Vent holes for altimiters... yet again I know.. and some other stuff.

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Tom

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So I searched this topic and man my head is just reeling. So much conflicting info, complicated formulas, and so on.

I just got a Jolly Logic Alt 1 and hope to fly it next weekend in a loadstar 1. I hope to go out the SEARS launch event which will give me a chance to really let her stretch her legs. C60 - C65. Someday I am going to build one for build one for 24mm but I digress.

Anyhow it has a clear payload section. The payload section is a BT60 by about 4" long (if you subtract the adaptor and nose cone shoulders.

I plan on drilling 3 x 1/8" holes at 120 degrees. Or is that too big?

Also some tips on getting clean holes would be great! My initial plan is to put some masking tape mark the positions and drill through the tape. Maybe tape on the inside too?

Thanks !
 
Jolly Logic devices aren't fussy about hole sizes like that. So...perhaps bigger than needed, but it won't hurt anything.

Your plan for clean holes sounds really good. You can deburr them carefully with a #11 X-acto type blade also. No need to clean up the insides unless the look just bugs you. Some careful knife and/or sanding work on the outside will take care of that.

You might want to think about how you'll keep the A1 from bouncing around in that payload section. I favor the thin sheet foam that some electronics come in (I just stash it when I get a new gadget) used kind of like recovery wadding. Actually, recovery wadding will work as well.....
 
Yea I was actually just going to use some wadding. Loosely packed. I figure it will be okay as long as it isn't slamming around :D
 
Drill the hole using a brad point bit in a drill press using extremely light down pressure, you do not want to drill too far through and the bit start self feeding or the plastic will crack.
 
Many many years ago Ace R/C sold a set of regular twist drill bits that you set into nice dowel handles for turning the bit by hand. For plastic payload section tubes like that in the Loadstar, this is what I use to make my static holes (3/32 or maybe 1/8 inch for this model). I use sharpened brass tubes with a stage coupler behind the intended site of the hole for paper body tubes.
 
So I searched this topic and man my head is just reeling. So much conflicting info, complicated formulas, and so on.

I just got a Jolly Logic Alt 1 and hope to fly it next weekend in a loadstar 1. I hope to go out the SEARS launch event which will give me a chance to really let her stretch her legs. C60 - C65. Someday I am going to build one for build one for 24mm but I digress.

Anyhow it has a clear payload section. The payload section is a BT60 by about 4" long (if you subtract the adaptor and nose cone shoulders.

I plan on drilling 3 x 1/8" holes at 120 degrees. Or is that too big?

Also some tips on getting clean holes would be great! My initial plan is to put some masking tape mark the positions and drill through the tape. Maybe tape on the inside too?

Thanks !
If you’re concerned about cracking the clear plastic payload section you could swap in a length of regular body tube - I use a hole punch for vent ports on paper tubes.
 
Thanks all some good ideas. Here is what I ended up doing.

I wrapped the tube with blue painters tape so I could mark the hole positions. 3 holes at 120 degrees. I then took the point of a new #11 xacto blade and 'drilled' carefully through the tube. Then took a drill bit (7/64") in my fingers and cleaned up the rough holes. A little scratching with the fingernails to remove the flash and they came out quite well!

20190709_174227 by Tom Whit, on Flickr

I stuck an index card in there so you could see the hole better :D

Thanks again!
 
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