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Worn pulleys/ additive metal

Posted: Tue Jun 11, 2019 1:59 pm
by spro
Thinner metal pulleys pulled a lot of belts but become worn over time. The profile is no longer correct for a new belt. Very few .001's truing can help once because there isn't any "meat" to work with. Somebody knows about metal application in a way to build up the inner surfaces. I'm not talking brazing or welding really. There is another process which escapes me. Thanks

Re: Worn pulleys/ additive metal

Posted: Tue Jun 11, 2019 4:01 pm
by choprboy
You mean plasma spray/metal spray? Using a plasma or acetylene torch to blow fine metal particles onto the part, which melt in the stream and then adhere to the part surface. Used for buildup of shafts/etc.

https://youtu.be/X43SJakLTA8?t=1263

Having had to repeatedly place pulleys that continually get worn down (A/C fans running 24/7), I've found the best long term solution is to replace original factory single sheave pulleys with dual sheave. Reduces wear on both the belt and pulley by almost an order of magnitude.

Re: Worn pulleys/ additive metal

Posted: Tue Jun 11, 2019 4:50 pm
by 12L14
spro wrote:I'm not talking brazing or welding really. There is another process which escapes me.
Galvanization?

Re: Worn pulleys/ additive metal

Posted: Tue Jun 11, 2019 6:25 pm
by spro
I think you guys got it. These are avenues worth exploring and I'll say why. Some things, like mower decks (fair large 60" ones ) are designed that the main pulley is two stacked yet very close together. The better iron ones with contracting insert are taller. It is a better design but may contact certain things that lower type doesn't touch. There are also alignment issues. Since the original worked near 40- years, the additive of metal onto the worn faces is the way to go. Thanks much.

Re: Worn pulleys/ additive metal

Posted: Thu Jun 13, 2019 7:20 pm
by spro
I have to say by looking at abom79 videos, he knows additive metal and much more. Thin pulley facing is different but good ride.

Re: Worn pulleys/ additive metal

Posted: Thu Jun 13, 2019 8:43 pm
by Bill Shields
you don't want to spray metal on these low end pulleys.

Re: Worn pulleys/ additive metal

Posted: Fri Jun 14, 2019 1:45 am
by spro
I suppose "low end" is correct. Since they are lighter, I don't see that process being used. There is more about metal transfer than I know. In an electrolysis bath the rust is usually extracted but a sacrificial electrode could slowly build thin surface. I just need more info about it.

Re: Worn pulleys/ additive metal

Posted: Fri Jun 14, 2019 2:50 am
by liveaboard
Belts have moved on in the last 40 years...
I have some experience with V-belt problems. Basically, they slip; a couple of percent and they last a long time, a couple of more and it all heats up and wears out fast.
As chaprboy did, I went to double belts, which solved my problem.
Today you can get cogged [timing belts] that don't slip at all, and multigroove [serpentine] belts in many widths and lengths. These can carry greater loads and have less heating / slipping trouble.

Re: Worn pulleys/ additive metal

Posted: Fri Jun 14, 2019 8:36 am
by spro
I get all that but it doesn't apply in this case. Just one section of a double Vee pulley needs to be built up. The pto exits the back, in line with the drive line. One long single belt is configured by idler pulleys to either reach a tow behind deck or a belly deck. In most cases, it contacts the top of dual pulley and that is where wear occurs.

Re: Worn pulleys/ additive metal

Posted: Fri Jun 14, 2019 8:46 am
by Bill Shields
i think that you will find that if you can find someone to do this, the cost will far outweigh the replacement $

Re: Worn pulleys/ additive metal

Posted: Fri Jun 14, 2019 9:11 am
by spro
I have a 5' belly deck and while it is physically right heavy, it is suspended at four points. Two points raise or lower at my whim over unequal terrain, via hydraulics and linkage to keep it parallel. Sometimes it must be raised high, so there are additional idlers to keep the long belt from rubbing the top of the deck. This is a Lo-Boy type tractor and it must sit low for the steep grades, yet maximum deck heights.
edit: Okay Bill. I understand. I'll probably go to a more serious Browning design pulley in the future.