David's carrier build.

Forum for discussion relating to the Universal Carrier
David Merritt
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Re: David's carrier build.

Post 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

Phil Woollard
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Re: David's carrier build.

Post 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.
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Jerry Carducci
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Re: David's carrier build.

Post 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
http://tanks.linite.com/ - RC tanks: stay home, build a tank and save a life!

Phil Woollard
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Re: David's carrier build.

Post by Phil Woollard »

Rubber sheet Jerry. I'm keen on encouraging others to get on with their carrier builds maybe Armortek will approve 👍
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Graham P Hough
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Re: David's carrier build.

Post by Graham P Hough »

It may be an unhelpful comment but those of us who are using two motors do not need brakes. :|

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John Clarke
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Re: David's carrier build.

Post 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
Oh Man, I only ride em I don't know what makes them work,
Definatley an Anti-Social type

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Jerry Carducci
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Re: David's carrier build.

Post 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
http://tanks.linite.com/ - RC tanks: stay home, build a tank and save a life!

Phil Woollard
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Re: David's carrier build.

Post by Phil Woollard »

Jerry you can fit that lovely brake system in your uc
We have a nice addition planned for Dave's carrier.
Attachments
Universal_Carrier_Mk_II_pic-10.JPG
Screenshot_20220630-210751_Samsung Internet.jpg
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Oliver Brüninghaus
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Re: David's carrier build.

Post by Oliver Brüninghaus »

It is interesting to see how the whirlwind develops with modified technology.
Exciting story!
it's grim up north

Christoffer Ahlfors
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Re: David's carrier build.

Post by Christoffer Ahlfors »

I, too, like it when it gets technical! :D
A little too much is about right...

Phil Woollard
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Re: David's carrier build.

Post 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.
Attachments
I have removed 15mm from the drive shaft so that we have more room for the flathead V8 motor. The electric motor now sits as close to the rear plate as is possible
I have removed 15mm from the drive shaft so that we have more room for the flathead V8 motor. The electric motor now sits as close to the rear plate as is possible
IMG_20220702_141721.jpg
IMG_20220702_141806.jpg
IMG_20220702_143546.jpg
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We are not using this rail
We are not using this rail
IMG_20220702_165229.jpg
IMG_20220702_170035.jpg
If you like fitting lots and lots of small nuts and bolts then you will love the carrier.
If you like fitting lots and lots of small nuts and bolts then you will love the carrier.
Last edited by Phil Woollard on Sun Jul 03, 2022 6:56 am, edited 1 time in total.
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Graham P Hough
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Re: David's carrier build.

Post by Graham P Hough »

Phil are you potter? Just seen your banding wheel. :)

Phil Dawe
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Re: David's carrier build.

Post by Phil Dawe »

I thought it was a lazy susan to help Phil when he decorates cakes with icing between kits! 8)

Phil Woollard
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Re: David's carrier build.

Post by Phil Woollard »

I'm potty! That's what we all need in our troubled times.....a bit of humour!
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This is one of my all time favourite cartoons as it just says it all about the human race! No more replies or we will be in trouble.
This is one of my all time favourite cartoons as it just says it all about the human race! No more replies or we will be in trouble.
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Commission builds considered. Email/ ptwoollard64@hotmail.com

Phil Woollard
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Re: David's carrier build.

Post 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.
Attachments
IMG_20220704_123103.jpg
IMG_20220704_112317.jpg
IMG_20220704_123158.jpg
IMG_20220704_133852.jpg
Mechanical engineer.
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Commission builds considered. Email/ ptwoollard64@hotmail.com

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