Good idea or not? (turret rotation)

[Andy in Cheltenham]

Some of you will know that I'm working on an old Leopad A4. Some of the methods I've seen that will rotate the turret are either too elaborate or take up too much internal space. I was wandering If anyone has considered a servo like this http://cgi.ebay.co.uk/56g-9-5Kg-6-Cir-R ... trolled_JN" onclick="window.open(this.href);return false;

I was thinking perhaps of mounting it in the turret and then connecting it mechanically to the hull ( the turret actually rotates the hull) Yes I know about the problem of tangled leads, I was also thinking of a second RX for the turret to make it seperate from the hull.

Andy

[Andy in Cheltenham]

Blimey 40 have viewed my post and they haven't submitted a response. I think I will give it a shot though.
I'm thinking that a large bearing race will keep the rotation silent and nice and smooth.

[Woz]

Probably (like me) they thought it was a mod for 360 rotation without tangled leads.

[BigPanzer]

Hi Andy,

My 1/8 Panther uses a modified servo in the turret for rotation. It has a v-profile pulley on the output shaft which engages directly with the inside rim of the turret hole in the hull. To give the pulley more grip I simply put a couple of layers of masking tape around the pulley.
It is simply a high torque servo, not a sail winch type.
It works well, but slips when it needs to. However the Panther is made of grp, which has a slightly rougher surface than plastic.

On my 1/16 Gepard I used one of the Tamiya plastic gearboxes in the hull (available from technobots) There is a gear on the output shaft which engages with an old Tam Sherman turret ring. There is one of the Graupner micro speed controllers to give variable speed rotation.
This also works well, but there is some over run on rotation, making accurate gun aiming difficult. The Gepard and Leopard have fast turret rotation, which might make a servo driven system too slow.
Both systems have cables running up into the turret, and the cables can jam the systems up if I'm not careful but I do get several turret rotations before this happens.
Sorry I cant send you any photos of exactly how I did the mod on the Gepard to help the turret turn smoothly, I don't have a camera at the moment, but I used a set of 3 wheels to locate it horizontally, the wheels are fixed to the underside of the hull and bear on the outside of the turret ring. (As on the Tam Sherman). One of the wheels is sprung to keep a bit of pressure on the turret ring. I also put 3 ball races on the underside of the hull and protruding through it for the turret to sit on. The bearings are mounted on bits of steel shaft about 1" long glued to the underside of the hull.
This probably sounds very complicated (it isn't) and a photo would have made it very easy to understand.

I had to sit and think quite a lot to get everything in the Geppy hull - rotation unit, a pair of twin speed gearboxes, 3 speed controllers, other electronics, speaker, Rx, switches and charge socket and an 8-cell battery pack but I found it was possible with room to spare.
I'm using a pair of Eco 27 Esc for the drive motors and a Benedini Mini sound module with a 6w amplifier.

Hope this load of drivel helps you and other Leo/Geppy builders.

Cheers

Peter

[Andy in Cheltenham]

Interesting....I'll look into that now that I now have unlimited internet at our new home. Yippee!

[Andy in Cheltenham]

I've sourced a large bearing for about £28. this will fit nicely into the area in the hull. It use some brass sheet to hold it all in place. I might then get a 6x360 degree rotation servo and then find a good means of getting quick roatation on the turret. I reduce the amount of actual rotation down to about 3 complete turns. I'll get another RX and put that in the turret (running of the same frequencey as the one in the hull) then I won't need to worry about tangled wires. I thinking that if in can create a free spinning turret then it will be more reliable and look a bit more realistic

[Saxondog]

THIS MODIFICATION WAS BUILT BY Bubbajoe and then copied by me and Dietrich in our King Tigers and soon My Tiger VI S13. This is done by mounting a Panzer-IV Ring gear flush with the deck. the the turret base is built up with plasticard and slotted for the gear-motor which is a Tamiya 3-speed crank axle gearbox #93 TAM-001-000. This gear-motor is simple to build and cost under 8.00us. The best thing is more controllable rotation speed, the turret has 360deg. rotation and can be removed in any position. This is the best way I have found to modify the turret on any tank. cheers Blake

Tamiya King Tigers turret modifications 005.JPG (255.64 KiB) Viewed 2505 times

Tamiya King Tigers turret modifications 006.JPG (227.34 KiB) Viewed 2505 times

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Tamiya King Tigers turret modifications 008.JPG (231.29 KiB) Viewed 2505 times

Forgot to mention the upgraded turret rotation wheels from WELSH DRAGON can be installed for the Tiger same as the KT
http://www.welshdragonmodels.co.uk/schu ... -112-p.asp" onclick="window.open(this.href);return false;

Andy this mod works very well, if you need more detailed photos just ask and I will take a few. Bubbajoe is a smart guy, and has helped me many times in building these two KT's and I want to be clear these were his mods which I copied in other tanks. If you follow the mod you will love it,the ring gear mounting requires a little trimming but once installed looks great from the top. cheers Blake

[xrad]

that is really cool! Is the turret locked to the hull somehow from below?

[Saxondog]

The Porsche King Tiger Version of the Bubbajoe Turret modification. This system really works well, and the added benefit of 360deg.rotation and removable turret solves many problems and creates an easy access to the inner hull. XRAD the turret does not lock in but does not bounce around as the turret ring is tight against the ring gear section in the lower hull.

Porsche King Tiger Turret Ring Modification 001.JPG (166.04 KiB) Viewed 2499 times

Porsche King Tiger Turret Ring Modification 002.JPG (227.11 KiB) Viewed 2499 times

Porsche King Tiger Turret Ring Modification 003.JPG (189.66 KiB) Viewed 2499 times

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Porsche King Tiger Turret Ring Modification 005.JPG (112.94 KiB) Viewed 2499 times

Porsche King Tiger Turret Ring Modification 006.JPG (155.53 KiB) Viewed 2499 times

Porsche King Tiger Turret Ring Modification 007.JPG (126.57 KiB) Viewed 2499 times

Porsche King Tiger Turret Ring Modification 008.JPG (124.29 KiB) Viewed 2499 times

Porsche King Tiger Turret Ring Modification 009.JPG (123.91 KiB) Viewed 2499 times

Porsche King Tiger Turret Ring Modification 010.JPG (224.91 KiB) Viewed 2499 times

[sassgrunt]

Blake, thank you for posting this turret rotation mod. I am looking forward to trying it out for myself, and have bought several of the 3-speed crank axle gearboxes that you suggested for turret rotation. I would assume that you build it with the slowest rotation possible (203.7 to 1). Did you have any issues mounting the pinion gear (the gear that drives against the turret ring gear) to the gearbox shaft? I ask because the shaft on the 3 to 1 gearbox is a hex, and the shaft on the drive gear on the stock Tamiya rotation unit is a round shaft. So, did you drill out the gear; replace the gearbox shaft; replace the pinion gear altogether; or something else? Thank you. -Mike