Announcing the Chip Can Challenge Contest

76 views
Skip to first unread message

Emma Humphries

unread,
Jan 10, 2025, 3:38:49 AM1/10/25
to LunarGeneral google
As announced at Sunday's Snow Ranch launch last Sunday, here's the rules for the Chip Can Challenge Contest LUNAR's holding this flying season:


The C3 challenge is an altitude contest for teams building a rocket out of a can of those hyperbolic paraboloid potato crisps. There are three motor classes for 24mm, 29mm, and whatever you can fit into a Pringle's can and fly safely!

If you want a starting point, I've published 3D printable files for a chip can rocket, and an Open Rocket file at Printables: https://www.printables.com/model/1142198-chip-can-challenge-builders-kit

If you have questions, reply here and start a thread. I'll bring my chip can rockets to next Wednesday's Build Night on the 15th.

Start building and be ready to fly at February's Snow Ranch launch! You have until the season ends at the Ranch to get your qualifying flights in.

Emma Humphries (they/she)
LUNAR Board of Directors (at large)
NAR 27698

Chris Dunn

unread,
Jan 10, 2025, 10:33:58 AM1/10/25
to lunar-...@googlegroups.com
Emma,

My kids are already coming up with some ideas for this. Couple of clarifying questions, are any size of cans viable (IE: snack size vs full height can)? Assuming the cans need to stay intact (IE: full length, so no shorting them)? Based on the example photos it looks like cutting off the metal rings at the top and bottom are OK?

-Chris

--
This list is moderated. Your first port will have to be approved prior to being posted. Feel free to chat about anything your fellow rocketeers would find interesting.
For that latest information be sure to subscribe to LUNAR Announce list at http://lunar.org/docs/lists/lists.shtml#announce
---
You received this message because you are subscribed to the Google Groups "LUNAR General" group.
To unsubscribe from this group and stop receiving emails from it, send an email to lunar-genera...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/lunar-general/CAGsAfh-G2cYpDAnmrNqmpNjEyRhUhVVQdYDxQuzcG2L0neuvyA%40mail.gmail.com.

do...@eljay.org

unread,
Jan 10, 2025, 11:26:23 AM1/10/25
to lunar-...@googlegroups.com
Oh, that’s fun.  Thanks for taking this on.

I assume any kind of reputable altimeter is OK for checking altitude?  (Estes/Jolly Logic/FlightSketch/???)

Doug


Emma Humphries

unread,
Jan 10, 2025, 8:21:46 PM1/10/25
to lunar-...@googlegroups.com
Hi Chris,

Yes, I've clarified in the rules that a snack or full height can is allowed, as is removing the top rolled paper ring and/or the bottom metal ring/end cap. And modifying the can with fin slots or holes for rail buttons is allowed.

Thanks for your question,

Emma H

To view this discussion visit https://groups.google.com/d/msgid/lunar-general/CAOpWzrfF_NuaiieUobhPVeoomNexZVbr%2BrDkJGVn88fBptaeeg%40mail.gmail.com.

Emma Humphries

unread,
Jan 10, 2025, 8:23:57 PM1/10/25
to lunar-...@googlegroups.com
The ARC approved altimeters are strongly recommended, as in the rules. Those are the Jolly Logic Altimeter One and Two, and the Perfect Flite Firefly and PNut.

Thanks,

Emma H

To view this discussion visit https://groups.google.com/d/msgid/lunar-general/76945D31-1C7C-4FC0-A12C-252799C7425D%40eljay.org.

William Kellermann

unread,
Jan 11, 2025, 12:13:51 AM1/11/25
to LUNAR, emce...@gmail.com
Why wouldn’t you allow any altimeters approved in APPENDIX E to the Contest Rules (attached?)  See https://s3.amazonaws.com/ClubExpressClubFiles/114127/documents/USMRSC_April-2024_1642889220.pdf


William Kellermann
wt...@me.com




USMRSC_April-2024.pdf

Rocket Supplies

unread,
Jan 11, 2025, 1:05:47 AM1/11/25
to lunar-...@googlegroups.com, emce...@gmail.com
Why not the easy mini, blue raven or Bluejay?

