U/C designs.. Removable and simple Under carriage systems, lightweight etc - RC Groups
Thread Tools
Oct 12, 2008, 04:36 AM
Registered User
davereap's Avatar

U/C designs.. Removable and simple Under carriage systems, lightweight etc

I thought I would show various ways to hold those wheels...And I hope you will post any good systems you use..

The actual wheels are held on to the wire with a bit of silicone fuel tubing each side...and they have stayed on ok so far in use..for thin wires fix the tubes with hot melt glue

Both removable wire UC systems have proved usefull and all work a treat..

System for planes with a lower spline

1...Two wheels at the front type.. the bends are shown below.. the cross body lengths can be made to the width of your fuz..
The V section goes up the outside of the fuz then you use a rod to hold it in place..you can have shorter V lengths but the longer one like mine spreads the loading ..A short one will damage the depron in a heavy landing/crash

shown below on my 24" nutball

RC nutball flying disc (2 min 45 sec)

after a bit of thought ive also made a trike system

and now 19-7-2010 a 4 leg version for lightweight floats
Last edited by davereap; Jun 18, 2012 at 04:08 AM.
Sign up now
to remove ads between posts
Oct 12, 2008, 04:44 AM
Registered User
davereap's Avatar
method 2.. A system for flat bottom wings or a wide Fuz.... a trike system

The bends are shown below.. made in two sections the wire is bound together with fishing line (dacron or firewire type), then cyano'd.. This is then bound to a 2" wide thin ply plate, again fishing line and cyano..Two velcro strips along the ply are enough to hold the unit to the bottom of your wing or fuz

this was made for a flat bottomed delta wing and holds on perfectly, but there is no reason you couldnt fit it to any flat bottomed foamy fuz ...
The rear pair of wheels should be fitted just behind the COG

It is use on the delta in this video
RC Delta KFm4 (7 min 46 sec)

and on this V wing.
HO229 KFm4 (3 min 34 sec)
Last edited by davereap; Aug 21, 2010 at 05:24 AM.
Oct 12, 2008, 04:51 AM
Registered User
davereap's Avatar
Please add on your methods below

The bend drawings were made with Google Sketchup..which took all of 1 minute..
thread here..

Last edited by davereap; Oct 12, 2008 at 05:07 AM.
May 16, 2009, 05:09 AM
Registered User
davereap's Avatar
Twin legs for a flat bottom wing

Heres another one that ive made..Used for my 36" KFm4 Nutball or any plane that is built with a flat bottom.

The triangle of velcro holds it very well - its a b.... to get off

make the UC to the size and weight you require...

I used 2mm ply and a heavy gauge wire on the one in the pictures. it added 3oz and was for a plane that already weighed 25oz ... so the AUW was 28oz

an alternative to the triange shape would be a T shape for the ply, with all the bars 1" wide to take the velcro..
I required a heavy unit so just made a simple triangle shape
Last edited by davereap; Nov 03, 2009 at 05:02 AM.
May 16, 2009, 03:26 PM
An itch?. Scratch build.
eflightray's Avatar
"the velcro holds it very well - its a b.... to get off"

Try a blunt thin blade knife, I use one and it works quite well without damaging the hooks or 'fuzzy'. Just slip it in between the two pieces and gently pull as you slide it about.
May 18, 2009, 04:38 PM
I use my 6 inch ruler, and its about a 1/2 inch wide.
May 19, 2009, 03:41 AM
Registered User
davereap's Avatar
cheers I wil try that... it might stop me swearing at it

oh you clever people..that works a treat.. on the triangle two rulers does it easy...now why didnt I think of that.....duh!
May 19, 2009, 03:51 AM
Registered User
davereap's Avatar
Here is a link to a simple float system that can be easily modified for either the spline or flat plate fitting

build here..


here they are on a Nutball
RC Nutball on floats (1 min 9 sec)
May 19, 2009, 08:02 AM
jackerbes's Avatar
Great thread Dave!

The tip of a prop blade is a great tool for parting Velcro.

It is also an OK tool for removing adhesive backed Velcro from surfaces that are covered with tape.

I usually have a couple of broken off propeller blades around the work bench and in the field gear bag. They make great PU spreaders too, especially the SF props.

Dave's probably never broken one... :>)

May 19, 2009, 09:07 AM
Registered User
davereap's Avatar
Some time back JIMSP had a nutball flying from water with nice simple add on floats.
see above
Ive now drawn them up in sketchup..now using the sketchup file from the zip they can be scaled to suit any sized Nutball or remembering the nutball cog for this 24" plan is at 6" back these floats could be added to almost anything.

the floats should be scaled up for the weight of the plane... a 24" nutball weighs about 8-10oz
the floats need to be positioned with a few degrees + for the wing and for the cog to be in the correct position
..for this size float the back of the front leg should be 1" in front of the COG of your plane..if you scale up remember to scale up this distance as well
Last edited by davereap; May 19, 2009 at 09:17 AM.
Jul 20, 2009, 06:12 PM
Registered User
davereap's Avatar
video by Parrot Pilot nice one

Nifty RC plane landing beer gear (4 min 26 sec)
Nov 03, 2009, 07:59 AM
For us He died, in me He lives
Jimmy JFlyer's Avatar
Just bumped into this thread from the NB thread. Nice stuff!
This is gonna help out a lot in the future on the build list that never ends.
Nov 03, 2009, 04:03 PM
Prop Buster Extraordinaire
philba's Avatar
Interesting ideas. I've been using more velcro of late and liking it a lot more.

One idea for a tail dragger that I've played with is similar to post #4 but used a plywood plate on the bottom and several small screws to mount the wheel assembly to that. I didn't like the weight implications but you don't have a lot of choice for a tail dragger.
Dec 09, 2009, 07:36 AM
Registered User
davereap's Avatar
The velcro strips grip more than strong enough.. the systems can be made lighter or scaled up for larger designs, As yet I havnt had one come loose despite all I put the models through.
I did rip one loose in a heavy crash, but I am sure this acted to lessen the damage on impact, like the softer crash areas built into cars, The motor shaft got broken the UC came off the model was just fine.. and boy did it hit with a bang..
Dec 21, 2009, 07:13 AM
Registered User
davereap's Avatar
A new trike version is added at post 1..as its suitable for planes with lower spline fuzes

also here is my horten using system no:2 the flat plate trike held with velcro
HO229 KFm4 (3 min 34 sec)

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Collector's U/C Kit plans (convert to R/C?) iker3 Aircraft - Fuel - Airplanes (FS/W) 0 Jan 22, 2005 07:59 PM
GWS Spitfire/109, Lithium Ion's and U/C mattski GWS (Grand Wing Servo) 6 Sep 13, 2003 06:40 AM
Twin Star plug-in trike u/c ... pictures Bill Glover Foamies (Kits) 9 Feb 18, 2002 08:44 AM
4/5's sub c's for power tool use.. Looooeeee! Power Systems 0 Sep 30, 2001 04:20 PM
C S R buzz3476 Electric Sailplanes 2 Jul 14, 2001 10:48 PM