Joe Turners L2 Build Thread

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joeman
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Re: Joe Turners L2 Build Thread

Postby joeman » Mon Nov 13, 2017 10:37 pm

Interesting story on the Soyuz 11! Poor chaps!

RE: Power/switches
I thought exactly same thing, what happens if it goes off. The SuperCap does help. I share your "paranoia" thoughts SMM.
I'm guessing the motion could be quite chaotic and you have something yank off in one direction and before you know it, there is a substantial force in some direction you wouldn't normally expect. If that stands to reason, perhaps almost any orientation of the switch could theoretically have an issue.

RE: Protection against abrasion.
Anyhow, I've moved on from that for now. I've used heat shrink on some of the threads like OTT suggested. Didn't bother applying heat to shrink it, I might want to take it off. It has a second benefit, reducing chance of shorting. While that should never happen...it is comforting.

RE: Remove-Before-Flight Pin
I found a piece of rod on the road and cut it to size, sanded down, got it nice and shiny and made a hemispherical end. Then proceeded to drill a hole through end to insert key-ring. Boy was that steel hard to drill. Finally did it. Re-use/recycle.

Then I drilled a hole in the wood block (where the pin is inserted), for semi-tight fit with 4mm. Then I got next size drill-bit and drilled about 80% of the way through the same hole. So this means the pin doesn't just fall out...it is a conscious effort to remove it. But it isn't too hard to insert.

I assume a steel pin is considered okay? [It won't be flying obviously!]

RE: Disconnecting Bulkhead
I decided to put in a connector. I settled on a Dean-Plug. What I will do is get a small Cable tie and use it to ensure it doesn't come apart.

RE: Battery
I was going to use a LiPo Battery, but saw talk of using extra batteries, so as to ensure that the Raven 3 did not get too much current. This seems like a lot of mucking around in the end, more points of failure, also when I go to ship the rocket down to the Goldcoast to fly, I have to work out how to get the LiPO down there (I know there are a few shipping restrictions). Seemed more hassle then it is worth. So, decided to go for a 9 volt battery. Will get an Energizer 9 volt one for the flight....available everywhere.
I used Bob Smith Epoxy to glue a block above the 9 volt battery as a stop. It mustn't move.


RE: Wiring
Finally figured out where I wanted things. Trying to make sure things seem to be in the logical place; have all the wires/connections focused around one area. I'm not too mad on screwing of wires in to the switch...though it should be okay. I might consider using Eye-Terminals.
I'll see. Admittedly, I'm not terribly happy about the wires from the battery either (particularly the red wire). Something to think about.

Anyhow, here are some pics.

IMG_3968_DEAN_Plug_SML.jpg
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IMG_3967_Battery_Side_SML.jpg
IMG_3967_Battery_Side_SML.jpg (124.64 KiB) Viewed 56 times


IMG_3966_Altimiter_Side_SML.jpg
IMG_3966_Altimiter_Side_SML.jpg (140.49 KiB) Viewed 56 times
L1 - Callisto (H133) - 11-Jan-2016

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SpaceManMat
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Re: Joe Turners L2 Build Thread

Postby SpaceManMat » Tue Nov 14, 2017 9:24 am

Looks pretty good I think Joe.

With that red battery wire perhaps consider just using some CA glue on the wood block to keep it in place.

One of the other things to consider is lining up the hole in the frame to the hole for the pin. I usually use a brass tube that you can get from hobby stores for this. To give you an idea this is one of the switches I made, the tube is about 2mm from the ID of the nose cone. You can clearly see it is aligned correctly from the outside. Not for space reasons the switch has to unfortunately be mounted vertically.
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Re: Joe Turners L2 Build Thread

Postby joeman » Wed Nov 15, 2017 10:06 pm

Hi SpaceManMat,
I can't visual that switch (lever?) mechanism? in that photo.

