fed up, Pinion T13 and OWB issue, slipping!?

[honkytown]

it's just me or someone else had slipping issues with Pinion T13?

i recently changed from T14 to T13 with the MSH 51098 4mm Adapter and bearing support. the T14 pinion worked great for over 100 flights, the T13 pinion slipped in my 5th flight...what a bummer

am i just unlucky on this one? should i buy a second one from the same store or try my luck somewhere else? as far is i know there is no pinion without OWB available like the solid pinion for the MiniProtos from lynx..

[DoubleCH]

Check the adapter shaft or long motor shaft. They are soft and wear out over time allowing OWBs to slip. As I mentioned on the other thread 13T with the bigger torque is more likely to slip than 14T. The OWBs themselves in the 13T pinions are not particular weak.

I gave up on stock soft aluminum pinion and soft steel 4mm shaft adapter and long shaft long time ago and did my home-made solid steel 13T pinion mod and double-idler mod. Super reliable. Nothing to slip even with super low belt tension. Pinion and belt last 600+ flights.

https://www.helifreak.com/showthread.php?t=638975

https://www.helifreak.com/showthread.php?t=639865

[honkytown]

thx for your advice DCH, i will look into it tomorrow. i think it's my own fault should have changed the adapter too... the worst part is i can't get a spare adapter for weekend flying - that's what really sucks

[DoubleCH]

Actually while 13T yields more torque than 14T, it's the reverse regarding torque on the OWBs. But yeah, check the 4mm shaft/adapter.

[honkytown]

unlucky again.

i bought a new motor shaft(long version) and a new pinion 13T including 3rd bearing support
yesterday i got 11 flights without any issues, stretch version with
470er MSH blades and 2000-2250 head speed with ~12.3° pitch
today on my 4th flight the OWB slipped again and the ESC shutdown
because of to high amp, haven't checked yet if i burned my motor this
time because there were some smoke coming out and it was very very hot



this really is frustrating - i can'T believe the OWB isn't holding my flying style with such low head speed
there aren't many reports about the OWB slipping, so i asking myself what i am doing wrong?
looks like DCH "home-made solid steel 13T pinion mod " is my only solution or just change back to 14T with higher HS

[DoubleCH]

OWB slipping should not cause motor to shut down or high current draw. I wonder if the culprit was mis-aligned 3rd motor bearing support. It takes extra attention to make sure all 3 bearings on the motor shaft are lined up properly. That traces all the way back to how the motor is mounted on the motor mount block. Despite the cross-mounted motor bolts it is possible to mount the motor slightly off center the motor mount block. Once that happens no amount of careful alignment of the 3rd bearing can fix it. You can check the motor alignment on the motor block by looking at the pinion side motor bearing thru' the motor mount block center hole.

Next step is to make sure the motor is mounted perfectly parallel with the mainshaft. It's very easy to have the motor mounted pinion-side more towards the mainshaft because of the belt tension. I pretty much had to hold my thumb against the pinion above the belt towards front of heli while tightening motor mount block side bolts. If motor shaft is not perfectly parallel to the mainshaft, no amount of alignment of the 3rd bearing can fix it.

Only after all of the above checked should you install the 3rd bearing support. I keep the bolts a little less than finger-tight and then run up the motor at the lowest speed possible (without any blades but the right belt tension) and then finger tight the Y-bracket bolts followed by properly tighten them in cross-pattern while the motor is still running.

Even with all the extra attention mentioned above, my 3rd bearing kept wearing out over time with my kind of flying and seize up (due to bearing balls inside wear out and lodge against each other). I used to buy those 4x9x4mm 3rd bearings i bulk. That's one main reason I run solid steel pinion without OWB which means 6mm shaft adapter which means no need for 3rd bearing support.

[whisperdancer]

What I used to do when installing a new pinion was to clean the inside of it with a rag or paper towel until it got dry.
After some time, spooling down sound isn't very nice (it squeaks), but it does does a good job grabbing the shaft.

[honkytown]

sorry for my late response, i had to take a break from this hobby...

to make a long story short: i bought another long motorshaft and a new 14T pinion. took my protos out and had 8 smooth (sport)flights with 2300/2400HS, the next day i started to fly little harder, on my 4th flight i noticed some odd power losses for a split second, the next 2 flights the same odd power losses and then on the 7th flight it happened again, the OWB slipped and i crashed for the third time because of this...

thanks for your advice, i religiously followed the alignment of the motorshaft and the third bearing support, but still doesn't worked out for me. on my miniprotos i haven't had any issues yet with the third bearing.
i never ever greased or oiled my OWB in any model i have

there are 3 options i can think of:
a. selling my beloved Protos and get something that can handle my flying style
b. motor rewind to something like 600-700kV and use msh pinions 16/17/18 - they have an much stronger 6mm OWB instead of 4mm
BUT is the stretch belt long enough to use pinions up to 20T? i don't think so.
c. getting the lynx 550x 13T mod1 pinion without OWB

this is the picture of the last accident, the OWB plastic inserts melted, i guess that was the smoke that was coming out last time

[honkytown]

this is my (new)long motor shaft after 15 flights on (new)14T pinion