# Progress Build of Evel Knivel’s 1/18th Scale X-2 Skycycle From A 3D Printed Model



## Phillip1 (Jul 24, 2009)

Fellow Modelers,

On September 8, 1974 stunt performer and entertainer Evel Knievel attempted to jump Snake River Canyon near Twin Falls, Idaho using a steam powered, 3-wheel rocket named the _X-2 Skycycle_. It was launched from a high angle ramp and was supposed to release a parachute for recovery after the engine cut off. However, an electrical malfunction caused the parachute to deploy almost immediately after lift-off and prevented the rocket from landing on the opposite side of the canyon. Knivel was unhurt by the stunt but came very close to drowning, as his vehicle barely missed landing in the water. I remember watching this event on TV when I was a young boy (yes I am not young). Does anyone else remember watching this too? I always thought the _X-2 Skycycle_ was a really cool design, but unfortunately no hobby manufacturer ever issued a model kit of the very sleek craft Knievel flew that day. A short-lived plastic model company called Addar issued a 1/24th scale kit of the _X-2 Skycycle_ in 1974, but they modeled their kit after an early version that was determined to be aerodynamically unstable and never made it past the mock-up stage. 

In 2020 I discovered the Evel Knievel Museum in Topeka, Kansas was selling 3D printed models of the _X-2 Skycycle _that were about 10.625” in length. Since the actual _X-2 Skycycle_ is 16 feet long (less the boom and probe) that made the printed model about 1/18th scale. I paid $50.00 for one plus $8.00 shipping. It is typical of a lot of other 3D printed items I have seen-crude and very basic. However, it has a hollow fuselage and is a nice size, so I decided to make it make it my next model project. This is not really building a “kit”, but it will require a lot of work with scratch-building, finishing, and creating custom decals. To get started I am posting multiple views of the 3D printing as I received it (warts and all). I am also including some internet images of the actual _X-2 Skycycle_, so you can see what the 3D printing is supposed to (hopefully) look like when I am finished!

Figure1: The finish is textured and very rough in areas, but the alignment of the body and tail surfaces is excellent. There are two main areas where the 3D printing is not correct in its shape. The first is the nose section, which should have a smooth tapered transition at the tip. The second is the rear body being flush with the vertical/horizontal tailfins, when it is supposed to extend past these parts. Correcting both of the issues will require work.


Figure 2: Here is a full side view.


Figure 3: A ruler is included to give an idea of the size.


Figure 4: As you can see the lower areas of the 3D printing are much rougher.


Figure 5: The lower rear section is shown. There is much work to do to get the finish smooth.


Figure 6: A view into the cockpit. It seems to include a representation of an instrument panel, although the X-2 Skycycle did not have one.


Figure 7-14: Photos of the actual X-2 Skycycle


----------



## Phillip1 (Jul 24, 2009)

More photos...







Until next time...

Phillip1


----------



## Milton Fox Racing (May 27, 2014)

I was young at the time as well. But dont remember watching the event though. Wasnt there a movie as well?


----------



## Phillip1 (Jul 24, 2009)

Milton Fox Racing,

The only movie I am familiar with was made in 1971 (titled "Evel Kinevel") starring George Hamilton in the leading role. I never saw it.

Phillip1


----------



## Milton Fox Racing (May 27, 2014)

I may be remembering a biography or documentary. It's been awhile. 🤙


----------



## Phillip1 (Jul 24, 2009)

Fellow Modelers-Here is an update on the progress of the _X-2 Skycycle_. All of my time so far has been spent cutting off pieces I do not need and sanding to get the proper shape and smooth finish. 

Figure 1: Every journey begins with a first step. My first step is cutting off the front ailerons (or anti-spin blades) and drilling holes where the support rods for the scratch-built ailerons will go.


Figure 2: The nose wheel is sawed off next. I have also started sanding down the nose section to get a sharper and smoother taper.


Figure 3: More sanding is done to the nose section. One thing I immediately noticed about the plastic used in my 3D printing is that it is harder than styrene plastic. I mostly use the Model Master 5-Grade Sandpaper set when I am building models, but I am having to use heavier grits to be able to shape the printing and get out the worst flaws.


