Hi Frank,

There is a standard Protech upgrade to the standard flat metal and plastic tail gear setup, the new gears being both plastic and a bevel type instead of flat.

I recently had a similar problem with one of my zoom's resulting in the plastic gear stripping more or less completely. The existing one only comes with a new tail output shaft and cannot be bought as an individual item as the one up the front is. When I ordered the replacement gear with the tail output shaft, Protech part no T0500.041, which is described as a "Tail output shaft set" I was told that this part is no longer available and has been superceeded by part nos, T0500.212 "Tail drive shaft, bevel type" and T0500.211 "Bevel tail gear 21 Tooth".

The new parts are a carbon drive shaft with a plastic beveled gear bonded to the end of it and the standard hex carbon end bonded into the other end of the drive shaft to accept the existing plastic gear up the front where it mates with the motor pinion. The other part is black alloy hex tail output shaft with the other beveled gear bonded on to it that sits inside the tail gearbox.

I havent had the chance to fly the model with the new tail gearbox configuration yet, but on the bench, at least, it looks like an altogether stronger and much more reliable setup.

I hope this helps.

Cheers,

Pete.

Pete

Thanks for info on the gears, I'll look out for those.

Let us know how you get on with these gears.

Thanks

Frank

I got my Zoom with the white plastic tail bevel gears. These did not last very long at all. Managed to take one tooth out ouf the bevel gear when setting the heli up. (10 minutes use!) Haven't hit the ground with the tails either. I havn't tached the main blades, but estimate that it must be that I'm running about 2000 head speed, (Will check on it later when all the rest is set-up) as I really want to be able to throw it around.

The speed that I have gone through all the stock gears, worries me a little, and not sure if it is going to be up for fast piro manouvers. I have tried a variety of things...including an aluminum from tail gear which I modified the rear tail to suit...but that wore away at an alarming rate. Several minutes hovering wore the teeth away leaving a lot of play...

I'm considering the belt drive upgrade kit, but I may want to try the BLUE gears which claim to be stronger. Not really sure of which way to go first.
There was an upgrade kit in Rotorworld.. but I don't like the sound of having to cut away at the frames.. and the other one which is from Heli-up is taking a bit more expensive...but does not require you to do any cutting..

Has anyone else done the mod, or even tried the blue gears with any success. I don't want to have to end up having the gears break in flight.

Tail Gears

Arghh, I replaced the standard tail gears with the white bevelled gears, and didn't get one flight. I knock the tail rotor when running it in the garage (weather has been really bad) and it shattered one of the gears.

Any other suggestions or is belt drive the only way to go?

Still using the stock tail gears that came with my Zoom - I keep a careful eye on the mesh - you want a little backlash and I put a light smear of triflow grease on them - The one saving grace for me is I don't run my Zoom in very confines spaces or on rough ground.Decided early days I would keep it for the indoor meetings in nice big gyms.
I have thought about a belt drive conversion but even with that fitted -if the tail blades are stopped suddenly by any outside cause something will go bang.
Dave

Dave

Thanks, unfortunately I don't have that luxury. Guess I will just have to try to be extra careful. But the white bevel gears are even worst than the original flat gears at least they didn't shatter.

Have you thought about taking your own landing pad for rough field landings - say a piece of carpet or lino.
Dave

I haven't had the chance to try mine out yet, I had this little mishap with it when I was flying it in my back garden a while ago. The resulting crash did a fair amount of damage, main shaft, feathering spindle, main blade grip bearings, tail gears, skids, main blades and one or two other odds and ends. I have only just picked up the replacement bearings for the main blade grips yesterday, I will be installing them and trying it again this week.

The crash was my own fault really, I had a bit of a problem installing a carbon fibre battery extension plate to the battery tray in the frames. The thing was, I thought I would be clever and bolt the carbon plate in with some small M2 bolts. That was fine until it came time to drill them, which as you will know the zoom isn't the easiest model to work on like that. I drilled the holes in from the bottom, through the plastic first and then through the carbon itself. I had done and put the bolts in on 3 of the 4 locations and I was holding the model with one hand, while drilling the final hole with the other. The carbon was pretty stubborn and took some drilling. Needless to say the drill went through the carbon rather suddenly, what I hadn't realised is I was actually holding the model right where the hole was I was drilling. The result was the 2mm drill bit entered through the front of my finger and emerged out through roughly the middle of my finger nail :cry:

After an hour or so of finding and putting on the biggest damn plaster I could find and a cup of coffee and a fag I decided to try and finish off the model. Being that I was sure the fourth hole was right the way through :wink: I stuck the last bolt in, strapped the battery on with some velcro, slapped the canopy on and went out to the garden to try it out.

I have to say with a Himax 2025 4200, Phoenix 25 ESC and a GY401 it flew really well, that was until the finger I had the damn great plaster on which happened to be the second finger on my left hand, and the one I use to control the Idle up switch on the transmitter, got wedged between the gyro mode and idle up switches, therefore I inadvertantly engaged Idle up 2. I hadn't yet set up an Idle up 2 in the transmitter, only to switch the function on. The next thing was this thing took off skywards like a bloody rocket 8O

I fought with it best I could for a few moments to get it back down to earth, but didn't quite manage it, the model ended up ploughing into next doors back garden :roll: Hence the crash.

The moral of this storey, don't try and fly with a damn great plaster on your finger :wink:

Cheers,

Pete.

you couldnt make up a story like that could you? hope your ok now?

Sorry to hear that story Pete - There's enough ways of crashing helicopters normally without inventing new ones.
Dave

Yeah, I'm OK now, this happened in about the middle of October last year. It took a good while for the finger to heal up, which meant I was a bit slow on the keyboard for a while.

The reason I mentioned it now is that I am still finding problems with the zoom following that crash. I rebuilt the model with most of the new components needed, when I ordered the bits it was then that I found out about the upgrade to the bevel gears for the tail gearbox. The model is now all but done, I ran it up last time briefly in my living room to discover that the blade tracking was wildly out. In the end I found the problem to be the two small bearings inside the main blade grips were shot. The new ones I ordered for it came in this weekend, so given any luck I will be fitting them and giving the model a good try out again this week.

I also picked up one of the latest generation Flightpower extreme 1600mah Li-Po packs and accompanying cell balancer for it so I am looking forward to trying it out.

Cheers,

Pete.

Wow, sorry to hear about your accident, makes my stiches in my fingers after brushing a 11 x 6 on a 46 seem mild by comparison.

Anyway, got the new gears in the Zoom 400 and test hovered it on the drive today. On reassembly I'd got some stiffness in the linkage to the tail rotor and with the gyro gain set up it made the tail difficult to control. I sorted that out and it seems OK now, but I'm thinking of going to one of those carbon fibre control rods as a direct linkage.

Anybody tried one of those?

The Carbon torque rod is the only mod I've done to my Zoom - other than a brushless motor of course.
If you do the mod , think about something to support the rod in the middle or it will buzz.
My solution was to fix an old plastic ball link to one of the boom stays - and let the rod run thro' the loop at the end. 8)
Dave