—

Fred 
Rocket.Supplies Team

408.707.0640  |  rocket.supplies

mot...@rocket.supplies




--
This list is moderated. Your first port will have to be approved prior to being posted. Feel free to chat about anything your fellow rocketeers would find interesting.
For that latest information be sure to subscribe to LUNAR Announce list at http://lunar.org/docs/lists/lists.shtml#announce
---
You received this message because you are subscribed to the Google Groups "LUNAR General" group.
To unsubscribe from this group and stop receiving emails from it, send an email to lunar-genera...@googlegroups.com.

David Smith-Uchida

unread,
Jan 11, 2025, 4:31:47 AM1/11/25
to lunar-...@googlegroups.com, LunarGeneral google
How about the “Party Snack” cans?

image0.jpeg

On Jan 10, 2025, at 00:38, Emma Humphries <emce...@gmail.com> wrote:


--

Rob Heil

unread,
Jan 11, 2025, 10:00:07 AM1/11/25
to lunar-...@googlegroups.com

What about…

 

 

From: lunar-...@googlegroups.com <lunar-...@googlegroups.com> On Behalf Of David Smith-Uchida
Sent: Saturday, January 11, 2025 1:32 AM
To: lunar-...@googlegroups.com
Cc: LunarGeneral google <lunar-...@googlegroups.com>
Subject: Re: [LUNAR General] Announcing the Chip Can Challenge Contest

 

How about the “Party Snack” cans?

 

image001.jpg
image002.jpg

Emma Humphries

unread,
Jan 11, 2025, 8:40:11 PM1/11/25
to lunar-...@googlegroups.com
On the altimeters question, I agree with Bill, that we should use the NAR Competition altimeter list (if you have trouble getting to that PDF it's linked from https://www.nar.org/content.aspx?page_id=22&club_id=114127&module_id=673903).

We should also add commercially available, off the shelf, dual deployment altimeters since people in the Unlimited class may need a dual deployment altimeter.

As for Peter's question about motors, I'd like to keep to a single motor design in each class, otherwise if we allowed clusters, then everyone would need to fly those to be competitive and that'd add a lot of complexity to what is supposed to be less complicated than (T)ARC.

Thanks,

Emma H

Gene Engelgau

unread,
Jan 11, 2025, 8:46:22 PM1/11/25
to LunarGeneral google
I agree, KISS is the way to go.

G

To view this discussion visit https://groups.google.com/d/msgid/lunar-general/CAGsAfh8eSH5%3DKk5Lk_VPf2S7MOaBPezTix0uVMTu1CMpAcutzw%40mail.gmail.com.

Jack

unread,
Jan 12, 2025, 2:13:42 AM1/12/25
to lunar-...@googlegroups.com, emce...@gmail.com

I would think that’s a reasonable thing to do.  Not sure how the ARC committee chooses which altimeters are certified each year, but it’s a subset of the contest-approved units.

 

- Jack

 

Jack Hagerty, ARA Press

http://www.arapress.com

"Were you born this stupid, or did you have to study?" – Robert Heinlein, Stranger in a Strange Land

Bill Orvis

unread,
Jan 12, 2025, 5:43:40 PM1/12/25
to lunar-...@googlegroups.com

What is it?


Bill

To view this discussion visit https://groups.google.com/d/msgid/lunar-general/064901db6439%247af7df60%2470e79e20%24%40pacbell.net.
-- 
----------------------
William Orvis
226 Joyce St.
Livermore, CA 94550
or...@compuserve.com
---------------------

srkendal

unread,
Jan 12, 2025, 5:56:57 PM1/12/25
to 'Bill Orvis' via LUNAR General
Haha, death in a can! 


On Jan 12, 2025 at 2:43 PM, 'Bill Orvis' via LUNAR General <lunar-...@googlegroups.com> wrote:

What is it?


