belt keeps coming off

[Luigi_tuga]

That is a critic area for shure.
My bolt(the one that only takes one tail pulley) is also at an angle.
I chose to open the pulleys and shim them between the bearings, and there is a big gap inthere.
I prefered to do that than having the pulleys wobling from the lack of torque.

[acidkindred]

This is what I determined as well.

Originally Posted by Luvmyhelis

What I finally found is this. I used a bolt that had a solid shank all the way through the tension roller. Then used a lock nut on the back. I will post up pics when I can. The hole isn't drilled incorrectly, just loose. So I spent quit a bit of time playing with this. And if I leave the tension roller just precisely loose enough, it will roll with the belt at the correct neutral angle. Bearing slop here allows it to level itself with the belt. But with the stock threaded bolt it leans over too far!

[acidkindred]

The threaded portion of the bolt I'm using is threaded into the block in addition to using a lock nut.

Originally Posted by Bob O

So you're not using the threaded portion of the pulley block at all? For either bolt?

[Bob O]

Originally Posted by Luigi_tuga

That is a critic area for shure.
My bolt(the one that only takes one tail pulley) is also at an angle.
I chose to open the pulleys and shim them between the bearings, and there is a big gap inthere.
I prefered to do that than having the pulleys wobling from the lack of torque.

Luigi,

Was there a big gap in the center of all the pulleys? Even with the one washer already in there? That would definitely cause issues as the purpose of those washers (on both sides of the bearing) are to "capture" the inner race of the bearing. If there's a gap between the bearings on the same pulley, then the inner races aren't being captured.

Being that I have a package of spare washers on hand, I might go ahead and take this apart right now and see if I can make things better.

[acidkindred]

If this is the case that is a flaw for sure. I'll have to look at mine.

Originally Posted by Bob O

Luigi,

Was there a big gap in the center of all the pulleys? Even with the one washer already in there? That would definitely cause issues as the purpose of those washers (on both sides of the bearing) are to "capture" the inner race of the bearing. If there's a gap between the bearings on the same pulley, then the inner races aren't being captured.

Being that I have a package of spare washers on hand, I might go ahead and take this apart right now and see if I can make things better.

[ScotY]

Originally Posted by Luigi_tuga

I chose to open the pulleys and shim them between the bearings, and there is a big gap inthere.
I prefered to do that than having the pulleys wobling from the lack of torque.

You took the bearings out of the pulley and there's no spacer between them?

[acidkindred]

Have you tried running a slower head speed like 2800?

Originally Posted by frito169

Just in case you're wondering my head speed is at 3500 RPMs at 90 % throttle on a YGE 60

[Luvmyhelis]

Originally Posted by Bob O

So you're not using the threaded portion of the pulley block at all? For either bolt?

Yes, I am. The longer bolt just doesn't have threads over the exact length of the tension roller. Then the threads engage the support plate, and extend roughly 4.92mm farther out the top of the plate. Where I now thread on a lock nut. Which anchors the bolt. Now I can leave just enough 'loose' on the other side so the smaller belt tension roller doesn't bind up. What happens is the non threaded shank tightens up the roller bearing slop here and the roller doesn't lean as badly. So the belt tracks better.

What really needs to be done here is to have a thicker support plate in this area! And a tighter thread clearance through the bolt hole. Then the use of the non threaded bolt that is longer with threads that engages the plate and lock nut.

[ScotY]

Think there's any way easy way to move the motor belt tensioner to mount on the motor mount itself? Could use smaller OD if there's excessive belt wrap. Might have to skew motor to one side which probably wouldn't be good.

[Bob O]

I put a nut on mine as well, but had to grind it down for motor belt clearance. How do you plan on dealing with the clearance issue with the full sized nut on there?

Notice the nut on mine in the same spot. There is very little belt clearance with it ground down.

[Stevemech]

Bob I wouldn't use the extra bearing it just makes thing difficult and could result in a broken shaft.The tensioners may/ might shift inflight resulting in alignment issues, mine broke( motorshaft) in 2 flights while I was trying to figure out what was going on.I had about 15 flights to that point.Without the bearing the pulley bearing block can remain staionary .Motor tension from motor mount and tailbelt from boom tension.
Steve

[Luvmyhelis]

Originally Posted by Bob O

I put a nut on mine as well, but had to grind it down for motor belt clearance. How do you plan on dealing with the clearance issue with the full sized nut on there?

Notice the nut on mine in the same spot. There is very little belt clearance with it ground down.

Excellent work Bob! On mine Helihaven is creating a new smaller 10T pinion to fit onto my 3mm motor shaft. So the new (maybe) 9mm wide belt is quite a bit farther away from the bolt and shouldn't need to be carved down. Oh yeah, did I mention a potential 9mm wide belt? This should make up for the lower tooth count engagement here and allow us to still use our 2221 cans for powering the Warp.

Looks like we are on the same page here with the tension roller.

An idea would be to run a separate aluminum support bar that ties the two lower tail tension rollers together on top of the bolts, and keeps them forced into a perfect alignment. I may fab one up later tomorrow and see if that works. But that will complicate the tail belt removal.

Edit: I did this with a simple CF plate. Check out the mod thread. The rollers and bolts are now true.

[kachur779]

maiden flight today flew nice except my belt came off the pulley

[kachur779]

what a piss offf

[Jeff_Barrett]

Are your pulleys straight or are they on an angle from loose thread on the bolt?

[kachur779]

there strait i spent a good day filling and making sure ,but the auto rotation gear or tail drive gear does wobble or its warpped iam thinking maybe thats what caused it

[heathy]

Guys. My warp was from a later batch that came with assembled tail pulley and links. I did have a issue on one side where 1 of the 2 smaller pulleys rubbed the bottom of the slot. I sanded this already thin area down which solved the problem. I also put the whole thing together as per the manual with all the stock parts. I didn't look for any of your problems as I was unaware off them at the time.

What I did do was run the Heli up on the bench without blades and watch both belts for misalignment. Both ran true.

[kachur779]

i ran it up a few times even hovered 3 packs ,today was the maiden flight and threw it around a bit ,it fley awsome love the way it flys ,i took the tail and pulleys apart tonight and try again tmrw

[Jeff_Barrett]

Make sure you haven't over tightened any screws. It can be easy to warp the gears by over tightening --- I'm notorious for this, but have gotten better over the years.

[kachur779]

everything seems ok now ,maybe the night before i didnt have the boom tight or something