Go Back  RCU Forums > RC Airplanes > RC Jets
Reload this Page >

HSD MB339 review anyone???

Notices
RC Jets Discuss RC jets in this forum plus rc turbines and ducted fan power systems

HSD MB339 review anyone???

Old 09-29-2019, 07:50 AM
  #101  
ms200a
My Feedback: (15)
 
Join Date: Apr 2002
Location: Las Vegas, NV
Posts: 63
Likes: 0
Received 1 Like on 1 Post
Default

Hi Randy, I have 3 sets of the JP brakes, Boomerang MB339, Boomerang Turbinator II, and a turbine converted Freewing F-18c. Mine are the older sets without the pots. They're proportional. However they all suffer from un even brake application which results in a very squirrelly landing and usually dragging a wing tip or nascar slide to stop. My friends Boomerang Sprint had the same tendency to zig zag and usually wound up dragging a wing tip. The work around that we both have had success with is to use a 3 position switch. POS 0 off, POS 1 drag, POS 2 full on. (On radio setup you need to setup in this order. Off, then Full On, then Mid) (kinda like setting up flaps). I'm using a JR 10x with dm9 airmod, He's using s Spektrum GX11,
I also have my elevator mixed to my brake, down applies brake and I use that feature for taxing. My friend copied my set up with the exception he mixed his slider to control brakes for taxi. We fly primarily off asphalt, but sometimes the dry lake bed. stopping is the same for both surfaces.

In landing approach on down wind to base I flip my brakes to POS 2 full on, this magnetically pulls both plates against brake coils, I count to 3 then I set to POS 1 which reduces the magnetic field and reduces braking force to draggy but not locked and then make a normal landing with partial brake applied, and just let it slow to a stop.. Plane lands straight, if more brake is needed I apply down elevator. Because the brake plates are already magnetically in contact plane stays straight.
Hope this helps
Mike
Old 09-29-2019, 09:45 AM
  #102  
Randy Smith
 
Randy Smith's Avatar
 
Join Date: Jan 2002
Location: Calgary, AB, CANADA
Posts: 213
Received 4 Likes on 3 Posts
Default

Thanks Mike! That's great information. I will give it a try with the three position switch. The pots on the controller really have no functional affect on the braking. Too bad we have to have this work-around. I wonder if there is an better aftermarket brake module that could be used?

Randy
Old 09-29-2019, 09:46 AM
  #103  
Thud_Driver
My Feedback: (1)
 
Thud_Driver's Avatar
 
Join Date: Dec 2001
Location: Victorville, CA,
Posts: 1,669
Likes: 0
Received 9 Likes on 7 Posts
Default

This works on my foamy Mirage with JP brakes:

https://www.rc-castle.com/index.php?route=product/product&product_id=7910

Check this video of a foamy F-16:


Last edited by Thud_Driver; 09-29-2019 at 09:49 AM.
Old 09-29-2019, 09:56 AM
  #104  
Afterburners
Senior Member
 
Afterburners's Avatar
 
Join Date: Feb 2019
Location: New City, NY
Posts: 303
Received 21 Likes on 19 Posts
Default

Originally Posted by Randy Smith
Thanks Mike! That's great information. I will give it a try with the three position switch. The pots on the controller really have no functional affect on the braking. Too bad we have to have this work-around. I wonder if there is an better aftermarket brake module that could be used?

