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Airtech DE air brakes, good, bad, ugly???

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Airtech DE air brakes, good, bad, ugly???

Old 09-22-2016, 08:54 AM
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CRye
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Default Airtech DE air brakes, good, bad, ugly???

I have a set of Airtech Germany air brakes with 100x21 high speed tires, solid rubber abut 4.4 inch across. When I pressure the brakes even to 80 psi I can still turn the wheel by hand without a great strain. But they do not take the same amount of effort to turn them ie uneven braking? And when I remove the pressure they still have a notable amount of drag. I cleaned the drum and o rings with alcohol and same result.
Any advise on how to set them up?
Are the O rings common or special?

These are on an Aurora that will scale near 50 Lbs wet.

Any advice?
Charles
Old 09-22-2016, 01:22 PM
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CRye
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FYI, I finally thought to contact the mfg. Erwin was very helpful. Cleaning with alcohol is WRONG. The brakes are intended to have grease in them. Sounds really strange but I can see how it would work. Also over 100 psi on the air and no proportional brake control! Will update as I learn more.
Old 09-22-2016, 10:27 PM
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Hi Charles

I have two sets of Airtech o-ring brakes and they work fine. There is some asymmetric brake force now and then but it is due lazy maintenance. If one have new thick grease without stones and dust they work well. I have used them on my Sport Hawk which is 30 lbs roughly.
But one thing. Brake force is not the problem it is the proportional control and making sure tire will not lock. I use about 3bar or 40psi for that. Even that is too much on wet tarmac. Using high pressure leads into locking and sliding and will grind your tires useless pretty fast. Hope this helps.

/Jyri
Old 09-23-2016, 06:34 AM
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CRye
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Hello Jjantti,
What type grease do you use?
Erwin sent me an email to use Noal but we do not seem to have that brand in US. Can you send grease rating if your brand not sold in US?
I think I understand the brake drag after release is probably due to the oring sticking in the channel due to lack of lubrication. Grease in a brake is counter intuitive but then wet clutches in motorcycles and automatic transmissions are also.
Also I was testing with direct pressure from a hand pump but I am going to eliminate the proportional valve per Erwin.
Thank you for the response.
Charles
Old 09-23-2016, 06:59 AM
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racer8297
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I use Super O Ring Lube by Parker.

http://shopbvmjets.com/zencart/index...products_id=26
Old 09-23-2016, 08:19 AM
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CRye
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Great, Thank you
Old 09-23-2016, 12:23 PM
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David Jackson
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Hey Charles,

Got Airtech retracts and brakes on my Rebel Pro. Just like the problem you experienced, when the brakes were engaged, it did not prevent the wheels from easily rotating. Read that others were having similar problem, and the oring lube did not help. The solution was to replace the original o rings with new o rings purchased from the O-ring Store, problem solved. New orings cost 15 to 20 cents each plus shipping.

If you model is equipped with the 100mm high speed wheels, replace the o ring with the 3mm thick 36mm diameter Buna 70 o rings that can be purchased from the Oring Store ( info for Elite Aerosport Rebel Pro thread page 10, post #235)

Last edited by David Jackson; 09-23-2016 at 01:25 PM.
Old 09-25-2016, 09:36 AM
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Originally Posted by CRye
What type grease do you use?
Sorry for the delay. I was flying for whole weekend and airfield was remote location...
I'm sure there is branded greases for this aplication and I have seen spray silicone oil used with ease of use and good results. I just hate silicone when painting thus unable to use it. I just added Super Adhesive Grease from CRC because it is sticky and I don't have to wipe the bottom of the wing so often Adding fresh grease say 3 flight hours is still needed for good and smooth braking. I have also used industrial Buna 70's as replacement.

/Jyri

Last edited by jjantti; 09-25-2016 at 09:38 AM.
Old 09-25-2016, 06:41 PM
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CRye
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Thanks guys,
Just got back from Georgia jet fly in but without jet and had a great time anyway.
David, i will get new orings and that makes a lot of sense.
Charles
Old 03-20-2017, 02:49 PM
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Use a 3mm o-ring with 1mm larger inner and outer diameter available from The Oring Store or other metric o-ring suppliers!
Old 03-20-2017, 04:13 PM
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Hello Pilot,
Thank you for the shout back. I may give them a try. However I went to the source, Erwin at Airtech, who shipped me some 36.3mm x3.04mm O-rings which are stock. I tested against rings from Oring Store including 37mm and the stock size gave better braking. Still not impressive but since it is a lubricated brake system, per Erin to not clean lube from drum, may not show its stuff until heat from braking gets in the picture. ???
Hope to finally finish the Aurora in a couple of weeks and test fly in time for MS Afterburner.
Cheers
Charles

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