HobbyZone Super Cub Mods Part 1 - Spektrum Radio Upgrade - RC Groups
Thread Tools
This thread is privately moderated by Boidster, who may elect to delete unwanted replies.
Oct 27, 2008, 06:00 PM
I am a Cessnaholic
Boidster's Avatar

HobbyZone Super Cub Mods Part 1 - Spektrum Radio Upgrade

HobbyZone Super Cub Spektrum Radio Upgrade

NOTE - This upgrade only applies to the older, pre-Spektrum version of the Super Cub. The new planes come in RTF and BNF versions, both of which already have DSM-compatible hardware.

This is Part 1 of a three-part upgrade to my HobbyZone Super Cub.

Part 2 is an aileron upgrade
Part 3 is a semi-scale lighting upgrade (link coming later)

Project Overview
The radio system included with the HobbyZone SuperCub RTF kit is, to put it charitably, of fairly modest quality. I personally like the X-Port technology as an idea (a standardized add-on module interface), but unfortunately it is only available with a (again, being charitable) modest quality receiver/ESC combo and non-standard 5-wire servos.

I found the servos somewhat jittery, and the throttle on the transmitter very crude and unsuited to smooth landing approaches due to the lack of fine control.

This project will upgrade the Super Cub to the all-digital Spektrum technology, meaning a new receiver, ESC, and servos. Unfortunately, the X-Port will be lost - at least until a project down the road where I try to resurrect it.

  • + All-digital radio equipment = fewer glitches
  • + Greatly improved throttle control
  • + Standardized equipment for easy repairs/replacement
  • + Net loss of about 1.1 oz, using parts listed
  • - Loss of X-port feature
  • - Loss of Anti-Crash Technology (ACT) (probably a '+' for 99% of people)

These items constrained how I approached this project. If you don't share the same personal preferences you can adjust the project steps accordingly.
  • The airplane must appear stock from the outside (not really a big issue with this project)
  • The original battery tray & door must be operational (this limits how crazy I could get with mods to the battery tray/receiver platform)
  • The original stock brushed motor will be retained (i.e. this is not a brushless conversion)
  • Original control linkages will be retained (again, not a big issue really)
  • New servos must be easily removable (for easy repair in case of gear stripping; I don't want to have to deal with tearing out a glued-in servo)

Parts List
  • DX6i Transmitter from the E-flite T-34 Mentor RTF Kit ($499 HobbyZone) *See Note
  • Spektrum AR6100 6ch Micro-Receiver ($35 eBay)
  • Hobbywing Eagle 30A Brushed ESC ($8 Hobby City)
  • 2x Blue Arrow BA-TS-64 Micro Servos ($10 Hobby City; HiTec HS55's would also be a good choice, I think - the Blue Arrows are kinda noisy)
*Strictly speaking, you can obtain your Spektrum transmitter however you want. In my case, the fact that the T-34 comes with a DX6i transmitter allowed me to rationalize buying Yet Another Plane because I needed it to complete the Super Cub project. The fact that I already had a LP5DSM from my Blade CX2 is totally irrelevant.

Tools & Materials
  • Phillips screwdrivers (small + jeweler's sizes)
  • Hobby knife
  • Double-sided mounting tape
  • Velcro industrial-strength adhesive-backed tape
  • 1/8" x 3/8" spruce strip (or similar, but not balsa). Used for mounting rails for new servos (many other servo-mounting options are possible; I chose wood rails due to my "easy servo removal" constraint.)
  • CA glue and foam-safe glue/epoxy

Step1 - Removing Old Receiver/ESC/Servos/ACT
  1. Remove wing, landing gear, and (optionally) prop from Super Cub. I didn't remove the prop, but it was always getting in the way as I was working. Probably should've taken it off in hindsight.
  2. Remove four screws holding battery tray door frame in place. These four screws also hold the battery tray/receiver tray in place.
  3. Disconnect all wires from receiver/ESC and remove battery box/receiver unit from fuselage. Detach X-Port and remove receiver/ESC from battery tray.
  4. (Optional) Remove Anti-Crash Technology (ACT) sensors from "windshield" and bottom of fuselage. These are glued in place, so some foam will be torn out of the holes as you pull the sensors out. No significant damage, however. Many people leave the forward hole open for extra cooling of the fuselage compartment. I left mine open because I'm lazy, but I will probably at least stick a black sharpie into the hole to make it less visible. Note that the only reason to leave the ACT sensors in the plane is if you don't want to deal with the holes they leave behind; Spektrum receivers can't use the ACT sensors for anything.
  5. Use small (or jeweler's) screwdriver to remove control horns from stock servos. Remove control horns from control wire.
  6. Use hobby knife to cut through white glue globbed over servo mounting flanges. Your Super Cub might not have been assembled like mine, but mine had a good smear of rubbery white adhesive over the mounting flanges of the servos. It cut away easily, and peeled right off the foam.
  7. Remove stock servos, which are attached to the bottom of the servo tray with double-sided mounting tape. I was actually able to reuse this tape for my mounting solution for the new servos.
At this point you should have an empty fuselage compartment, with only the motor lead poking through the firewall and the rudder & elevator control rods sitting near the servo tray. Now to install the good stuff!

