’m sure you've considered it but some v belted decks are B section where hex can be AA

You've lost me - does that mean like this VV ?

 

[lostinthelight]

You've lost me - does that mean like this VV ?

Double A belt means its hexagonal A section 13 mm x 10mm