450 Main Gear Binds With Front Tail Gear Axel

[Vincent Woudstra]

Ok, so I'm having another problem with my alzrc devil 450 build. I have build the tail more or less and have now tried to test the gear mesh between the main/autorotation gear and the front tail gears. So far it looks to me the gear mesh between the autorotation gear and the front tail gear is fine, but somehow the main motor gear is touching the axel of the front tail gear.

I've included a picture to clarify the situation.

Am I doing something wrong and is there something I can do to correct this?

 

[Tony]

These are all gears that came with the kit? Mine had a hard mesh issue with the auto gear and tail drive gear that was solved by using Align gears in the back. I don't remember having this issue though. In fact, I have never seen this issue before.

 

[Vincent Woudstra]

Just a quick addition. The situation improved very much after installing the other side plate, but still occurs slightly when only a little force is placed on the main gear.

 

[Vincent Woudstra]

I have replaced the front tail gears and the back tail gears with official align gears. They run a lot smoother indeed. The main gear is the one that came with the kit.

 

[Tony]

I just looked at mine (same helicopter same gear config) and I have maybe 1mm of a gap between the main gear and the tail drive gear shaft. Very close, but it's still there. One thing you can do is loosen all of your main shaft bearing blocks, push the motor out of the way, and then push the main shaft blocks forward a bit. Only other option is to use a small micro round file and just kiss the front of the bolt holes for the main bearing blocks.

 

[Vincent Woudstra]

I have not even installed the motor yet.

As it is almost 2 am here, I will try to do as you suggested tomorrow and let you know the results.

 

[Tony]

Copy that. Have a good night.

 

[Vincent Woudstra]

Ok, so I did as you suggested. I loosened the screws of the main shaft bearing blocks and pushed it as far forward as possible. This cleared the problem of the main gear touching the tail drive gear shaft.

However, now I noticed some binding in the system. After much tinkering and evaluation, I concluded this binding came from the umbrella gear being pinched inside the tail boom mount. I tried to loosen that up by removing and replacing the umbrella gear some times and this seems to work somewhat.
Since I'm a complete noob I have no idea how smooth it should all run from the main head to the tail, but at least the binding I do feel is fairly even along the full range of motion so I'm hoping I will be ok and the rest will wear in.

 

[murankar]

Those gears sometimes have shims. Is it shimmed? If so take out the shims.

 

[Admiral]

You could try replacing the ALZRC gears with Align ones I believe they are the same but better quality.

I had a similar issue with a 450L and used and electric drill with a Phillips driver to seat the gears in, you could also use some toothpaste as a cutting agent if necessary.

 

[Tony]

Yea, this bird is sounding like one of the bad ones the further you dive into it. It happens and sucks when it happens to you. I have been there.

There should be no binding at all on any gears. All gears should have some play (lash) so that they do not overheat by rubbing together. I had to play with mine for a while to get it just right. If I remember right, it was the horizontal gear that I had to sand so that the bearing could slide on further.