BllisticAccelerometer Device
Initiation Delay; Engineered for Artillery
- II -
Parts are here and hooked up
Yes this is 3D-CAD for children
Scrutinize Datasheets
Draw test
0.6A my Amps...
I took a portion of a Tesla level of fire hazard off my desk
2023-06-10 10:25PM <
See...
Accelerometers
I know that the BMA220 works but the library seems cumbersome
The ADXL345 came with the starter kit. Saving this.
Bought two MMA845X's; after much goofing around I found a library with clean example code.
Hardware and Software Tested:
Yes, there's a lightly fried microcontroller in the background
The board is powered by 12 Volts from 3x 18650 cells at Vin
Vin splits to power the Solenoid through the Relay
The board's 5V output powers the Accelerometer and the Relay
18650's can dump a lot of amps into something
Checked and Freshened Up the Battery Pack:
https://makermax.ca/articles/discharge-characteristics-of-lithium-ion-batteries/
The cells were at 4.1, 3.8, 3.5 Volts, the last two were replaced with fresh cells at 4.15V
Code
I found: MMA8453_n0m1 by Noah Shibley, NoMi Design Ltd. http://n0m1.com Michael Grant, Krazatchu Design Systems. http://krazatchu.ca/
Looking things up...
Lead-free solder melts at 440°F
The silicone insulation melts at 392°F
The solder in any non-ROHS components I purchased is low oven temperature.
if I can dress for the temperature
up to it boiling water
Celsius
If I'm baking it in an oven
up to melting metal
Fahrenheit
Outside of those ranges
none of
Kelvin, Fahrenheit or Celsius
mean any more to me than
Smurfs
as a unit of measurement
A switch option
Normally Open contacts connected.
Button/Lens and light bulb removed
Bolt-Down for Off
It's armed on assembly and bolted down into Off
Fail = Armed.
The control box
0.062", (16 Gauge) 304 Stainless.
$10 in metal - $14 in Shearing.
Priceless.
My hand shear curls the metal horribly
I'm trying to make a box.
New Guy at the metal supplier's saw today
Back from the farm.
Work on the control box.
Revised Code.
New Draw Test
I've been sick for most of a week.
Designing the layout
Packing the control box
Safety
Extra Safe
NO
Now there's no way
that anyone
will accidentally arm it.
Board soldered up and connected to the relay.
The control box is live; 9:30pm Tuesday, 2023-07-18
The battery holder is from a fourth Robot parts suppler...
Done. 10pm Thursday
I'm looking for time delay feedback
Post Mortem.
From what I can tell:
- the box released from the cage early
- the safety wire (holding the box closed) broke (leaving the parachute with the cage)
- the solenoid frame is not suitable as a structural member
- the solenoid armature/pin and top plate could even be behind the trebuchet
It appears that the batteries at the bottom of the box added to the leverage that pulled the solenoid apart.
The Robot was designed and programmed to respond to multiple G's of acceleration.
Acceleration seems to have pulled it apart.
I have since learned that my goto metal supplier lists:
- 304L SQUARE TUBE 180 GRIT 1.250" x 1.250" x 0.065" (0.095" of play)
- 304L SQUARE TUBE 180 GRIT 1.250" x 1.250" x 0.120" (0.015" too small)
- HOT ROLLED 44W SQUARE TUBE 1.250" x 1.250" x 0.100" (0.025" of play)
which could make a suitable mount for the solenoid a frame for the control box.
That last bit, yes, but new design
- parachute size calculator going...
- make a rectangular box,
- I already have a piece of Hot Rolled Steel for the face
Have the lid on the bottom during launch, lower CG for the components
4'x6' welding blanket as a parachute and heat shield at the front of the box
probably use thin steel cable, no good source of fiberglass rope (not the wood stove variety)
- the box released from the cage early
- the safety wire (holding the box closed) broke (leaving the parachute with the cage)
- the solenoid frame is not suitable as a structural member
- the solenoid armature/pin and top plate could even be behind the trebuchet
It appears that the batteries at the bottom of the box added to the leverage that pulled the solenoid apart.
The Robot was designed and programmed to respond to multiple G's of acceleration.
Acceleration seems to have pulled it apart.
I have since learned that my goto metal supplier lists:
- 304L SQUARE TUBE 180 GRIT 1.250" x 1.250" x 0.065" (0.095" of play)
- 304L SQUARE TUBE 180 GRIT 1.250" x 1.250" x 0.120" (0.015" too small)
- HOT ROLLED 44W SQUARE TUBE 1.250" x 1.250" x 0.100" (0.025" of play)
which could make a suitable mount for the solenoid a frame for the control box.
That last bit, yes, but new design
- parachute size calculator going...
