[How do I?] Modifying a snow plow

[dave_r_1]

And the result of those bits welded together again looks like this:


It just fits with the power brush in it's usual location, with room for a 2-stage 28" snowblower right in front on the power brush..

The revised setup is definitely better, the plow can lift further up without any danger of damaging the drive unit (there were a couple cross members and the two hydraulic motors that could have been bent/damaged by the plow lifting too high), as the plow now mounts to the very front edge of the drive unit. With the whole weight of the plow on the front, it goes up and down the ramp on the truck feeling much less like it wants to go over backwards (but I still have to be careful, as it's pretty powerful and the controls are twitchy).

Now to take it off, maybe grind some of the uglier welds flat and paint it up. I might also look for some thick flat iron that I could bolt to the front of my "weldment" instead of using those weights, to get the center of gravity a bit lower and towards the front.

 

[dave_r_1]

Having finished the bagger unit for this lawn mower, and with snow imminent in the forecast, I switched back to finishing up this plow.

Yesterday I finished making 2 support ribs for the new "ends" of the shortened plow, similar to the ones the manufacturer had on the original ends and welded them on.

Here's the picture of the rib, welded onto the plow:


Unfortunately, I had decided to install the two ends of the plow to aid in holding the shape of the plow when I welded the rib on, and that turned out to be a HUGE mistake. When I tried removing the two ends, one side came out with with a bunch of persuasion of hammers and various prying implements, but the other side would only budge maybe 1/8" or so. I tried heating it up, hammering on the ends of the pins, hammering on the end of the plow, pounding in some wedges, it would just not go any further. There wasn't much more I could do, as it's pretty awkward, so I decided to just cut the pins between the main part and the extension, then pound out the pins the other way, as I could really wail on it that way. One moved back 1/8", other one, nothing doing. Fortunately, there was just enough room between the base of my drill press and the chuck to get the plow underneath, and then drill down about 1" with a 1/2" drill bit, and that was finally enough to be able to punch out the two pins. Yuck.

The two pins (you can just see at the top the part that was drilled out):


With the pins out, and being too late to get a 19/32" drill bit (slightly bigger than 9/16, but I think 5/8" would be a bit too sloppy), I went for filling in end of the brace running along the bottom of the plow, similar to what the manufacturer had as well. I also had welded the end of the top edge of this brace to the plow, as it bent away from the plow during my earlier trial. These two things should prevent that from happening in the future.

This is how the end looked before:


And this is after:


Tomorrow, it's back to making the end pieces slide in and out again, as welding the ribs in slightly altered the alignment of the tubes, as well as changing their inside diameter.

 

[dave_r_1]

Carried on with this, made 2 new replacement pins for the ones I cut yesterday, finished boxing the ends of the 2 extensions, and drilled out the holes the pins go into, from 9/16" to 5/8". I would have liked to have used 19/32", but the only place I could find that had one wanted $50 for it, which is a bit much for drilling 6 holes.



During my test use a couple weeks ago, I found that when the plow was angled, the force of the snow on the edge and the vibrations from scraping would cause the extension on the trailing edge to separate from the main part. So I came up with the idea of welding tabs to the extensions and the center part, and then drill a hole through both tabs. Now, I can slide the extension on, then slide a pin into the hole, and that will hold the extension in place.




After drilling out the tubes to 5/8" and seeing how the extension can flex, I wish I had found a reasonably priced 19/32" drill bit :-( It's not terrible, and likely will work fine. And I was in a rush to get this done as we are expected to get another 2-4" of snow in the next day...

 

[dave_r_1]

Well, we got about 2-3" of really wet snow, so I got a chance to use the plow on a number of driveways.

Here's an example of how it works:



It leaves a little bit behind, but it did a pretty good job. It can push snow the full width of the driveway (about 40'). I basically went over the area twice, once to get most of it to the sides, then a second pass to clean up what tumbles over the "high" side of the angled plow.

And when doing the sidewalks, with the plow at an angle, it goes nicely, but at least with wet snow, the snow bunches up, and is pushed off the edge, then rolls back a bit onto the sidewalk. And putting the edge of the plow over the grass will wreck the grass or the plow (in this case, with the temp being above zero and the ground really wet, I plowed away the edges of some grass...).

It wasn't all good, though.

1) If the pavement is uneven, the edges of the extensions are more likely to catch on it, and the pins are the weak point. They bent a little. The extensions still worked, but I probably will add a few more pins to support them better.

2) I checked that the extra weights I need to add to the front would clear the plow. And they do. But then I added the ribs to the ends of the center section of the plow, and they wedge against the weights when the plow is at an angle and it is raised. :-( I'll need to see exactly how much they interfere, and either move the weights back a bit or grind a bit off the ribs.

3) I didn't take all the weights I bought along (I bought 140 lbs, and only took 70). The 70 lbs I had was OK for balancing the drive unit by itself, but it's not enough when pushing a lot of heavy snow. Since the front mount is angled upwards (which is nice for clearance when going up the ramp on my truck), it winds up lifting the front of the drive unit and I have to manually force it down. I'll see tomorrow how it works with the extra 70lbs I have...

