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-   -   Brakes for giant scale RC airplane? (https://www.rcuniverse.com/forum/rc-giant-scale-cars-234/9235042-brakes-giant-scale-rc-airplane.html)

ljsoarinson 11-07-2009 09:38 AM

Brakes for giant scale RC airplane?
 
1 Attachment(s)
I have a 1/3rd scale Super Cub modified to tow up large scale RC gliders. I'm looking for a brake system to keep it under control on the runway. The large wheels help give prop clearance but they sure like to roll...

I'm seeing some ingenious brake systems on giant scale RC cars and figure you can help me find brakes.

Who makes hydraulic or pneumatic calipers and master cylinders?

I can machine a disk if I have to. The rims have a 3.5 inch inside diameter. I would like to have two separate servos to control the caliper on each wheel to help steer it on the ground. This would probably require two master cylinders. The plane weighs about fifty pounds but is moving fairly slowly when the brakes would be needed.

Thanks in advance for your help!

Larry

motionmachine 11-07-2009 10:57 AM

RE: Brakes for giant scale RC airplane?
 
Nice plane...

Have you considered using a mechanical set up, much like those commonly used on 1/8 scale buggies? IMO, it would be easy to fabricate, and far less expensive than a hydraulic system. Just a thought...

ljsoarinson 11-07-2009 11:42 AM

RE: Brakes for giant scale RC airplane?
 
Thanks for your suggestion. I'll admit I don't know a lot about how the mechanical systems work. Since the brake needs to be on the wheel and at the end of the landing gear, is there a system that uses a cable to actuate it? In my case the servos will need to be in the fuselage.

motionmachine 11-07-2009 12:15 PM

RE: Brakes for giant scale RC airplane?
 

[link=http://www.davesmotors.com/s.nl/c.885035/n.1/it.A/id.4613/.f]Mechanical[/link] or [link=http://www.davesmotors.com/s.nl/c.885035/n.1/it.A/id.2856/.f]Hydraulic[/link]. I think either of those brake systems could easily be adapted and/or modified to serve your needs.

Here is a less expensive [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&P=SM&I=LXUUW3]Mechanical[/link]

Lars from Norway 11-07-2009 12:54 PM

RE: Brakes for giant scale RC airplane?
 
Larry,have a look in my [link=http://www.rcuniverse.com/forum/m_7970048/tm.htm]project thread[/link],post #6,there you'll see some -if not highly- detailed pics of the mechanical brakes

VassilisG 11-07-2009 02:29 PM

RE: Brakes for giant scale RC airplane?
 
Larry , I think that the best choice is :hydraulic kit from bicycle (calipers and master cylinder ) and hand made rotors (laser cut ? ).
Hydro brakes from rc cars aren't enough power for your plain.

http://www.chainreactioncycles.com/C...CategoryID=580

ljsoarinson 11-08-2009 01:40 PM

RE: Brakes for giant scale RC airplane?
 
Thanks for the information and ideas, you guys are a great resource. I appreciate the links.

This gives me a few options to work with. I'm guessing the hydraulic brakes would have more power, but the cost is higher and I'd need to come up with a second master cylinder to get steerable braking. The mechanical brakes may be the better choice since it would only require an extra servo for steerable braking.

If anyone has other ideas or products that might work, please share what you know.

rangerfredbob 11-08-2009 05:34 PM

RE: Brakes for giant scale RC airplane?
 
either can make the same stopping power, with mechanical, it's just a matter of adding more leverage or a stronger servo, I would go that route myself

studysession 11-08-2009 09:34 PM

RE: Brakes for giant scale RC airplane?
 
Something from a 1/8 scale buggy would do fine for what you are trying.

bigglesB 06-16-2010 04:54 PM

RE: Brakes for giant scale RC airplane?
 
Hi Larry,

I'm building a 1/3 Supercub and will also be fitting it out for glider towing, what solution did you use for the brakes?

SteveB

Mudgy 06-17-2010 03:21 AM

RE: Brakes for giant scale RC airplane?
 
have a look on youtube..a guy named rcwizzard has made a huge conley V8 powered grave digger. On the last video (17 or 18 I think) he was going to use FG hydraulic disc brakes, but he's found some from (can't remember where) the calipers are double piston.
The guy has som great manufacturing skills, and problem solving.

Worth a look, it's a cool project.

ljsoarinson 07-22-2010 03:15 PM

RE: Brakes for giant scale RC airplane?
 
Steve, I just got the brake system up and going a couple weeks ago. I decided to go with this one: http://www.vsmodelsport.com/downloads/08450-1.pdf

The FG Modellsport offering is a mechanical disk brake. I am using one Hitec HS-645MG servo on each caliper. For this plane I wanted differential braking for better steering on the ground. That could be programmed in my transmitter but I only had one channel available on my Futabe 10C. This I used for braking on the left slider switch. To mix rudder with the brake channel I found a programmable v-tail mixer. Servo direction and throw is programmed by stick movements. It's the DigiMix-II from firmtronics.com (http://firmtronics.com/rc-products/digimix-ii.php). Best $15 I've spent on RC stuff!