Bill


On 1/11/25 6:59 AM, Rob Heil wrote:
--  
----------------------
William Orvis
226 Joyce St.
Livermore, CA 94550
or...@compuserve.com
---------------------

--
This list is moderated. Your first port will have to be approved prior to being posted. Feel free to chat about anything your fellow rocketeers would find interesting.
For that latest information be sure to subscribe to LUNAR Announce list at http://lunar.org/docs/lists/lists.shtml#announce
---
You received this message because you are subscribed to the Google Groups "LUNAR General" group.
To unsubscribe from this group and stop receiving emails from it, send an email to lunar-genera...@googlegroups.com.

Rob Heil

unread,
Jan 12, 2025, 6:01:32 PM1/12/25
to lunar-...@googlegroups.com

161cm long Pringles can.  As far as I can tell: not avail in the US.

 

Rob

image001.jpg
image002.jpg

Emma Humphries

unread,
Jan 12, 2025, 6:16:13 PM1/12/25
to LunarGeneral google
I've posted additional files to Printable.com:

- a fin slotting jig for making through the wall fins
- a shim for adapting a 3"/75mm Estes/Apogee nose cone.

I'll bring the chip can rockets and components I've made to Wednesday's build night so you can inspect and get ideas. 

Emma H

On Fri, Jan 10, 2025 at 12:38 AM Emma Humphries <emce...@gmail.com> wrote:

Emma Humphries

unread,
Jan 12, 2025, 6:16:37 PM1/12/25
to LunarGeneral google

Jack

unread,
Jan 14, 2025, 12:15:10 AM1/14/25
to lunar-...@googlegroups.com

I thought it was just a really good Photoshop…

 

- Jack

 

Jack Hagerty, ARA Press

http://www.arapress.com

"Were you born this stupid, or did you have to study?" – Robert Heinlein, Stranger in a Strange Land

 

image001.jpg
image002.jpg

William Kellermann

unread,
Jan 14, 2025, 10:38:55 AM1/14/25
to LUNAR
Released in Japan in 2020 as part of a promotion.  It was taller than the average person there.  If you can find one, it’s probably too valuable to modify for a rocket.

William Kellermann
wt...@me.com




On Jan 13, 2025, at 9:15 PM, Jack <jhag...@juno.com> wrote:

I thought it was just a really good Photoshop…
 
- Jack
 
Jack Hagerty, ARA Press 
"Were you born this stupid, or did you have to study?" – Robert Heinlein, Stranger in a Strange Land
 
From: lunar-...@googlegroups.com <lunar-...@googlegroups.com> On Behalf Of Rob Heil
Sent: Sunday, January 12, 2025 3:01 PM
To: lunar-...@googlegroups.com
Subject: RE: [LUNAR General] Announcing the Chip Can Challenge Contest
 
161cm long Pringles can.  As far as I can tell: not avail in the US.
 
Rob
 
From: 'Bill Orvis' via LUNAR General <lunar-...@googlegroups.com> 
Sent: Sunday, January 12, 2025 2:43 PM
To: lunar-...@googlegroups.com
Subject: Re: [LUNAR General] Announcing the Chip Can Challenge Contest
 
What is it?
 
Bill
 
On 1/11/25 6:59 AM, Rob Heil wrote:
What about…
 
<image001.jpg>
 
From: lunar-...@googlegroups.com <lunar-...@googlegroups.com> On Behalf Of David Smith-Uchida
Sent: Saturday, January 11, 2025 1:32 AM
To: lunar-...@googlegroups.com
Cc: LunarGeneral google <lunar-...@googlegroups.com>
Subject: Re: [LUNAR General] Announcing the Chip Can Challenge Contest
 
How about the “Party Snack” cans?
 
<image002.jpg>

Jamie Clay

unread,
Feb 4, 2025, 10:19:32 PM2/4/25
to lunar-...@googlegroups.com
I really dig this idea, so I'm developing some 3D printable parts for this challenge and plan to share the source files if anyone wants to tweak them to their needs. :) 
 
Here's a sample - 29mm Sprint themed airframe parts. 

