6HVU belt tension

[DarkSyd3D]

I'm new to this model and not sure about the belt tension. With the boom and tail case push all the way in the belt is very tight and the tensioner is nearly all the way relaxed. Is this normal?

[sewerfly]

https://www.helifreak.com/showthread.php?t=735237

[DarkSyd3D]

Originally Posted by sewerfly

https://www.helifreak.com/showthread.php?t=735237

Ok I see how to do it properly BUT I'm not able to go any looser on the belt tension. So should I trim the boom?

[dominator]

The pic shows that your tensioner is fully relaxed and not adding any tension to your belt. So you would need to pull the boom out a little until the tensioner is adding pressure on the belt. Trimming the boom would be the opposite of what you need to do

[DarkSyd3D]

It's already very tight the way it is now with the tensioner that way, as stated above

[DarkSyd3D]

Originally Posted by dominator

The pic shows that your tensioner is fully relaxed and not adding any tension to your belt. So you would need to pull the boom out a little until the tensioner is adding pressure on the belt. Trimming the boom would be the opposite of what you need to do

It's not like the Protos Max heli

[dominator]

I fly this heli weekly. You are saying the belt is already very tight but your tensioner says otherwise. Unless you have something assembled incorrectly then the tensioner should be almost perpendicular to the boom if the belt is tight. I'm trying to help but things are not adding up correctly.

Can you pull the boom out at all to move the tensioner? You will have to apply a few pounds of force to fully tighten it.

[DarkSyd3D]

I can not. I will go through the tail assymbley again. But now I have another problem. I have to say the ball links for the swash are GARBAGE! Extremely tight on the balls and are easily broken by trying to get them the proper length. I've destroyed two now and the kit only came with one spare.
Also, the elevator link is too thick and I can't get the arm past the case of the servo when the link is attached. They are BK 7002hv cyclics. I'm probably going to have to shim the horn if that will even help.
Things like this make me regret buying the kit to begin with

[Fauropitotto]

I had to shim the left side aileron servo too. Turned out at full negative and full left cyclic, the servo arm could actually contact the tail rotor pulley while using the BK 7001HV servos.

[dominator]

Take your time building. Ball links do need resizing sometimes. I'd prefer them being a little tight than loose. I'm sorry you broke 2 ball links. Try using a different method to adjust them.

Also not all servos are the same size so yes some servos do need to be shimmed. This is common heli practice.

[DarkSyd3D]

Originally Posted by dominator

Take your time building. Ball links do need resizing sometimes. I'd prefer them being a little tight than loose. I'm sorry you broke 2 ball links. Try using a different method to adjust them.

Also not all servos are the same size so yes some servos do need to be shimmed. This is common heli practice.

I was adjusting with my bare hands when the rod poked theough. Barely felt resistance. I don't mind tight links but tight to the point of bending my link pliers is too much.
I've been flying helis for about 15 years now and this is the first time I've had to shim a servo horn. A servo yes, but never a horn :/

The tail is ok now. Inadvertently put the boom on backwards like a noob

[Ah Clem]

"Take your time building. Ball links do need resizing sometimes. I'd prefer them being a little tight than loose. I'm sorry you broke 2 ball links. Try using a different method to adjust them.

Also not all servos are the same size so yes some servos do need to be shimmed. This is common heli practice."

Excellent advice from Dominator (as always)!

When tightening the ball links on ANY helicopter, always measure the distance that you can safely thread the rod into the link FIRST. Hold the ROD with pliers and twist one link on at a time-NEVER hold the link on one end of the rod and twist on the link at the other. Invariably, one will turn harder than the other and the rod will come through the end of one of the links. I found this out the hard way in the early 1980s' with Kavan links (also with my bare hands). One clue that it is about to happen is that the ring on the end of the link will start to bend off center.

Compass links always have to be sized (as do the links on many machines). I do this with all brands of machines to get the fit I want between the link and the ball.

Make sure that you ground the boom and spray the belt with silicon.

[DarkSyd3D]

Originally Posted by Ah Clem

"Take your time building. Ball links do need resizing sometimes. I'd prefer them being a little tight than loose. I'm sorry you broke 2 ball links. Try using a different method to adjust them.

Also not all servos are the same size so yes some servos do need to be shimmed. This is common heli practice."

Excellent advice from Dominator (as always)!

When tightening the ball links on ANY helicopter, always measure the distance that you can safely thread the rod into the link FIRST. Hold the ROD with pliers and twist one link on at a time-NEVER hold the link on one end of the rod and twist on the link at the other. Invariably, one will turn harder than the other and the rod will come through the end of one of the links. I found this out the hard way in the early 1980s' with Kavan links (also with my bare hands). One clue that it is about to happen is that the ring on the end of the link will start to bend off center.

Compass links always have to be sized (as do the links on many machines). I do this with all brands of machines to get the fit I want between the link and the ball.

