RM48 deck belt routing improvement

[JSinMO]

Anyways I received a lot of push back from users on the old forum for doing this. They essentially stated I was the only one with the problem and the belt drive was sufficient for 1000's of users which both of us disagree with. One thing they were right about was my center drive spindle was worn out and needed replacement. The pulleys were pitted and worn down.


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Yes, I figure I would get some pushback either for the insult to the divinity of the original engineer. Or for the hubris to think that I can do better.

And I am all in favor of brand loyalty. And I certainly have never seen any brand of lawn tractor that I like as much as a Case / Ingersoll.

But my loyalty to basic physics surpasses my loyalty to the brand



Bob
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Having a well reasoned discussion on the pros and cons of an idea can be quite helpful during a project, but to receive negative feedback simply because the original design of something must have been at the apex of engineering and couldn’t possibly be improved seems ridiculous to me. I have experienced this on other sites, this is why I’m happy I found this place! You can actually put an idea out there and get good feedback, not just a snarky comment.

You guys have more than shown well reasoned, logical solutions to observable problems. Not changing something because it’s going on display is one thing, but improving the machines usefulness is quite another. Frankly people that push back for the sake of pushing back can pound sand!

I’m sure no one here needed me to say this, but after reading @MattA and @thebuildist posts I couldn’t help myself!

That ends this ramble, please carry on!

[MattA]

And because that idler pulley is now in the tension path of the belt, as opposed to the slack side of the belt, that idler is going to be subjected to greater stress on the bearing than you would normally expect an idler to experience. So the bearings in that static idler are going to have to be replaced more often.

That's probably why the bearings in my idler pulley lasted about 4 years. I'd go with your approach but I don't have a welder. I'd probably end up hooking the spring up to a bolt or something.

How does your main drive spindle lower pulley look? Pitted and worn? Is the belt bottoming out in the pulley V groove? Are you getting enough spring tension? Is your idler bracket moving freely?

I'm excited to see what you come up with. My approach works but I've thought for several years that the approach your going with is a much better way to do this.

[thebuildist]

I'll try to address this very questions in my soon coming post.

Bob

[thebuildist]

I got to this project last night, and I'm pleased with the result.

Pulling the cover off, we find that the belt isn't tight all all. To quote Clem down t' the gas station: "Well, THERE'S yer' problem!"

I honestly have no answer for why it's like this. It's an 82" belt, matching Ingersoll spec. Maybe it got oil on it and stretched? I really don't know.
And what is with all those packed in leaves over there??? That has to be fixed too.

But moving on:

I cut off the welded on tab using a cutting wheel in a 4.5" grinder, since it's right in the middle of the area we want to move to, and painted the bare steel with matching paint.

Then I unbolted the idler arm and, with the new 96" belt in place, I positioned the idler in a spot that isn't rubbing the main pulley and won't interfere with the long belt run at the trailing edge of the deck.

I grabbed a sharpie and marked the new bolt/pivot point.

It turns out to be 3.5 inches from the edge of the center pulley and 2.75 inches from the "wall".

I drilled the 3/8ths inch hole (the size of the bolt) and then grabbed a square file. 5 minutes of filing produced a square hole that the carriage bolt can slide up into.

And then bolted the idler arm back into place.

When I stretch the spring using a vise, I find that it can stretch about 2 inches. So with the belt in place and the ilder pulled snug, I marked the point that the spring tab touches the deck. And then welded the spring tab 1 inch farther back from that mark. (About half of the spring's stretch) If I had it do do over again, I would have located the spring tab ONE AND A HALF inches farther back from that mark. I think it's ok as it is, but another 1/2" of stretch would be better.

Note that if I didn't have a welder, I could have used a bit of angle iron as the spring tab, and bolted it in place with a couple of carriage bolts.

A little paint over the welded area, and it's ready to reassemble

(continued on next post)

[thebuildist]

Now I like the overall routing, but I don't like that the belt could vibrate over and hit the idler arm where the "1/2 inch ratchet tab" sticks out.

I think that over time that steel edge may chew up the belt, so I grabbed the cutting wheel and zipped it off.

That ratchet hole part is unnecessary anyway. You can easily install a belt like this just by engaging the belt hard against the edge of the final pulley and then rotate the pulley through one full turn, and the belt will just feed itself right into the pulley groove.

Or if you're not used to doing that, then you can just use a Crescent wrench to grip where the ratchet used to insert.

Voila! Our belt routing improvements are complete.

[thebuildist]

Lastly, a couple general deck improvements:

1. I didn't like those leaves packed up in there with the belt. I decided to make some caps to put on the open ends of the bolt-on deck belt cover.

I grabbed some cardstock and cut/folded it to the shape of the caps I want to make.

Then I used the cardstock as a template and cut out both end caps from some 1/32" sheet metal, and bent them to shape.

Then I riveted the new end caps onto the ends of the main deck belt cover.
Note that it's important to use STEEL rivets when riveting steel pieces together. If you use aluminum rivets, it will very quickly begin corroding due to galvanic/dissimilar metals corrosion.

A little more painting and the improved cover is ready to install.

Lastly, I needed to repair and reinforce the left edge of my deck. In one of the spots I mow I end up backing the left edge of the deck into some landcaping blocks, and the last time I did it, it bent the deck edge inward, causing the blade to strike and damage the deck.

So after I welded the place where the blade tip penetrated through the deck, I grabbed a strip of 3/16" steel plate, bent it to the correct profile, and welded it in place at the outermost lower edge. That covers up the welded repair, and also adds some general strength to the deck in that area, so it shouldn't bend as easily next time.

(If you can't improve your driving, then fortify your equipment.

And with that, the deck is ready to go back on the machine.

Bob

[Eugen]

Looks like significant improvements Bob. You don't fool around do you! Nice!

[MattA]

Looks good Bob. If you could do it over, would you move the idler up and to the left some more? I like your idea of using angle iron for the spring mount.

Your old belt is likely worn down which causes it to sit lower in all three spindle pulleys. Since the belt is sitting lower in the pulley "V", the pulley circumference is now less which is why the belt seems too long.

[thebuildist]

Matt,

If I moved it any higher up, it strikes the center pulley when it's loose. You MIGHT fudge it 3/8 of an inch, but certainly not a lot.

Thanks for the observation on the old belt.

Bob

[Seabee]

Thanks for the information. I get a lot of leaves and grass in there.

Bill Moyer