Punisher 3 for Level 1

[NateB]

2019 came and went and I never started on my Punisher 3 I intended to do my level 1 with. When the build is complete, I hope to fly it on a Loki H-144.

As is often the case, family life and work responsibilities pushed some hobbies to the side. I had a big change in my job assignment and a lot of educational responsibilitie last year. Now, I have 1 class this semester to finish my degree and it looks like I might stop swing shifts and go to mostly days in March or April. I'm crossing my fingers, but I should have more time and energy for hobbies this year.

This was my weekend for night shift and most of the shift we have had 300' ceilings with snow and ice coming coming down. With poor weather forecasted all weekend, I had packed up some things to keep me occupied.

Everyone starts with the motor mount, I'm starting with the electronics. First up, was my Eggtimer Classic. This is my first time soldering anything other than bike cables and connectors on wires. I went slow and step by step per the instructions. It took me a little over 3 hours, but I have a complete altimeter. I did not bring a battery or the parts for my sled, so I have not added the pigtails for the battery and switch yet. My eyes need a break anyway. I might do that later today or my next shift. Then comes the moment of truth to see if the board powers up and allows me to program it.

 

[mbeels]

Very nice! I really like the eggtimer classic, it's a versatile flight computer.

 

[Joe Rocket 97]

Keep it simple

 

[crossfire]

KISS method for L1 flight

 

[Flyfalcons]

Electronics are great to work on while waiting for epoxy to cure....

 

[mbeels]

Yup, my Classic Altimeter rode along in my Level 1 rocket so I could download the data afterwards.

 

[NateB]

My Eggtimer turns on when connected to a battery. That's the good part.

After some frustration, I was able to get the USB cable to communicate with my computer and the flight settings screen popped up in a terminal when the Eggtimer is powered on. When it is powered up, it cycles through some beeps and the red and amber LEDs are on. At first it is silent, then it won't stop beeping. On the flight settings screen, pressing CTRL-Y to perform a master reset does nothing. No warning screen, no confirmation, nothing.

 

[NateB]

The Eggtimer is now initialized after missing a simple step on the programming screen. Next step is testing with e-matches and then moving on to the e-bay constriction and assembling the tracker. It looks like we could be grounded by fog again tomorrow afternoon, so if they don't have office work or a long chore list for us, I'll get more work on this project done in the morning.

 

[NateB]

Back at it, the Eggtimer is programmed and pops e-matches on each channel.



I also moved on to some easy steps. The harness was attached to the eye bolt in the nosecone.



Vent band is epoxied in place on the coupler. Yes, I remembered to account for the bulkhead plates. The drill will come out tomorrow.

 

[mpitfield]

From a stability perspective, the Loki H160LB is a better choice of motor than the H144LW, for that rocket. Plus the blue flame is way cooler! I like the fact that you are trying electronics on your L1. I used an altimeter with a long delay motor backup on my L1. It didn't quite work out the way I hoped but it ended well. Just get used to it on the bench, do lots of ground testing, and get your prep down before you hit the field. That way you will be prepared.

Good luck

 

[NateB]

I do like the blue flames, my motor choice isn't set in stone so I will definitely keep all options in mind after a sims when the build is complete. For my cert flight, I was planning on single deployment with the altimeter and using the motor delay as a backup. One reason I picked the Punisher is the flexibility it gives with deployment options and a relatively low and slow flight on an H.

 

[NateB]

The locations for altimeter vents and the screw switch access were marked and holes started using a center punch.



3 - 1/8" vent holes for the altimeter and a 5/16" hole for the screw switch holder from Additive Aerospace. The flush mount switch holder is easy to install I just sanded each surface, cleaned the dust with alcohol, and glued it in place with Maxi-Cure.



I am expected the combination terminal blocks and charge wells to arrive tomorrow so I can finish the bulkheads and AV bay. The leads for the deployment charges are soldered directly to the Eggtimer and will be attached to the terminals with ring connectors. This should be pretty secure.

 

[mpitfield]

I looks like you went with the larger screw switch. That was one of the reasons I originally looked at the FingerTech mini screw switches https://www.fingertechrobotics.com/proddetail.php?prod=ft-mini-switch

Besides being rugged and designed for the abuse of robotics, they only require a 3/32 hole to arm.

 

[NateB]

Yes, I used the larger ones. I ordered several a while back from Missleworks. Thanks for that link. I didn't know or even think to look for smaller ones. I might try them for future builds, especially on anything smaller than a 3" rocket.

 

[NateB]

I got some more work done today. The aluminum bulkhead plates were drilled and the terminal blocks with charge wells were installed. I might swap out the ring terminals for spade terminals on the forward end to make it easier to remove the sled.The leads are long enough to remove the bulkhead plate and charge the battery, but a quicker disconnect might be nice down the road. I also need to get some eye bolts for the recovery attachment. Lowes and Menards didn't have anything that would work. Next time I made an order from McMaster, I'll add some.

Everything fits in the nosecone, but it is still too tight. I'll have to sand the nosecone end of the coupler and then drill holes for shear pins.

