8 inch disc brake kit for Cheetah - COMPLETED

[John Boucher]

And so the wheels come off and in the courier today to Turbo for some much needed braking TLC

And tonight the wheels fly in a different set of wings....

[Turbo]

hey John,

got the package a few minutes ago -- am busy with AWACS set at the moment, please allow a few days to complete and get to yours.
I have seen a nice way of supporting the caliper (without using a key-way) onto the knuckle, and will be updating AWACS with this design. The keyway works 100% and is in use on my own plane, however the easier installation and removal if required will be simpler and two larger spaced bolts will offer even more support incase you have a fully loaded plane.

Comments:-

1) the brakes are the units supplied for 1500lbs MASS planes -- overengineered
2) the design in terms of installation, puts no additional load onto any parts of the existing planes components - overengineered
3) the new update for caliper support will make things easier and even stronger than the existing setup - overengineered
4) the two sets with older design can be upgraded to the new support (pictures coming soon) easily (however require wheels to be removed again) - upgradability

pics so long of AWACS setup - much the same as the others in fact identical, however pics anyway. you will see the product from other angles and also the fittings installed and bits and bobs.

[flybynite]

Very very NICE! I want as well.............

[ZULU1]

Chaps, i would hate to piss on someones battery, this is a great piece of work...however having been involved with many mechanical structures, fabrications and so on over the years. I ask a question? The original design obviously with stress, load and bending member calculations was developed using the integrity of mounting points, stressed and loaded members under full load etc. Has the uprated braking system been developed with the additional loads been considered in this upgrade. Ie will the added improved braking loads put undue stress on mountings and other stressed airframe components that may cause failure in service. I would hate to see a report on a structural failure. Just my two cents worth.

[Turbo]

hi Zulu

In my limited knowledge there are two issues here:-

1) the braking system itself.
2) the planes ability to withstand the additional forces applied

1) -- I have these brakes on my cheetah and have had for almost 60hours, with 5 inspections by an AP since the upgrade - no problems at all. The brake system is rated for 1500lb planes and ours as you know are not even half that weight (over engineered) These brakes are manufactured in the USA by Black Max, who have sold and installed over 3000 units around the world on many different applications and continue to do so.
2) the planes ability to withstand additional forces -- after chatting to Walter and seeing the tests that the cheetah (NOT BUSH CAT) has undergone (im referring to the undercarriage specifically) and the drop tests that they have subjected this to, it is clear that the small stopping forces that the brakes apply to the undercarriage are miniscule in comparison.

I personally have locked my brakes on tar to see what happens (with engine off) and the 'dreaded nosewheel' held out just fine. I did this test around 10 times (marks are still on the runway 03 at FASI) no signs of any fatigue what so ever. a personal friend of mine is a metalurgical engineer and does work for various high level parastatals and he was involved with the brak upgrade from day one -- aswell as the inspections on the nose wheel (you will notice i do not have spatts on, for this reason)

All i can say and comment on is what i have done personally, and tests i have conducted myself, i am not claiming to be an aircraft engineer, and the fact that these planes are NTCA planes and very light, lend themselves to the fact that the brakes were needed, and work well thus far. Sure with everything there will be improvements over time which i am more than willing to share with everyone. Keep in mind that this is a hobby for me, and i dont make a cent off the upgrades, its a fellow enthusiast lending a hand to those who want it. Anyone is welcome to taxi my plane and test the brakes if you have any doubt about it.

At the same time keep in mind that you are braking to stop your plane, and not in the shortest distance possible, but instead to simply stop. in an emergency sure you going to have to grab a handful, but in normal operation i have yet to grab more than two fingers worth to come to a stop for the runways i have landed on.

[ZULU1]

No problem, why i raised concerns are simply because many years ago, i had zero brakes on CEW an Aquilla, so i bought a 4pot hope mountain brake disc and caliper assembly for a mountain bike..brilliant, a third of the weight, machined all to fit and all was well. So i did a few hours albeit with good brakes and then decided to test it properly at FALY with a relatively heavy pax, stopped perfectly skidding on the tar but bent the forks good and proper. Discussed with Aiden and i ended up going back to a original brake but cleaned up. However what i did notice was the additional inertia that the wing had to lose by a sudden stop. This does put undue load on the bottom of the pylon mounting where the device hinges...i dont think ideal.

