What did you do rocket wise today?

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bobby_hamill

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Been tinkering with solidworks 2011 to see how I can simulate the ring joint that holds the fin assembly onto the back of the motor that is used on the 4 fin Black Brant 2
Hoping to make the ring out of metal so I can attach functional launch lugs to the ring :)

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tOD

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Finished the last few Eggtimer kits. Took about two weeks to do the 35 kits. View attachment 394803View attachment 394804
I like the idea of slipping the shrink wrap over the battery leads. I'll have to use that, thanks. Any other tips n' tricks you'd like to pass along? I've got a way to go with the Quantum (mounting the optoisolators now) then a Quark to build after that. Just got my eyeglass prescription updated, so that's a big plus.
 

Eric

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Just go one step at a time. Also note, the Quark SMD pieces are a lot smaller then the Quantum's. Some fine tip tweezers and a hot iron (650-700).
0919191814.jpg
 

tOD

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Just go one step at a time. Also note, the Quark SMD pieces are a lot smaller then the Quantum's. Some fine tip tweezers and a hot iron (650-700).View attachment 394824
I did get one Quark built previously. Had an embarrassing glitch with it on first use but has flown successfully twice since then. I'm using a Hakko 650 iron with the fine tip which seems to work well.
 

jqavins

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Some fine tip tweezers and a hot iron (650-700).
I just ordered some tips for my old Weller TC201. One of them is an 800 degree very small, so a rapid transfer of heat but not a great deal of total heat. Is that a good choice? I have no experience soldering SMT components, but a lot with other stuff, and I've always liked this tip for small sensitive items.
 

Eric

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I just ordered some tips for my old Weller TC201. One of them is an 800 degree very small, so a rapid transfer of heat but not a great deal of total heat. Is that a good choice? I have no experience soldering SMT components, but a lot with other stuff, and I've always liked this tip for small sensitive items.
Yes. I notice when I put on a very fine conical tip, I do require more heat. I find this to be more true with my older Weller 51 at home. The Weller wx1 that I use at work is digitally controlled and holds temperature much better.

But higher heat for less time works good. A second of heat and the solder flows in nice and smooth.
 

jqavins

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Prompted by this thread (posts #14 and 15) I had a flash of an idea. Below is a conceptual, not to scale sketch of rail button as seen from an end.
upload_2019-10-3_12-55-46.png

The idea is, it's a launch lug and rail button in one; a rod can go through the hole.
 

kuririn

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Prompted by this thread (posts #14 and 15) I had a flash of an idea. Below is a conceptual, not to scale sketch of rail button as seen from an end.
View attachment 394839
The idea is, it's a launch lug and rail button in one; a rod can go through the hole.
Many years ago, Estes sold a "C" rail. A standard lug glued to a dowel stand-off would slide inside the rail, so you could use both the rail or a rod with that set up. I'll try and find some pics.
 

OverTheTop

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Some fine tip tweezers and a hot iron (650-700).
Tweezer technique is the primary skill IMHO.

650-700degF (343-371degC) for soldering small parts? What is the rationale behind that? Normal lead solder melts at 183C. You need about 30C more to form the intermetallic bonds. You should not need more than 270C (530F) on a bad day to solder a PCB. The glass transition temperature of the FR4 is around 140C. Higher temperatures just melt the substrate and also weaken the adhesive that holds the tracks and pads onto the laminate. Bad idea to give that a hard time with high temperatures. Higher temperatures also give thicker intermetallic bonds which are more brittle. A good iron and/or as large a tip (chisel, not conical) as you can get away with assists with heat transfer, rather than higher temperature. Iron technique is also important. A fast joint (by using high temperature) is not a good joint.
 
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Greg Furtman

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Tweezer technique is the primary skill IMHO.

650-700degF (343-371degC) for soldering small parts? What is the rationale behind that. Normal lead solder melts at 183C. You need about 30C more to form the intermetallic bonds. You should not need more than 270C (530F) on a bad day to solder a PCB. The glass transition temperature of the FR4 is around 140C. Higher temperatures just melt the substrate and also weaken the adhesive that holds the tracks and pads onto the laminate. Bad idea to give that a hard time with high temperatures. Higher temperatures also give thicker intermetallic bonds which are more brittle. A good iron and/or as large a tip (chisel, not conical) as you can get away with assists with heat transfer, rather than higher temperature. Iron technique is also important. A fast joint (by using high temperature) is not a good joint.
I bought this set of tweezers and they are great!
https://www.amazon.com/dp/B073SJD7L...olid=28MCO3MULBK62&psc=1&ref_=lv_ov_lig_dp_it
 

tOD

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More progress on the Quantum. Next step is attaching leads to the WiFi module.
I find a toothpick to be a good tool for holding parts in place while soldering. I've got a pair of Dumont 3C tweezers left over from my watch repair days.
 

