Pulleys sit too high **solved itself**

[DarkSyd3D]

I just finished the majority of my build tonight. Got the belts tensioned to find both belt seem to be riding on the bottom flange of the pulleys or at least on the very bottom of the pulleys. I'm hoping there's an easy fix for this as putting the pulleys on was quite challenging.
I have a second or later batch and my pulleys were nearly touching so following Scotts thread I set the high bearing in a little and it looks and sounds fine now.



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[dogbreath]

That's what my tail belt looks like and it jumped off the pulley twice in flight. Lower frame finally in stock at Experience and on the way. YMMV so this is just a heads up. Dan

[DarkSyd3D]

What's the fix for it?


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[dogbreath]

I don't have one yet. I raised up the tail belt guides a bit, but that didn't solve it. I'm going to check alignment of the boom when I can get it back together. I ordered parts that Experience didn't have from the Compass Shop but they haven't shipped those either. Right now I'm DOA. Dan

[DarkSyd3D]

That sucks man. I delayed getting this model in hopes the issues would be sorted out by now. I will be pissed if I just bought a $700 paperweight.


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[DarkSyd3D]

After looking at it again it looks like a problem with the main shaft. I have a small gap between the bottom of the bottom pulley and the top of the bearing on the bottom plate.
It seems the hole for the lower Jesus bolt is a half mm too high! If this was drilled lower this would fix the issue


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[Ah Clem]

I will go out and look at mine (which is sitting on the bench right now). It has quite a bit of time on it.

The thing that makes belts jump off is usually a shaft or pulley that is not straight. Belts climb uphill.

[Ah Clem]

I went out and took a few photographs of my Red eXo, which has been accumulating quite a bit of time.

Photobucket will not let me post them here, for some reason, so I am uploading directly to HF for the first time. I hope that these photos are visible.

At no time have I had an issue with the belts attempting to jump off. The belts on both of my eXo's are as set fairly loosely, and are lubed with silicon spray.

I would look for alignment of the idler shafts to make sure that they are parallel to the main shaft, as flat belts will climb uphill.

[Mateyhv]

Your looks like mine, the upper belt is perfect, the tail belt runs on the low side. I have not been flying almost three weeks now, because of several non related problems but I am turning a little bit paranoid with this helicopter anyway.

[dunkonu23]

While it's true that you have spent money on it, it's also true that I told each of you that it's absolutely no issue in private messages and publicly.

It's also true that Dan made modifications to his helicopter before ever flying it and that the modifications have since proven to be unnecessary after lengthy discussions with me in PM's long ago. Nobody but Dan to my knowledge has had problems with the tail belt coming off in flight. That doesn't mean it's not a problem, but I'd like to see the modifications removed before going further.

People, this is a solid flying machine. Seriously. Just go out and have fun with it.

Scott

[Ah Clem]

"People, this is a solid flying machine. Seriously. Just go out and have fun with it. "

AMEN!

The only issue I have with mine is that mine needs a better pilot!
(same problem with every machine I have ever owned!)

[DarkSyd3D]

Originally Posted by Ah Clem

I went out and took a few photographs of my Red eXo, which has been accumulating quite a bit of time.



Photobucket will not let me post them here, for some reason, so I am uploading directly to HF for the first time. I hope that these photos are visible.



At no time have I had an issue with the belts attempting to jump off. The belts on both of my eXo's are as set fairly loosely, and are lubed with silicon spray.



I would look for alignment of the idler shafts to make sure that they are parallel to the main shaft, as flat belts will climb uphill.

I wonder what the variable is that makes some main belts ride close to center and other along the bottom flange like mine?

I have no worry about my belts coming off at all as it seems like it would be pretty difficult for them to as long as tension is good.


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[dogbreath]

I have all new upper/lower trays/cross members etc coming to remove all the mods. I ordered most from Experience but some parts were out-of-stock so ordered from overseas. I'm thinking Compass-shop has gone on vacation so it will be a while before I'm reassembling.

I'm still impressed with the flight characteristics and just want to get this bird in the air. I've not slammed anyone, and I've had great help here, but I don't want someone else to have the problems I've had so I'm asking them to be cautious. I think I was the first with the main/tail pulleys rubbing due to the bearing seating tolerances. I pointed it out and others got to see it was solvable.

I'm just the guy out at the end of the bell curve, I think. I don't wanna be.....

Dan

[dunkonu23]

Originally Posted by dogbreath

I have all new upper/lower trays/cross members etc coming to remove all the mods. I ordered most from Experience but some parts were out-of-stock so ordered from overseas. I'm thinking Compass-shop has gone on vacation so it will be a while before I'm reassembling.

I'm still impressed with the flight characteristics and just want to get this bird in the air. I've not slammed anyone, and I've had great help here, but I don't want someone else to have the problems I've had so I'm asking them to be cautious. I think I was the first with the main/tail pulleys rubbing due to the bearing seating tolerances. I pointed it out and others got to see it was solvable.

I'm just the guy out at the end of the bell curve, I think. I don't wanna be.....

Dan

And <long pause> we're the guys in the sights. All kidding aside, we do appreciate you taking the time to report things you have seen, Dan. Finding the cross member alignment issue was something that I will never forget and I truly appreciate your sending me all the pictures you sent. It was greatly helpful. Just know that everything you found has been reported. We're out to make sure you and others enjoy your helicopter to the fullest and you have been instrumental in that goal! Thank you, Dan!

Scott

[DarkSyd3D]

For a quick update, I was attempting to set the gov store on my HW in the driveway yesterday when the tail whipped 60* and caused a near tip over. Tail blades broken and main blades knicked on the tips.
Could not figure out for the life of me why it did that as I'm running the HW gov which has zero issues with spooling up.
I had an "emergency" set of tail blades so I attempted to do it again in my front yard thinking the grass would help keep things stable...nope. Tail whipped out again but no tip over this time.

Puzzled I go back to the bench and triple check correction direction then it hits me.
Are my tail grips flipped!?!?

Referring back to Scotts build thread I found they were! I feel like a noob for overlooking the orientation of the pitch arms but it's a fairly easy miss since there is no branding or channel for the lock nut to distinguish correct from not.
Still, my fault but thankfully after making the correction I was able to set the gov and maiden in my driveway.
I'm also happy to say the belts appear to have aligned themselves much better.
I did find having the tail belt under-tensioned caused a vibe that was both audible and visual. Another 3mm pull on the boom and its gone!
My ONLY partial complaint about the model is I wish the landing gear was more stable. I wish it was a bit wider and more rigid.

Thanks Scott for being patient during my time of worry about the belts. Your were right (you already knew that). 😜




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[dunkonu23]

Dave,

I'm happy the belt alignment thing went away. A key point to remember here is this: If the main drive belt rides low at build but is properly positioned on the motor drive pulley, any alignment will sort itself out.

I'm sorry about your grip flipping thing. Stuff happens. I've had things like that happen to me. When I built the test model, I moved a Spartan from another helicopter to the test EXO but had to change orientation of the unit from forward upright to rear inverted. Well, you can imagine the kind of problem that caused when I didn't compensate in the radio. I sent a panicked message to Angelos and five minutes later it was fixed.

Bottom line: We all make mistakes and life goes on.

Have fun with it, sir!

Scott

[Mr.Andersen]

I had reverced tail befor maiden on a point i thought my setup was ready.
Found it changing some other parameters and got it right.
Alternativly i would have found it on the preflight check.
Be thorough with that befor a maiden ore small misstakes will bite back.

[Mateyhv]

The reversed Spartan thing happened to my other heli but was due to updating versions and not checking proper swash movement at home. The preflight check saved the day...