Figure 4: Next to be cut off is the windshield. Before this is done I put a piece of masking tape over it and used a pencil to trace around the edges. I did this so I will have a properly sized template to use when I create a new windshield out of clear plastic much later.


Figure 5: I am making multiple templates because I KNOW I will not get it right the first time I try make the windshield.


Figure 6: The windshield is sawed off close to the base.


Figure 7: The remaining edges of the windshield are removed with heavy grit sandpaper. The false instrument panel is also cut out and the cockpit interior that is visible is sanded smooth.


Figure 8: As you can see, one of the worst areas is the lower rear body. I have to cut off both molded-in tires before I can finish sanding the section. The first tire broke off easily in one piece. The second tire would not budge, so I am clipping it away a little at a time with wire cutters. The interesting thing to note with the tire cut in half is you can see the cross-stitching pattern inherent in the 3D printing process. This also means the 3D printing is not 100% solid and if I sand too deep the cross-stitching will be revealed, which is a bad thing.


----------



## Phillip1 (Jul 24, 2009)

Figure 9: The lower rear body is shown after all the heavy cutting and sanding is complete. All the remaining tiny gaps and flaws will have to be filled with either superglue or primer paint.


Figure 10: Slow-set superglue and careful sanding created the unique curved transition at the nose. Getting this shape right is critical in obtaining the correct look of the _X-2 Skycycle_. All of the “basic” sanding that has been done took about 20 hours.


Figure 11: Here is a close up view of the smooth tapered nose section. 


Until next time...

Phillip1


----------



## Phillip1 (Jul 24, 2009)

Fellow Modelers-More progress to share. This update deals with modifying the basic body and scratch-building some parts. 

Figure 1: The easiest way to extend the body length is by adding a strip of thin Evergreen styrene. For this scale, about a 1/4” extension is appropriate. I rolled the thin styrene to a tight radius to make it easier to fit the circular shape of the body. I also cut off the engine nozzle and opened up a large hole so the replacement will have clearance.


Figure 2: Regular superglue is used to carefully tack the extension in place a little at a time as it is wrapped around to the same diameter as the body.


Figure 3: The extension is almost completely in place.


Figure 4: The extension overlap is cut off and the two ends are butted together. A bead of thick superglue is added along the interior connection to make the extension strong. Next a thin bead of regular superglue is applied to the outside seam line and sanded away so the extension looks like a natural part of the body. Primer paint has been applied the lower horizontal tailfin surfaces and sanded away to help make them smooth.


Figure 5: Next the rear cover plate is added. A matching diameter is traced on a thin piece of Evergreen styrene. It will be cut out and then glued to the open end of the extension.


Figure 6: The cover plate is shown after being glued into place. The replacement engine nozzle shown in this photo came from my spares box. 


Figure 7: After measuring and marking the center of the cover plate, a hole will be cut and sandpaper used to carefully widen the hole to the largest diameter of the nozzle.


Figure 8: Once the engine nozzle was able to fit flush against the cover plate it was glued into place. Whew! Glad this modification is done.


----------



## Phillip1 (Jul 24, 2009)

Figure 9: Two pieces of small brass tubing are used to represent the axles for the rear wheel replacements.


Figure 10: For the rear wheels I am using parts from the bomb cart of a Monogram 1/48 B-17G airplane kit. They will work for what I need but the diameter had to be reduced 1/8” and the width had to be reduced 3/16” to be able to properly fit inside the wheel wells. I believe the actual _X-2 Skycycle_ used wheels from a small pleasure aircraft, like a Cessna or Piper.


Figure 11: The rear wheels are shown being test fitted to the body. I had to do this about two-hundred times before I got everything to line up and sit level!


Figure 12: Another view showing the left wheel in the wheel well.


Figure 13: The nose wheel presents a different problem since there is no body opening for it to fit into. Cutting a slot opening is not an option (at least for me) because of the hardness and thickness of the material. My solution will be to only attach a partial wheel-what is exposed outside the body. The key to this option being successful is in getting a tight, gapless connection between the body and partial wheel. This photo shows my starting point (more Monogram B-17 parts) since what I use will end up being less than one-half of a wheel.


