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Re: David's carrier build.

Posted: Tue Jun 28, 2022 11:34 am
by David Merritt
Hi Phil, the problem with a braking system on the Carrier is that, because it has a differential system, not only does it have to provide sufficient force to slow down the track that it is applying the braking force to, it also has to supply sufficient force to accelerate the track on the older side. This is because any reduction in speed on one side has to be matched with an increase in speed on the other side, or a reduction in the speed of the drive motor.
I have tried to design a braking system for the Carrier, and have made one work, but the wear rate on the pads in the braking system have provided to be higher than is acceptable, so regular adjustment was required.
You will probably need to redesign the servo operating mechanism so that greater force can be applied by the servo motor to the braking system, again this I have done and achieved a increase in force at a ratio of 3:1, (3 times the rated servo force at the pads) which greatly increased the force available but it has a down side that to achieve the greater force there is a reduction in the movement available, which again due to the wear rate of the pads and the reduced available movement of the operating system, regular adjustment is required.
To achieve the required adjustment mentioned above, my design required the removal of the back axle and this is not a simple process as it requires the removal of the 16 nuts and bolts holding it in.
If you manage to find a solution to this problem please let us know as I would prefer to have the original differential system running on the Carrier as I have had to resort to running it with two motors and gearboxes across the back which enables it to run well but ruins the appearance of the vehicle.
David

Re: David's carrier build.

Posted: Tue Jun 28, 2022 12:18 pm
by Phil Woollard
Well I'm doing it Dennis lol. David see below.



It works, I just have to learn to drive it! The guinea pig squeaking sound is the friction material as it grips the steel brake disc just before it stops it, this is on one side only as I left one very smooth the other slightly dressed with emery paper to prove a point, so just dress the other side and then another trial. I'm a happy bunny! 8)

I have used a cast iron vee block as ballast along with the large battery, this should replicate the all up weight.

Now how well it will work on the brown stuff is next.

Re: David's carrier build.

Posted: Tue Jun 28, 2022 1:10 pm
by Jerry Carducci
What material are you guys using as brake pads? I've not yet cracked open my UC kit so I don't know how the original
brakes were implemented either. In my models that use a braked differential type steering- effecting a turn when
the transmissions is in a low gear ratio/ high torque situation the required braking force required is tremendous.
These were my first ever application of servo savers. Brakes tend to 'grab' more at higher speeds making gradual turns
needing more driving finesse...

I'd love to get my hands on a 'spare' UC transmission/transaxle...

The more of this I read the more I'm thinking this will be my next kit project to have a go at after my current one is complete.


Jerry

Re: David's carrier build.

Posted: Tue Jun 28, 2022 6:26 pm
by Phil Woollard
Rubber sheet Jerry. I'm keen on encouraging others to get on with their carrier builds maybe Armortek will approve 👍

Re: David's carrier build.

Posted: Tue Jun 28, 2022 9:01 pm
by Graham P Hough
It may be an unhelpful comment but those of us who are using two motors do not need brakes. :|

Re: David's carrier build.

Posted: Wed Jun 29, 2022 9:46 am
by John Clarke
Graham P Hough wrote:
Tue Jun 28, 2022 9:01 pm
It may be an unhelpful comment but those of us who are using two motors do not need brakes. :|
Or diffs :D
Phil, felt like I was watching Daytona with that last clip. looked promising, eagerly waiting for the brown stuff.
As for the lining I thought you may a have borrowed some asbestos from the shed roof. :?
I still think there's some mileage using slitting disk material as a brake lining as I've seen some RC car drivers use on You tube. I'd like to see it tried. :P

Re: David's carrier build.

Posted: Wed Jun 29, 2022 2:40 pm
by Jerry Carducci
For brake lining in similar applications I used RC clutch material, sold in strips or high temperature gasket material
that's 1.5-2mm thick. Here's an example of a drum brake using it.

brake lining

Jerrry

Re: David's carrier build.

Posted: Fri Jul 01, 2022 8:01 am
by Phil Woollard
Jerry you can fit that lovely brake system in your uc
We have a nice addition planned for Dave's carrier.

Re: David's carrier build.

Posted: Fri Jul 01, 2022 2:52 pm
by Oliver Brüninghaus
It is interesting to see how the whirlwind develops with modified technology.
Exciting story!

Re: David's carrier build.

Posted: Fri Jul 01, 2022 11:19 pm
by Christoffer Ahlfors
I, too, like it when it gets technical! :D

Re: David's carrier build.

Posted: Sat Jul 02, 2022 5:56 pm
by Phil Woollard
Prepping parts, I needed to know the internal available space of the engine cover so I can decide where everything is going to go.
I've machined the squeaky side brake pads to match the other side, I've opened up the servo arm clearance holes in the chassis and used thread lock on all the parts that need to stay in place.
I'm having trouble loading more than 2 files at a time for some reason.

Re: David's carrier build.

Posted: Sat Jul 02, 2022 9:19 pm
by Graham P Hough
Phil are you potter? Just seen your banding wheel. :)

Re: David's carrier build.

Posted: Sat Jul 02, 2022 10:03 pm
by Phil Dawe
I thought it was a lazy susan to help Phil when he decorates cakes with icing between kits! 8)

Re: David's carrier build.

Posted: Sun Jul 03, 2022 7:24 am
by Phil Woollard
I'm potty! That's what we all need in our troubled times.....a bit of humour!

Re: David's carrier build.

Posted: Mon Jul 04, 2022 6:19 pm
by Phil Woollard
Tech stand. I want all the motion pack fixed to this frame, I'm not sure where the battery will go just yet but I'm sure we will find a space . Shelves to be added to the stand.