Should I remove the idle pulley ???

[nmdesertracer]

My tail boom cant move forward I got a extra plastic servo mount against the tail block. Thats the first thing you should do to your heli.

[Wolfpackin]

Originally Posted by bchrny

Imagine this- you are flying and your tail boom loosens up in mid flight, slides forward thus loosening the belt: with the pulley in place the belt is forced to make contact with the rotor pulley. Without the IDLER pulley in place-well you get the picture. Your call, your machine, your money. They make more silicone! Should I remove my blinker switch in my car- Nobody uses them anymore. Do they???

If that happened the belt could just slip on the front tail drive pulley.
The idler pulley is known to cause issues, crashes, and many have eliminated the problem by removing it with no ill effects.

Others have no problem with the pulley on the heli.
So yes, always up to the user.

[bchrny]

Again I will ask the question, WHAT ISSUES? Everyone keeps saying it causes problems, so what are they? I have mine on and I don't notice problems. Discoloration of the back side of the belt thats not a problem (cosmetics). Thats the only thing I have seen mentioned, Yeah I've seen the posts about the silicone to stop static but that is an assumption, to release a static discharge into something the thing has to be grounded- did you ever experience a lightning strike to an aircraft? It does nothing without being grounded. So in essence I would really like someone to explain what these 'so called' problems actually are? Thanks for your input! Any knowledge would be helpful. Thanks again.

[Wolfpackin]

Originally Posted by bchrny

Again I will ask the question, WHAT ISSUES? Everyone keeps saying it causes problems, so what are they? I have mine on and I don't notice problems. Discoloration of the back side of the belt thats not a problem (cosmetics). Thats the only thing I have seen mentioned

Back in the day SE V2 owners were experiencing belt problems like it coming off the pulley/gear, not riding true and getting stuck between the pulley and shaft or side plate of the tail case. Most times this type of failure caused crashes due to loss of tail control.

It's been years since I read this whole thread but some of those issues are discussed here. There are also multiple other threads regarding belts getting stuck, jammed or broken due to the idler pulley system. Read this whole thread and try a search, there should be lots to read.

But for those that did have problems like belt jams or jumping on the SE V2, removing the idler pulley solved them.
As I stated, not all owners of the SE V2 had catastrophic belt failures or chronic issues. But for those who did, removing the idler pulley made that stop.
Note that Align no longer has that pulley on most of the newer designs...it's just not needed and does more harm than good.

Originally Posted by bchrny

Yeah I've seen the posts about the silicone to stop static but that is an assumption, to release a static discharge into something the thing has to be grounded- did you ever experience a lightning strike to an aircraft? It does nothing without being grounded. So in essence I would really like someone to explain what these 'so called' problems actually are? Thanks for your input! Any knowledge would be helpful. Thanks again.

Using silicone on the belt does not discharge a static charge it prevents the system from generating static electricity, generating a charge, in the first place.

Silicone on the belt also helps condition the rubber compound helping it break in, makes it more supple and improves longevity.

I do this on all of my belts and have several that lasted over 500 flights before being replaced. The belt on my 450 has almost 550 flights and it still looks fine.

I've also never had any static issues and I live in a very low humidity environment pefect for static charge buildup.

[bchrny]

Thanks for that info, I did try to find the problems as stated but like you said "there are many posts" too many to sort through them all. As many posts as I did search, I could'nt nail down any one particular that refered to above said problem. So could that be the cause of my occasional slight twitch which does'nt happen to often? I suppose the only way to find out would be to take it off and test it. Should I remove the screw also?

[bchrny]

: banana

[Wolfpackin]

Originally Posted by bchrny

Thanks for that info, I did try to find the problems as stated but like you said "there are many posts" too many to sort through them all. As many posts as I did search, I could'nt nail down any one particular that refered to above said problem. So could that be the cause of my occasional slight twitch which does'nt happen to often? I suppose the only way to find out would be to take it off and test it. Should I remove the screw also?

If you don't see any belt damage like fraying or scuffing then it's probably not related to the idler pulley.
BUT, it could be static discharge.

Some people put the bolt back in to clean up the look, no holes in the side plate.

Originally Posted by bchrny

Just another quick question: My girl and I have been discussing a very similar issue, she as it seems has a couple of friends that are about the same age and ran into problems at the recycling plant in which they work. At times the reek of the refuse just gets to be intolerable, they need their jobs and replacing jobs these days really isn't a viable option. So the question is, should they just have their olefactory glands removed??? RLMAO:bana na

That's up to them...maybe a little Vicks under the nose to mask the smell.

Any other life questions I can help with?

[maraispc]

Ok - to give some further credit to the problem that Wolf described above...