Randy
I believe xicoy makes a controller that has built in accelerometers or a gyro that pulses each brake separately to keep the plane straight.
Old 09-29-2019, 10:23 AM
  #105  
ms200a
My Feedback: (15)
 
Join Date: Apr 2002
Location: Las Vegas, NV
Posts: 63
Likes: 0
Received 1 Like on 1 Post
Default

I think Afrerburners is correct on the pulsing controller. However I'm tired of spending money lol. I believe the JP flaw is there are no springs behind the brake disc so it needs a good bit of current to create a large enough magnetic attraction to move the plate to the coiled housing, by then you are in a locked situation and then need to reduce the current to relax the attraction. Because no 2 brakes are the same you get an uneven result. When I have time (after the Best in the West Jet Rally) I'm going to research some small springs to see if that would prove or disprove my theory. Till then it's the work around.
Old 09-29-2019, 10:39 AM
  #106  
Randy Smith
 
Randy Smith's Avatar
 
Join Date: Jan 2002
Location: Calgary, AB, CANADA
Posts: 213
Received 4 Likes on 3 Posts
Default

Thanks guys. Great ideas. I will keep experimenting. Mike, let us know if you find success in adding some springs.
Thud_Driver, thanks for the recommendation and the video. Huge difference in your foamy braking.

Last edited by Randy Smith; 09-29-2019 at 10:45 AM.
Old 09-29-2019, 12:41 PM
  #107  
Thud_Driver
My Feedback: (1)
 
Thud_Driver's Avatar
 
Join Date: Dec 2001
Location: Victorville, CA,
Posts: 1,669
Likes: 0
Received 9 Likes on 7 Posts
Default

Not my video, just a data point. Xicoy has something too but a little more expensive and I don't know about JP brake compatibility.
Old 11-23-2019, 07:48 AM
  #108  
Randy Smith
 
Randy Smith's Avatar
 
Join Date: Jan 2002
Location: Calgary, AB, CANADA
Posts: 213
Received 4 Likes on 3 Posts
Default

Here is another work-around for the brake problem. I have implemented this work-around and it does help with the extreme ON/OFF condition of the brakes. I can get a bit more control in terms of proportional braking. Difficult to get both wheels the same.

JP Brake Work-around

Randy
Old 11-17-2021, 01:50 AM
  #109  
extra 300
Thread Starter
My Feedback: (3)
 
Join Date: Jan 2004
Location: BeirutBeirut, LEBANON
Posts: 1,304
Received 9 Likes on 9 Posts
Default

Hello,

can anyone advise where i can get hold of an MB 339 (actually 2 or maybe 3 kits are needed)?

Thanks
Old 11-17-2021, 06:28 AM
  #110  
Randy Smith
 
Randy Smith's Avatar
 
Join Date: Jan 2002
Location: Calgary, AB, CANADA
Posts: 213
Received 4 Likes on 3 Posts
Default

I understand they may be available from Nova Jets.
https://nova-jets.com/collections/tu...9-v2-1-75m-arf


Randy
Old 11-17-2021, 07:21 AM
  #111  
Bob_B
My Feedback: (11)
 
Bob_B's Avatar
 
Join Date: Nov 2003
Location: Bluegrass State of Mind
Posts: 4,691
Received 81 Likes on 70 Posts
Default

Originally Posted by ms200a
I think Afrerburners is correct on the pulsing controller. However I'm tired of spending money lol. I believe the JP flaw is there are no springs behind the brake disc so it needs a good bit of current to create a large enough magnetic attraction to move the plate to the coiled housing, by then you are in a locked situation and then need to reduce the current to relax the attraction. Because no 2 brakes are the same you get an uneven result. When I have time (after the Best in the West Jet Rally) I'm going to research some small springs to see if that would prove or disprove my theory. Till then it's the work around.
A friend took small "O" rings and placed them in the circular pocket to hold the disc away from the magnets ever so slightly, he claims the brakes works more evenly.


Old 11-17-2021, 11:52 PM
  #112  
extra 300
Thread Starter
My Feedback: (3)
 
Join Date: Jan 2004
Location: BeirutBeirut, LEBANON
Posts: 1,304
Received 9 Likes on 9 Posts
Default

Originally Posted by Randy Smith
I understand they may be available from Nova Jets.
https://nova-jets.com/collections/tu...9-v2-1-75m-arf


Randy
already sent emails and reminders but no reply.... thanks anyway

Last edited by extra 300; 11-18-2021 at 12:16 AM. Reason: typing error

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.