Figure 14: This photo shows the finished partial nose wheel, which turns out to be about 40% of the whole part. The height is mostly determined by what is required for the _X-2_ body to sit level when all three wheels are temporarily attached.


Figure 15: This photo shows a temporary test fitting of all three wheels. After the model is painted I plan on placing a small rectangle black decal (slightly larger than the partial wheel) on the body to represent the open space where the wheel is coming through. I know it sounds like a cheesy effect but I think it will work okay. 


Until next time...

Phillip1


----------



## John P (Sep 1, 1999)

That's a lot of work! A friend with a 3D printer gives me sci fi ship prints every now and then, and they sit in a box because I can't imagine doing all that sanding.


----------



## Phillip1 (Jul 24, 2009)

John,

You are right-it is ALOT of work trying to improve a 3D printed model. The large amount of sanding required is tedious and not fun. I have wanted an X-2 Skycycle in my collection for a long time and believe this offering may be the only way to get it. I will say this is probably the last time I will try to upgrade a 3D printing.

Phillip1


----------



## Phillip1 (Jul 24, 2009)

Fellow Modelers-In this update the final modifications and scratch-built parts are reviewed. 
Figure 1: I found a 1/18 scale car seat on E-bay that is close to what I need. However, it was way too big and had to be drastically cut down to be able to fit inside the cockpit. The photo shows two identical seats giving a “before” and “after” comparison.


Figure 2: This photo shows the seat being test fitted into place. The arrangement kind of reminds me of a miniature dragster, where the driver’s legs extend straight out and there is very little extra room in the cockpit.


Figure 3: A very thin piece of Evergreen styrene was cut and glued to the floor and sides of the cockpit to cover the interior’s textured finish.


Figure 4: The lifting lug is scratch built out of Evergreen styrene. At this point I am making a compromise on the build. The photos of the _X-2_ I have seen show it with a “U” shaped attachment (that greatly resembles an air inflated neck cushion) located next to the lifting lug. I do not know what this is. My guess is it acts like a roll bar and protects the pilot’s head if the vehicle lands upside down. I tried to scratch build the shape and searched for a similar shape in my spares box but with no success. After a couple of days I decided to let it go and move on.


Figure 5: The vertical tailfin’s rear corner was carefully notched and a small hole drilled. This is done to accommodate the (pressure/temperature?) probe the _X-2 Skycycle_ carried when it was launched. A piece of small diameter wire will be used to represent the probe. 


Figure 6: The scratch-built ailerons (anti-spin blades) were made out of Evergreen styrene and small diameter rod.


Figure 7: One of the ailerons is shown being test fitted to the body.


Figure 8: The scratch-built part shown here is a reinforcing plate and it attaches to the rear cover plate. After the engine cuts off the pilot engages a mechanism that blows off the rear cover plate/reinforcing plate, causing the recovery parachute to deploy.


----------



## Phillip1 (Jul 24, 2009)

Figure 9: The reinforcing plate is shown being test fitted against the rear cover plate.


Figure 10: A section of angle iron was located on the bottom of the _X-2 Skycycle_ where the pilot was located. I assume this was added to give him protection from being crushed in an unexpectedly hard landing. It was made from two pieces of Evergreen styrene.
how do you print screen

Figure 11: This is the nose boom and it was made out of a piece of solid rod and a round plastic part from my spares box. At this time, I located and drilled the mounting holes for the nose boom and all the tailfin guy wires.


Figure 12: The replacement windshield was made from very thin (.007”) clear plastic sheet purchased at a local Hobby Lobby. 


Figure 13: I took the masking tape tracing of the 3D printed windshield I had done earlier, taped it to the clear plastic and cut it out with scissors.


Figure 14: A radius was put on the windshield by carefully rolling it around the body of a round pencil. I thought rolling such a tight radius might cause some micro-fracturing of the clear plastic, but fortunately that did not happen. The photo shows the new windshield being temporarily held in place with small pieces of masking tape. I still have to determine the best way to permanently attach the windshield to the body.


