Go Devil 38 L2 Cert Build

[ksaves2]

Tin your wire ends and use the screw blocks. Unscrew and check the wire before every flight and give a gentle tug to make sure it's snug. If you are shooting for a "crazy stupid" record flight that's a one time deal, solder everything and convert back
to terminals when the flight is done. Kurt

 

[OverTheTop]

Unscrew and check the wire before every flight and give a gentle tug to make sure it's snug.

If you tin your wires before putting them in the blocks make sure you check them every flight. Solder is not very good mechanically and creeps under mechanical pressure.

I generally don't tin them, just screw them in. If I decide to get really serious I put ferrules on the stripped ends.

 

[dford]

So are we talking about tinning and ferrule (ing) the actual ematch wire into the blocks? My ematch wires are quite long. I could go with that...
As I mentioned above I wanted to avoid using switches to minimize connection issues. I'm having the same thoughts here. Keep it as simple as possible with as little room for error as possible.
Best way it seems to do so is connect an ematch directly to the blocks through the bulkhead.

I picked up everlast .25" eye bolts from home depot. I have zero idea what the load rating is but I figure if I weld them shut they will be just fine.
I also picked up 36" of #8 all thread along with #8 set screws. I hope the set screws aren't to big. They were the smallest home Depot had. I couldn't find any shear pins so I'm going to check a local hardware store one day I'm off early enough.
On second thought I should have bought all of the hardware from the local store to support small business. Uggh. Maybe I'll buy another set just because.
Anybody know what size the threaded closure is on a 38mm motor case? Just in case I go that route....

 

[OverTheTop]

So are we talking about tinning and ferrule (ing) the actual ematch wire into the blocks?

If you tin, don't use a ferrule.

If it is single-strand wire, don't bother tinning.

These comments apply to whatever you put in the terminal blocks.

 

[KenRico]

I like terminal blocks , but may remove them just for room on these smaller rockets.. not for reliability.

If you do solder some wire connectors directly to the board i recommend encapsulating the wire where it meets the board with a dallop of epoxy.. should help avoid an accidental shear

Kenny

 

[ksaves2]

I like terminal blocks , but may remove them just for room on these smaller rockets.. not for reliability.

If you do solder some wire connectors directly to the board i recommend encapsulating the wire where it meets the board with a dallop of epoxy.. should help avoid an accidental shear

Kenny

Only problem there is if you need to replace the wire sometime in the future. Hard to get the epoxy off. Kurt

 

[ttabbal]

I use hot glue for strain relief on the wires. Holds them well enough, but lets go with a couple drops of alcohol.

 

[OverTheTop]

I frequently tack wires down to sleds using Loctite 401 CA glue.

I have been known to use hot-melt when I want a slightly more temporary solution. It is also good for securing connectors for batteries that are deserving of some retention.

 

[dford]

Mmmkay. Well. I picked up 280mah 2s lipos and all that jazz. Soldered in the processor to the Rx LCD and I can't get the screen to turn on. I have checked all solder joints and basically get a long beep and both lights to flash then nothing happens. The screen is blank.
UNTIL I plug in the TX then I get simultaneous flashing GREEN light on the RX and a RED light on the Tx. What is going on? I have checked the troubleshooting and continued with troubleshooting but the screen doesn't turn on. I also bought new AA batterries but same situation.

 

[dford]

https://www.rocketryforum.com/showthread.php?137588-E-Quantum

this is where i'm at. soldering resoldering soldering trying buying trying and soldering and doing with nothing doing.
i haven't given up on this build thread.
nor the rocket. i'm in determination mode.

i found 4F black powder in Utah i will be using once I figure out how in the world people solder so well. i ordered quantum #3 today. i'm taking my time on it. i now have everything needed for sure to be successful including trial and error when it comes to building this thing. i'm going to solder one piece, inspect one piece. all with ultimate care.

anyone know how these guys make this look so easy and good???


[video=youtube;5uiroWBkdFY]https://www.youtube.com/watch?v=5uiroWBkdFY[/video]

 

[OverTheTop]

anyone know how these guys make this look so easy and good???

Temperature controlled iron set to the right temperature, clean parts, straight parts (coplanarity is king when soldering fine-pitch!). I have done down to 0.4mm pitch using the manual wave technique. Works well. Main trick is to not have the iron too hot. No more than 250degC for tin/lead solder (30deg hotter for Pb-free). The iron takes the excess solder away from the joint.

I have said this before. Solder follows three things: 1) heat, 2) flux, 3) other solder. Remember this and work with it.

Oh, I forgot to mention to practice. Iron technique helps a bit.

 

[dford]

anyone know how these guys make this look so easy and good???

Temperature controlled iron set to the right temperature, clean parts, straight parts (coplanarity is king when soldering fine-pitch!). I have done down to 0.4mm pitch using the manual wave technique. Works well. Main trick is to not have the iron too hot. No more than 250degC for tin/lead solder (30deg hotter for Pb-free). The iron takes the excess solder away from the joint.

I have said this before. Solder follows three things: 1) heat, 2) flux, 3) other solder. Remember this and work with it.

Oh, I forgot to mention to practice. Iron technique helps a bit.

I appreciate the input. Not sure why i'm so handicapped at this. Usually i can pick up on things through trial and error relatively quickly.
Thought I should mention the Tx/Rx is working and fully functional. The receiver is happily in its black box itching for more use.