Make sure that you ground the boom and spray the belt with silicon.

The links were already installed on the rods in the package so I didn't actually put them on myself. They were a little to long from what the manual stated they should be so I figured there was room left but turned out they were nearly bottomed out already.
Most links I've dealt with still have about half the inside left to go when set to the manual spec but like I said, I'm brand new to Compass and I'm learning they do things a bit different than I'm used to.
No biggie, ordered new links so hopefully they will be in Saturday so I can maiden Sunday.
As for the belt, I read in the thread you posted that it was already lubricated? I'll go back and read it again to be sure. The outside of the belt is very shiny, not like conventional belts I have on my machines. Almost feels plasticy but not in a cheap way.
Boom was grounded when I had it backwards so I'll have to drill and tap a new hole but not biggie lol.

[DarkSyd3D]

Ok, reread what you said about the belt being lubed. Are you also spraying the teeth?
Most manufacturers don't recommend that as it can cause the belt to slip.

[Ah Clem]

DarkSyd3D,

All great points/questions!

Every helicopter that I have built over the last 40 years (I have not built them all, but I did give it a try) had pushrod lengths/recommendations in the instructions that were close, but never accurate. I always used them as a starting point (as you did here) and did what I needed to do to get things working properly.

The original 6HV came with a swashplate leveling tool which gave the the correct height and level adjustment automatically. This worked on the 6HV-U (as well as the 7HV-U) but was, unfortunately, discontinued.

As far as the ball links go, there are new, very heavy duty ones that came out with the Chronos that will work on the 6HV-U (although I have to check on the two on the upper deck of the swashplate to make sure that there is proper clearance for their width-I know that the is not on the Atom 500).

The Compass belts are not pre-lubricated. Although they do not require it, a long time of experience with them has proven that proper lubrication will provide both lower friction and longer belt life. The silicon will soak into the belt, and need only be done once every year or so.

All of the belted machines I have built/flown so far have benefited from lubrication-the teeth will not slip (anymore than a greased gear will slip with a correct, light tension). This includes Compass, Align, Mikado, SAB, Kyosho, Hirobo, JR, and others. The key is setting the tension just enough that they don't (as in the other post referenced above and its attached video).

I know, from reading Alex/On the Snap's posts, that MSH does not recommend lubing the belts on the Protos helicopters (this is the only manufacturer I know of that actively states not to lube the belts-most do not comment at all on the subject). Alex is extremely astute and does a lot of testing and developement for MSH. His machines are completely reliable and always fly extremely well. I defer to his expertise with the MSH Protos machines-if he says not to lube the belts on them, I would follow his advice to the letter.

[DarkSyd3D]

Originally Posted by Ah Clem

DarkSyd3D,

All great points/questions!

Every helicopter that I have built over the last 40 years (I have not built them all, but I did give it a try) had pushrod lengths/recommendations in the instructions that were close, but never accurate. I always used them as a starting point (as you did here) and did what I needed to do to get things working properly.

The original 6HV came with a swashplate leveling tool which gave the the correct height and level adjustment automatically. This worked on the 6HV-U (as well as the 7HV-U) but was, unfortunately, discontinued.

As far as the ball links go, there are new, very heavy duty ones that came out with the Chronos that will work on the 6HV-U (although I have to check on the two on the upper deck of the swashplate to make sure that there is proper clearance for their width-I know that the is not on the Atom 500).

The Compass belts are not pre-lubricated. Although they do not require it, a long time of experience with them has proven that proper lubrication will provide both lower friction and longer belt life. The silicon will soak into the belt, and need only be done once every year or so.

All of the belted machines I have built/flown so far have benefited from lubrication-the teeth will not slip (anymore than a greased gear will slip). This includes Compass, Align, Mikado, SAB, Kyosho, Hirobo, JR, and others. The key is setting the tension just enough that they don't (as in the other post referenced above and its attached video).

I know, from reading Alex/On the Snap's posts, that MSH does not recommend lubing the belts on the Protos helicopters (this is the only manufacturer I know of that actively states not to lube the belts-most do not comment at all on the subject). Alex is extremely astute, and does a lot of testing and developement for MSH. His machines always fly extremely well. I defer to his expertise with the MSH Protos machines-if he says not to lube the belts on them, I would follow his advice to the letter.

Thanks dude. I'll do the belt on the 6hv then. I ordered the 2.5mm links so I'm hoping they're the correct ones you're talking about. They look the same as the ones in the kit (didn't reference the part number like I should have) and they are very beefy.
I appreciate all the help/advice. This will get me ready for the EXO

[Ah Clem]

My pleasure, sir!

[shadco]

.

Fwiw I've been using Mikado ball links far superior to Compass links, they are cheap to boot.

I don't think the Chronos link will fit the swash to grip links.

.