L3 Project Build Thread - Performance Rocketry Competitor 4

How & why did you choose those push buttons?

From my experience -- I'd never trust one wire tie to hold a 9V battery....seen many break under thrust.
Or, in your case, the battery will slip out the bottom.

chuck5395 said:

Nice. Looking good there Wilson.

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Thank you Chuck!

FredA said:

How & why did you choose those push buttons?

From my experience -- I'd never trust one wire tie to hold a 9V battery....seen many break under thrust.
Or, in your case, the battery will slip out the bottom.

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I used push-buttons for a number of reasons:
Easy to implement.
Can mount inside the bay instead of to the switch band - easier to wire.
Convenient.

What type of switches do you use?
Will probably add an extra cable tie or two to the batteries, just for safety sake...

AlnessW said:

I used push-buttons for a number of reasons:
Easy to implement.
Can mount inside the bay instead of to the switch band - easier to wire.
Convenient.

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+1 to this. I use locking pushbuttons all the time. Never, ever had trouble with them.

dixontj93060 said:

+1 to this. I use locking pushbuttons all the time. Never, ever had trouble with them.

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Cool! Good to stick with those "tried and true" methods.

AlnessW said:

Cool! Good to stick with those "tried and true" methods.

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Go with what works for you, others can fly what works for them.
Ain't it grand?

chuck5395 said:

Go with what works for you, others can fly what works for them.
Ain't it grand?

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So very grand!

llickteig1 said:

Fred, You do what you think you need to do, but I guarantee you you are in the deeply out-numbered minority. It is easy to draw the proper line but much more difficult to get 3 buttons installed at exactly the correct angle. Most people are going to have to hand-drill the holes, introducing lack of precision. I'm not a fine craftsman, why would I introduce that frustration when it is completely unnecessary?

I have seen flyers remove that third button at the field, but never install a third one.

--Lance.

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Lance, on four inch and up rockets I have gone to three rail buttons. I put two within a foot or so of the bottom of the rocket, and another a foot or so above that. It works well.

It is a little more time consuming to get aligned, but not difficult. I use a piece of angled aluminum to draw a straight line. Locate the holes. Then I use pem nuts on the inside of the airframe to screw the buttons to I do also check this out with my rail as I am doing it. Obviously the pem nuts will not work on a minimum diameter rocket, but I find them very useful.


Mark Koelsch
Sent from my iPhone using Rocketry Forum

markkoelsch said:

Lance, on four inch and up rockets I have gone to three rail buttons. I put two within a foot or so of the bottom of the rocket, and another a foot or so above that. It works well.

It is a little more time consuming to get aligned, but not difficult. I use a piece of angled aluminum to draw a straight line. Locate the holes. Then I use pem nuts on the inside of the airframe to screw the buttons to I do also check this out with my rail as I am doing it. Obviously the pem nuts will not work on a minimum diameter rocket, but I find them very useful.


Mark Koelsch
Sent from my iPhone using Rocketry Forum

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And back on this topic again...

I use an angled piece of aluminum as well for all my rockets. For this particular project, I attached the buttons with t-nuts, as per my photos. Then I test-fitted it onto my launch rail...no problem at all.

Just a little point of interest....
I mentor a SLI team for NASA.
They have a rather unique rocket configuration that requires their rail buttons to be on 2" standoff's holding them away from the body.
For this reason - they are LONG and because of the length they moved to 14-20's to use 15-15 rail buttons -- they wanted to use only two.

NASA DINGED THEM POINTS FOR ONLY TWO RAIL BUTTONS.

FredA said:

Just a little point of interest....
I mentor a SLI team for NASA.
They have a rather unique rocket configuration that requires their rail buttons to be on 2" standoff's holding them away from the body.
For this reason - they are LONG and because of the length they moved to 14-20's to use 15-15 rail buttons -- they wanted to use only two.

NASA DINGED THEM POINTS FOR ONLY TWO RAIL BUTTONS.

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Well there we have it then!

Time to start coming up with a good color combination. A few ideas...

Red/gold
Blue/silver
Green/silver
Blue/gold

Other suggestions?

Evidently, the $8 air sprayer I found at local thrift shop did not work very well. Of course rattle cans would do the job just fine, however, a friend of my dad's works at a car dealership that has an auto-body shop. I am going to see they'd be willing to paint it for me, and if so get a price quote for 2 colors. That would be cool...

AlnessW said:

Well there we have it then!

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OK, I'm officially sorry I ever brought the question up.

emckee said:

OK, I'm officially sorry I ever brought the question up.

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Were you the first??? Haha

AlnessW said:

Were you the first??? Haha

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Well at least we know he won't be the last.

chuck5395 said:

Well at least we know he won't be the last.

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So he is!

Rocketman 10' main chute has been ordered! Ky says it's all boxed up and ready to go in the mail first thing Monday morning.

AlnessW said:

Rocketman 10' main chute has been ordered! Ky says it's all boxed up and ready to go in the mail first thing Monday morning.

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Rocketman is still alive and selling? :y:

mrwalsh85 said:

Rocketman is still alive and selling? :y:

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You bet!
www.the-rocketman.com

AlnessW said:

Rocketman 10' main chute has been ordered! Ky says it's all boxed up and ready to go in the mail first thing Monday morning.

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I love KY's chutes. You can easily spot a Rocketman chute as they "pulse" during descent.
My only complaint is that the newer ones have gotten pretty heavy using larger shroud lines and hardware.
I have a friend that looks Ebay for Ky's older Classic style because they are much lighter and easier to pack.