The pin/rod I found on the ground, was 4mm...and I knew I had 5/32" (== 3.96mm) holes in the airframe. So I made one of them 4mm. (not much difference). I've sanded down the pin/rod, till it was a close fit...glides past. When I push it through hole i don't get much deflection. I didn't have an brass tubing... so glued a block of wood to the Avionics tray, which brings it out within about 10mm of the inner diameter. Then I drilled a hole through the air-frame into the wood.... everything in position, tightened up, just as it will be at flight. I have markings so i know how to align things up when I assemble it. I did make the start of the wood hold a little bit bigger (4.5mm) for some of the distance, so it is a little forgiving if it is slightly off. I also sanded the pin to hemispherical shape to help it find its way. The pin does have a "little" bit of flex...enough to help. I'm sure it would a lot more fickle if it was stiffer.

Today I decided to make my own little Eye connectors using some thin copper plate. epoxying wire to help it strength wise. Also got some better quality 9 volt clips. I have many memories of these falling apart in my earlier years. Though I suspect I was probably not so gentle on things back then. I'll put a tiny drop of CA glue like you suggested

RE: Battery
To be honest I'm amazed that this nine volt battery with the associated wiring clip is adequate for the task... I know it should be, but it does make me wonder a little. Anyhow it is only two Ematches and only has to deliver a lot of current for a very small amount of time.

Off to talk to someone about paints on Friday.

Thanks for your feed back, photos and suggestions.

Cheers

Joe
L1 - Callisto (H133) - 11-Jan-2016

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SpaceManMat
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Re: Joe Turners L2 Build Thread

Postby SpaceManMat » Wed Nov 15, 2017 11:48 pm

Sounds like you have the switch and hole figured out, there are of course many ways to solve issues. It’s about finding what works for you.

In mine the top of the brass tube is ground away with a file so that the trigger sits down inside the tube. Inserting the pin forces the trigger up opening the switch.

I usually use Lipo batteries, with the 9 volt I would zip tie them end to end. Also most 9 volts are simply a collection of cells that are sandwiched together not soldered / welded. There are reports of 9 volts loosing power under launch conditions due to them being compressed. I cannot remember which type to buy, but it’s been discussed here before. If in doubt take them apart and see.
QRS: 124
AMRS: 32 L2 RSO
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Largest Motor: CTI 1115J530 IM
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Re: Joe Turners L2 Build Thread

Postby kopius » Thu Nov 16, 2017 7:02 am

Great work Joe, as for 9V batteries, (much like Glad Bake) use Duracell (accept no substitutes) as they used to have welded cells, however have now switched to plates which are set in epoxy and SOOO much better again.


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Re: Joe Turners L2 Build Thread

Postby joeman » Thu Nov 16, 2017 11:32 am

SMM:
Yes - many ways to skin a cat. Sounds like you had a lot more constraints to deal with.

ok. Going to pull apart two batteries (with the boys) and see how they compare.

Thanks for tips.

Cheers

Joe
L1 - Callisto (H133) - 11-Jan-2016

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Re: Joe Turners L2 Build Thread

Postby kopius » Thu Nov 16, 2017 3:33 pm

I should mention the MN1604 and MX1604 are the coppertop batteries if you are looking for a specific part number.

FYI, here are old (left) and new (right) Duracell internals.
Image


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Re: Joe Turners L2 Build Thread

Postby joeman » Sun Nov 19, 2017 12:13 pm

Cool. Thanks!

Batteries
Got the boys to pull apart batteries.

IMG_3988_good_pic_SML.jpg
IMG_3988_good_pic_SML.jpg (155.37 KiB) Viewed 4 times


I've obviously got old-construction of Duracell on left hand side. Must be a MN1604. I take it the MX1604 is the 'Ultra' version.

MN1604 - all cells are soldered (welded) on. Seems to be well constructed.


Paints
Finally purchased some paints. Decided to give Two-Pak paints a go. Never used Two-Pak paints, but always a first time..
I have a feeling Two-Paks paints are probably not as forgiving as acrylic paints, so I guess I'll just need to do a bit of practice painting.
What I did like about the Two-Paks was the ability to have greater control over the delivery of the paint. I'm guessing that if I do get a spray gun with a finer nozzle, I can potentially get a finer paint job, so reduce skin friction drag.

Most likely looking at:-
- Primer (2 or three coats)...sanding back between coats...trying to remove lines/transitions
- Paint the design (Still to figure out)
- Clear (not sure how many layers).

Anyhow, got some time to think about it and research it a little more.

Cheers guys!
L1 - Callisto (H133) - 11-Jan-2016


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