 

[mpitfield]

Everything fits in the nosecone, but it is still too tight.

What chute are you packing in there?

 

[NateB]

What chute are you packing in there?

Sorry, I meant just the coupler with the charge wells. The coupler is still too tight. It was tight when I dry fitted the parts, but after assembly it is too snug.

For main recovery, I'm planning on a Top Flight 45 as Jim used in his Punisher build thread. If my build comes in too heavy, I'll have to make other plans and see what can fit.

 

[crossfire]

A Top Flight Par45 thin mill chute would save you some space.

 

[Steveo]

Couple thoughts. I beveled the bulkplate edge with a file so it fit smoothly. I also found I put my charge well too close to the edge and it hung up on the the nosecone. Can’t tell from your pic but you might check for rubbing. I switched out to a smaller well with more room and it fits much better. I’ve seen a lot of folks skip the wells on the Punisher and use glove tips.

 

[mpitfield]

For HED configurations, I place the coupler, with the end caps on, push it all the way in until it gets tight. At this stage, I back it out a bit and mark the tube; that is where I glue the AV Bay band. This should prevent the coupler from going too deep and binding on the taper of the nosecone.

 

[NateB]

I am not sure if the well is rubbing or not. I think the binding is coming from the aluminum bulkhead, so grinding an angle on it is a great idea. I did glue the vent band in place after placing the coupler with the plate in place and backed off a touch. I don't think it will take too much effort to make it fit like I want. I would much rather remove a little material for a perfect fit than try to shim it to tighten it up anyway.

 

[tim cubbedge]

You're right about the bulk head. I recently bought an AL bulkhead & NC from Wildman and the fit was really tight and I had to do same.

 

[NateB]

I haven't taken a dremel to the aluminum bulkheads yet, but did get more work on the electronics done tonight. I was able to assemble the Eggfinder LCD Receiver without any difficulty. This was my first time soldering and SMT parts, and it powered up right away. That boosts my confidence for when I assemble the Eggfinder Mini.

 

[OverTheTop]

Nice work. I like that you took your time on the assembly. Speed will come with practice. Keep thinking and doing and you will have success .

 

[NateB]

Some packages were on the porch from China and Blackaero yesterday when I came home from work. The Eggfinder LCD case dry fit nicely and I like it better than the project box included with the kit. I think I am going to order the GPS module and the 3db external antenna before I enclose everything in the Blackaero case. It looks like everything just fits in that case, so I won't want to take it apart unless I have to repair something.

The Turnigy Nano-Tech 2s 1500 mAh 20c battery is a perfect fit for the handle of the Blackaero case. I also ordered several Nano-Tech 2s 300 mAh 35-70c batteries for altimeter and tracker. They are slightly smaller than a 9 volt, fit in the battery compartment on the 3d printed sleds I own, and would be easy to secure on a traditional sled for future products. The other batteries I have will go back in their airplane. Each battery was charged for storage and look to be in good shape. I have heard of some issues from China with the battery leads swapped, but this brand has been good for me so far.

My wife works today too, so assembling the Eggfinder Mini with my curious 4 year old would be difficult. He helped me get the shock cord loop on nosecone eye bolt already. He is really excited to work on the fins, but we aren't ready for that step yet.

 

[NateB]

I spent a few minutes grinding the aluminum bulkhead and adding a bevel at the top. No more binding and the nosecone still fits snug. I haven't drilled a vent hole, but the coupler may still need a little sanding for the best fit. Better snug than loose, and I'll be drilling for rivets / shear pins and a vent hole too.

 

[NateB]

Tonight, I assembled the Eggfinder Mini. I found it considerably more difficult than the LCD Rx and the Classic. I had some difficulty with the GPS chip and the small resistors. I was surprised that the unit powered up. The red light on the RF module was blinking as expected, but the amber LED never lit up to indicate a satellite fix. I am sitting inside a large metal hangar, so I'm not really worried. I stepped outside for a better fix, but we are getting a nice mix of rain, snow, and sleet so I didn't stay outdoors. I'll see if it works tomorrow and sends data to my LCD Receiver. If it doesn't work, I'll troubleshoot it, but probably end up skipping it for my cert flight. I don't plan on going out of sight with it yet.

 

[HVArcas]

I looks like you went with the larger screw switch. That was one of the reasons I originally looked at the FingerTech mini screw switches https://www.fingertechrobotics.com/proddetail.php?prod=ft-mini-switch

Besides being rugged and designed for the abuse of robotics, they only require a 3/32 hole to arm.

those are a lovely form factor but a bit expensive and we have had a decent number of them fail. not like they are junk or anything, but, definitely not as fail/fool proof as the missileworks, where there is basically nothing to go wrong

 

[HVArcas]

i built my punisher heavy, flies great/easy/fun/trackerless on high thrust motor deploy I motors with a 38mm adaptor (then it takes 54mm6G XL when we want to go gonzo)

 

[NateB]

Good news! I turned the Mini on during my drive home from work. I'm not sure how long it took, but I got a fix somewhere during my 25 mile commute. The LCD Rx picked up the signal quick and showed the correct coordinates and altitude for my house.