All the 'kits' will have specially notched fin cans that allow easy swapping of the fins if a different design is wanted. 
 
I plan to have 24/29mm options, and a V2 and Little Joe I parts.

Stay tuned
 
--
Pringles_Rocket_Parts__v21_2025-Feb-04_04-23-17PM-000_CustomizedView12949188490.png

Emma Humphries

unread,
Feb 4, 2025, 11:40:22 PM2/4/25
to lunar-...@googlegroups.com
Jamie!

This is wonderful and exactly the sort of thing I was hoping for the contest to inspire. Thank you. I look forward to seeing your builds this weekend.

I've been wanting to print and make one of those Sprints you have on your Printable's page.

Emma H.

To view this discussion visit https://groups.google.com/d/msgid/lunar-general/776569334.3682279.1738725567941%40connect.xfinity.com.

Emma Humphries

unread,
Feb 4, 2025, 11:44:16 PM2/4/25
to lunar-...@googlegroups.com
That depends. Does it cost more than a L1000? 😁

To view this discussion visit https://groups.google.com/d/msgid/lunar-general/6B962A43-C9DA-4E12-A1B5-396391D5CF90%40me.com.

Kimball Tucker

unread,
Feb 5, 2025, 9:08:26 AM2/5/25
to lunar-...@googlegroups.com
Nice!

To view this discussion visit https://groups.google.com/d/msgid/lunar-general/776569334.3682279.1738725567941%40connect.xfinity.com.


--
Kimball Tucker

Huy Ton

unread,
Feb 5, 2025, 11:18:14 AM2/5/25
to lunar-...@googlegroups.com
The pdf refers to this link for altimeter but the link does not work

Approved Altimeter List
The Contest Board approves altimeters for use in NAR competition. Follow this link for a list of approved 
altimeters:
approved-for-contest-use/

To view this discussion visit https://groups.google.com/d/msgid/lunar-general/CAGsAfh8eSH5%3DKk5Lk_VPf2S7MOaBPezTix0uVMTu1CMpAcutzw%40mail.gmail.com.

William Kellermann

unread,
Feb 5, 2025, 11:44:21 AM2/5/25
to LUNAR
Attached is the list as of 2024

William Kellermann
wt...@me.com




Gregory Wong

unread,
Feb 9, 2025, 4:05:28 PM2/9/25
to lunar-general@googlegroups.com General
I’ve been having trouble locating 4F black powder for dual deployment. The rocketry retailers I’ve checked seem to be out of stock. Can someone recommend a source that has it in stock?

Thanks.

Greg

Aleksandar Milivojević

unread,
Feb 9, 2025, 4:33:29 PM2/9/25
to lunar-...@googlegroups.com
Rocketry stores are by far the most expensive option. Because they'd usually sell it in very small packaging. But our local vendor seems to have it in stock: https://rocket.supplies/proddetail.php?prod=RSECK5g

Good news is that there are many online stores that sell black powder in bulk; such as grafs.com (and many others). Which is by far the cheapest option -- $25 for a pound.

Bad news is that almost none of them will ship less than 4 pounds. Which you'd go quickly through if you were into antique muzzleloading firearms, but will last you a couple of lifetimes if you only need it for ejection charges.


--
This list is moderated. Your first port will have to be approved prior to being posted. Feel free to chat about anything your fellow rocketeers would find interesting.
For that latest information be sure to subscribe to LUNAR Announce list at http://lunar.org/docs/lists/lists.shtml#announce
---
You received this message because you are subscribed to the Google Groups "LUNAR General" group.
To unsubscribe from this group and stop receiving emails from it, send an email to lunar-genera...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/lunar-general/2F4890F1-B0E5-4F51-BE0D-94A188D23A7E%40soundingrocket.com.

Anthony Cooper

unread,
Feb 9, 2025, 5:11:02 PM2/9/25
to General LUNAR
If you have a small container, I have about a pound that I will never use. I can certainly donate some. My motors supply almost all the BP I ever need.