So my concerns are with experience...especially by having to replace the forks and other toys, but a worthwhile excercise..

I think that what this means in service, just because you have good brakes, it doesnt mean that you have to use them with anger on every flight...unless you are flying off an aircraft carrier..

Good luck with this.

Paul

[John Boucher]

No structural changes have been made.
There are Cheetah's with the drum brake installation that really works well but they are in the minority...
Minor mod
AP installs / checks / signs out in airframe loogbook / flight folio
Proving flight or two
Paper exercise to RAASA/CAA and onto your plane's file

The same brakes are used on the Bantams and I suppose the Bathawk.... proven system.

http://www.blackmaxbrakes.com/apps/testimonials/

Simply put - we couldn't wait for the board of Skyreach to make a decision which we pleaded for. The appropriate system was identified and Turbo with his team stepped up to the plate. I can't wait for the wheels to return, fit and be able to have peace of mind of stopping if needed!

[Turbo]

Two of the brake upgrades were signed off by an AP at the weekend, and only good comments from the AP and other by-standers were given!
The braking system is now on 4 planes and accumulated (including mine) just under 100hours of un-incedental time.

ZULU1 - regards the undercarriage - i seriously doubt that you can compare an aquilla to a cheetah -- secondly a 4 inch brake disc is hardly able to apply enough force nearly strong enough to damage the triangulated undercarriage and related parts of the cheetahs undercarriage mount. As im sure you already know, the cheetah has 1 x 10mm bolt securing the pivot arm (one of three) which holds the 'shock absorber' and another two 6mm bolts which hold the inline pivot arm, aswell as another 6mm bolt that holds the forward leading support arm -- all connected to the triangulated undercarriage, together. This equates to 28mm steel support (thicker than the axle!) that the undercarriage relies on, then you have the 4mm thick stainless steel plate (called the knuckle) to hold the above mentioned structures together. Walter mentioned to me that the undercarriage was drop tested to over 4g's which was NOT a limit test, as they needed to re-use the plane -- another comment from Richard who is the aeronautical engineer at skyreach "if you have a hard landing the wings will break off before the undercarriage breaks!" now seriously - do you honestly think 4 inch disc brakes will break the undercarriage? i think not!

remember guys, this is something i do as a favour to cheetah owners, i make nothing on it, and i give up alot of my time to help other cheetah owners - if you have doubts -- dont do the upgrade simple!

[Jetman]

Well said Turbo!!!!!!

Thank you very much for your super professional brake design and support. With your willingness to help others without expecting anything back, you're definitely a benefit to our Cheettah and flying community.

Thanks again for all your help!!!!

Skin

[Turbo]

Skin -- copy that!

John, an update on your setup, it's almost done, the spacers are machined, the adapter plates ( which are totally different and needed to be drawn and machined from the ground up due to the three spoke wheels) will be finished tomorrow, and then it's figment and spacing for the spats, ill use my spat for this, hopefully this isn't different to the normal ones on all other cheetahs - please confirm this before I space anything.

[John Boucher]

Chris, I only got the spats 2 years ago and bolted straight on with the supplied brackets. I would therefore say that there is no difference between the spats....

[Turbo]

Thanks John,

Will continue and space accordingly. I hope to have them finished tomorrow afternoon.
Ill blast your wheels aswell, make EM look nice and new again, they are rather dirty.

Will post pics of the setup for your three spoke wheel tomorrow at the office.

[CHARLIE WHISKEY]

Hi Turbo

Wheels removed .

Will come see you on Monday 29th.

Regards

[John Boucher]

they are rather dirty

Didn't clean the buggers 'cause we tried in vain to get them to work with doepa and other stuff.....

Charlie Whisky... now you will have a complete package Cheetah that is afraid of no short runway or ATC

[John Boucher]

Turbo just sent me a couple of pics.... I am IMPRESSED to say the least and sincerely look forward to the finished product!!!