Thus far, I have been very pleased with flying the DOG Aviation RV-12 …
it is truly a nice flying airplane. My only minor complaint stems from the
rudder pedal configuration, in that, I find it difficult to make large rudder inputs with my feet on
the rudder pedals without also pressing on the brakes unless I keep the balls of my
feet pulled back in an unnatural position. Of course, for most ground
operations or while in the air, this is not an issue … but on short final or
during takeoff roll it requires a cognizant effort to pull the tips of the toes
aft to insure large rudder inputs are not accompanied with unwanted brake inputs.
Sliding the feet higher on the rudder pedals would help but then the
tips of my shoes (size 12) run into interference with the firewall shelf.
Admittedly, it is not a big deal … just a few moments of uncomfortableness
while pulling the toes aft to keep them off the brakes during takeoff and
That got me thinking ... Gee, if the F-1290 pedal blocks were a little thicker,
it might put my feet in more of a natural position on the rudder pedals and help keep
them off the brakes. With all the buzz about 3D printing, I decided to see if I
couldn’t make a set of pedal blocks that are exact copies of the Van’s F-1290
pedal block … just a little thicker so the feet are in more of a natural
position when on the rudder pedals. But that posed a problem … I have never
used any type of 3D modeling software, so where do I begin?
EAA (Experimental Aircraft Association) to the rescue. I was talking to some
friends at the airport about wanting to 3D print a set of thicker rudder pedal
blocks, but didn’t have access to 3D software. I was informed that as an EAA
member it was possible to obtain a free full featured (minus stress analysis)
version of Solidworks Educational Premium that college student’s use. The EAA
has formed a partnership with Solidworks allowing EAA members to download Solidworks
Educational Premium for free … along with a 1 year license agreement which can
be renewed as long as EAA membership is valid.
Knowing nothing about Solidworks (or any other drafting program), it
seemed like learning to draw the thicker pedal blocks would be a daunting task.
When first launching Solidworks, my eyes immediately glazed over … the sheer
number of menus, options and submenu items available is truly daunting for a
beginner. Fortunately, within Solidworks (under the help menu) there is a very good
built in tutorial that starts out simple and builds on previous lessons.
After playing with the tutorials for a few evenings, I was able to
acquire enough knowledge about Solidworks to successfully draft up a thicker
rudder pedal block by carefully measuring the F-1290 pedal block and entering
those dimensions into Solidworks then adding an extra ½" to the overall height
of the petal block. I did not want to change the mounting bolt hardware so a recess
was made for the mounting bolt to drop into. With a little bit of tutorial
practice and some patience, making an accurate drawing for a thicker pedal
block was not that hard. Below are a few screen shots of the finalized design
Top view of the thicker rudder pedal blocks drawn using Solidworks.
Bottom view of the thicker rudder pedal blocks.
Side view of the thicker rudder pedal blocks.
End view of the thicker rudder pedal blocks.
A couple of years ago Tom, a friend who is building a RV-10, mentioned
he bought a 3D printer and made the offer should I ever want to have something
printed, to let him know. I told Tom about my using Solidworks to create a
drawing for thicker rudder pedal blocks and he said he had plenty of blue HDPE
filament … so Tom printed two blocks for me that are hollow inside with a
crosshatch pattern for strength to save on material, since they are just for
proof of concept. Thanks Tom!!!
The blue RV-12 rudder pedal block on the left was printed by Tom using
the Solidworks file I made.
Side by side one can see the blue pedal block is the same as the black
Van’s pedal block on the right … just a ½" thicker.
Bottom view of both rudder pedal blocks. Have to say, as a first time
effort at making a 3D drawing and then having a part printed from the drawing,
the thicker rudder pedal block looks great.
The big question now is how well will the thicker rudder pedal blocks
actually work out? Only one way to find that out … install them.
The thicker proof of concept rudder pedal blocks installed on the pilot
side of the DOG Aviation RV-12.
For comparison, these are the original Van’s F-1290 rudder pedal blocks
on the passenger side.
So you are probably wondering … was it worth the effort … absolutely! My
feet are now in a much more natural position when placed on the rudder pedals. Although
the blocks could even be a tad thicker, the positioning of my feet on the
rudder pedals is much more comfortable while moving the rudder pedals and staying
off the brakes ... so I’m calling this effort a success.
Now that I know the Solidworks drawing I’ve made will produce a
functional part, the plan is to make up four rudder pedal blocks from a tougher
black material such as NylonX or CarbonX. Unfortunately, Tom’s 3D printer does
not have the proper type of printer nozzle required for those filaments, so I
will need to have the final pedal blocks printed elsewhere.
