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Bobs 1st 3D Project

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  • #31
    Just an update picture here.

    I am almost done printing up all the frame stuff. Next I need to wind the coils and hookup the switching.




    • #32
      It's ALIVE !!!!

      Hello Group,
      It's been awhile in the making but today I am ready to show this machine running. I made a video which is pretty long because I spent a lot of time trying to explain how it is all configured. Hopefully you will enjoy it.

      Here are a few stills of it:



      I go over it in detail in the video so I'm going to keep the text minimal but some basic info on it:
      It has one 30awg pickup coil which is feeding the solid state relay, one 21awg power coil, the magnets are 1/4 inch X 1/8th samarium cobolt, Obviously since I just said it , the switching is on a SSR and I have mode one and common ground configured on a switch.

      The video is showing it hooked up to several sources. I started on some 18650's and then some 9volt, and finished on regular garden batteries. I wanted to show how minimalist this thing can be by using the small batteries. The video is not of a full run, it's just a few min in each battery and in each mode.

      Let me know what you think,, thanks--Bob



      • #33
        That looks great Bob. Thanks for sharing!!



        • #34
          That looks great Bob. Thanks for sharing!!
          you share STL files ?


          • #35
            Very cool and clearly a lot of hard work.


            • #36
              Very nice machine Bob, liked the video too. I soooo want a 3d printer.


              • #37
                Thanks guys.

                I have started adding more coils and it's going well so far.


                • #38
                  Originally posted by BobZilla View Post
                  Thanks guys.

                  I have started adding more coils and it's going well so far.
                  Looking forward to a video update.


                  • #39
                    Posting a few pics today.

                    I have added all the coils, 8 power and one genny. I did change the circuit around a bit when I added all the coils. I now have one SSR per coil with independent diodes. I found that the genny coil setup I was driving the single SSR with was not strong enough to drive the 8 new ones so I added a 18650 battery to supply the trigger for now.

                    Brian I started a garden battery run a few hours ago and took some video so I will post something tomorrow as I monitor this run.

                    Here are a few pics of it:




                    • #40
                      Nice work, i hope it is doing well for you.
                      Happy testing


                      • #41
                        Hello group,
                        I have changed the circuit back to a single SSR and am using the genny to supply the trigger again, how it was originally. I blew a fuse with the other configuration and suspect that one of the SSR's had shorted out but I need to take the bus bars off of the array and test them to confirm. I liked the way it ran originally so rather than muck around with the smaller relays I decided to put the large one back at least for now.

                        Today I am posting a chart and video of a full discharge/charge on a garden battery. It is explained in the video but I will give the basic info here in text also.

                        The chart shows where at first the battery is fully charged and I just gave it a quick spin up. After that I did a load test on the CBA pulling at 1A down to 10.5v. That is more like a C10 rate for such a small battery, in hindsight it may have been better to do it at a C20 rate because it sort of skews the results but this is just for fun anyway. So at the end of that the CBA reports 5.444 AH were consumed. Then I charge the battery back up in mode 1. The machine is set to draw about 1A in mode 1. I had to go to bed before it was finished charging so by the morning it had already been fully charged and was just wasting energy and keeping the back at 15.8 at which time I shut it off. I may do this type of run again and try to monitor things a bit closer and use a C20 rate on the discharge but for what it's worth I am happy with the results of this run. I have also charged much bigger batteries with the same setup but the garden is something everyone is familiar with.





                        • #42
                          Hey Bob
                          Great video, i really like how it triggers the ssr from a genny coil, it's like getting "a little extra" out of your machine.
                          Keep up the great experimenting.


                          • #43
                            One problem I am having with this design is the axle/bearing. The coils keep pushing the wheel horizontally out of the field. I tried wrapping some tape around the axle but it still happens at times. I think I am going to redesign it to use half inch axle and bearings which I have used on several of my other machines. Those bearings have a keeper screw that prevents this issue. I really like the size and spin on the current setup but cannot find any bearings that have the same keeper screw in this size.

                            I might post a video a bit later. I have changed the wiring a bit on the machine. I now have 2 sets of 4 on the power coils. The first four are in parallel and spaced every other coil and then the second set are in parallel to each other also but the two sets are in series. This increased the resistance and lowered the draw a bit. Now I am pulling about 4ooma in mode one and about 1100ma in common ground. Charging is still fantastic, especially on smaller batteries like the garden tractors.


                            • #44
                              If you have room for them (probably take as much space as the tape) you could use a sleeve on the shaft with set screws. (see pic)


                              Or if you have the tools to do so you could take an off the shelf brass bushing and drill and tap for a set screw.
                              It's always a good feeling when you can lower the amp draw and still maintain the charging.
                              great experimenting, look forward to the video.
                              Last edited by Brian McNece; 07-03-2017, 12:27 PM. Reason: wasn't finished before


                              • #45
                                You could also print some snug fit bushings quickly to whatever size you want...