author
4Instructables20,698Views19CommentsJoined August 15th, 2011

Tell us about yourself!

Complete Your Profile

Achievements

10K+ Views Earned a bronze medal
Make it Move Contest
Contest Winner Second Prize in the Make it Move Contest
Show 1 More »
  • dcolemans's entry DIY Submersible ROV is a winner in the Make it Move Contest contest 15 days ago
  • dcolemans's entry DIY Submersible ROV is a finalist in the Make it Move Contest contest 19 days ago
  • dcolemans commented on dcolemans's instructable DIY Submersible ROV4 weeks ago
    DIY Submersible ROV

    I think that the need to recalibrate at power up is the nature of the beast. My mobile phone compass also requires moving it around to calibrate when the app is brought up. I read somewhere that this is normal and perhaps unavoidable. After I power up (connect the battery) I just dangle my sub and turn in 360 before putting it in the water. But I can see that for a ground based rover it would be awkward, more awkward for a big one.For the non-automatic 9 axis compasses, I have seen code that does a calibration at the beginning. I've not been successful with that. Good luck.

    View Instructable »
  • dcolemans's instructable DIY Submersible ROV's weekly stats: 6 weeks ago
    • DIY Submersible ROV
      2,380 views
      74 favorites
      19 comments
  • dcolemans commented on DIYunderwater's instructable ROV Quard Patrol System7 weeks ago
    ROV Quard Patrol System

    Thank you for the response. Wi-Fi enabled by temporary connection between ROV and wire to the surface has got me thinking...

    View Instructable »
  • dcolemans's instructable Gas Heated Hot Tub's weekly stats: 7 weeks ago
    • Gas Heated Hot Tub
      45 views
      0 favorites
      0 comments
  • dcolemans commented on dcolemans's instructable DIY Submersible ROV7 weeks ago
    DIY Submersible ROV

    For the acrylic dome, do a search in Amazon for Acrylic Dome 4". It was $12.99.Re. the RC, the receiver I use is one that has a separate PPM output. You have to look for that when you buy a receiver. To decode the PPM signal, there's pretty good discussion in Instructables here https://www.instructables.com/id/Reading-RC-Receiv... And many other sources if you Google "decoding PPM with Arduino". The only extra trick I needed was that stray erroneous signals would come in and cause the thrusters to twitch and spasm. The prefect solution was to use a Median Filter https://github.com/daPhoosa/MedianFilter to get rid of the extra high and extra low values. The filter takes the last 5 (in my case) readings, sorts them in value sequence, and gives you the center readin...

    see more »

    For the acrylic dome, do a search in Amazon for Acrylic Dome 4". It was $12.99.Re. the RC, the receiver I use is one that has a separate PPM output. You have to look for that when you buy a receiver. To decode the PPM signal, there's pretty good discussion in Instructables here https://www.instructables.com/id/Reading-RC-Receiv... And many other sources if you Google "decoding PPM with Arduino". The only extra trick I needed was that stray erroneous signals would come in and cause the thrusters to twitch and spasm. The prefect solution was to use a Median Filter https://github.com/daPhoosa/MedianFilter to get rid of the extra high and extra low values. The filter takes the last 5 (in my case) readings, sorts them in value sequence, and gives you the center reading. Hope this helps.

    View Instructable »
  • dcolemans commented on Tustin High T-Tech's instructable First Person View RC Car7 weeks ago
    First Person View  RC Car

    Very cool project! Makes me want to do a VR goggle FPV project.

    View Instructable »
  • dcolemans commented on DIYunderwater's instructable ROV Quard Patrol System7 weeks ago
    ROV Quard Patrol System

    Very interesting project. The induction charging and autonomous patrolling are impressive. Several questions though:Can you provide a few more details about how the wifi signal goes via "metal guide rings" and how this retrieves the video recording and allows re-programming the Arduino? Where does the video go after it "comes up" via wifi. Does someone manually scan 24 hours of recording to look for damage?What is the status of the project?

    View Instructable »
  • dcolemans commented on dcolemans's instructable DIY Submersible ROV7 weeks ago
    DIY Submersible ROV

    Good old Amazon, where two day shipping has made me an impatient person. Here's the link to the 500 GPH cartridge https://www.amazon.com/gp/product/B001446X1Q/ref=o... If the link doesn't work, just search for Johnson Marine Pump Cartridge. BTW, the 500 GPH has the same dimensions as the 1000 GPH. I guess "cheap" is relative - compared to ready to go thrusters.

