Upscale Estes Venus Probe Build Thread

[Ray Lecture]

This build thread is for an upscaled version of the Estes Venus probe. I have an original Venus Probe from 1997 which I still fly today.

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The rocket was always somewhat under powered, so I upgraded it to a 24mm motor mount recently, but the limited tube size to stuff two parachutes always made it difficult to prep for flight. I thought an upscaled version could solve both those issues. Originally, I upscaled it to a 2.6 in tube size but I did not generate a lot of documentation for a build thread.


Photos by Wes Munn

The 2.6in version ended up heavier than I had planned and ended up being a Level 1 rocket. The plastic in my original rockets has gotten pretty brittle over the years and I want one to fly more regularly, so I decided to do a BT-60 version with a 29mm motor mount. Since a lot of the pieces are 3D printed, most of the effort is just scaling the STL files in the slicer and printing new parts. I did do some small design improvements based on lessons learned from the first build.

Design Overview:

The overall design was scaled from a rocksim file from the RocketReviews website https://www.rocketreviews.com/unknown-venus-probe.html. The lower section was increased to fit a mid power 29mm engine.

The 3D printed alien pod and legs were designed in OpenSCAD and are approximations to the Estes design. The alien bust was used from Thingiverse https://www.thingiverse.com/thing:2668660. Cura was used as the slicer and all the parts were printed on a Creality CR-10S Pro using PLA+

 

[BABAR]

I built the Estes version but modded up front for 24 mm. Look under BABAR for Venus Probe. The eBay source had no decals, so I kinda went wild on paint scheme.

Great flier. As you said, PITB to pack.

If I upscaled I’d probably lengthen the main body tube more than simple scaling (at least if you keep the ALIEN, it takes up a lot of space! Pun intended.) you can keep EVERYTHING else scale, just lengthen the section of tube TAILWARD of the leg retention ring.

If anything, lengthening it will make the rocket MORE stable, and definitely will make packing it more enjoyable and successful deployment more reliable.

 

[Ray Lecture]

Before I finalize the upper tube, I'll see if the two parachutes pack ok. I think nylon chutes may make it easier. I have started 3D printing the parts in PLA, but a friend is going to print some on a resin printer which my save time on paint prep.

Alien Pod: The alien pod is composed of a bottom, top and the alien head.

The bottom piece slides over the body tube for launch and has three tabs to attach the hinges from the landing legs.

A string of Kevlar is attached to the bottom and then threaded through the bottom, along a channel in the pedestal in the alien head and then used to attach the parachute.

The pedestal of the alien head is glued into a ring on the bottom piece and then the bottom piece is glued on the top. It is suggested to glue this with a body tube inserted to make sure all the parts are registered properly.

 

[GlenP]

This guy approves!

 

[ljwilley]

Awesome!

 

[BABAR]

Looks good!

I modded mine to have two shock cord attachments, one each shoulder. I felt like I’d rather have it like a parachute harness than a hangman’s noose.

So what is the alien’s skin color gonna be?

 

[Ray Lecture]

I am going with a Neon Yellow for the Alien so he really pops

I should be getting some parts in the mail today so I can start the sustainer.

 

[BABAR]

Great minds think alike.

I think I did the eyes and mouth with Mylar tape.

 

[Ray Lecture]

Landing Legs:

The Estes landing legs were made of wooden dowels. Plastic pieces were used to hold them together and hinge them to the pod. For the 2.6 in upscale, I used carbon fiber rods and 3D printed attachment pieces. This worked, but the carbon fiber rods are not cheap. For the BT-60 upscale the legs are 3D printed as one piece. To fit on the 3D printer, the leg has to be rotated 45 deg.

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The 3D printed legs do not have the strength that the carbon fiber tubes do, but this may be ok since a little flex may act as a shock absorber. If it turns out that they are not strong enough, it is easy to convert back to the carbon fiber approach.

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[BABAR]

Landing Legs:

The Estes landing legs were made of wooden dowels. Plastic pieces were used to hold them together and hinge them to the pod. For the 2.6 in upscale, I used carbon fiber rods and 3D printed attachment pieces. This worked, but the carbon fiber rods are not cheap. For the BT-60 upscale the legs are 3D printed as one piece. To fit on the 3D printer, the leg has to be rotated 45 deg.

View attachment 631819
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The 3D printed legs do not have the strength that the carbon fiber tubes do, but this may be ok since a little flex may act as a shock absorber. If it turns out that they are not strong enough, it is easy to convert back to the carbon fiber approach.

View attachment 631820​

FWIW, my recurrent breakage point was the CAPSULE where the legs attached. Been a while, not sure if the failure was at the impact point of the leg “stops”, or tension where the HINGE base was pulled OUT. I was a bit surprised, I thought either the legs or the hinge mechanism itself would break. In any case, resulted in a bout a 2 cm oval of plastic broken out of the roughly egg shaped capsule.

The long length of tail end body tube may be a great place to put a baffle. Packing space in the upper tube as mentioned is at a premium, so might reduce the amount of wadding require.

I suspect you are gonna paint the legs before gluing into the plastic doodads?

No matter how you color it, it’s a cool rocket. Mine came from eBay with no decals (interesting, the box was “sealed” but the flaps were loose, only thing missing was the decals. Without them, I felt free to imagine. I went with a different color scheme. One thing, since paint is not my best friend, I used Mylar tape to color the leg sticks. Especially given their orientation, you can palace the seams medially, so they are just about invisible. Nice easy way to get a chrome silver look at a small diameter part.