When I built my SEV2 a few years ago there were quite a few posts of folks who had the belt coming off the rear toothed pulley and jamming in between the side plate of the tail unit and the toothed pulley. In many cases this resulted in crashes.

Anyway, so while I completed the build I kept the "idler" pulley in place as per the manual, guided also by many counter-posts of folks who never encountered any problems and arguments that the manufacturer must know what they are doing (also if I removed the pulley then the tail unit will look so "incomplete"!!)

Ok, all went well...for 15 or so flights and then it happened...belt ran off the toothed pulley and partially jammed in between the toothed pulley and side plate. At that stage I was still at the hover stage - heli about 2m up - this caused a sudden & dramatic power loss, but other than a hard landing - no other damage. I this had occured during FF it would have been a crash for sure.

New belt, removed the "idler" pulley and no more problems with hundreds of flights lightly lubricating the belt with silicon spray every 15 flights or so. Removing the "idler" pulley was an easier decision at this stage as the 450 Sport was released and the tail unit did not include this.

If you do decide to keep the "idler pulley", keep an eye out for belt edges fraying and ensure the"idler" pulley & belt is lubricated (silicone). Contributary factors that I identified when the belt jammed were slightly frayed belt edges and dry belt & pulley.

[Wolfpackin]

I appreciate your first hand account of the idler pulley problem.
Thank you kind sir.

[maraispc]

[bchrny]

That goes double, thanks for the responses I'll go ahead and remove it. Better to voluntarily lose a part than pay for others for a grave error! Thanks a heap! Or more like one less heap

[n1977m]

I haven't tried to run mine without the idler (pressing pulley). I installed another tail unit that was designed without the idler. Problem solved. I did notice that the tail unit with the idler has a base where the screws pass all the way through to the other side requiring the belt passes to run closer together. The unit designed without the idler has a base where the screws thread into the base and do not pass all the way through thereby allowing the belt passes to run farther apart.

[TomRex]

Also the old Rex's used a first version tail shaft with a pressed on plastic cog pulley so belt slippage was reduced with more contact on the pulley. Just so all concerned will know the idler pulley is really called a snubber pulley in the mechanical world.

old school by todays standards but probably works better than the new stuff now.

[Wolfpackin]

That picture should be in the HF Hall of Fame.
It's been posted more than most and shows the pulley removed, fuel tube mod and chinese weight mod at the same time.

Classic old school stuff for sure.

[Bladecpnitro]

Originally Posted by Wolfpackin

That picture should be in the HF Hall of Fame.
It's been posted more than most and shows the pulley removed, fuel tube mod and chinese weight mod at the same time.

Classic old school stuff for sure.

Hey what does the fuel tube mod do you mention?

[FuntanaS]

Originally Posted by Bladecpnitro

Hey what does the fuel tube mod do you mention?

I would guess it reduces the slop in the tail. But for about $35 you can upgrade to the new dual Align tail. Very nice.

[yayan]

The idler wheel maintains proper engagement of the teeth on the synchromesh belt in the teeth on the synchromesh drive sprocket. On larger applications synchromesh belts are kept taught, suchas when used as auto timing belts. However, on small helicopters such an application would sink too may watts. The cause of the belt riding up to one side lies with the tail drive shaft and bearings, rather than the idler wheel itself.

If the synchromesh belt rides up onto the flange of the tail-shaft drive sprocket, the cause has to be the tail drive shaft is not running perpendicular to the line of the drive belt when under certain loading conditions.
The shaft will pull out of true if there is excessive clearance between the shaft and the inner diameter of either radial bearing, and or that bearing moving in it's housing, then the tension developed by driving forces exerted on the belt itself will pull the drive shaft out of true and the belt will move to that end of the drive sprocket; any sigh of fraying will indicate which bearing/housing to inspect and rectify. If the shaft/bearing movement is excessive the belt will bind-up.

The best cure is to fit a double-flanged pulley wheel, like those used on the Walkera 60B or the Walkera Hiko 400.

[deebee]

+1 to that I have the CX450 Black angel (beam E4 clone) both the beam and the BA have the double flanged pulley which in fact does hold the belt in contact with more teeth on the tail pulley, especially important if the belt gets loose. this will keep the tail turning and keep the belt from skipping teeth alot bettter than without.

I get that if you are running a heli with a problematic belt drive you might want to remove the pulley as a quick fix. But IMHO the way to go is to fix the tracking problem and get a better pulley, or just get an upgraded tail set and as always keep it properly lubed. I crash enough without having to worry about poor tracking, poorly designed idlers, or a loose belt causing me to plant it in the field.

The proper fix is less inexpensive than my worries or even one crash.

[tommyboy1229]

I just bought a new plastic tail box yesterday and the stand off and screw holes to moving the idler pulley are no longer there! I didn't know anything about this.