TT drive gear to crown mesh

[CyprusFlyer]

Just getting the mesh adjustments, all makes sense on the crown gear, alignment is critical because the diameter changes due to the cone profile of bevel gears.
However, have a slight issue, when you move the boom in and out, instructions say that the edge/faces of the gears should be parallel, well, the mesh was not optimum there, out by 0.5mm.
How did I deduce this, two ways:

a. Spin the main shaft and the gears are noisy when not at the optimum alignment, I could actually tune for minimum noise by moving the boom in and out.

b. With the crown gear and boom out I align the two gears at 90 deg in my hand, by moving the boom gear closer or further away, the gears push appart, there is a discernable dip at the same optimum postion found by method a.

I shimmed at that position for a little backlash, nice quiet mesh now.

Any one else notice this? Only 0.5mm in it but all other tolerances are near perfect.

[AcidDrink]

Well, I did try to set it up so it's least noisy, I just don't know how much noise should I get (it won't be totally quiet, I suppose). I verified mesh visually (posted a photo here and it people confirmed it was fine) and moved boom back and forth (within 0.5) mm to find the best spot (less noisy).

Still, when I spin it without the blades, there is some noise when I spin it faster.

Maybe you can post a video spinning the head without blades, so we can hear the level of noise?

[CyprusFlyer]

Yes there is always noise and just turning by hand, point is there is quite a dicernable difference when I hit the sweet spot, must be when the gear splines are all exact distance appart and parallel. I am going with my engineering instincs and using my posted result for getting the mesh just right.

[AcidDrink]

Originally Posted by CyprusFlyer

Yes there is always noise and just turning by hand, point is there is quite a dicernable difference when I hit the sweet spot, must be when the gear splines are all exact distance appart and parallel. I am going with my engineering instincs and using my posted result for getting the mesh just right.

Well, that's the problem for me, I have no mechanical engineering instincts whatsoever
I just went with what sounded the best

[CyprusFlyer]

Yes best way, BTW spent quite a while in the RAF as electronics engineer, early days spent fixing teleprinters. Full of gears, belcranks drive shafts etc, showing my age now but came in handy again. One unwritten law was turn everything by hand and listen for any strange noises binding etc and investigate any thing unusual before applying power and wrecking everything.

[Groucho_]

Originally Posted by CyprusFlyer

spent quite a while in the RAF as electronics engineer, early days spent fixing teleprinters.

I was in what was previously an underground RAF command centre last year, and the teleprinter room was still there though empty... Smallish room with a 'Teleprinter' sign above the door.

[CyprusFlyer]

Interesting although most of the time we were chatting up the girls in the communication centre (COMMCEN). Now its all email and no pool of girls :-(

[Mercuriell]

Originally Posted by CyprusFlyer

Interesting although most of the time we were chatting up the girls in the communication centre (COMMCEN). Now its all email and no pool of girls :-(

Akrotiri? I got a load of TTY stuff as a kid when Reuters junked them, fascinating machines - loved the tickertape ! Didn't get the girls that went with them though

[CyprusFlyer]

Did two tours at Akrotiri and one at Episkopi before that, at Epi just caught the last of the old post war Creed machines, totally electro/mechanical, Siemens electronic stuff came into service a little later! Ticker tape and everything. Funny old thing, I had a nitro heli at Akrotiri, tail gyro had old fashioned spinny weights! Never ever learned to fly it lol

[richardmills]

Yep mine was the same. I set it where it was quietest. There was quite a big difference as well. I was surprised.

[ZuvieleTeile]

When I was younger and more into it, I was able to read the ticker tape like a newspaper. . .
But this and also Morse code came out of fashion somehow

[Mercuriell]

Originally Posted by ZuvieleTeile

When I was younger and more into it, I was able to read the ticker tape like a newspaper. . .
But this and also Morese code came out of fashion somehow

Wow, never knew people could read punched ticker tape, never did figure it out I too am a Morse veteran but attempts to teach my 14 yr old sons are met with blank WTF stares Funny I had a patient who was an ex Morse operator and we annoyed everyne else in the OR by dit dahing to each other