Tank Turret building - Need Help

[avadon77]

Hello All,

I'm trying to build a 1/16 scale RC-style tank turret for a robot. I was trying to find out how full scale tanks like the M1 Abrams accomplish driving their turret in the hopes of scaling it down, but couldn't find any great information.

From what I researched there are numerous ways:
Worm Gear + Worm drive
Belt Drive on pulleys
Powered Slew Ring
Servo motor with gear.

My initial assessment showed that worm gears are slow and wear faster and are generally only for very heavy turrets (E.g. cranes). Belt drives and pulleys are less accurate and slip. Powered slew rings only seem to be monstrously big and heavy and very expensive. So unless i'm missing something it seems that Servos with gearing is the best way to go? I however don't know if you'd use one servo or two in parallel?

It seems like with servos there must be three main components: A servo with a gear head, a large ring gear for the turret, some sort of bearing for the large gear to rotate on. But I'm having trouble ascertaining the best way to do this.








I found these pictures.

[Pak36]

Heng Long RC tanks use a very simple system...

a motor with a drive gear ..
https://www.ebay.co.uk/itm/Heng-Long-Ta ... Swg2FbWZAu
bolted to the upper hull of the tank hull. This drives a plastic gear ring

https://www.ebay.co.uk/itm/Heng-Long-1- ... Sw9idZ5Zq0
attached to the bottom of the turret.

Heng Long put a 'lump' on the turret ring to prevent it going 360 and knotting up the wires running into the turret for the electrics there. I converted mine to use a slip ring for 360+ rotation, and filed teeth into the blob to allow it to rotate. The motor drive for the tank will just drive until blocked.

You could quite easily use the base part of a Heng Long turret, turret ring and motor...then put whatever turret top you want on for the look you need. The parts to do this are available on E-Bay used or new, and won;t break the bank.

[avadon77]

Heng Long RC tanks use a very simple system...

a motor with a drive gear ..
https://www.ebay.co.uk/itm/Heng-Long-Ta ... Swg2FbWZAu
bolted to the upper hull of the tank hull. This drives a plastic gear ring

https://www.ebay.co.uk/itm/Heng-Long-1- ... Sw9idZ5Zq0
attached to the bottom of the turret.

Heng Long put a 'lump' on the turret ring to prevent it going 360 and knotting up the wires running into the turret for the electrics there. I converted mine to use a slip ring for 360+ rotation, and filed teeth into the blob to allow it to rotate. The motor drive for the tank will just drive until blocked.

You could quite easily use the base part of a Heng Long turret, turret ring and motor...then put whatever turret top you want on for the look you need. The parts to do this are available on E-Bay used or new, and won;t break the bank.

I'm trying to find something with much more precision. Would you know of any lightweight slew ring in the 4" vacinity? For example a light industrial version of heavy duty slew ring or flanged bearing. I know others have used 4" lazy susans but I'm looking for something a bit more precise.