Snowblower Conversion - Pics

   / Snowblower Conversion - Pics #1  

RedDirt

Gold Member
Joined
Dec 4, 2007
Messages
469
Location
Northern Idaho
Tractor
Kubota BX23, Wards 16HP HST Garden Tractor, (previous) D2 Logging Cat
In November's CraigsList I found a $250 snowblower built for a garden tractor that I thought I could convert to a TPH for my BX23 for a couple of hundred more. I bought it and, long story short, more than a couple of hundred, but once committed I had to continue.

The conversion has worked well, or so it seems; need snow to test. It has been an unusually small snow season thus far at my elevation in the Sierras. Even on a "good" snow year I only expect to use the blower only several times a season when we get a dump that is bigger than I want to blade.

The following few posts will document my conversion.

This is what I started with:

A OrigSide.JPG B OrigFront.JPG

The unit was built for the front of a small garden tractor and was belt driven from the mower deck pulley via a chain drive gear reduction box:

C OrigGearBx.JPG

You will notice the rotation of the impeller is opposite of that normally found on a TPH machine. Not only did I have to reverse rotation I also had to change the gear reducer to a speed increaser. Belt drive would have been the cheapest method but although I could get the rotation reversed fairly simply or the speed changed as individual drives I had difficulty designing a combination belt drive that would do both efficiently and compactly. I considered a sprocket drive but it became rather cumbersome. I finally chose a gear drive.

Gears are expensive and they got more expensive when I learned enough about them to pick the right ones. Rush Gears.com has a great engineering tool that helped considerably.

My post regarding impeller speeds led me to look at impeller tip velocity rather than RPM. I was designing around a 4000ft/min tip velocity. To get this from my 14" dia impeller and 540PTO speed I needed a 1:2 increase in speed to get 3953ft/min at the impeller. Using the Rush Gear tool I chose a 6"dia PTO gear and a 3" impeller gear. These are #6 gears with a 1 1/2" gear face to withstand the 16HP PTO.

It took almost a month spare time to research various designs, draw and reject several plans and come up with a final design. Here's my plan. The bottom right drawing is the blower in working position. I was trying to keep my lower and top links fairly flat as well as keeping a small PTO shaft angle. The Upper right is the blower raised. I don't know if I'll ever need to lift it this high but I was looking to see if there was any binding in the linkage, specifically the top link. This view primarily showed me where to place the tie for the TPH "A" frame. The left drawings are the bearings and gears viewed from the tractor. The design added a 1/4" plate to the back of the blower housing to add strength to attach the two flange bearings. The cross members carry pillow bearings. The shafts are 1 1/4" dia.

View attachment Snowblower1_121109-FINAL.pdf

Here is a pic of the almost finished conversion. Next posts will go into the conversion in more detail.

M ToTractor w-o ChuteDrive2.JPG
 
   / Snowblower Conversion - Pics
  • Thread Starter
#2  
I ordered parts and started on the TPH conversion while awaiting their arrival.

D TPHmount2.JPG E TPHmont3.JPG

Once gears and bearings arrived it was time for the milling. My good friend and former college shop instructor graciously offered me his fine machine shop and services. I mostly watched. We needed to lengthen the original chain drive shaft so it would extend to the pillow bearing. He machined a "V" groove in the original 1 1/4" dia shaft and a 1 1/2" dia extension piece, welded them together, then turned them down to 1 1/4" on the lathe. Then he bored the two gears to 1 1/4" and cut keyways in the two shafts.

F Oewn.JPG


Next we had to mount the four bearings for the correct pitch diameters and gearlash.

G Brng&Shaft.JPG H Gears1.JPG

Owen did not have a keyway broach large enough for the 5/16" keys and 1 1/4" bores so the gears went out to a commercial shop for this work and I took the blower back to my shop where I fabricated gear shields, cut and fitted the PTO shaft and modified the existing skids.

I GearShield1.JPG L Skids.JPG

Next installment will be the chute rotor.
 
   / Snowblower Conversion - Pics
  • Thread Starter
#3  
The original blower used hand crank to a wire screw drive. I had thought to use this while testing the blower then convert to a powered rotator later. The screw drive had a terrible fit and would have taken considerable work to have it run well so I went ahead with the power drive.

Borrowing a fine idea from TBN members I bought a new car window motor from ebay for $20. The challenge was to convert the attached gear to a pulley for a cable drive system. I chose to build my own pulley from a 3/4" thick sink cutout scrap of Corian.

I cut a 1 1/2" dia plug with a hole saw. Then I needed to bore the pilot shaft from 1/4" hole saw shaft to 5/16" motor shaft.

1 ChuteGearRough1.JPG 2 ChuteGearRough2.JPG

Next I traced around the gear with a 3mm drafting pencil.

3 ChuteGearTrace1.JPG 4 ChuteGearTrace2.JPG

Now I wanted to counterbore with a spade bit the depth of the gear to remove most of the waste. The problem here is keeping center with a spade bit so I modified an old woodworking trick. I secured a flat plate to the drill press table and bored a blind 5/16" shaft hole int it. I did not have a 5/16" dowel so I spun a 3/8" dowel on a disc sander to make a tight hand press fit. I pressed the dowel into the hole and trimmed for height, placed the pulley blank on the wood shaft, set depth for the spade bit and counterbored the gear.

5 ChuteGearCounterBore1.JPG 6 ChuteGearCounterbore2.JPG

Next the tough part. Freehand the remainder of the recessed gear profile. My Dremel does not have a "router" attachment so I used my RotoZip and a Dremel bit. It took a steady hand but I was pleased with the fit.