Figure 15: Shown are almost all the parts that were either scratch-built or modified from the spares box. Included are small diameter rods for the horizontal/vertical tailfin guy wires, as well as miscellaneous internal and external details. 


Until next time...

Phillip1


----------



## f1steph (Jan 9, 2003)

Nice project......


----------



## Phillip1 (Jul 24, 2009)

Thanks

Phillip1


----------



## Phillip1 (Jul 24, 2009)

Fellow Modelers-This project now moves into the painting phase. Time to add some color! 

* 
*
Figures 1 and 2: I knew from testing that enamel paint did not adhere as well to the 3D printing plastic as it does to styrene plastic, so I began by airbrushing the body with Model Master Primer. Unfortunately, the primer revealed LOTS of small scratches all over the body. This is common when heavy grit sandpaper is used. The best way I know to get rid of the scratches is by brush painting a very thick coat of primer paint over the entire body and then sanding it all back down. I have used this technique before so I know it works, even though it requires a great deal of sanding. These photos show the thick, brushed on primer before being sanded away. 



Figures 3 and 4: These photos show the body after the brushed-on primer has been sanded down to a soft buffed finish. The pattern reminds me of a tie-dye T-shirt. Doing this task required about five hours. 



Figure 5 and 6: A new coat of MM primer is applied, but this time the finish looks fantastic with all the scratches gone bye-bye...



Figures 7 and 8: The cockpit interior was painted next with Alclad Dull Aluminum.


----------



## Phillip1 (Jul 24, 2009)

Figures 9 and 10: From the photos I have seen there is very little interior detail in the _X-2 Skycycle’s_ cockpit (i.e. some support stiffening, electrical cables, some rudimentary controls and a seat). There are no dials, gauges, or control stick because the pilot did not need them and there was probably not room anyway. From what I am told the pilot only had control over:


> When the vehicle took off-
> Adjusting the angle of the ailerons-
> Releasing the parachute to deploy-


The miscellaneous details I added are representative, based on the photos I have seen.


Figure 11: Painting the exterior of the body is next, so the cockpit was masked off. Blue painter’s tape is used to reduce the risk of pulling up the aluminum paint later.


Figure 12: The _X-2 Skycycle’s_ very attractive American Flag paint scheme began with Testors Flat White. This photo was taken after the first coat was applied. A total of at least four heavy coats will be given. I will use a soft cloth to gently buff the finish between each coat.


Figure 13: The last coat of white paint has been applied. I let the paint cure for a couple of days before I handled the body. 


Figure 14: I did not like any of the blue paint colors in my stash, so made a special mix. I used 80% Testors Flat Colbalt Blue and 20% Model Master Flat Insignia Blue. The blue on the actual _X-2 Skycycle_ is a darker shade but I really liked the color I mixed. In this photo the mixed color is on the far left.


Figure 15: The special mix blue paint is applied. A lot of tape masking care was taken to make sure no blue overspray ended up on the pristine white finish!


Figure 16: The masking tape is peeled away.


----------



## Phillip1 (Jul 24, 2009)

Figure 17: A sharp demarcation line is produced.


Figure 18: The tops of the smaller, outside tailfins were masked off and painted blue.



Figures 19 and 20: Close-up views of the rear and front are shown. 


Figure 21: A seat backing plate was made out of Evergreen styrene, painted Alclad Aluminum and glued inside the cockpit.


Figure 22: The tedious tape masking was done once again, and then Testors Flat Red was applied over the lower portion of the body. 


Figure 23: An overall view of the red underside after the tape has been removed.


Figure 24: A close-up view of the nose section.


----------



## Phillip1 (Jul 24, 2009)

Figure 25: Full side view of the red, white and blue painted body.


Figure 26: Here is a full top body view. Multiple coats of Model Master Metalizer Sealer were airbrushed over the entire body to provide a uniform satin finish.

Until next time...

Phillip1


----------



## Milton Fox Racing (May 27, 2014)

I like the satin finish! Good job on the paint lines, too. 🤙


----------



## Phillip1 (Jul 24, 2009)

Thanks!

Phillip1


----------



## Phillip1 (Jul 24, 2009)

Fellow Modelers-This update includes more painting and some decaling. 

