19T OWB temperature

[hommer75]

I changed to a Z20 motor and changed the gearing to 15/50/19/61. It's been flying quite nicely for like 8 flights and today I somehow decided to measure the temperature of the gears and the 50T gear was 40 deg. Celcius, but I was quite surprised to see that my 19T OWB was 68 deg. Celcius (~155F). I was almost impossible to touch very long.
This OWB has been in there since day one and has had something like 40 flights.

Has anyone ever looked at this, or any thoughts on this?

[kahn10]

order a 20 tooth bro.those 19 tooth ones suck and your ones getting ready to join that club.....

[hommer75]

That was my best guess as well. I already have one which I'll be putting on soon.

I just keep thinking that the meshing on a 20T owb would be tighter than on a 19T one. In that way I would expect a 20T gear to run hotter.

[kahn10]

they seem to be only a very slightly wider diameter (or so it looks) one extra tooth adds very little to the circumference, they gain there strength by the outer gear being the full length of the bearing spreading the load more i think.side by side the outer gear is about 4 mill longer.the heat generated by your one is either the actual rollers inside dragging on the shaft or the outer gear sleeve slipping on the bearing.thinking about it i would replace the shaft as well....
marco

[hommer75]

I'll replace it and see how it comes out. I don't expect the shaft to have any issues, but I'll look at it closely.

[mjdee14]

I think Marco isright about the slipping....he only reason you would have more heat there is if the rollers were slipping or the the one way is slipping...in any case...change it out....I have a new 19 in my cf and I just got rid of it....not worth $1000 worth of heli for a $9 bearing that is KNOWN to fail regularly. Tjis is one time when it's not worth getting your money's worth out of the 19T

[bearwood]

You guys realise there are 2 types of 19 tooth one way bearings! so the assumption that all 19 tooth one way bearings are suspect is invalid.

One has the bearing completely covered by the gear (the same as the 20 tooth) and the other has the gear only partially covering the bearing . Next time I strip a front gear I will post pics of the 2 types.
My 19 tooth came with my heli ex Hong Kong in early Jan and has 130+ flights on it. I have another 19 tooth here which has a gear not much wider than the front gear.

[hommer75]

I would expect Gaui to have dealt with the splitting gears and would also expect the current 19T gears to have no quality issues any more.
Fact is that my 19T gear was a small one, as bearwood suggest, and came with the kit which is quite an early one so it might have issues, I don't know. I had the 20T gear already and wanted to try it anyway. I did mount it already but haven't thown away the 19T gear yet. I haven't found time to fly it yet. I'll report back how the 20T temperature is after flight.But if that one runs considerably cooler, than the 19T gear will end in the trash quite fast.

[hommer75]

For those of you who are interested;
I flew the Hurricane again and the 20T gear held up much better. After about the same flight this one was only 32 degrees Celsius (~89F), which makes me feel a lot better about it. I think I'll be throwing the 19T gear in the trash....

[xodarap1]

I had (3) 19T OWB's, one failed after a few flights on my z20 hurri so I replaced it with a 20T OWB. The second failed on my z30 hurri after a few flights.

I replaced the 19T OWB on the z30 hurri with another 19T OWB and it has been on there for 151 flights without any problems.

It is the same outer diameter and isn't thick walled like the 20T's, but it is holding fine. Either this is a fluke, or Gaui has done something to the 19T OWB's to make them better because I'm flying the z30 harder now than i was before. No squeal, no slip, nadda.. :confused:

As for temp of the 19T OWB, It isn't hot to the touch (sorry, i don't have any high tech probes, loggers, tachs etc.. every time i save up to get some of that stuff, i get helis, parts or batteries lol) :)