______________________________________
Anthony M. Cooper
31120 Chicoine Ave.
Hayward, CA 94544-7432
VP and Membership for lunar.org
Membership for mgscv.org
Cell: 510-589-5292

--
This list is moderated. Your first port will have to be approved prior to being posted. Feel free to chat about anything your fellow rocketeers would find interesting.
For that latest information be sure to subscribe to LUNAR Announce list at http://lunar.org/docs/lists/lists.shtml#announce
---
You received this message because you are subscribed to the Google Groups "LUNAR General" group.
To unsubscribe from this group and stop receiving emails from it, send an email to lunar-genera...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/lunar-general/2F4890F1-B0E5-4F51-BE0D-94A188D23A7E%40soundingrocket.com.

Jamie Clay

unread,
Feb 9, 2025, 6:22:25 PM2/9/25
to lunar-...@googlegroups.com
So here is 'the kit' - I've tested the print elements, even did a Rocksim file
 
It's a fun design - I may do another I've got an idea for...we'll see.
 
 
Feel free (anyone) to ask questions

srkendal

unread,
Feb 9, 2025, 6:23:40 PM2/9/25
to 'Jamie Clay' via LUNAR General
😏👍


Gene Engelgau

unread,
Feb 10, 2025, 10:43:29 AM2/10/25
to lunar-...@googlegroups.com
Hi Jamie, That is pretty cool!

-Gene

- Regards

Gene Engelgau
Web: http://fruitychutes.com - Professional Aerospace Recovery Systems
Twitter: @fruitychutes


To view this discussion visit https://groups.google.com/d/msgid/lunar-general/1679573807.3810868.1739143341723%40connect.xfinity.com.

Emma Humphries

unread,
Feb 10, 2025, 2:05:40 PM2/10/25
to lunar-...@googlegroups.com
This is awesome! Thank you for sharing the design. I'll fire up the Prusa tonight. 

To view this discussion visit https://groups.google.com/d/msgid/lunar-general/1679573807.3810868.1739143341723%40connect.xfinity.com.

Jamie Clay

unread,
Feb 10, 2025, 3:05:11 PM2/10/25
to lunar-...@googlegroups.com
Which Prusa?  The nose cone shell is too tall for my MK3 so I use the CR10.

I forgot to put holes in the nose cone for atmospheric avionics.  Because there are so many avionics options, I really didn't dive too deep into that.
 
 
 
 

Jamie Clay

unread,
Feb 10, 2025, 8:49:21 PM2/10/25
to lunar-...@googlegroups.com
So - I've  made a shorter nosecone shell that fits on the Prusa MK3 - I'm doing a test print now and will post a notice once I'm satisfied.

Emma Humphries

unread,
Feb 11, 2025, 1:23:27 AM2/11/25
to LunarGeneral google
Important: are Pringles crisps or not? UK chefs respond: https://www.youtube.com/shorts/vJkwX9NsnQM

Emma Humphries

unread,
Feb 11, 2025, 1:24:18 AM2/11/25
to lunar-...@googlegroups.com
Okay, thanks for the update. I'll make a print of the other parts.

To view this discussion visit https://groups.google.com/d/msgid/lunar-general/1376484296.3848107.1739238556974%40connect.xfinity.com.

Jamie Clay

unread,
Feb 11, 2025, 5:44:47 PM2/11/25
to lunar-...@googlegroups.com
So I've update the files and included the changes in a single .ZIP file on the website.
 
The new shorter nosecone looks just as cool - I also made an update that should make putting avionics in the nose cone easier,  changed the BT-20 support tube to BT-50 (I thought the AltimeterOne fit in a BT-20).
 
Everything should be pretty straight forward - feel free to ask any questions.
 
 

Jamie Clay

unread,
Feb 13, 2025, 5:20:08 PM2/13/25
to lunar-...@googlegroups.com
So naturally I had to add a camera mount.  In this case, the Astrocam and mounted it into the nosecone - the update is posted to the printables site.
 
Reply all
Reply to author
Forward
0 new messages