Figure 1: The last part to be painted on the body was the interior of the engine nozzle. The diameter was carefully masked off and painted Alclad Dull Aluminum. This photo shows the process of removing the protective masking tape.


Figure 2: The painted engine nozzle.


Figure 3: The completely painted 2-1/2 wheel assemblies are shown. The tires were painted Testors Flat Black and the hubs/wheels were painted Alclad Dull Aluminum. I applied Windsor & Newton’s Raw Umber oil paint all over the aluminum area, then wiped most of it away with a Q-tip. This gave the parts much more depth and a realistic look. 


Figure 4: Finishing the seat was next on the list. It was painted the same blue color as the upper body. Tamiya’s 1/20 scale Seat Belt Set “A” was used to add realistic detail.


Figures 5 and 6: This is an outstanding seatbelt set and was really easy to assembly. Each part was already detached from the metal sprue so no cleaning was required! The only thing I had to do was overspray the metal parts with Testors Dullcote to tone down their shine. Note: The actual _X-2 Skycycle’s_ seatbelt straps were a dark tan, but I think my red ones look sharp.



Figures 7 and 8: Here are two views of the seat after it was glued into the cockpit. 


* 





*


----------



## Phillip1 (Jul 24, 2009)

Figure 9: Time to move on to decaling! I wanted to start with something I thought would be simple, so I chose the red stripes on the upper horizontal tailfins. These were cut from a red decal film sheet. First, a paper template was created and the overall shape was cut using a metal ruler. 


Figure 10: The “dry” decal is placed on the upper tailfin to confirm the shape was cut correctly.


Figure 11: Seven stripes were then measured and cut, with about 1/16” trimmed off each one to allow for the white spacing when each stripe was located on the tailfin. The individual red stripes were then applied and maneuvered into place. In this photo you can see the finished product looks good, but I had ALOT of problems getting to this point. Although the red decal sheet was new, many of the pieces I cut ended up cracking and breaking apart and required multiple repairs. These decals turned out to be not simple at all (and I still have the other side to finish)! 


Figures 12 and 13: After a lengthy internet search I was able to find decal sheets containing various sizes of silver and gold stars. K4 is the name of the company that makes them. These photos show what they look like. 



Figure 14: This photo shows the largest size silver star decals as they are being applied to the blue background. 


Figures 15 and 16: Three different size silver star decals were used on the upper blue section. The gold star decals were only added to the vertical tailfin. Micro-set and Micro-sol decal setting solution were used to get them to lay down against the surface.


----------



## Phillip1 (Jul 24, 2009)

Figures 17 and 18: Here are two full body views after all the star decals were applied. Even with only half of the decals added this is an eye-popping scheme!



Until next time...

Phillip1


----------



## scotpens (Sep 6, 2003)

Beautiful work so far. You have the patience of a proverbial saint!



Phillip1 said:


> The only movie I am familiar with was made in 1971 (titled "Evel Kinevel") starring George Hamilton in the leading role. I never saw it.


There was also a 1977 movie called _Viva Knievel!_ with Evel Knievel playing himself. It costarred Leslie Nielsen (as the bad guy), Gene Kelly and Lauren Hutton.


----------



## Phillip1 (Jul 24, 2009)

Thanks for the compliment.

Phillip1


----------



## Phillip1 (Jul 24, 2009)

Fellow Modelers-This update includes adding the remaining decals and gluing all of the sub-assemblies in place. This will be the final progress update (I hope) before posting photos of the finished build. 

Figure 1: Making the side lettering (X-2 EVEL KNIEVEL) decals are next on the list. The first step is determining the correct size and font to use. I am using Microsoft WORD to print off several letter/number variations, then holding them against the body to see how each one looks compared to what was on the original _X-2 Skycycle_. For this project the closest fit was Narrow Arial-60 Font-Italacized, shown in the photo.


Figure 2: The letters and numbers will be cut from a sheet of Super Scale Gold Trim Decal film, shown in this photo.


Figure 3: A group of letters is printed, cut to a small size and taped to the gold decal sheet. Fortunately, almost all of the characters are straight and squared off, which makes them fairly easy to cut out using an X-acto knife and metal ruler.


