450 Tarot 450 Pro V2 FBL DFC - Torque Tube Bevel Gear wear

[GrantW]

Hi all.
A relative newbie to RC heli flying and still learning the basic art of hover.
I built up my model about 12 months ago, adapting it with a number of metal upgrades as guided by EVERYTHING cpo's excellent build You-Tube videos.
Loving the model. however one observation I've made is that I'm wearing through the torque tube bevel gears within approx 8 to 10 flights - this is low load hover flights I'm talking, not heavy 3D. Early flights I can put it down to ground-strikes of the tail rotor, however I've been very mindful to avoid this and haven't had a single strike on the current set of gears. However the last flight this afternoon showed the tell-tail signs of tail rotor slippage with the tail starting to slide anti-clockcise.
So my question is, what would a typical life-span of a set of these nylon gears be, given my type of flying? I'm wondering if there may be too much play in the system and whether doing something like slightly over-sizing the tail-mount bracket fixing holes in the carbon side plates may be needed to allow some tightening up of the gear meshing?
Thoughts appreciated please.

 

[Admiral]

Hi GrantW, haven't flown 450's for a while but 10 hover flights without incident sounds a bit of a short life, I'm sure I got more than that unless I did something silly.

Thing I found about extending TT gear life.
The White gears are very soft and don't last as long as the Black.
The Umbrella gear fit should be as close as you can get without binding.
I fitted Align 470 skids to mine to tilt the frame nose dowm and lift the tai to make take offs safer for the TT.

 

[GrantW]

Hi GrantW, haven't flown 450's for a while but 10 hover flights without incident sounds a bit of a short life, I'm sure I got more than that unless I did something silly.

Thing I found about extending TT gear life.
The White gears are very soft and don't last as long as the Black.
The Umbrella gear fit should be as close as you can get without binding.
I fitted Align 470 skids to mine to tilt the frame nose dowm and lift the tai to make take offs safer for the TT.

Thanks Admiral. Two new items added to my shopping list then, Black gears and 470 Skids.

 

[Blade 400]

Hi all.
A relative newbie to RC heli flying and still learning the basic art of hover.
I built up my model about 12 months ago, adapting it with a number of metal upgrades as guided by EVERYTHING cpo's excellent build You-Tube videos.
Loving the model. however one observation I've made is that I'm wearing through the torque tube bevel gears within approx 8 to 10 flights - this is low load hover flights I'm talking, not heavy 3D. Early flights I can put it down to ground-strikes of the tail rotor, however I've been very mindful to avoid this and haven't had a single strike on the current set of gears. However the last flight this afternoon showed the tell-tail signs of tail rotor slippage with the tail starting to slide anti-clockcise.
So my question is, what would a typical life-span of a set of these nylon gears be, given my type of flying? I'm wondering if there may be too much play in the system and whether doing something like slightly over-sizing the tail-mount bracket fixing holes in the carbon side plates may be needed to allow some tightening up of the gear meshing?
Thoughts appreciated please.

Hi GrantW,
I bought a Tarot 450 Pro V2 a few months ago and cpo`s videos are a great help.
I had one heavy landing on the tail and was surprised compared to a belt driven tail how easy it is to damage a TT Heli, the TT drive shaft sheared off! My white gears held up but the tail drive shaft was bent. Admirals advice is spot on, he`s helped me a lot, I put a pair of 500 size skids on a few days ago Geena helped me a lot getting the Beast x setup properly, especially tail setup. She also advised me to put a 3mm packer between the rear landing skid and frame of the Heli which raises the tail. I take a small piece of plywood for taking off on grass to make sure the tail doesn`t catch. I also replaced the TT with an Align one which seems better quality than the stock one. I changed the settings in the FBL gyro unit to `Transmitter` recently and that`s helped me tame her down a lot. I can`t comment on how long the white gears last as I`ve only had a few flights so far - I fly my Blade 400 with half my Lipo`s on the same day.
All the best
Blade

 

[GrantW]

Just re-read your response, Admiral, specifically about getting the umbrella gear as close as possible. How would you achieve this? By deepening the locator slots in the Torque Tube, maybe?

 

[Admiral]

No I've never had to do that, I only had to seat the boom as hard in as I could and it would feel a bit notchy when I turned the main rotor, then I would back the boom up a mm or so until it turned freely. There should also be very little backlash.

 

[GrantW]

Well, looking closer at the metal Torque Tube/Front Gear Holder block that I'd installed to replace the original nylon one, it appears to have way too much back-to-front movement in the horizontally mounted bevel gear (is this the backlash you referred to?). the gear can be moved in and out 2 to 3mm, whereas the original nylon unit shows pretty much none. Looks like I need to revert back to the original block, which is a shame as that will impact the routing of my servo wiring.

 

[GrantW]

Further progress made...
On removing the complete tail-boom structure and examining the head end bearing block I've decided there is scope to install a shim in behind the forward-most bearing to close down the gap between the horizontal and vertical gear-sets. A variety of thicknesses of 6x10mm shims are now on order. Meanwhile, I discovered there is a very small amount of adjustment in the after market metal gear block, the top and bottom plates of which are removeable and have a small amount of forward and backward adjustment, which I've done.
As for the tail end gear set, applying a similar thought, I've replaced the spacer tube installed between the two bearings at the end of the torque tube with a small length of brass tubing, cut to length about 1mm or so longer than the original one removed, trial fitted and filed down until a tight but free moving fit was achieved.
With both these fixes applied I've had a very successful run through two battery packs with absolutely no slipping, all without swapping out the gears for a new set. The meshing at both ends of the torque tube is now a lot closer.