7 ChuteGearCarve1.JPG 8 ChuteGearCarve2.JPG

9 ChuteGearCarveDone1.JPG 10 ChuteGearCarveDone2.JPG


Here is the motor assembly and cable drive attached. The motor base plate is a 1/4" thick piece of Corian giving me a flat, rust free, fairly slippery base. The baseplate pivots on one through hole and the drive cable is tensioned with a spring.

12 ChuteMotor1.JPG 13 ChuteMotor2.JPG

14 ChuteMotor3.JPG

This is the cable attachment to the chute

15 ChuteCable.JPG

And finally, a cover for the motor.

16 ChuteMotorCover.JPG

The chute rotated just a little faster than I wanted so I wired in a pair of Radio Shack 1ohm resistors into the circuit and now it seems just fine. If I find I want to rotate faster later I can just remove one or both the resistors

Tomorrow I'll trim those long bolts at the chute motor cover and use the acorn nuts. Then I just need to drill and tap a few holes for thumbscrews to hold the gear covers in place and I'm done except for painting. I'll probably just prime for now and topcoat in the spring when it warms up.

Now I need snow! The machine powers up to full PTO speed with no vibration. There is a little gear noise but it is not sever and was expected with square cut spur gears. It's hard to wait to post pictures of snow a'flyin but that's all I can do unless I trailer upcountry.
 
   / Snowblower Conversion - Pics
  • Thread Starter
#4  
In review I see I forgot to show an important step in making the chute motor pulley. I can't see a way to add an attachment in edit mode.

I needed to cut the recess for the cable in the outside diameter. I don't have a lathe so I chucked up the blank in the drill press and used a makeshift lathe cutter in a cross travel vise. It worked.

11 ChuteGearMill Groove.JPG
 
   / Snowblower Conversion - Pics #5  
Very nice RD. Ok now....bottom line.....would you do it again? What was your total cost? Rear PTO blowers you could probably pick up used for anywhere from 1-$1500 or so.
But that is a nice clean job!! 2 Beers!!! ;)
 
   / Snowblower Conversion - Pics #6  
Wow, Reddirt, that is a great job of designing and fabricating and a great job of documenting. I'm sure I'll be back to this thread when I get ready to convert my manual chute rotator to power.

Now, just to be a smart *****, when are you going to convert it to front mount so you don't have to strain your neck? Seriously though, great job. I'm also interested in what you have into it, if you're willing to let us know.
 
   / Snowblower Conversion - Pics #8  
Interesting how people have similar thoughts Every year the local hardware store pulled out a dusty old 48 Blower for a garden tractor and every year I offerred them $900 (asking 1500) but no sell. This was for my Kubota. The difference in our thought was that I was going to put it on the front of my Kubota using the MMM forward facing PTO and connecting it directly to the existing gearbox on the blower. Lots of work but hey that is why this section is called build it yourself. Great work. My own homemade blower ate a tree branch this past week and bent the 1/4 inch plate impeller. Never know whats hiding in the snow. Get some spare shear pins.
 
   / Snowblower Conversion - Pics
  • Thread Starter
#9  
Thanks for the looks and compliments.

Ezlivn,
I have about $750 in the finished unit. $250 for the blower and a little over $500 for the conversion. Though the photos don't show it, the used blower was never used. The previous owner had a similar intention to convert it but moved to a lower elevation out of the snow and it just laid in his yard for years until he was moving ten years later and "lightening up". He said he paid $1200 for it at Orchard Supply.

It cost me about $250 over my initial budget (my pie in the sky estimate!). This was mostly due to using the expensive gears ($230 for the pair at McMaster) instead of belts and the addition of the electric motor (and motor components/accessory parts) that I had not initially counted on doing at this time (about $60 for the chute rotatory assembly). $40 to cut the gear keyways at a commercial machine shop was not in my original budget either. If I had used 1" dia shafts instead of 1 1/4" then Owen could have had them done free. Bear in mind too that Owen gave me a couple of days of free machine work that would drive a conversion cost up dramatically if one were to buy this work.

Would I do it again? Probably not. As you say rear blowers are available for around what I've spent on this one (although relatively scarce around here for some reason or another). At my initial estimate of $450 to $550 complete I was hoping for a very reasonable "new" blower. At the $750 price tag I wish I'd have been more patient and waited until I could have found a used one in decent shape that did not require all the work.

Like many DIY projects, especially" make-overs", once committed, the project itself often dictates the budget and not preconceived plans and estimates.

I must say however, part of my decision to take on this project was a chance to work with my friend in his machine shop. I had queried him prior to the purchase and he offered his resources. I have only little tight tolerance machining experience, I am intrigued with this work, and looked forward to the opportunity to work with him. We both enjoyed the time we spent together on the project.

GPintheMitten,
I thought about a front mount but chose rear because I didn't know if I could lift a front unit high enough to use my rear blade. Of course I can't use the rear blade now with the blower attached but my plan was to see if I liked the blower this season, swaping back and forth if needed, and if I liked the blower I'd build a front blade before next season. I figure to mostly blade because our typical snow is normally small enough. I'd have the blower for the few times a season when we get more than I want to blade. General plan is to blade a windrow to the center of the drive then blow the windrow. So my intention is to mostly face forward. The blower can also be used for some otherwise close quarters where it is difficult to find a home for the bladed snow.

I also chose the rear mount because I think a front mount would be more expensive yet and more complex. I was trying to keep the conversion cheap and simple...Oh well.

David,
If you intend to hook up to an existing gear box just be sure to check rotation first. I am reasonably sure I would have had to change rotation for a front or rear mount. My advice would be to stay away from a conversion that requires a change in rotation. Speed changes can be made fairly inexpensively with belts and pulleys but changing rotation with gears like I did drives the cost way up. Rotation could be changed with a three sprocket and chain assembly but, for me, having to increase the speed too, made a sprocket/chain assembly unwieldy.
 
 
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