So i've downloaded finsim thanks to John Cipolla. This is what I get. And it seems the fin set with a little extra thickness from the added two plies (both sides) on the fins will be plenty for any J motor i throw at it. As it sits it would be able to handle a K motor with about 200mph to spare. (if there was enough room for the parachute)

A new quantum is in the mail. Wish me luck with it. Patience patience patience. And when that doesn't work. I'll exemplify a little more patience.

 

[ksaves2]

Just be "extra" careful with the WiFi module when soldering. I wrecked one when I presume I got solder under the module and shorted some pads. The voltage regulator heated up as hot as the soldering iron so that Quantum was toast.
I figured not worth the time to mess with it so it ended up in the junk box. It's just one of those things. I had built two other successfully and one of those I really "cooked" it and it still works fine. Built a third Quantum with no issues.

Make sure you peruse the instructions carefully. I have them on an Android device or laptop along with all the build photos and constantly refer back and forth to make sure everything is correct. Good luck and this go around, take your time. This isn't a race that has to be won in an hour. Kurt

 

[dford]

Okay fellas. Instead of using nylon washers couldn't I just layer electrical tape squares to stand the #4 head and nut off the circuit board and sled?

In the meantime with the whole electronics fiasco I'm having I've been doing body work on the fin can.
Hope everyone is having a joyous Christmas season.

 

[OverTheTop]

Okay fellas. Instead of using nylon washers couldn't I just layer electrical tape squares to stand the #4 head and nut off the circuit board and sled?

If you are desperate then possbily yes. Need to work out if any movment during flight (boost, pyros, landing) will cause enough movement to short the screw to any tracks or parts. PVC electrical tape is a bit squidgy and can move around. Especially look out if the mounting hole on the PCA is plated through and connected to ground. Depends what you want to keep insulated from what.

My preference for an improved hack would be to put some heatshrink on the head of the screw (and maybe down the shaft a bit if needed too). A little more robust IMHO.

 

[watermelonman]

I did a loop of black duct tape (Gorilla brand) for a big washer in the field once.

Buy a few packs of these -
https://www.missileworks.com/store/#!/Standoffs-&-Washers/c/5760494/offset=0&sort=normal

 

[dford]

I had a thought to be like Cerving and just use tubing to cushion the board and prevent shorts.....

should work. after all it is his product.

 

[OverTheTop]

I have been known to use short lengths of pneumatic tubing (plastic) for PCB spacers in the past. Works well.

 

[dford]

I have been known to use short lengths of pneumatic tubing (plastic) for PCB spacers in the past. Works well.

I have some "fuel line" tubing that is going to be perfect for this. Basically the same thing as pneumatic tubing.

Well if anyone hasn't seen my frustration thread in the electronics section I now have two Quantums working. All of it fell on me missing two steps. Very humbling experience.

Anyhow, I took advantage of the holidays and ordered a bunch more stuff. Bolts, nuts more LiPos and JST connectors and a LiPo charger. The most important thing was the fly away rail guide. Pretty excited to try that thing out.

That is where im at for now though.
All electronics are complete so i'll be able to move on again.
I have to apologize for such a hugemongous delay.

 

[dford]

This is where I'm at.
Eggfinder in place. It'll stay where it is for sure. I only need to zip tie a battery into the bottom.
Set screws hole are shown.

Eggtimer Quantum fits nearly perfectly. It is a very tight fit but I think tighter is better in a way at this point with the AV bay. I will place door jam insulating foam at the bulkheads of the AV sled wich will help hold the batteries and sled in place. I can honestly say I've used every bit of space possible.

After reading the "users manual" to the E Q I've learned much more about the dual battery option. I am aiming to utilize it.

Once I get the two estes BP canisters cut for the charges and ground testing I will update again.

 

[bill2654]

I use the BP in the latex glove figure tip method and I just let it sit on the bulkhead. Saves you weight, and extra stuff on the bulkhead.

 

[dford]

I use the BP in the latex glove figure tip method and I just let it sit on the bulkhead. Saves you weight, and extra stuff on the bulkhead.

have you noticed any wear and tear worth mentioning by placing the charge that way?
i had the thought that a small canister would direct the force forward more without damaging the air frame as much.

i really have no idea to be honest.

 

[bill2654]

I did it that way just because I couldn't come up with a small canister. But I haven't noticed any extra wear as I try to "aim" the finger tip away from the side of the airframe. I clean the bulkheads and any other residue left in the airframe with a toothbrush and bottle brush and Simple Green. I'm a big fan of canisters, I was just too lazy and Ive seen a bunch of other old timers use the glove tips.

 

[Banzai88]

I use the centrifuge vials. Works perfectly to contain the charge.

 

[CzTeacherMan]

I use the centrifuge vials. Works perfectly to contain the charge.

+1
I got 200 for like $10 online...

 

[BDB]

I am in the process of changing over to centrifuge vials (aka Eppendorf tubes). Two glove tips failed me earlier this month. Maybe I was doing it wrong, but I think it's hard to keep the BP tight and the e-match centered in them. I just bought a pack of the 2 mL tubes from Amazon so they could hold the charges for my 4" rockets. You can surely get by with the 0.6 or 1.5 mL tubes for this project.