Finally pulled the trigger for L1

[Ronz Rocketz]

After drilling a DMS delay, pour in a small amount of BP and shake it into the touch hole. Then add the rest and cap it. The DMS motor comes completely assembled and you remove the cap and ejection charge to access the delay.

Interesting. I wonder why the AT instructions say the opposite to what we've learned?

 

[novahobbies]

I will be bringing the tool I use on the 18 and 24 mm motors. It's a drill bit with a collar you can use as a stop. Measure distance to delay, add amount you want to remove, set stop and drill.

I might be missing something, but is there a special tool for the 29mm motors? I see the one for the DMS 38mm motors (I need to buy an H100 for my L1 as well) but u didn't see one to mod a 29mm G80. Or am I missing it?

 

[Ronz Rocketz]

I might be missing something, but is there a special tool for the 29mm motors? I see the one for the DMS 38mm motors (I need to buy an H100 for my L1 as well) but u didn't see one to mod a 29mm G80. Or am I missing it?

This seems to be adjustable using the set screw. Sorry, G80 reloadable, right?

The DMS Univeral Delay Drilling Tool™ (or UDDT) is designed for shortening DMS delay elements to adjust the time delay of an AeroTech DMS reloadable motor. The UDDT consists of a machined drill tool body and a 1/4” stub drill bit with an attached knob. The tool also has a provision for calibration, as the tip of the drill bit must be flush with the end of the tool body for accurate use. Though adjusted initially at the factory, a set screw placed within the knob makes any necessary readjustment easy.

https://aerotech-rocketry.com/products/product_d208be9f-32da-778d-77e9-093c84bb0508

 

[-Slick-Ice]

AeroTech G80T-14A - "You will need to set the desired delay time using the Universal Delay Drilling Tool (UDDT), Not Included, and then pour in the ejection charge."
https://aerotech-rocketry.com/products/product_12ac810d-0472-e322-6e54-c5d35b4eb0e5I am not aware of any Aerotech G80 RMS or LMS. There are 7 or 10 second fixed delay G80 also.

 

[novahobbies]

Guys, thank you. It was a little less clear on the Apogee website if the universal would work on the G80T-14 DMS. Now I know.

 

[Ron Soto]

as i sit here with my morning cup o' coffee getting ready to leave for Dalzell.. i'm officially nervous.. LOL

 

[kjhambrick]

as i sit here with my morning cup o' coffee getting ready to leave for Dalzell.. i'm officially nervous.. LOL

Good Luck, @Ron Soto !

I'll make an offering to Vulcan ( and to Hephaestus if you prefer ) !

It can't hurt and I'll bet you'll do great !

-- kjh( those launch-morning butterflies are part of the fun, huh )

 

[Ronz Rocketz]

Good Luck, @Ron Soto !

One end is for taking away 4sec delay and other end is for taking away 8sec delay. To get 6sec, you use the washer because it's 1/16in thick or 2sec. You'll want the 6sec to go from 14sec to 8sec.

Aerotech says "As is always the case with drilled DMS (and RMS) delays, the delay element should be installed in the motor with the drilled end facing the propellant grains (or away from the ejection charge) for best delay accuracy. Also, no delay should be shortened to less than 4 seconds."

I was taught to tap the poured ejection charge into the drilled hole then insert the plug. Anyone do it this way?

I asked our mentor why it's better to have the drilled end facing AWAY from the propellant grain. He said this way avoids propellant burn inconsistency with reaching the ejection charge. I asked why AT has it the other way, and he doesn't know.

 

[Ron Soto]

Good Luck, @Ron Soto !

I'll make an offering to Vulcan ( and to Hephaestus if you prefer ) !

It can't hurt and I'll bet you'll do great !

-- kjh( those launch-morning butterflies are part of the fun, huh )

all went well.. and i got my L1.. so there's that. BUT, on my second flight that rocket got in the trees! i had to go home and get my chainsaw.! sheesh. it didn't take that long.

r-

 

[Ron Soto]

well my 2 flights went well! And i got my L1. here's the telemetry data from the second flight:

Motor: CTI I204
Altitude at apogee: 2379'
Speed: 383 mph
Mach: .3401
Motor Burn Time: 1.38 sec
Coast to apogee: 9.4 sec
Max Accel: 18.1 G's
Aver Acell: 12.7 G's
Parachute Ejection: 463 (set at 500')
Flight Duration 71.3 sec

shroud lines.. OK.. swivels forsure! what a mess with the twisting. saying this maybe my parachute folding skills are not what they should be. i noticed that the shroud lines were short and twisted around the NC attachment point. so i'm thinking it's either my 'chute folding, or the JLCR is somehow involved. What i did do, was just remove both the shock cord, and parachute from the NC, untangle, then re-attach. (Maybe... just have connection points for both on the NC so i 'can' take them off.. hummm)

Damage: yup.. one of the fins sustained damage to 1/2 of the fin, and BT damage at the rear.. nothing too extreme, but will definitely repair.. abet not quite sure how to fix the damage on the fin yet. as for the BT, i was thinking straighten, then apply thin CA to strengthen.

I have Tom's CTI casing, and i have a universal drilling tool that was loaned to me, but when leaving for the chainsaw, i totally forgot about it, i need to get the UDT back to its rightful owner.

thank you to everyone who's chimed in! i totally appreciate your help..

r-

 

[MarsLander]

Congrats!!!!

 

[Ron Soto]

thanks for the photos Wes..

r-

 

[-Slick-Ice]

I don't follow the JLCR instructions where they show a picture of it on a shroud line. I attach it to the end of the shock cord.

 

[Rocketjunkie]

I do have video of the cert flight. I'll be posting to Youtube soon.

 

[Hobie1dog]

all went well.. and i got my L1.. so there's that. BUT, on my second flight that rocket got in the trees! i had to go home and get my chainsaw.! sheesh. it didn't take that long.

Congratulations, usually those trees are a long way away.

 

[Rocketjunkie]

Congratulations, usually those trees are a long way away.

One small patch pretty close. Unfortunately, it didn't miss.

 

[Bob Yanecek]

all went well.. and i got my L1.. so there's that. BUT, on my second flight that rocket got in the trees! i had to go home and get my chainsaw.! sheesh. it didn't take that long.

r-

Just don't forget to stand the tree back up after recovering the rocket.

 

[kjhambrick]

Congrats @Ron Soto !

Too bad about the lumberjack recovery on the 2nd flight but all's well that ends well !

Thanks for the pictures !

-- kjh

 

[Ron Soto]

Congrats @Ron Soto !

Too bad about the lumberjack recovery on the 2nd flight but all's well that ends well !

Thanks for the pictures !

-- kjh

and the stories i'll get to tell.. !

 

[Ronz Rocketz]