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Alternative to Standard HL Turret rotation unit?
Posted: Sun Apr 09, 2017 1:36 pm
by 43rdRecceReg
I'm just wondering if there's some ingenious alternative product, that's a lot smaller than the standard motor. It will need to work with the standard ring gears. Why? Well, I'm now at the stage in my Cromwell build where I need to decide the electronic layout. I
could fit the HL unit, but it will entail sawing some of the centre support bulkhead out of the Cromwell's upper hull.

What I really need is something really simple: a motor just to drive the output wheel (final drive to the turret ring wheel..), like a small servo arrangement. That way, the unit would fit neatly in the front part of the hull....
Brainwaves

and inspired ideas, are most welcome

But, since it's raining and driech here in the far North, a timely jest might help

By the way, did anyone notice that one of the horses listed as a runner for the Grand National was called 'Hoof hearted'...honestly.

Google it, if in doubt...

Re: Alternative to Standard HL Turret rotation unit?
Posted: Sun Apr 09, 2017 2:42 pm
by AlwynTurner
Hi 43rd, you can get low rev motors from China, check eBay, some of them are quite small. Look for 6rpm 6v geared motors. The ones I use for the nashorn are going to be too long for your needs as otherwise I would have suggested them.
Regards
Alwyn
Re: Alternative to Standard HL Turret rotation unit?
Posted: Sun Apr 09, 2017 3:02 pm
by 43rdRecceReg
AlwynTurner wrote:Hi 43rd, you can get low rev motors from China, check eBay, some of them are quite small. Look for 6rpm 6v geared motors. The ones I use for the nashorn are going to be too long for your needs as otherwise I would have suggested them.
Regards
Alwyn
Thanks, Alwyn, I'll follow that lead.

Re: Alternative to Standard HL Turret rotation unit?
Posted: Sun Apr 09, 2017 3:10 pm
by 971wright
Hi Swop the motor in the traverse unit for the BB motor its a lot faster so gives you more speed on traverse.
that's is the easy way to speed up. without having to change the boards. If you want to fit a servo which hang down a long way also you will have to change the board to a IBU pro or similar .
regards pete
Re: Alternative to Standard HL Turret rotation unit?
Posted: Sun Apr 09, 2017 4:10 pm
by 43rdRecceReg
Thanks, lads. I think- notwithstanding the issues of proportional speed; what I would like to do is hack half the case away. Not having opened one of these units up before, i've no way of knowing how much I can hack off it to make it fit in the spot I've chosen for it. Maybe I could take the gears out and remount them in a narrower arrangement, with the motor repositioned. Is there a more compact rotation unit out there, or would a Tamiya unit be a decent option? Again, this is something I've not had to surmount in the past. RTR tanks have prescribed places for these things..

Maybe I'll post a couple of pics so that you can see the nature of the problem..
Re: Alternative to Standard HL Turret rotation unit?
Posted: Sun Apr 09, 2017 4:34 pm
by RobW
Talk to Tankbear, pretty sure he's got some direct replacements for the HL unit with different ratios. Think they're also OK with the standard radio gear as I'm looking at one for the KV2.
Re: Alternative to Standard HL Turret rotation unit?
Posted: Mon Apr 10, 2017 12:41 am
by 43rdRecceReg
I was thinking about servo control of the traverse and elevation functions in part, as well as space saving solutions. Just found this older thread with some relevant interesting stuff from Michael C
viewtopic.php?f=195&t=17964
Re: Alternative to Standard HL Turret rotation unit?
Posted: Mon Apr 10, 2017 12:47 pm
by wibblywobbly
This is how I positioned a rotation motor in my scratch build Comet, which has the same upper hull design.
Re: Alternative to Standard HL Turret rotation unit?
Posted: Mon Apr 10, 2017 4:42 pm
by ausf
Just keep in mind most rotation units use the 180 motor through a reduction gearbox so there's very little load on a relatively robust motor.
If you take a servo and mod it for continuous rotation, it will work, but you're asking a smaller motor to do a job it wasn't designed for. Servo motors are chosen to do short swift bursts.
The gear head motors are a better choice since the load will be minimal, just choose a ratio and center the final rotation drive gear on it. It'll take some work to mount it, etc.
Adapting the hL parts will ultimately be the easier route if at all possible.
Re: Alternative to Standard HL Turret rotation unit?
Posted: Mon Apr 10, 2017 11:54 pm
by 43rdRecceReg
Thanks, Wibb and Ausf. Food for thought.