    View Instructable »
  • dcolemans made the instructable DIY Submersible ROV7 weeks ago
    DIY Submersible ROV

    I see where you are headed with the mesh bag. Other folks have used wine corks for tether floats, but hey, we lucky folks with 3D printers... Good idea about hollow forms. Clip on would be better. They could be pretty skinny with thin plastic. Make a hole and shoot in some foam as you say. Float in pic is 30mm long.

    View Instructable »
  • dcolemans commented on dcolemans's instructable DIY Submersible ROV7 weeks ago
    DIY Submersible ROV

    Thanks.

    It's a 10 Amp/Hr battery. Just observing the Ammeter, it draws 2 to 4 Amps only when it's pushing hard one direction or another. So based on the assumption one is not constantly travelling, it would only be drawing an average of 1 Amp, it should last several hours, say 5, taking it to 50%. That sounds optimistic though huh? Just playing around with it in the pool etc, the battery never seems to go down much. The voltage shown on the pics of the screen is not valid, not calibrated right.

    Re.filling the pipes with silicone: Why not just let it flood with water?You're right about risking the cable getting nicked. I hope it's well enough protected with the rope. The depth meter wires are individually potted but not the tether cable.You're right about the tether drooping down to the lake floor. If it all works well, I may try a longer tether at which time I'll try for positive buoyancy (maybe a larger poly rope). I've also read where folks have used cork floats strung along the tether, but that sounds like a mess. I'm not clear about how the light mesh bag approach would work... Would it uncoil as needed, coming out of the bag? Or is the bag more of a long sleeve?Re. salt water conductivity: It would be an easy experiment to dip a couple of terminals and see how cl...

    see more »

    Re.filling the pipes with silicone: Why not just let it flood with water?You're right about risking the cable getting nicked. I hope it's well enough protected with the rope. The depth meter wires are individually potted but not the tether cable.You're right about the tether drooping down to the lake floor. If it all works well, I may try a longer tether at which time I'll try for positive buoyancy (maybe a larger poly rope). I've also read where folks have used cork floats strung along the tether, but that sounds like a mess. I'm not clear about how the light mesh bag approach would work... Would it uncoil as needed, coming out of the bag? Or is the bag more of a long sleeve?Re. salt water conductivity: It would be an easy experiment to dip a couple of terminals and see how close they can get before they short out. My battery terminals are a good 2 inches apart. And maybe one could coat it all with waterproof goop. Then you'd need a reed switch inside the dry tube and a magnet on the outside.

    Thank you.

    View Instructable »
  • dcolemans entered DIY Submersible ROV in the Make it Move Contest contest 7 weeks ago
  • dcolemans commented on dcolemans's instructable DIY Submersible ROV7 weeks ago
    DIY Submersible ROV

    Right now it's limited by the 50 foot tether. I've only had it to swimming pool depth so far. I don't know how much pressure it will withstand before it leaks. I think the seal around the acrylic dome is weakest point. The potting around the holes seems secure and the rubber hub-less connectors seem secure too.

    View Instructable »
  • dcolemans commented on joesinstructables's instructable Snake Robot11 months ago
    Snake Robot

    Thanks for the reply. I guess I'll do some experimenting as soon as I can get the snake untethered (electronics and batteries onboard). I do want it to go as quickly as it can.

    View Instructable »
  • dcolemans commented on joesinstructables's instructable Snake Robot11 months ago
    Snake Robot

    Very cool project. I am making a robot snake with 3d printed parts and am using your neat math for the serpentine motion. Question though, if you have a 12 segment snake (12 servos), why did you calculate angle of lag between segments using 11 as the divisor? I plan to increase my current 12 to 16 segments. Should I divide 2Pi by 15?

    View Instructable »
  • dcolemans made the instructable Solar System Orrery (3D Printed)1 year ago
    Solar System Orrery (3D Printed)

    I did make it, but gave up trying to get the moon to go around. It's a wonderful design, quite thorough and well documented. I did enlarge the x&y dimensions of the gear arms by 1.5%. Also there was a bit too much reliance on superglue so I used set-screws to secure the gear arms and the body to the center shaft (threaded into the plastic). To mount the slip ring, I replaced the motor driven gear with a gear with riser and flange. Also I got fancy for Earth and used a beautiful little painted marble I bought on Ebay.

    View Instructable »
  • dcolemans commented on Mixed Output's instructable Wifi Dot Matrix Sign1 year ago
    Wifi Dot Matrix Sign

    My dream is to have a heads up karaoke display in the car so I can sing while driving. My vague plan is to use an Arduino with MP3 module to send audio to the car's stereo and send synchonized text to the scrolling display on the dashboard. However most karaoke files are MP3 + a CDG video file. I'd need something like an SRT file where the timing and words are in text. Ideas?

    View Instructable »