Snowblower Conversion - Pics

[cdcole]

You are very talented. A machinest and artist. Good job.

 

[cdcole]

oh...and a heck of an engineer too

 

[RedDirt]

You need to head to Durango, Colorado as they've gotten about 4-feet of the white stuff the past few days courtesy of the storms from California. Wolf Creek ski area east of Durango has gotten 64" in the past week.

That should be a good test!

Looks good!

Ha. Up the hill the past week's storm has laid down 8 to 10 feet! We used to live another 1000ft elevation higher. I do miss the snow but I don't miss THAT much snow!

Thanks guys for the compliments. Since my initial trial it has been trying to snow some more but it has just been 1/3 snow, 1/3 slush, 1/3 rain so we've ended with no more additional accumulation to play with.

 

[smog]

Ha. Up the hill the past week's storm has laid down 8 to 10 feet! We used to live another 1000ft elevation higher. I do miss the snow but I don't miss THAT much snow!

Thanks guys for the compliments. Since my initial trial it has been trying to snow some more but it has just been 1/3 snow, 1/3 slush, 1/3 rain so we've ended with no more additional accumulation to play with.

I have the very same snowblower that I would like to match with my Kubota B7200.

I may go the v-belt way with 2 facing pulleys and 2 idler reusing most of the original setup from the mtd blower and only have to find a pto driveshaft and a pulley. changing the ratio will be as simple as changing the pulley.

 

[RedDirt]

I have the very same snowblower that I would like to match with my Kubota B7200.

I may go the v-belt way with 2 facing pulleys and 2 idler reusing most of the original setup from the mtd blower and only have to find a pto driveshaft and a pulley. changing the ratio will be as simple as changing the pulley.

Smog,

I got my PTO shaft from Surplus Center, $54+/- as I recall. They have a good variety of pulleys too.

I'd be very interested in seeing a sketch of your design. Others would too as a pulley system would certainly be a cheaper retrofit than my gear design.

I considered a two facing pulley system but couldn't get the design off the ground. My problem was I could get the speed increased OR the direction changed with a belt and pulleys but not do both at once with one belt, two pulleys and two idlers.

My belt design had a PTO shaft powering a horizontal shaft mounted small 4" (?) pulley . The belt went over the top of this pulley and down to idler turning pulleys then up and over an 8" (?) pulley. The problem was aligning idlers between the two different sized pulleys. The idlers must be angled to accomplish this task at no matter how I tried to align them on CAD it seemed that the belt would certainly jump a pulley or idler. Another problem was vertical space limitations did not allow the belt enough length to twist while changing directions. As the belt comes off the small pulley the idler must be angled outward to intersect the large pulley diameter and the resulting twist in the belt is greater than 90 degrees. As I considered adding extra components (shafts, idlers, etc) to compensate for the radical changes in direction the design l became more complex and physically longer. After a few more alignment attempts per the original concept I canned the idea as being way too fussy and committing too much fabrication for a questionable outcome.

When I get to my other computer tomorrow I'll post my CAD pulley design to better illustrate the problem. But who knows. I could have been barking up the wrong tree and you've got a design concept different than mine that would work. That's what these discussions are all about anyway...what works and what doesn't.

 

[RedDirt]

Here is that failed belt drive design drawing.

View attachment Snowblower Belt Drive_111909.pdf

Notice the contortions the belt needs to traverse to change speed and direction. I found it unworkable.

The botom portion of the drawing is a top view where I was trying different idler positions to keep the belt from apparently jumping the pulleys. The pillow bearing is not shown in the correct orientation; it was just a place holder for this step of the design.

The Xed out designs had the drive and driven pulleys further apart and I played with moving the idler. When neither of these worked I moved the two pulleys closer together so they were the same distance apart as the angled idler. Still no luck.

I see at this phase I was using a 5" blower pulley and a 10 3/4" PTO pulley shooting for a bit more than a 1:2 speed increase. Maybe other pulley and idler sizes would reap different results but I still see this as a difficult and questionable design.

 

[mjncad]

RedDirt:

I think you made a wise choice going with gears. Besides the hassles of changing directions by twisting the belts, there would be mechanical efficiency loss due to belt slippage, which could be problematic on a snowblower.

I know I don't like the belt & pulley system on my JD L130 lawn tractor, and there isn't a direction change involved in powering the deck.

Like you, I'd be curious to see Smog's design for a belt & pulley system.

 

[Arnie_T]

Glad I found this thread--
I picked up a used Craftsman 46 inch blower--while looking for parts for another project-- want to mount it on my PT425 that has hydraulic PTO--
I want to power the blower with hydraulic motor-- Anyone have any idea what the input RPM for this type of blower might be so I can size a suitable hydraulic motor

 

[RedDirt]

Glad I found this thread--
I picked up a used Craftsman 46 inch blower--while looking for parts for another project-- want to mount it on my PT425 that has hydraulic PTO--
I want to power the blower with hydraulic motor-- Anyone have any idea what the input RPM for this type of blower might be so I can size a suitable hydraulic motor

Arnie,
The general consensus at TBN seems to be to look at impeller tip velocity rather than a catch-all RPM. I chose a 4000ft/min tip velocity which calculated to 1090 RPM for my 14" dia impeller.

Some guys use as high as 5000ft/min velocity and I've calculated some commercial units to be as low as 3000ft/min so for me the 4000ft/min was a happy medium.

To calculate needed RPM find your impeller circumference in feet and divide the design velocity by that number. EG. for me, 14" dia impeller = 3.67ft circumference. 4000/3.67 = 1090RPM.

The 4000ft/min worked OK for me. We never got enough snow last season to give it a workout so at one light snow I had to test it at the eave drop of my roof. This is some wet, slushy stuff.



And I just finished painting last season's 7 build projects. Here's the blower.



Good luck with your blower project.

 

[Arnie_T]

Arnie,
The general consensus at TBN seems to be to look at impeller tip velocity rather than a catch-all RPM. I chose a 4000ft/min tip velocity which calculated to 1090 RPM for my 14" dia impeller.

RedDirt--
Great response--I talked to so many people--and no one had the foggiest idea
My impeller is 16 inch and square with beveled corners--so I measured 16 inches across the bevels (End of shovels??)-- and now I will play with your formula--and should be on my quest for a suitable hydraulic motor. I've got several choices including using the existing pulley with some more math (9 inch) to a whatever dia pulley on the motor or direct to the shaft (thrower) impeller behind the second stage if I get a Motor RPM close enough --the key is to come close to the ~4K velocity for the tips.

Here in Tug Hill we do get a fair amount of snow--( Google--Tug Hill Snow--and or Lake Effect) but is is usually pretty fluffy for a while. If it is thick and heavy-- I can use the 52 inch plow or bucket--etc.
Thanks again