Finally remembered to take some pictures of the PTO assembly and the spline stub I broke off the end of the shaft. I had thought about welding it back on and I may still do that at some point in the future but I believe I have another shaft on the way to me - hope to see it in about a week. I am still thinking of a couple of different ideas to reduce the PTO shaft angle on the blower.
Homemade Two Stage Snow Blower Speed Reduction Upgrade
Posted February 18, 2016 - 01:10 PM
- LPBolens, chris m and WrenchinOnIt have said thanks
Posted February 18, 2016 - 11:35 PM
Ouch!! I hope the shaft you have coming is the right one! Good luck
- 29 Chev said thank you
Posted February 23, 2016 - 05:51 PM
I thought about modifying the PTO unit on the tractor to make it slower as well as lower or adding a frame work behind it and driving off the back of the tractor PTO and using a long PTO shaft to the snow blower but didn't like either idea very much. Came to the conclusion the simplest way to lessen the PTO shaft angle was to add a second stage to raise the input shaft back up. This now lets the PTO shaft run on a very small angle when the blower is on level ground attached to the tractor. I made a new bottom shaft which is longer, extended the lower section back and then made another upper box to house another gear and two more bearings for the input shaft to run on and allow me to adjust the rear chain tension independently of the front chain. This second stage also gives me the ability to use it as a speed reduction as well - went with a 16 tooth upper gear and an 18 tooth lower gear - using the smaller tooth gears allowed me to keep the chain short which should cut down on the amount it stretches with use. Unfortunately with this second stage the weight of the blower will now be about the same as it was before I modified it but I believe this is a better design than the pillow blocks I was using. I got the snow blower back on the tractor today and powered it up and everything seems good with not vibrations. I also added two machinery bushing washers and a cotter key to hold the pto yoke on the input shaft if the shear bolt breaks or comes out - should have done that on the first modification and the tractor PTO shaft probably would not have gotten broke. I had broken the shear bolt a few times before and the yoke always stayed put on the input shaft - live and learn they say. Attached are some pictures of the latest modifications - will have to wait until we get some snow so I can try it out and see if it hangs together or gives me another education lesson.
- limebuzz, LPBolens, chris m and 1 other said thanks
Posted February 23, 2016 - 07:10 PM
- 29 Chev said thank you
Posted February 23, 2016 - 07:38 PM
Nice job and thinking. I was wondering thou, in picture number 7, the drive shaft coming from the tractor to the blower, on the slip part of the driveshaft, is there enough room for the blower to raise up, and the female part of the slip part, to come ahead and not hit the joint yoke, not much room for movement. I could be looking at it wrong also, just wondering.
Good eye. Yes there is about 3/4" of clearance with the blower fully raised. Tried to keep the second stage as compact as I could for that reason which is why the rear bearing on the input shaft is inside the upper box - this let me run the upper gear right ahead of it. I double checked as I was building the second section to make sure the PTO yoke on the input shaft was in the same spot as it was when I was using the pillow blocks (used the remains of the welded on rear support as a reference. I have run the pillow block set up for about six years with the slip joint that close without any problems so it should still be ok with what I have now.
- propane1 said thank you
Posted February 23, 2016 - 08:06 PM
- 29 Chev said thank you
Posted February 24, 2016 - 12:38 PM
Thanks for the picture - that is an interesting setup they used - looks to be a bit of an angle on the shaft but it could just be the picture. Attached are a couple of pictures of mine with the blower fully raised - not a lot of clearance but it should be ok. I will keep an eye on it and if it becomes a problem I will cut the grooved portion off of the yoke where it is attached to the shaft and grind the weld and reweld it - should give me about another 5/8" clearance and should leave the yoke still strong enough for the horse power I am using.
- WrenchinOnIt and propane1 have said thanks
Posted February 24, 2016 - 05:06 PM
Yes, the shaft is ahead a bit, which makes it look angled, but thats the way it was made by the factory. The joints allow for up and down and the slip joint allows for side ways movement. Because its 35 years old, I probably have more side to side movement than It should, but thats the way it is.
Now that I see your second picture, it reminds me of another problem I had. When the my blower moved side ways, the male part of the slip joint was moving in and hitting on the universal joint. This was on another blower I have. Yours looks ok, just some thing to check.
- WrenchinOnIt and 29 Chev have said thanks
Posted February 25, 2016 - 01:50 PM
Thanks for the heads up on the length of the male shaft - I tried to keep it so that it has about 1/4" sticking through the slip yoke when the blower is on a level surface and when it is fully raised there still appears to be lots of clearance.
We got some snow / freezing rain and high winds yesterday and last night so I tried it out for about 3-1/2 hours this morning. There were spots where the snow was quite heavy (over 12" deep) and one drift in the yard that was over 24" high and it handled the job nicely other than I had to replace my shear bolt twice - I think the nut came off the end rather than the bolt breaking as when the blower stopped it was only under a light load. Will have to get some 1/4" lock nuts and see if that cures the problem. Going with the 16 and 18 tooth gears seems to have slowed it down enough so that it does not kill the motor now unless you are in really deep snow (12") and taking a full cut.
Edited by 29 Chev, February 25, 2016 - 06:53 PM.
- limebuzz, LPBolens and propane1 have said thanks
Posted March 09, 2016 - 10:15 AM
I decided I would try and repair the broken PTO shaft by welding the end back on. Attached are a few pictures of how it turned out. You can check out this thread (post 7 and 8) to see how I did it - I figured the worst that can happen is that it will break again. http://gardentractor...o-shaft-repair/
Edited by 29 Chev, March 09, 2016 - 10:17 AM.