4) I need to make the bed of my truck a little less slippery. The top edge of the ramp is flat steel, and the rest is wood, and the wheels spun a bit as I was loading it one time, and I wound up dumping it over the side of the ramp. It wasn't damaged, but it's still not particularly safe going up and down the ramp. The ramp itself is extruded steel, so there is good grip for the tires, but the transition between the ramp and the bed is the iffy part... I think I'll put a strip of extruded steel along the steel that's there already, so there is grip on the edge, and then it should be ok, or at least significantly better. And extra weight on the front will also help with keeping the unit stable.

5) Don't plow the grass. :-(

 

[dave_r_1]

And this is the primary place that I made the plow for. A large driveway, with 1/3 of it having garages on both sides and the house joining them, so all the snow has to first be pushed/thrown out of that area, then pushed/thrown to the sides.

The first pic is just 3 adjacent passes, pushing the snow straight ahead then turning slightly to get it off the driveway.

And this is after two passes with the plow:


Normally, this job would come close to giving me a heart attack. The snow is too much and too wet to use my powerbrush, as it would just make 8-12" large ice balls along the edge it's work, and then the snow gets too much for it. The 21" Toro single stage can throw the snow twice, but the snow being so heavy, it can only throw it 5 or 6', so it can't get the snow out from the garage area, and the larger 28" ariens 2-stage has no problem throwing the snow a good distance and re-throwing it multiple times, it also winds up leaving a relatively large amount of snow behind (just not enough snow for it to work effectively). I would normally wind up having to manually push a good portion of snow out from the garage area by hand. But the plow could push the snow pretty well, and it also did a decent job of peeling up the packed stuff where the homeowners had driven over.

I put another 70 lbs on the front, and that helped with keeping the front of the plow down when pushing a lot of snow.

And here's a pic of how the extensions have been bent (the extensions themselves are still straight, just the pins appear to have bent):


It still worked well doing this large place, with 3" or so of snow, but doing a couple of places with only 1" of snow (having done them yesterday), the bent ends caused the whole plow to chatter on concrete and let snow underneath it when it didn't have much snow to push, and then it would settle down as more snow was being pushed.

Now, I'll spend the summer thinking of a better way to join the extensions to the center part of the plow, to both support the forces involved and to keep the bottom edge even.

 

[dave_r_1]

After bending the extension back to roughly it's original shape, this is my next try at supporting/connecting it:


It's 1.5" x .100 wall square tubing, with 1.25" x .125 wall square tubing as an insert. The elastic section modulus for this is significantly higher than that of 9/16" round solid steel (about 2 orders of magnitude), so it should be a lot less likely to bend (at least, that's my understanding of how it works).

As well, I'll drill a 1/4" hole through the bottom piece of square tubing to put a pin through to hold the extension on instead of using the existing overlapping pieces of 1/8" flat iron, as it permits a lot of play (the extension blade can separate from the center part by almost 1/2"). The pin through the square tubing should significantly reduce it.

And from looking at other commercial plow extensions, they either are bolted on (which is too time consuming for how I want to use it) to keep the bottom edge solidly together and in a line or they have the extension either be a little off the ground or use something like rubber instead, likely because when just the edge of the extension catches, that puts a tremendous force on the connection (as the center part still has a lot of momentum going forward while the extension stops). I've got some thick rubber strips, likely from a big conveyor belt, that I'll try to use for the bottom edge of the extensions. I wish I knew where my dad got these rubber strips from (rubber with embedded cords for strength, about 1/2" thick), as I'm running out of it... :-(

Anyway, I'll get the other side done like this one tomorrow, and should be able to test it on Sunday, as we should get another 2-4" of wet snow between later tomorrow and early Sunday...

 

[dave_r_1]

Well, after a long day of work, I can report success. The plow worked well, and the extensions showed no obvious sign of bending, under similar conditions as the last time (between 2-4" of wet snow, with some driven over patches).

I also think 2 things helped with the extensions not bending:

1) the last time I used it, the extensions bent, but I kept using it, and the scraper bar on the extensions wore about 1/4" more than the scraper bar on the main part of the plow, so when I straightened the extensions out and reattached them, the scraper's on the two extensions are slightly off the ground, so the extensions are MUCH less likely to catch on pavement cracks/uneven parts
2) the last time I used it, I also angled the plow left and right to do various parts of the jobs. This also was a good cause of the extensions catching pavement cracks, so only the extension was stopped. Instead, today I only used the plow facing straight ahead. It still caught pavement edges (probably more than last time, as it would wind up catching more expansion joints), but now the center section would take most or all of the force, and it has some trip springs to absorb the energy instead of something breaking/bending.

So, with the primary problem seemingly solved, now it's on to working on fixing some usability things like:
-need larger front wheels, possibly air filled instead of solid, as the current ones have some difficulty with going through deeper snow, and with obstacles like the ramp on my truck and some curbs
-rework the ballast weight on the front. As part of the bagger system I bought for the summer use of the drive unit, it came with some cast iron counterweights in a long rectangular shape, that I should be able to attach to the front, in the open area, where it won't obstruct the plow when it is angled.
-mount the winch remote switch in a better location, so I can operate the switch without having to lock the controls. Now I have to lock the controls in neutral, so I can take my hand off of them to operate the switch.