On the subject of switches I was told by the older and wiser types that mentored me when I got into HPR that push button switches and phone plugs could be problematic so I never tried them. I started out using the switches that Aerocon and Missileworks sell, now I use Featherweight screw switches. I mount them on the board and access them through the vent holes. Not saying your way is wrong just putting another option out there. Ultimately it really is what you are comfortable with. :handshake:

I agree with the others that more zip ties on the batteries are a good idea. I use the plastic battery holders plus at least two zip ties. :sigh:

Good luck on your flight.

Sailorbill said:

I love KY's chutes. You can easily spot a Rocketman chute as they "pulse" during descent.
My only complaint is that the newer ones have gotten pretty heavy using larger shroud lines and hardware.
I have a friend that looks Ebay for Ky's older Classic style because they are much lighter and easier to pack.

On the subject of switches I was told by the older and wiser types that mentored me when I got into HPR that push button switches and phone plugs could be problematic so I never tried them. I started out using the switches that Aerocon and Missileworks sell, now I use Featherweight screw switches. I mount them on the board and access them through the vent holes. Not saying your way is wrong just putting another option out there. Ultimately it really is what you are comfortable with. :handshake:

I agree with the others that more zip ties on the batteries are a good idea. I use the plastic battery holders plus at least two zip ties. :sigh:

Good luck on your flight.

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Yep, I've heard lots of great things about Rocketman chutes. Simple design, and reliable.

Will add a few extra cable ties to make sure the batteries won't pop loose, for sure. Thanks for the kind words and the input on switches, as well!

Mail ordering the last few things I need for this bird:



75mm Aeropack motor retainer. (The 54mm one is for another project.)


And a Rocketman 10' main! This ought to be plenty big enough to slow her down...

Many thanks to Aeropack and Rocketman for the fast service!

Main harness is now assembled with hardware and the 10' chute. Just ordered motors last week, as well...

Flight dates have been set!

May 17 at the OROC Spring Thunder launch - L850W (shakedown flight)
June 28 at the OROC NXRS launch - M1297W (cert flight)

Been doing lots of "shopping" around recently for paint options. I was really hoping to do a nicer finish on this rocket than standard rattle cans.

A few members pointed me towards a local guy who has been "contracted" for rocket painting many times before. However, he is currently "out of business" as his paint shop is not set up right now. Plus, he said that even if he could do it, he'd have to charge upwards of $500 for time, materials, and labor...way out of my price range.

Got in touch with a few local auto-body shops - they also wanted $200 or more...still beyond my budget.

There is an Industrial Finishes shop not far from where I live, so I stopped by there today for a price quote. The guy there who I talked to was VERY helpful! They will be able to mix colors for me right there in their shop, but he didn't suggest automotive paint - rather a catalyzed urethane-based paint with the gloss clear coat pre-mixed in. For less than $100 worth of paint, materials, and supplies, they will be able to provide my 2 colors in spray cans which will be a lot easier and cleaner than using a spray gun.

Wuh-wuh-wuh-winner!

That said, I started prepping the airframe today - removed the rail buttons, the altimeter sled, the aluminum tip of the Von Karmon nosecone, etc and then started sanding the entire surface with 80-grit sandpaper on a sanding block.

Nice research and awesome conclusion.

We have an Industrial Finishes here in Salem and I used to go there when I was painting the kids soap box derby cars. They were always helpful and never lead me astray.

chuck5395 said:

Nice research and awesome conclusion.

We have an Industrial Finishes here in Salem and I used to go there when I was painting the kids soap box derby cars. They were always helpful and never lead me astray.

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Thanks! I'm really looking forward to painting this thing - just need the sun to come back out now...
My experience at Industrial Finishes was exactly the same - very helpful and informative.

AlnessW said:

...catalyzed urethane-based paint...

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Be sure to do your homework before you start working with this stuff. Read the MSDS and take appropriate precautions. I have no experience with polyurethane based paints, but it is my understanding that at least some of them are not exactly healthy.

Reinhard

^+100

I hope the $100 of included materials and supplies includes a full-face respirator with new carbon and P100 particulate filter. If not, add that to your list.

Also do not spray where kids or neighbors can breathe the overspray. Premixed catalyzed urethanes usually employ a curative that is moisture activated. Which means do not let it get into your's and anyones moist respiratory system or eyes. It will never leave.

Good luck and be safe.

Reinhard said:

Be sure to do your homework before you start working with this stuff. Read the MSDS and take appropriate precautions. I have no experience with polyurethane based paints, but it is my understanding that at least some of them are not exactly healthy.

Reinhard

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I have a respirator if need be...plus I'll be working out-of-doors.
But then again, eating hamburgers is also "not exactly healthy."

jderimig said:

^+100

I hope the $100 of included materials and supplies includes a full-face respirator with new carbon and P100 particulate filter. If not, add that to your list.

Also do not spray where kids or neighbors can breathe the overspray. Premixed catalyzed urethanes usually employ a curative that is moisture activated. Which means do not let it get into your's and anyones moist respiratory system or eyes. It will never leave.

Good luck and be safe.

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Will have to check the MSDS to be sure - I don't even have the paint yet, though I believe the brand is called Limco Supreme Plus. I have a respirator.

Here is a link to the MSDS sheets on the product.
https://www.basfrefinish.com/cgi-bi..._code=&country=All&language=All&pageName=home

The most hazardous component is the hardener (isocyanates, health rating 3). The color and clears are 2. But I do not understand how/if they can mix the hardener in the rattle can. I don't think they can without the paint curing up in the can. Talk to your supplier and ask if there mix includes the hardener. It may not.

Still you will want to use the charcoal respirator cartridges anyways.