- make a rectangular box,
- I already have a piece of Hot Rolled Steel for the face
Have the lid on the bottom during launch, lower CG for the components
4'x6' welding blanket as a parachute and heat shield at the front of the box
probably use thin steel cable, no good source of fiberglass rope (not the wood stove variety)
New Chassis Design
The List:
Calculations:
Assuming 1/8" material thickness
I just found 8' of 3/4"x3/4" angle left over from a garden ornament project. If I substitute this for some of the angle that works out to a 5lb weight reduction.
It's time for Popsicle sticks.
Tennis balls with liquid in them for fun, if we miss the net, folks grab hockey sticks and try to score!
The solenoid tube was ordered tonight.
What is the ideal weight? 30-35lbs is easy under 30 takes design work.
What is the best timing?
Frame members mostly cut:
1.5" Angle
2x24"
.75" Angle
4x 12"
4x 9"
Still to cut
1.5" Angle 2x 27"
1x 13"
We're not corner mitering like this: https://youtube.com/shorts/DZ60MuXujRI?si=8IAd9CaIYC_MxpXZ
I've got a swivel bandsaw, we're not mitering, we're corner stacking for weapons grade corners.
It's time for Popsicle sticks.
Tennis balls with liquid in them for fun, if we miss the net, folks grab hockey sticks and try to score!
The solenoid tube was ordered tonight.
What is the ideal weight? 30-35lbs is easy under 30 takes design work.
What is the best timing?
Frame members mostly cut:
1.5" Angle
2x24"
.75" Angle
4x 12"
4x 9"
Still to cut
1.5" Angle 2x 27"
1x 13"
We're not corner mitering like this: https://youtube.com/shorts/DZ60MuXujRI?si=8IAd9CaIYC_MxpXZ
I've got a swivel bandsaw, we're not mitering, we're corner stacking for weapons grade corners.
FCAW:
Layout marks on the solenoid tube:
I turns out HOT ROLLED 44W SQUARE TUBE 1.250" x 1.250" x 0.100"
is an excellent size and wall thickness match for welding
BADIDEA-II was harvested 2023-09-19
The robot runs well and is a direct reconnect to replacement or substitute components.
BADIDEA-II's New Chassis
Machine shop time has been shared with an art installation (Due before welding)
New Chassis and such on a scale
Density/geometry calculations were reasonably close.
Upgrading Welding Helmet auxiliary power supply for the Anti-Fog Fans
18650 with a 5V step-up boost converter.
Done.
Design from lessons learned.
It is conspicuous for a reason.
Zero F's FCAW
This might be worth learning.
Nylocks Burn
So yeah.
Populating the Faceplate
Far enough along to see how much work is left to do.
Wednesday Morning welding at Da Moose
1" x 1/2" x 0.125 Channel Pull-Bar
Eyebolt pulls on the bar
the bar pushes on the sides of the front
The front sides push the top and bottom of the front
The Faceplate is bolted to the front top and bottom
The Robot is bolted to the Faceplate
The front sides also pull the rest of the chassis
The least complicated system I could come up with.
Morning welding wasn't pretty
Updated Estimated Weight
BADIDEA-II was transplanted to Chassis 2 2023-09-30
That was 9 days chassisless.
Do people fear the robots trying to destroy us
Because we're afraid they'll figure out how they've been treated?
2023-09-29 11PM
I'll finish it tomorrow
I'll finish it tomorrow
The focus of this project was figuring out
How to get the Robot to deploy a parachute
From a ballistic dumpster fire.
Success
Minor chassis damage.
Specify:
Incendiary-Ballistic-Weapons-Grade Electrical Tape
Incendiary-Ballistic-Weapons-Grade Electrical Tape
The only part of the payload that didn't deploy.
Code Update Time
Considering adjustments to the parameters.
That's some G's
We knew that the acceleration opened up the Eye Bolt
The next day I found out that the Pull-Bar
got bent during launch.
VIDEO
I don't think that I'll have to increase the sensitivity of the accelerometer.
Reinforcemnt
I'm leaving the spelling mistake here.
When you see the picture, just remember, same guy.
I'm leaving the spelling mistake here.
When you see the picture, just remember, same guy.
I've ordered a +/-24g accelerometer.
I want to build a data logger.
See DataLogger
Robot Reattached
Yes, Don, Gorilla Tape.
Yes, Don, Gorilla Tape.
heat shield snugged down too.
Ballistic Dumpster Fire
DataLogger was recovered.
The clasp did not release prematurely.
Datalogger captured acceleration data and was gracefully shut down.
B.A.D.I.D.E.A. II survived.
Chassis 2 - less so.
Notes to future Me:
Buy a fire extinguisher and a laptop.
DataLogger Graph
It's quite telling.
Monday - Supplier Holiday -yeah, this is left over from B.A.D.I.D.E.A.
I leave this here because I think it's funny.
I leave this here because I think it's funny.