I have the brakes set up so they start to grab at 1/3 slider. At 2/3 slider they slow the plane down very well when taxiing. At 2/3 the rudder stick is effective to put more grab on one wheel and release some on the other. With full brakes applied the model slows down well but I have to use elevator to keep the tail down. With an aggressive setting it's possible to flip over the plane. The setup suits my needs for better ground handling and safe stopping when taxiing.

Larry

nitrosportsandrunner 07-22-2010 03:25 PM

RE: Brakes for giant scale RC airplane?
 
maybe you can fab up brakes like on a mountain bike. the brake line would be flexable and run up the landing gear and into the plane where a servo can pull the cable in the line to close the shoe onto the rotor.

bigglesB 07-22-2010 04:18 PM

RE: Brakes for giant scale RC airplane?
 
Hi Larry,

thanks for that, very useful info, nice to know it all works ok. Would be great to see some photos.
I have a 9 channel JR and I'm running out of channels fast, 2 for aileron, 2 for flap, 2 for elevator, 1 for rudder, 1 for throttle and 1 for throttle kill switch, may have to get a big servo for the elevator and free up a channel or y lead the flaps. I'm using the Rcxel Opto kill switch, seems to work ok static.
My build is on RCscalebuilder
http://www.rcscalebuilder.com/forum/...TID=13726&PN=1.

Cheers..SteveB

bigglesB 07-22-2010 04:43 PM

RE: Brakes for giant scale RC airplane?
 
Hi Larry,

I see at FG Modellsport the kit is 71.8 euros, where did you source yours from and did you need any other parts?

SteveB

wan6176 07-23-2010 07:32 PM

RE: Brakes for giant scale RC airplane?
 
[:o]is this forum for largesscale car or airplane?

ljsoarinson 07-24-2010 10:18 AM

RE: Brakes for giant scale RC airplane?
 
Hey, I really appreciate the guidance given me by the RC Universe car forum guys. Before I posted my request I spent a number of hours with online searches without finding a solution. Between the posts and PMs I had it figured out pretty quickly. I was able to buy the brakes from a hobby shop not too far away. I picked up some longer cables and housing from a bike shop and was good to go.

Thanks for the help!

sekkenes 01-30-2011 03:12 PM

RE: Brakes for giant scale RC airplane?
 
Can you post a picture or two of your brakes mounted? I am in the proses of making my own brakes for a large scale Bellanca.

Mudgy 01-31-2011 01:24 AM

RE: Brakes for giant scale RC airplane?
 


ORIGINAL: wan6176

[:o]is this forum for largesscale car or airplane?

Wan, the poor guy only wanted to ask car guys about HD car type brakes.

when you're building something, or modifying it, RC shops aren't the only places to source materials and ideas.

I'd go looking in the plane section if I had the need for (as an example) gyro assisted steering......Pilots would have the experience to draw from, whereas car guys don't use it.

It's all relative;)

VassilisG 01-31-2011 05:16 AM

RE: Brakes for giant scale RC airplane?
 
My first ,proposition was a kit from bicycle .
The new one is this.

http://www.rcuniverse.com/forum/m_9994627/tm.htm

ljsoarinson 01-31-2011 01:28 PM

RE: Brakes for giant scale RC airplane?
 
1 Attachment(s)
Here are a few photos of the system.

Lars from Norway 01-31-2011 03:15 PM

RE: Brakes for giant scale RC airplane?
 
This looks nice! Are you satisfied with the way they perform?

ljsoarinson 01-31-2011 03:30 PM

RE: Brakes for giant scale RC airplane?
 


ORIGINAL: Lars from Norway

This looks nice! Are you satisfied with the way they perform?
Absolutely. They modulate well and have no problem controlling this fifty pound plane on the ground. The mixing to rudder works very well for differential steering. The system adds a lot of safety and reduces the time on the ground between tows. The stopping power could be increased but that would make it more likely to flip the plane over. It feels like the setup is using about half of its braking power.

It was a tight fit to get it all in the hub. I modelled it cad (Pro-E) to build it right the first time.

Lars from Norway 01-31-2011 04:38 PM

RE: Brakes for giant scale RC airplane?
 
Nice to hear! So you have mixed the rudder with the brakes so when you steer left the the left wheel brakes harder (or the right brakes less), is that right? Looks like a tight fit indeed, but it isn't close until it touches;)

ljsoarinson 01-31-2011 05:52 PM

RE: Brakes for giant scale RC airplane?
 


ORIGINAL: Lars from Norway

Nice to hear! So you have mixed the rudder with the brakes so when you steer left the the left wheel brakes harder (or the right brakes less), is that right? Looks like a tight fit indeed, but it isn't close until it touches;)
Just as you say, it increases pressure on the caliper it turns toward and decreases pressure on the opposite caliper. The great thing about the firmtronics.com v-tail mixer is the programmability. It allowed me to get longer throw on the braking feature and shorter throw on the differential (steering). It can also reverse one or both servos, an important ability when short on channels!


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