 

[Ray Lecture]

I like the green on that one. I will probably get some vinyl decals from Mark at stickershock. The solar panels on my big one catch the sun and can really see it when its up there.

 

[BABAR]

Landing Legs:

The Estes landing legs were made of wooden dowels. Plastic pieces were used to hold them together and hinge them to the pod. For the 2.6 in upscale, I used carbon fiber rods and 3D printed attachment pieces. This worked, but the carbon fiber rods are not cheap. For the BT-60 upscale the legs are 3D printed as one piece. To fit on the 3D printer, the leg has to be rotated 45 deg.

​

The 3D printed legs do not have the strength that the carbon fiber tubes do, but this may be ok since a little flex may act as a shock absorber. If it turns out that they are not strong enough, it is easy to convert back to the carbon fiber approach.

​

More to point, whether you print as one piece plastic (with doodads built in), or you go with carbon fiber or wood, with either of the latter approaches, the wood or fiber is still going to be attached to the plastic doodads.

Are the plastic doodads still gonna be a failure point? Or are they short enough or thick enough build to stand up to the stress?

Regarding price of carbon fiber, wood is cheaper, and I doubt wooden dowels would be a failure point.

 

[Ray Lecture]

I agree that the weak point in the legs with the carbon fiber rods is the plastic attachment pieces. Both the feet and the hinge have been beefed up due to breaks during landing. I think you are also correct that the wood dowels probably are plenty strong. I am going to try the 100% printed leg first and if it fails the go to the wood dowels/ plastic attachements

 

[K'Tesh]

To hurt to type. This is a link to a build thread I did over on yorf https://www.rocketryforum.com/threa...uild-kits-once-in-a-while.121864/post-1408623

Okay, I'm using voice-to-text here, so please forgive any spelling errors and weirdness.

What I did to solve the problem of the hinges popping off of the pod was to glue them to the pod and then on the inside of the pod, I glued small sections of popsicle sticks.Then I drilled holes through the hinge mounts into the popsicle sticks and then screwed them together with small screws that came out of old broken electronic toys.

 

[Ray Lecture]

Fin Can
The fin can utilizes a 29mm motor mount inside a BT-60 tube using a pair of centering rings. An Estes motor retainer is used to secure the engine. I am not a fan of the strakes in the retainer, so these were ground off for a smoother look. The through the wall fins are cut from 1/8” plywood and 3D printed fin alignment guide will ensure they are all strait. This will be all glued up in epoxied over the next several days.

 

[K'Tesh]

One thing I do on my Venus probes is I cut the alien off at the joint where it meets the back of the shoulder of the piece that he's mounted to.

I'll scar up the edge of the joint where the remaining piece then meets with the top of the pod (or the bottom of the pod, depending on its orientation). I drill holes in that piece as well at the joint, then tack it in place with super glue and use epoxy to create epoxy rivets to hold it in place.

After I tie in the line that attaches to the parachute, I'll then glue in the alien to the pod assembly at a lower height. This way it does not protrude quite so high above the pod, and thus giving me more room for my parachutes.

I realized this is probably overkill because I secure my shock cord to the pod exterior directly, but better safe than sorry.

 

[K'Tesh]

In thinking about it again. I realize that I really don't need to glue the alien in place, I could just simply slide it in with the shock cord passed through its head. Perhaps using a lightweight compression spring to force him out upon deployment from inside the cavity inside the pod.

This would provide even more space for the parachutes inside the sustainer.

 

[Ray Lecture]

Fin Can Assembly
The motor retainer was attached to the 29mm tube with JB weld and then a centering ring was glued to the tube just above the retainer. This was then glued into the BT-60 tube but only dry fitting the leading centering ring. The square fins were epoxied in first using 3D printed fin guides


Then the solar array fins were epoxied in place. After the expoxy was cured filets were added.





Alien
The alien was painted neon yellow and dry fitted into the pod

 

[Ray Lecture]

The sustainer is made up of a section of BT-60 tube with a 3D printed ring to hold the legs in during flight. This is attached to the fin can with a section of 24mm tube with center rings on each end. A piece of Kevlar is attached to the upper centering ring


Dry fit of sustainer

 

[Ray Lecture]

Leg Painting
Printing the legs as one piece made things easier to assemble but made it a pain to paint. In hind sight, I may have been better off printing the individual part and painting the silver and black separately. I ended up laying down a couple coats of metallic silver paint then taping off the rods and painting the rest black. I did spray some silver on the tape seams to seal them before I painted the black.

 

[Blast it Tom!]

Nice job! Alien Elvis approves!

 

[BABAR]

Thank you verrry muuuuch!

 

[Ray Lecture]

There is still some painting to do, but I had to attach the legs to the pod just to see how it will look. I 3D printed a pin to attach the leg to the pod. When I am totally done with painting, there is a button that is glued to the other side to hold it in place.

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[Ray Lecture]

Paint: Have been doing a lot of sanding and painting and it's now it's coming together. Right now, I have finished the white and black sections. I still have some silver to add to the body tube. Once Mark from Stickershock is back, I'll order some vinyl stickers and then paint the silver. Till then, I'll attached the bungie cords and get the tension set and probably fly it at the next club launch I can get to.

 

[Blast it Tom!]

Paint: Have been doing a lot of sanding and painting and it's now it's coming together. Right now, I have finished the white and black sections. I still have some silver to add to the body tube. Once Mark from Stickershock is back, I'll order some vinyl stickers and then paint the silver. Till then, I'll attached the bungie cords and get the tension set and probably fly it at the next club launch I can get to.

View attachment 636665

That's a beauty, hope she survives to get fully decorated!