Japanese Class A 1/16

[MFR1964]

Tea and scones guys?

[He Who Shall Not Be Named]

The Cat fell asleep from boredom, or he would have told me that

(in the urgent voice of William Shatner) "cat... must.... be.... destroyed!"

[Von Hilde]

The Cat fell asleep from boredom, or he would have told me that

[He Who Shall Not Be Named]

[ATTACH=CONFIG]30431[/ATTACH]After a few hours of consultation, His Royal Higness, Tigger the cat said,"Why stick a square box in a round hull?" Only one trunion, will go on a pin thru the side of the case. Teflon shims will adjust the slop in the play

... because you want to ballance the lateral pressure presented by the bevel-gear. Use two, not one.

M

[Von Hilde]

After a few hours of consultation, His Royal Higness, Tigger the cat said,"Why stick a square box in a round hull?" Only one trunion, will go on a pin thru the side of the case. Teflon shims will adjust the slop in the playOk, two trunions, and now an end cover to keep the input shaft in line and its on to some propeller issues for a drill motor test, then I can scramble some eggs in a bowl.

[HardRock]

Good stuff, HardRock. Tell me more about the outrunner. How do you get two counter-rotating outputs from the thing. Most interested in this.

M

The central (black) mounting ring has three lugs that carry three spacing rods to mount on the silver bracket at the left of the photograph. Just read this back and even I don't understand it. Here's a photograph. or two The front out runner is directly connected to the large (black) forward spindle and the rear out runner drives the central (silver) spindle. It needs two ESCs to run and provides quite a serious amount of contra-rotating power.

[HardRock]

There seems to be quite a few solutions to the contra counter egg beater enigma. With this many people workig on a design, it should produce several ideas that work. At this point, it looks lke everyone's rig has to be fine tuned, for various reasons. Sort of like a defense dept contract and all the contractors are scrambling to get a proto up for bidding. One thing I notice, is the metal gears are nice looking, but have such a tighter tollerance, are subject to water compression, and are noisey. The plastic gears, not so much. Price would be another factor. Corrosion, in my case, is a big issue. copper and brass end up looking like the Statue of Liberty in less than a week. That green funk builds up quick. I dont want to have to take the gears out once a week to polish, like I have to do with the cymbals on my drum kit. So I'm taking the day off working on the type IX, and jummping into my old gearbox, and rummage around the junk bin for usable parts.[ATTACH=CONFIG]30427[/ATTACH]Its a start. 4 gears one bicycle spoke, one telescoping portable radio antenna, now a cup of coffee, and find a magic wand.

I love this McGuiver. A used thum tac, a small bottle of nitro glycerine, a copy of the girl guides field manual, one used condom and a hamster. Yep, we're ready!

[He Who Shall Not Be Named]

I also tried this [ATTACH=CONFIG]30426[/ATTACH] as a refinement of the crown and pinion wheels and again, it worked but it was no where near as smooth as the final gearbox that used old nylon servo gears.

Good stuff, HardRock. Tell me more about the outrunner. How do you get two counter-rotating outputs from the thing. Most interested in this.

M

[redboat219]

Good catch, Romel. I'll see if I can punch out a 555's motor-shaft. Film at eleven!

M

Any luck so far?

Was expecting you'll go with building your own contrarotating gearbox.

BTW, with the tandem motors vs single motor with contrarotating gearbox, which would be more electrical power hungry?

[Von Hilde]

There seems to be quite a few solutions to the contra counter egg beater enigma. With this many people workig on a design, it should produce several ideas that work. At this point, it looks lke everyone's rig has to be fine tuned, for various reasons. Sort of like a defense dept contract and all the contractors are scrambling to get a proto up for bidding. One thing I notice, is the metal gears are nice looking, but have such a tighter tollerance, are subject to water compression, and are noisey. The plastic gears, not so much. Price would be another factor. Corrosion, in my case, is a big issue. copper and brass end up looking like the Statue of Liberty in less than a week. That green funk builds up quick. I dont want to have to take the gears out once a week to polish, like I have to do with the cymbals on my drum kit. So I'm taking the day off working on the type IX, and jummping into my old gearbox, and rummage around the junk bin for usable parts.Its a start. 4 gears one bicycle spoke, one telescoping portable radio antenna, now a cup of coffee, and find a magic wand.

[HardRock]

I also tried this as a refinement of the crown and pinion wheels and again, it worked but it was no where near as smooth as the final gearbox that used old nylon servo gears.

[HardRock]

Here is a contra-rotating out runner. Its about 16mm dia at the mounts.

Before finding this I tried this: Both of these worked but were difficult to keep aligned. The larger one took up too much space.

So I tried this: It worked but it was fiddly to keep aligned and, again, it took up too much space.

So I made this from some old servo gears: Much better performance and smoother running, so I incorporated it into the servo / receiver tray and ended up with this: Its quiet, strong and it fits in a 1/72 scale Type A.

[george]

Hi Manfred

Thanks again for the new posting. Question, could you post a still picture of the gear box as close and clear as you can? That way I can enlarge the picture to better see your working mechanism. From the video it is a little hard to see the setup. Also where did you buy your gears from? It is hard to find them here in Canada.
George

[Von Hilde]

just rwalized the correct term for this set up , it should be contra rotating props not counter rotating. Contra is used for 2 props on a single shaft turning in opposite directions, counter is 2 props on 2 different shafts turning in opposite directions.

Tecniclly you have two props on a centerline shaft in a shaft that rotate in opposite directions Its called LCT( limited to centerline thrust) so since you designed it you can call it anything you like. but it sure is cool. Your prototype gadjet could make a nice soufle' or crepe'. I should rip into my wife's, mother's old Hammelton Beach portable cake mixer for the gears inside there.

[redboat219]

just rwalized the correct term for this set up , it should be contra rotating props not counter rotating. Contra is used for 2 props on a single shaft turning in opposite directions, counter is 2 props on 2 different shafts turning in opposite directions.