Return from the future:
As previously mentioned, the printer nozzle on Tom’s 3D printer is not suitable
for printing stronger filament plastics like CarbonX or NylonX … so a few
months back, I contacted Steve at rvplasticparts.com who is a fellow RV owner on
the Van’s Aircraft Forums (VAF) that has a cottage business of 3D printing accessories
for owners of various models of Van’s aircraft. I told Steve I've made a drawing
of a taller rudder pedal block and had already printed a prototype which fit
nicely. However, I wanted to have a set printed using a stronger material such as
CarbonX or NylonX … Steve decided NylonX would be a good choice. I told Steve he
could have my drawing to use if he wanted to add the thicker rudder pedal
blocks to his product line and he decided to take on the project.
Steve tweaked my drawing a tad and will be offering the taller rudder
pedal blocks in an assortment of thicknesses. The prototype Steve sent me is
3/16" taller than my original prototype … which should be perfect since
my prototype blocks felt good … but, as mentioned earlier in this
post, could stand to be a little thicker. Another change Steve made was increasing
the thickness of material under the bolt head from ½" to ¾" feeling
the end result will be much stronger. The original rudder block from Van’s was ½"
so I made my drawing using the same thickness which created a surprise when I tried
to test fit the new taller NylonX rudder pedal blocks Steve sent me …. the original
AN4-15A bolts were not long enough, so I needed to order longer AN4-17A bolts.
Below is a photo showing the new NylonX rudder pedal block on the right, my proof
of concept prototype in the center and Van’s stock rudder pedal block on the left.
As can be seen in this photo, the NylonX rudder pedal block on the right
is 3/16" taller than my original blue prototype in the center which is 1/2"taller than the stock Van's
rudder pedal block on the left.
As previously mentioned, my blue prototype shown above felt good and is
a vast improvement over the stock Van’s rudder pedal block … but I felt the
block could stand to be even a tad taller. When the longer AN4-17A bolts arrived
today, I headed to the hangar to test the fit of the new NylonX rudder pedal
blocks Steve printed for me. At first, I only replaced one block so I could
compare the feel of my prototype with Steve’s 3/16" taller rudder pedal
blocks. The overall feel was about the same … but I noticed Steve’s NylonX rudder
blocks allowed larger rudder inputs before the foot actually began pressing on
the brake pedal. So overall, I’m very happy with the thicker NylonX rudder pedal
blocks Steve printed and will order another set for the right side of the
The new taller NylonX rudder pedal blocks installed. Note to fellow
RV-12 owners, changing to these rudder pedal blocks will require longer AN4-17A
bolts to replace the AN4-15A used to install the stock Van’s rudder pedal
A big thanks to Steve at rvplasticparts.com for taking on my project and sending me a
prototype to test. I think this is one modification other RV-12 owners will
want to look into … especially if keeping your foot off the brake during rudder
inputs feels slightly uncomfortable for your foot.
The photos below are just stored here so I can post them on the forums. Basically,
kicking around an idea here. Background: The owner of a RV-12 has a grade in
front of his hangar to traverse and is trying to figure out a good way to get
his airplane into the hangar without holding onto the tow bar so he can hold a
winch controller or pull a rope connected to pulleys.
I suggested reversing the tow bar and pull it with a winch or
rope/pulley setup connected to the reversed tow bar. However, it was pointed
that without locking the nose wheel somehow, should the tail begin to track off
center a little, the castering nose wheel will make matters worse and quickly
get the airplane off track … true enough.
So that’s had me thinking for a few days and I think I’ve come up with
an idea that may solve the guy’s problem. During the last unexpected warm day
we had here I slipped up to the airport to take a few photos I will post on the
forums. The idea is to use the RV-12’s steps to support a board traversing the
bottom of the fuselage that the tow bar can rest on and be secured between blocks.
The blocks will prevent the tow bar from moving side to side thus keeping the
nose wheel locked straight while the tow bar is being hauled aft into the
hangar by a winch or rope/pulley arrangement. Below are proof of concept mockup
photos using a yard stick so the RV-12 owner can see my vision in a picture form.
The tow bar is placed on the nose wheel reversed as shown here and will
sit on horizontal piece of wood or metal traversing the belly of the airplane.
The areas where the blue tape is placed around the tow bar will need blocks attached
to the horizontal piece to capture the tow bar. The blocks will capture the tow
bar preventing side to side movement thus keeping the nose wheel held straight
as the airplane is pulled backwards into the hangar.
The horizontal piece needs to be connected to the RV-12’s steps using a
vertical piece that has wooden pins which will insert snugly into the step’s
tubing as shown in this photo … or the vertical piece could slide over the
step’s tubing, builders choice. The vertical piece will likely need some gussets
where it meets the horizontal piece to stiffen the assembly, so the fixture has
no side to side play. The steps will lock the whole structure preventing ant side
to side movement and also support the tow bar as the airplane is pulled aft
into the hangar.
As can be seen in this photo, the Van’s tow bar ends well forward of the
Looking aft, As can almost be seen in this photo (bad focus), the com
antenna is biased to the pilot side of the RV-12’s bottom fuselage … so a cable
or rope connected to the center of the tow bar handle will easily pass by the
I believe my idea will likely work well, however not having
an incline to traverse to get inside my hangar, won’t be constructing a working
version to prove the idea actually works.