Step 2 - Installing New Servos
(See drawing attached below.)
  1. Lay a spruce strip across the fuselage approximately over the aft end of the servo tray and mark it so it can be cut to fit inside the fuselage. Feel free to cut it a little short; it does not need to be a tight fit.
  2. Repeat the above step at approximately the forward end of the servo tray . You should now have two short pieces of spruce servo mounting rails that can lay on top of the servo tray edges at fore and aft.
  3. Place the mounting rails across the fore and aft ends of the servo tray and position the Blue Arrow micro servos in the tray. You will need to push the mounting rails together so they are snug against the ends of the servos, with the servo mounting flanges on top of the rails. I put my servos in with the control shaft towards the fore of the airplane, and pushed towards the outside so there's a gap between the servos.
  4. Using a hobby knife (or a mechanical pencil), mark the rails where the servo mounting holes line up.
  5. Remove the spruce and using a sharp #11 blade (the standard long pointy X-acto blade) bore out the servo mounting holes slightly from both sides. If you happen to have a 1/16" drill, you can use that too. I don't, so I didn't.
  6. (Optional) Spread a layer of CA glue on both sides of the mounting rails and allow it to soak in and dry. This helps prevent splitting when the servo mounting screws are tightened up. If you drill out the mounting holes, you probably won't need to do this.
  7. Attach both servos to the mounting rails (still outside the aircraft), and gently snug the screws down. Careful not to overtighten.
  8. Attach a piece of double-sided sticky tape to the underside of all four outboard ends of the mounting rails. I was able to cut the original mounting tape (from the bottom of the servo tray) into 4 pieces that still had plenty of stickum left.
  9. Lower the servo rail/servo assembly into the fuselage, being careful to get the servo wires through the original wire slots in the servo tray. Press down firmly on the corners of the rails, where the sticky tape is. Ta da! Your servo rails should be firmly mounted and the servos will be easy to remove if needed.
  10. (Optional, but recommended in a do-as-I-say-not-as-I-do way) Blob some foam-safe glue (hot glue would probably work too) over the ends of the servo rails as a backup to the sticky tape.
  11. Attach servo arms to z-bend in control rods (might need to bore out the hole in the arm a little bit) and press onto servos. You may wish to bind your Tx/Rx now and adjust centerpoints and servo throw. After that you can screw down the servo arms. Otherwise, you can adjust during Step 4.

Step 3 - Installing Receiver and ESC

Note: I am assuming that you have already soldered whatever connectors you want onto the ESC, the battery leads, and the motor leads. I used Deans T-connectors (or this "Deans style" clone, anyway; they work fine).
  1. Cut out a rectangle of velcro approximately the same size as the back side of the receiver
  2. Attach one half of the velcro (I used the "loops") to the top side of the battery tray, where the old receiver used to sit. There is a square of plastic there that is large enough to hold an AR6100-sized piece of velcro.
  3. Attach the other half of the velcro to the back side of the receiver.
  4. Cut another rectangle of velcro about 2x as large as the back side of the ESC. Separate the velcro and cut the "hooks" down to the same size as the back side of the ESC. Attach the rectangle of "hooks" to the ESC.
  5. Reinstall the battery tray and attach the receiver to the top of the tray.
  6. Connect the ESC to the receiver and the motor lead. Connect both servos to the receiver as well.
  7. Install a battery in the battery tray (no need to actually connect it to the ESC yet) and play with the position of the ESC to allow for your particular wire-routing configuration. The side of the fuselage is a great place to stick the ESC. You want to make sure it's easy to connect/disconnect the battery when using the battery door (so the ESC's "battery" wire has to reach down into the battery compartment), and you don't want any wires interfering with the servo arms.
  8. Once you have found a good place for the ESC, attach the 2x-sized "loops" piece of velcro in that area of the fuselage compartment. The velcro is 2x sized to allow for repositioning of the ESC for CoG purposes later.

Step 4 - Bind, Test, and Set CoG
  1. Following the instructions for your transmitter, bind to the AR6100 receiver and test out all controls. I had to reverse the rudder servo to avoid an overly-exciting first flight.
  2. If you didn't do it at the end of Step 2, now is the time to adjust center point and throws of your servos. Don't forget to screw down the servo arms!
  3. Reattach the wing and set your CoG. HobbyZone does not (apparently) publish official CoG values, but general wisdom is somewhere around 2.25-2.50" aft of the leading edge of the wing. Move the receiver and/or ESC to adjust as much as you can, then look at moving the battery. Add weight only as a last resort.

Step 5 - Fly!

