What did you do rocket wise today?

[teepot]

Today I started my next project and finished the whistle pod rocket [WPR]. The WPR is a 2.6" heavy tube from BMS. It has a 29mm mmt. The fins are 1/4"ply. The pods are 2.2" tubes. I put a funnel made of paper mache in the top of the pod and used a balsa CR soaked in CA to center the funnel. I put balsa pads on thee high points of the whistles and sanded them to fit. I then inserted the whistle with its CR into the bottom of the tube until the pointy end went into the whistle. I secured the whistle with a ring of balsa to keep the whistle from blowing out the bottom. I had thought I was going to finish up a couple more. But on close inspection I decided to put another coat on the fins. Last Sunday one of our newer members came over so I could help him with his second high power rocket. A LOC Payloader. He wants to start to do dual deploy. When he first came out to a launch he happened to park next to me. He was flying LPR. After he saw the first HPR launch he was hooked. Asked a bunch of questions that I was a happy to answer. Bought his first HPR rocket at Springfest. I advised him as he built it. He got his L1 on the second try. So with 2 HPR launches he wants to do dual deploy. He might be a L2 with the bare minimum of flights. Here are some pictures of The WPR build. This will be the 4th attempt at making a rocket whistle. The first three were failures. I have hope for this one. I blew in one of the pods and the whistle worked. The whistles are supposed to the worlds loudest. The put out 142 db according to the manufacturer.

 

[OverTheTop]

Retail therapy. Ordered a stepper motor driver board:
https://www.pololu.com/product/3141This is a very versatile drive that can be commanded to drive using many methods, and has some clever firmware for configuration of the operation. I will likely be using the PWM (RC) interface.

This will probably be used to drive my Automatic Antenna Tracker azimuth axis, driving a fairly serious stepper motor rated to 5.3A and 65V. These are NEMA 42 motors and have a 3/4" (keyed!) output shaft so is quite a powerful motor. Torque at rated power is around 10Nm. I obtained some of these motors when they were to be thrown out a few years ago. If this works well for one axis I will get another driver for the other axis.

 

[jqavins]

[A] fairly serious stepper motor rated to 5.3A and 65V. These are NEMA 42 motors and have a 3/4" (keyed!) output shaft so is quite a powerful motor. Torque at rated power is around 10Nm.

First reaction: "10Nm doesn't sound like much for such a hefty looking motor. 7.38 lbf∙ft or 88.5 lbf∙in. OK, not so tiny, but still..."

Second thought: "5.4 A times 65 V over 10 Nm over 2π times 60 comes to 329 RPM at full torque. Not so bad after all, but that's still not a lot of torque. Plenty for the application, but still seems low for the size of that motor. Doesn't seem like it would need a 3/4" shaft, since it barely exceeds the recommended torque for tightening a ¼-20 bolt. And this has nine time the area of a ¼" shaft, so nine time (about) the strength. Breaking torque is way higher than tightening torque for the bolt, but then breaking torque is way higher than rated torque for the shaft, so that's probably more or less a wash. So, maybe. It still doesn't seem like much, but maybe I'm all wet. And it could be geared down if higher torque is needed in some other application."

Doug,

As someone who is dealing with multiple losses, I'll let you know something I realized (for me at least) only recently. When I get one of those "I can't wait to tell/ask dad about this idea" which is my real reaction, but I realize its no longer possible, I used to be knocked off my feet.

I still have those thoughts and "I can't wait to tell/ask dad about this idea" but now instead of getting the wind knocked out of me, I think about how he would have listened to the idea...

And it never stops, but it does get easier and less frequent. I still have those "I've got to tell Mom" moments once in a great while, and she died in 1989. And those moments are bitter-sweet; I can smile at them more than be saddened.

 

[mjremijan]

Baby Bertha build. I did some sanding on the fins to round out the leading edges. This is my first time doing this and I of course messed up the first fin by sanding the side that attaches to the body tube.

 

[jqavins]

Yeah, that's especially easy to do with Bertha's fins.

 

[Back_at_it]

Did a quick refresh on a well used and forgotten Monarch that came from someone's forgotten collection.. The fins on this one were originally put on incorrectly so they needed to be cut off and put on correctly. Not sure what was originally used to build it but I was able to pull it apart at the coupler and pull the entire coupler out of the rocket.

Did the basic stuff. Added a motor block inside the motor tube. Added Kevlar leader and elastic shock cord. Painted with Duplicolor metallic black with Duplicolor Deep Green Metallic for the fins and nose cone. From there I cut some vinyl for the name and stripes. Not sure I'm entirely happy with the colors but it's a million times nicer than it was and will go on to fly another day.

 

[Sandy H.]

Retail therapy. Ordered a stepper motor driver board:
https://www.pololu.com/product/3141This is a very versatile drive that can be commanded to drive using many methods, and has some clever firmware for configuration of the operation. I will likely be using the PWM (RC) interface.

This will probably be used to drive my Automatic Antenna Tracker azimuth axis, driving a fairly serious stepper motor rated to 5.3A and 65V. These are NEMA 42 motors and have a 3/4" (keyed!) output shaft so is quite a powerful motor. Torque at rated power is around 10Nm. I obtained some of these motors when they were to be thrown out a few years ago. If this works well for one axis I will get another driver for the other axis.
View attachment 480873

I look forward to a follow-up post after you test things. It looks like the driver is pretty under-rated for full output, but that is also a monster stepper! I learned about the de-rating curves a few years back on another project, but don't remember much more than certain configurations had a much worse de-rate than others.

