Gear changes

Adrian Harris · Post by **Adrian Harris** » Sun Jan 23, 2011 9:43 pm

As we're looking at the finer details, has anyone considered a way to imitate the changing of gears, with the associated lurch ?

I guess it should be possible to play Thomas's engine rev sound, to simulate a de-clutch, but the lurch is a little more difficult, especially with the ramps designed into the older speed controllers.

Adrian.

Antony Rowley · Post by **Antony Rowley** » Sun Jan 23, 2011 10:12 pm

Great point Adrian.

The truck boys use a 3 speed gear box. See below.

A servo is used to shift gears which would give you the "jerk" especially if the throttle was dropped momentarily. The sound would have to match the gear change which might be a bit tricky. Also fitting in a 3 speed gear box in an already full hull might too be a problem too far.

Thanks Antony

Brian Leach · Post by **Brian Leach** » Mon Jan 24, 2011 12:18 am

Antony,

just watched the video and couldn't stop laughing at the thought of those gears stripping as you change gears that fast with a 300 pound tank!

I know that dosn't really apply, but it would make a cool video all that stuff flying about!

Brian

Phil Woollard · Post by **Phil Woollard** » Mon Jan 24, 2011 7:33 am

It's all to do with "dogs"
I try to simulate gear change but it is difficult.
Maybe Thomas could come up with a system to change gears (up and down the box) that uses say the throttle cut switch, I would be first in the line wanting one of those.
The Tiger1 and the Tiger2 that we are using at present both have reduction gearboxes and exstension spring suspension, the spring set up enables me to get that nice lurch on excelleration and decelleration with a good rock when firing the main gun, the wieght of the Armortek models gives us the inertia that looks so real .....when driven at a sencible speed!

Adrian Harris · Post by **Adrian Harris** » Mon Jan 24, 2011 10:15 pm

The only way I can see to do it with the current setup (and I know Mark will curse me for saying this and probably wander off muttering about running gear stress and track link breakage) would be to put high power relays (or equivalent solid state device) in the feeds to the motors, such that the supply could be interrupted briefly. Heaven only knows what that would create in the way of back-EMF though.

Adrian.

Jan_Donadoni · Post by **Jan_Donadoni** » Tue Jan 25, 2011 6:44 am

http://members.tele2.nl/s_weggeman/CG.htm

this is the final solution to the issue.
Designed also for big heavy metal tanks.
Maybe Armortek could develop next motion pack with this.
Also suited for gas-petrol engines, saw them working. Just take a look around on you tube.

Adrian Harris · Post by **Adrian Harris** » Tue Jan 25, 2011 7:04 am

Now that would be impressive

The website says suitable up to 30kg, so I guess it would need some strengthening to be usable with Armortek models.

I would guess that the clutches would be the parts most in need of increased capacity.

Adrian.

Jan_Donadoni · Post by **Jan_Donadoni** » Tue Jan 25, 2011 9:51 am

The strength goes with the material and the size you use.
On youtube you can find a UK modeler who build a 1/6 full metal Stug (3 or 4) with Cerjak Gearbox and a Honda 31 petrol engine.
The problem is with the sound of the motor, but otherwise it's really great and powerful. It also work 2 gears forward (high and low) plus back.
It also gives the tank a real BUMP when shifting from low to high gear.
Take a look at this series.

http://pktube.onepakistan.com/video/Pjg ... now-2.html

Also look after Mike Tull. He's the gentleman which built some CG for 1/6 metal tank models. Goolge Mike Tull petrol tank

I am just dreaming about an Armortek with a powerful electric motor (thus really silent) with a CG....

Jim Fowler · Post by **Jim Fowler** » Tue Jan 25, 2011 5:09 pm

Actually, a change in motor technology may/would be a solution to all of this; but, its a big leap that would take a major electronics refit and redesign.

What I am talking about is the use of stepper motors and an associated, computer-based speed controller.

I saw a demo of a line-shuttle robot some years back that used this sty;e setup = it was quited, very powerful, and could be controlled to simulate speed shifts (they did it in the demo as a lark). I know that steppers allow for precision "jog" control; so, it could also give you the "rocker" action you may want for the simulated main-gun fire control as well.

Well, its a suggestion,

Jim

Jan_Donadoni · Post by **Jan_Donadoni** » Wed Jan 26, 2011 2:11 pm

I believe it would not be so difficult.
Instead of two separate motors we would have only one, we would have 1 additional servo (high torque)for the gear shift and finally would need some space in the front of the tank to place the gearbox.
Actually already someone is using such system.
Most of all, from a technical point of view, it is the nearest thing to real tank transmission, as much as I know.

Adrian Harris · Post by **Adrian Harris** » Wed Jan 26, 2011 2:18 pm

An electric-motor driven gearbox would also hopefully allow for the tank to be put into neutral and hence it would be possible to push them around when the battery is low.

I must admit I'd want properly cut gears in the gearbox though, the ones I have seen running are quite noisy in themselves, though I guess flooding them in oil might alleviate that to some degree.

I wonder what Ncm strength servo motors would be equivalent to the current EMD motors ?

Adrian.

Bodo Langbehn · Post by **Bodo Langbehn** » Wed Jan 26, 2011 6:00 pm

I have build gearboxes for all my models and it makes a lot of fun to drive such a model.
I have started in scale 1/10 with 3 gears and overlapsteering with differentials.
In the 1/6 Panther gearbox I have changed the differentials into planetary drives, because they are stronger. I only need one drive motor and a smaller steeringmotor. In the first gear the max. speed is about 2,5 km/h and in the third gear the tank is about 8km/h fast and I think that`s enough.
The weight from the Panther is 140kg and I can shift during driving, the tank doesn`t stop when I put the next gear in.

Bodo

Jan_Donadoni · Post by **Jan_Donadoni** » Wed Jan 26, 2011 6:14 pm

I believe Bodo made the right thing.
As much as I saw it goes with 3 gears. Or all 3 forward or 2 forward and one back.
Hope to see one real in person one of these days.

Bodo Langbehn · Post by **Bodo Langbehn** » Wed Jan 26, 2011 6:22 pm

I have forget to tell, The Panther is electrical powered, so I have three gears forward and backward.

Bodo

Ad Wouterse · Post by **Ad Wouterse** » Wed Jan 26, 2011 8:20 pm

Hi Bodo,

I think that you have the solution that the guys here are looking for.
Could you please post some pictures from your "Ãœberlagerungsgetriebe" and the new planetary gearboxes ?