Don't forget to do a range check before taking off for the wild blue yonder!
Last edited by Boidster; Sep 05, 2013 at 12:19 PM.
Sign up now
to remove ads between posts
Oct 05, 2009, 06:15 PM
Registered User
Boidstir, this is an absolute genius post. I have a new Super Cub LP and bought a Spektrum DX5e system at the same time because of my reservations about operating on 27 MHz. After I finished setting up the Cub I turned on the radio to check the control surface and got a rather disappointing chatter from the elevvator servo. So, it's on to the Spektrum conversion a bit earlier than I had anticipated. Because of your thread I anticipate an easy conversion. Thanks for taking the time to develope your blog and posting. It's a big help and I'm grateful.
Oct 19, 2009, 03:27 PM
Registered User
I upgraded to the DX5e, E-Flite 20a brushed ESC, E-Flite mini servos. The throttle control does not go as slow as it did stock. Am I doing something wrong?
Nov 13, 2009, 03:58 PM
Registered User


Great post. Does the stock Lipo Battery fit without any further mod?
Dec 29, 2010, 01:14 AM
Registered User
soory but this isnt for me, becasue i dont have the cash for a DX6i
Jan 30, 2011, 10:12 PM
Registered User
does this work with a DX5e?
Jan 31, 2011, 10:49 PM
Registered User
Originally Posted by pilotguy172
does this work with a DX5e?
Feb 08, 2011, 08:49 AM
Right Rudder
PittSpecial's Avatar
Great Blog Write up!
Nov 20, 2011, 04:20 PM
Registered User


Just got a Supercub that needs this conversion....

You make it so simple as it should be!

Great writeup and thanks for taking the time to do this.

Feb 14, 2012, 11:34 PM
Registered User

Before sinking

I have a brand new wing already cut with ailerons servos mounted and brushless setup.... However before I did that I figured I would give water landings a try before I put the time and money into the mods. This is how it turned out
Super Cub maiden with floats (3 min 30 sec)
. To anyone getting bored with the stock cub the float addition really spices it up!!!
Mar 26, 2012, 02:47 PM
Registered User
Boidster, Did you ever figure out how to incorporate the X-port? As for the drop module it is a simple electromagnate and seems that it would be easy to figure out. I am doing this mod now and would like to figure out the drop module.
Sep 12, 2012, 06:19 PM
I am a Cessnaholic
Boidster's Avatar
Thanks for all the kind comments. Sorry I did not follow up for the last...oh...three years.

I never did wire in the X-port module, sorry. I do still fly the Super Cub, and after turning my P-51 into packing peanuts last season, it'll be my go-to plane when I get back into RC later this year.

I will configure RCGroups to e-mail me if anybody comments, so I don't ignore people. Sorry again and clear skies!
Apr 11, 2013, 08:32 PM
Registered User
Did you complete steps 2 & 3 or are you going to? Love to see what ya come up with.
Sep 04, 2013, 03:10 PM
Brand Newbie
I'm preparing to purchase a Super Cub and stumbled on this post when trying to decide the RTF or BNF version. Is it safe to assume that the parts list in the OP is still valid? Would it be worth it to purchase the BNF version and the upgrade parts listed in the OP?

Thanks guys.
Sep 05, 2013, 12:14 PM
I am a Cessnaholic
Boidster's Avatar
Originally Posted by ChappyEight
I'm preparing to purchase a Super Cub and stumbled on this post when trying to decide the RTF or BNF version. Is it safe to assume that the parts list in the OP is still valid? Would it be worth it to purchase the BNF version and the upgrade parts listed in the OP?

Thanks guys.

It has been a while since I checked up on the Super Cub. From what I can tell, they no longer sell the non-Spektrum version so, in effect, this blog/upgrade article is no longer relevant (except for folks who own the older SC and want to upgrade). So ignore all the upgrade instructions above; they don't apply to you, which is a good thing!

If you're buying new, then the choice of RTF vs. BNF comes down to the radio you want to own. The RTF version comes with a 4-channel Spektrum radio (the Spektrum DX4e), which is a beginning/training radio. If you're new to the hobby and want a painless way to enter into a neverending stream of new purchases then the RTF is just the ticket. The DX4e can be used with other RC aircraft, and you could add ailerons to your SC to get started with 4-channel control.

If you want to start out with a mid-range 6-channel transmitter - something that you can use for more advanced aircraft as your skills progress - then you can get the BNF version and buy a transmitter separately. Expect to spend $130-170 for a new 6-channel DSMX transmitter.

I hope that helps!

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Wanted Hobbyzone Super Cub radio Norm66 Aircraft - General - Radio Equipment (FS/W) 2 Mar 08, 2008 11:22 PM
Discussion Hobbyzone Super Cub matthew954 Parkflyers 10 Aug 25, 2006 10:16 PM
New Product Hobbyzone Super Cub FuntanaS Parkflyers 3 Jul 07, 2006 12:25 PM
New Product HobbyZone Super Cub RTF Jim T. Graham Product Announcements 0 May 13, 2006 01:55 AM