Figure 4: This photo shows the gold decal film after the cuts have been made using the lettering template.


Figure 5: The gold decal film is super thin and fragile. A gentle touch is required in removing the unwanted pieces and locating them on the body without tearing.


Figure 6: Getting the lettering decals positioned on the body was a tedious and difficult task. The only tools I had to get everything evenly spaced and lined up straight were my eyeballs and a metal ruler. In this photo the “X-2” decals are about to be added to the left side. The thinness of the gold trim decals meant they laid down on the body really well. I used only a very small amount of Micro-set on them, as I was afraid anything stronger might mar the finish.


----------



## Phillip1 (Jul 24, 2009)

Figures 7 through 10: Here are several views of the body with all of the lettering decals added. I am very happy with it looks, since it turned out better than I thought it would. The gold letters really give off a shine when the light hits them. On the actual _X-2 Skycycle_ the gold lettering has a red outline, but I did not attempt to reproduce this. 





Figure 11: The rear wheels are permanently glued into place.


Figure 12: As I mentioned in an earlier post, a black rectangle decal is added where the nose wheel goes to represent an opening in the lower body. 


Figures 13 and 14: In these photos the nose wheel has been glued into place. You get to see how the black decal helps create an illusion of an opening where the wheel comes through.


----------



## Phillip1 (Jul 24, 2009)

Figure 15: A couple of more details are added to the lower body.


Figures 16 and 17: The ailerons are glued into place.



Figure 18: Here is an overview of the lower body.


Figure 19: The final decals to be added are the sponsor logos that include Chuckles Candy, MACK Truck and Harley-Davidson (and the designer of the _X-2 Skycycle_-Truax Engineering). These have to be made. I have never made my own decals before, so this is a learning experience. First, I did a Google search to find images of the logos painted on the actual _X-2 Skycycle_. I was not able to find exact images but got very close on all of them. Next, I watched 3 to 4 hours of various YouTube videos on how to make your own water slide decals. The logo images were first printed on regular copy paper to make sure they were the correct size to go on the body. Next, Testors White Decal Paper was used with my home printer. There is nothing special about my printer, other that it does has the ability to print images on photography paper and has a “very fine” print setting. My wife helped me arrange the decal printing to save space and not waste the decal paper. I made sure to print more logo copies than needed just in case there were any unfortunate accidents. The photo shows the logos printed on white decal paper. I was impressed by how clear and sharp the printing turned out. Finally, Testors Decal Bonder in a spray can was applied. I did not spray on enough initially, since a “test” decal disintegrated as soon as it got wet. A much heavier coat of Bonder was applied to the decals and everything worked just like it was supposed to.


Figure 20: The photo shows the logo decals being put in place. No setting solutions were used since I did not want to take a chance on damaging the decals and causing the printer ink to run.


Figure 21: After the last decals were on, the windshield was very carefully glued into place. I used two small dots of superglue to tack it down, and then added a bead of white glue to reinforce the connection. Attaching this part was probably the most nerve-wracking part of the entire build due to how flimsy the windshield is and the huge risk of damaging the paint finish if it was put in the wrong location.


Until next time!

Phillip1


----------



## John P (Sep 1, 1999)

Cutting out the gold lettering was... brave!


----------



## aussiemuscle308 (Dec 2, 2014)

Amazing build


----------



## Phillip1 (Jul 24, 2009)

John P-My man, cutting the gold decal film was the only way I could think of to make the lettering!

aussiemuscle30-Thanks for the compliment.

Phillip1


----------



## Phillip1 (Jul 24, 2009)

Fellow Modelers-This project is finished! The total build time was about 136 hours. Thanks for the comments and to everyone who followed along. 

Phillip1


----------



## Phillip1 (Jul 24, 2009)




----------



## Phillip1 (Jul 24, 2009)




----------



## Thunderbird (Mar 4, 2009)

Phillip, Your workmanship and attention to detail is absolutely top notch! A beautiful model!


----------



## Phillip1 (Jul 24, 2009)

Thunderbird-Thanks very much for the compliment.

Phillip1


----------

