Thoughts on converting lawn tractor snow blower to PT422

[MossRoad]

If I were going to convert one, personally, I'd look for one that is belt driven, and then use a pulley on the hydraulic motor and a V-belt connection rather than direct coupling. IMO, this offers two advantages:

1. The V-belt can slip should you ingest an indigestible object such as frozen newspaper or a tree limb (been there, done that). A Lovejoy can absorb some shock but cannot readily slip without some damage, should movement come to a screeching halt. Lovejoys are intended to absorb initial shock and compensate for imprecise alignment, not to serve as a slip-clutch...

2. Then, you could use variations in pulley sizes (and corresponding belt lengths) to fine-tune the performance once you've put it in operation. Otherwise, you're limited to your one-time choice of hydraulic motor displacement, and then varying the engine speed to vary hydraulic output. By using pulleys and a belt, you could fine-tune it operate optimally at full throttle, providing more torque to the snowblower and more hydraulic flow to the wheelmotors.

My 2 cents...

EDIT: Impeller speed is critical for proper operation of a single-stage snowblower. Impeller speed and keeping the "intake hopper full" are the two primary keys to good performance. With a single-stage on a normal garden tractor, you should always operate at wide-open-throttle, and vary the ground speed and width of cut as needed to keep the "intake hopper" full of snow. Impeller speed is not quite as critical for a two-stage, but still very important, and a key determinant of how far you throw the snow...

I think you and I had a similar discussion on this several years ago when we were discussing single stage Simplicity blowers. Great advice and insight! :thumbsup:

 

[KMA]

Yeah, keeping the pulley and belt drive in tact shouldn't be too difficult looking at the pics of the snowblower I could be buying. Plus, I've decided I'd like try to "borrow" the motor off of my finish mower for this job since I have a commercial zero turn that I use in the summer. That will allow me to come in way under budget, and if the single stage doesn't work out I'm only out $100 or so.

Thanks again for the input and Happy New Year!

 

[smilindave]

I built my my snow blower from a single stage unit. I was pretty pleased with the results. I used a pulley system, but would rather have it direct drive. Smokes too many belts. Plus I don't have any frozen obstacles to get in my way. I also used the motor from my finish mower. It works good on the speed, but I wish it had a little more power.

 

[KMA]

Thanks for the input Dave. I also have the brush cutter which looks to be a much bigger motor. Does anyone have the specs on that model? I could borrow it for use on the snowblower and replace it in the summer months when I need it. I wonder if it spins fast enough for this application...?

 

[smilindave]

Just wanted to let you know, if you use the pulley system, the snow blower will be longer which poses 2 problems. First, the turning/steering radius changes and it is much harder to navigate. This means that you can not make sharp turns. Otherwise, you end up running over the fresh snow and packing it down. Second, the snow blower also becomes very heavy in the front when lifting it off the ground, causing more PT pucker. Just my experience.

 

[3238dpw]

Wow Dave! Any pictures?:thumbsup:

 

[KMA]

I picked up this snowblower for $80 today. I have some ideas on how to mount the pulley without extending it much (might even be able to shorten it up from the stock length). I have two motors to play with (PT brush cutter and finish mower). I can replace the 6" pulley on the shaft with something smaller, and use a large pulley on the motor to increase the auger speed if needed.

 

[KMA]

Quick question regarding motors...

For discussions sake, let's say I have two motors and both run off of the PT422 PTO circuit (8gpm / 2500 psi): Motor 'A' is the smaller one and will spin at 3600 rpms, and motor 'B' is the larger one and spins at 1800 rpm. The larger, slower motor 'B' has more torque but would need a bigger pulley in order to get the snowblower auger spinning at the proper speed (e.g. 3600 rpms). Conversely motor 'A' would need a much smaller pulley, or could even be direct mounted. Would there be a significant difference between using one or the other? In other words, would the larger pulley required by motor 'B' nullify any torque advantage?

Obviously if I had an application where 1800 rpms was ideal then motor 'B' would be a no brainer, but I didn't know if the larger motor would help if I needed to work at the much higher speeds handled by motor 'A'.

Thanks.

 

[MossRoad]

Well, I would use the brush hog VS the finish mower as a comparison.

The brush hog's larger motor is designed to get a large mass (the heavy blades) spinning and keep them spinning.

The finish mower's smaller motor is designed to get a smaller mass spinning at a higher speed to make clean cuts, not spin mass.

Snow is heavy. I'd use the brush hog motor. You can gear it up for higher speed if needed. If you use the smaller motor, it may not have the ability to keep the impeller turning under load.

 

[J_J]

If I remember correctly, the hyd motors on the finish mowing decks are about 3 cu in, and with 8 GPM's, that makes the motor turn at 616. You will have to bump up the speed by belt/pulley or a gear box setup.

In order to get direct driving speed using the 8 GPM's, you will need a hyd motor of .6 cu in for a speed of 3080 rpm.

Torque will be about 287 in lbs, using 3000 psi, and a .6 cu in hyd motor.

If the brush hog motor is larger in cu in, you will have more torque, but you will still need to bump up the speed even more as a 5 cu in hyd motor using 8 GPM's, is only 370 rpm's.

If you have a 6 in pulley on the impeller, in order to up the rpm to say 3000, rpm, you will need about a 5:1 ratio, so if using the 3 cu in motor, at 616 rpm, that ratio will provide about 3080 rpm's, however, the pulley will be huge.