Hope it does what you want. If not, maybe a smaller motor closer to operating voltage/current would be a possibility. I like the Pololu stuff and have used it for a few projects.

Lets see it all put together!!!

Sandy.

 

[OverTheTop]

I look forward to a follow-up post after you test things. It looks like the driver is pretty under-rated for full output, but that is also a monster stepper! I learned about the de-rating curves a few years back on another project, but don't remember much more than certain configurations had a much worse de-rate than others.

Hope it does what you want. If not, maybe a smaller motor closer to operating voltage/current would be a possibility. I like the Pololu stuff and have used it for a few projects.

Lets see it all put together!!!

Sandy.

I like the functionality of the driver, even though it doesn't quite drive the motor to the max. I can graft some bigger FETs on if I feel so inclined in the future. My antenna boom is not overly large, relatively speaking.

 

[rocket_troy]

I remember driving NEMA 35s and 42s with a 220V driver (unloaded) and they seriously sounded like dentist drills

TP

 

[Doug Holverson]

I went to a rocket launch in the morning. I had mixed success with the boost gliders, but I got out of the house and had fun in the sun. I measured out and cut out the wing spars, LEs and TEs for a Skydancer.

 

[russell_t]

Set aside work on an Estes Vapor today and started gathering and printing parts for a Bomarc scratch build.

​

 

[Doug Holverson]

As for today's launches: I finally got a Delta-Katt clone and an own design Lark to fly right. The "cursed build" Silver Hawks II don't want to fly right. Previous ones flew so well that I never got them back. One just wants to go schizocarp and the other has a wicked Dutch roll. Then again the tail can't get any smaller compared to the wing....

 

[Cape Byron]

As for today's launches: I finally got a Delta-Katt clone and an own design Lark to fly right. The "cursed build" Silver Hawks II don't want to fly right. Previous ones flew so well that I never got them back. One just wants to go schizocarp and the other has a wicked Dutch roll. Then again the tail can't get any smaller compared to the wing....

What's the difference between the Silver Hawk original and the Hawk II? The originals were great flyers.

 

[Wayco]

Started cleaning up the toy hauler after Airfest. Lots of mud.
Also cleaned up three 75mm snap ring cases we flew there.

 

[Doug Holverson]

What's the difference between the Silver Hawk original and the Hawk II? The originals were great flyers.

More Horten-like planform with a beaver tail and less sweep to be theoretically more efficient. John Carroll and I timed one at four plus minutes before we lost sight of it back in '04.

 

[Cape Byron]

More Horten-like planform with a beaver tail and less sweep to be theoretically more efficient. John Carroll and I timed one at four plus minutes before we lost sight of it back in '04.

Sounds interesting. Any pics to share?

 

[dhbarr]

Started cleaning up the toy hauler after Airfest. Lots of mud.
Also cleaned up three 75mm snap ring cases we flew there.

You should have got a phone call about your sparkly V2.

 

[teepot]

Did some more on my current project. I also wet sanded the booster section of the missile. When I put another coat of paint on the fins some of the overspray was a little rough. So I wet sanded wit 400, 800, 1000 and 2000. I'll repaint the booster tomorrow.

 

[Doug Holverson]

Sounds interesting. Any pics to share?

They're part of this big build that I did in June when I should have been working on the Studebakers.

 

[Cape Byron]

Got the Brocket instructions completed. Time for a proof read...

 

[GrouchoDuke]

Electronics design stuff.

 

[Wayco]

You should have got a phone call about your sparkly V2.

I did David, Bob Brown and Kim Cary both left messages on my phone Monday afternoon. Do you know who recovered it?

 

[dhbarr]

I did David, Bob Brown and Kim Cary both left messages on my phone Monday afternoon. Do you know who recovered it?

No idea, just helped sorting the lost and found pile when it popped out.

 

[Joekeyo]

Monthly club lauch 9 is days away. Never too early to take inventory and plan. I have a bunch of E12-6s and C6-5s left over from NARAM. I checked the status of the fleet and came up with a good ensemble of rockets that are suitable for these engines. I have a dozen B engines in case it's a windy day. I am thinking about leaving the hanger queens behind unless it is excellent weather. Otherwise, I am going to concentrate on getting a lot of launches in.

 

[messedupryan]

Got the Brocket instructions completed. Time for a proof read...

Got my 's on this one

 

[OverTheTop]

Ordered some Yalga kits from Cape Byron Rocketry. One of the few times I can order rocket parts and get to pay local rates rather than international for postage .

 

[Cape Byron]

Got my 's on this one

Just a little resizing on the wraps and we'll be heading for beta testing...

 

[Antares JS]

Finally finished off my tiny electronics sled with epoxy. It was CA'ed before, once it was confirmed everything fit, I removed everything and permanently fastened all the wood bits and the switch with epoxy.

 

[messedupryan]

Finally finished off my tiny electronics sled with epoxy

Forgive me for not searching for the answer, which rocket is this going in?

 

[messedupryan]

of course messed up the first fin by sanding the side that attaches to the body tube

Hey, another kindred soul!