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Bruiser

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I started making the plywood fins, centering rings and baffle plates for my Ventris kit.

-Bob
 

Doug Holverson

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The printer didn't come with any resin. :( Anybody know of a place in Omaha to get 3D printer resin?
 

prfesser

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Primed my Cherokee-E. Contacted the students who want to do a senior rocketry project; meeting on Tuesday.
 

Charles_McG

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Assembled the fincan for my replacement Tomahawk-12. Tube in fincan, motor mount in tube (with Kevlar Y-anchor and wiring chases), carbon fiber stiffeners in fins all the way to anchor channels on the motor mount.

IMG_1297.jpg
 

Edward Beauchemin

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Saw a thread on YORF where they discussed rockets by Pitsco and Estes where you have to build your own body tube and remembered I had this in the build pile:
View attachment 393500
So of course I had to build it.

Cardboard mandrel for shaping body tube:
View attachment 393501

Motor mount
View attachment 393502

Recovery gear rigged to Jadebox's method I learned today:
View attachment 393503

Cardboard fins cut out and aligned and tacked on:
View attachment 393504

Fins and launch lug filleted, motor mount glued in:
View attachment 393505
The tube was constructed by taking a piece of regular copy paper and convolutely gluing it to itself on the mandrel, then taking one strip of the orange wrap, wetting the adhesive backing with a damp sponge, and doing a right hand spiral, butting the seams together. Follow with a second piece doing a left hand spiral.
My kind of rocket. No filling, sanding, primer or paint.
An interesting build exercise, but I see why this was probably not a big seller.
More of a niche product for the educational sector.
Easier to just sub a bt-50 tube.:D
I can cut quite a few bt-50 couplers from the mandrel though. I think it's long coupler tubing.
Anyway the discussion thread is here:
https://www.forums.rocketshoppe.com/showthread.php?t=18068&page=1&pp=10
hcmbanjo's build thread is here:
http://modelrocketbuilding.blogspot.com/search/label/Tech-Pak
AC Supply still sells this:
https://www.acsupplyco.com/estes/estesmain.htm
Laters.
Hey everyone, So after being away from rockets for like 45 years I stumbled back into it after helping my 9 year old with his Cub Scout project.
So after going out and buying a new Estes starter kit I found out how expensive this has gotten. So being the really "frugal" guy I am, I went online to find some DIY alternatives.
I found some YouTube videos on rolling your own body tubes from copy paper and fins from card stock.
We built one and it flew great, and I didn't get all itchy about my 9 year old coloring an expensive model with magic markers. But now I'm hooked again on model rockets.
So I searched some more for other plans to build and found Art Applewhite and Chris Michielssen paper models and eventually JimZ and the OldModelRockets and this forum.
I started figuring out how to build the old models I remembered when I was a kid without spending a bunch of money.
I made the body tubes from scrap paper and the fins from layers of cereal box cardboard glued together and the nose cones from paper from some of the ideas I found on other sites.
So 1st I built a Mosquito,
20191005_123953.jpg
Then some Centuri Akela 1s to launch with the Scouts,
20191005_123129.jpg
Then I gave myself a mission to try to build every single Centuri model. Why the Centuri's? I guess because they don't exist anymore.
So first the Lil Herc
20190919_222002001.jpg
Then I stumbled across kuririn's post about the Estes DIY pack so had to reply with what I was working on today.
The Centuri Twister and the Sea Killer #5331
20191005_105910.jpg
Now remember this long post is your own fault for letting me do it. :)
Have fun guys
 

John Taylor

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Excellent build technique. This thing is practically fool proof. You could fly it on just about any motor that would fit, if you can get it back that is.
Assembled the fincan for my replacement Tomahawk-12. Tube in fincan, motor mount in tube (with Kevlar Y-anchor and wiring chases), carbon fiber stiffeners in fins all the way to anchor channels on the motor mount.

View attachment 395036
 

Charles_McG

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Excellent build technique. This thing is practically fool proof. You could fly it on just about any motor that would fit, if you can get it back that is.
Thanks. Getting it back is the key phrase. I lost the first one on an H54 upper staged flight where the tracker failed and I flew anyway.

The mount looks like this:

IMG_1269.jpg


And Ulexis - great looking Goblin.
 

Doug Holverson

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I'm getting a bunch of stl files ready to print while ordering and waiting for my resin. I'm getting some white because Centuri, some red because Centuri, some blue because Centuri, and some orange... because... Allis Chalmers!
 
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