Greg's Batch 4 build

Finishing motor arms.
Second idea. Decided to space the hoop mounts out instead of cutting the bolts.


The bolts fit really tight through these so I drilled them out with a 1/8" bit. Still plenty snug. The bolt heads still fit quite tight into the recesses

Lining up the arm hinges in pairs.

The nuts are metric but a 9/32" wrench worked nice. Tighten, then back out 1/4 turn or so.

An evening’s labour. Getting a blister from the screwdriver handle. :-7

Note that I’ve not added all of the hoop mount blocks. The kit was short on the bolts for them. I’ll have to go by a handful.

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At this stage I coated all moving parts with white lithium grease. This makes them move much smoother, and will prevent wear of the rather soft aluminum and anodization.

I had the same problem with the kit being short on these longer 45mm M3 bolts. The kit is ALSO short on M3 lock washers which are used when mounting the speed controllers. This was annoying, on both parts. Ordered extras of both from McMaster Car

Center plate.
Applied some hot glue to these sites of the circuit board. The just felt a bit loose, I wanted some strain relief.


Should the kit have two main switches? Mine only had one. There seems to be four corners where the circuit board will bolt down. I choose the lower left corner - or will that be the right corner?

Connections
Time to solder the more to the speed controllers. Solder, check, flux, check 35 Watt iron, check…!


LOL no. That wire is way too heavy for my little iron. This should work better. Torch, flame shielding, needle nosed pliers.

First one. Serviceable I think.

One motor connected. Carefully wiped them off and inspected and tried hard to pull them apart. By the time I got to the last set I was getting fast and the connections were looking better too.

All done. Hooked up two controllers each way. Guessing that’ll give me two spinning in each direction.

You really need to invest in a higher watt iron. You will need that later for the main wires anyway.

Hook each arm up to the controller to check the spin direction because the wires could be crossed before coming out of the motor. Mark the direction of each one. If you need to reverse one just swap any two of the three wires.

Paul didn’t include a second switch with batch 4 because it uses higher volts and lower amps. The switch is rated for 300 amps which is what you will get at full throttle. However, the true problem with the switch is when it gets damaged from arcing. Therefore, I highly recommend a pre-charge switch or button to protect the switch from damage. In addition, I prefer two switches so each only has to handle 150 amps.

Here is a link to the pre-charge switch I designed. Scroll up in the thread to get more details about how it works.

Hey gliderpilot. I was wondering if the batch 4 kit Incorporated your pre-charge switch. I guess I have my answer. I don’t have a 3d printer. How much do you charge for your switches?

Since I’m still waiting for batteries I did two more flights (#s 9 and 10 ) today on a Blackhawk 125. Did my first reverse launch with a motor. Five mins sniffing two stroke fumes waiting for the right wind.:roll_eyes::smirk::nauseated_face:. Still way worth it though :grin:

Definitely I’m not going to assume the motors will be correct without checking them. Just starting out with the best bet.

If you can’t find someone local you can order prints online. That’s a really small print so my price would only be a dollar. The shipping would be a lot more though. If you have other parts you would like me to print to make it more worth my time I’d be happy to help you out. Feel free to PM me.

Ha. Totally slipped my mind that there are local 3d shops. Thank you. I’ll check into it.
Meanwhile… Testing the ESC wiring.
I still don’t have bonkas but I do have a 40 Volt Ryobi lawn mower battery. Temporarily squashed the battery cables together with controller power to alligator clips. Clipped to the battery and… Nothing. :thinking: Ok touched positive clip to check it and zap snap then lights and bleeps :notes::bulb:. Everything checked out. Two motors spinning each way. :grin:.


Dang I’m taking blurry pics again. :confused:

I can print them for you. Post which files you need.

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Nice job on the load switch! What’s the expected current surge? I see you spec a 150W resistor for it, so 3A at 50V? Does it get hot?

@grejen711 parts are ready for you.

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Thanks! The expected surge is quite high but it’s just a quick spike. The resistor will get warm if you hold the precharge on for several seconds but it only needs to be held for a second. Sorry, I don’t remember the actual calculations but I do know it protects the switch really well.

Awesome. Thank you very much. Will PM details.

Mounting the speed controllers
Cable ties and a foam pad under each one. The pad is cut from the motor packaging. Thinking I might cut that large strap of and go with a second small one through the mounting holes at the other end. Would look tidier.

Wireing harness
Bought some ring connectors and lit up the soldering torch. First pair is a bit toasted.


By the time I finished they were looking pretty. Strip, flux, insert, crimp, heat, feed in solder.

Mocked up one side. All the ESC wires were cut to the same length. Battery cables are waiting for actual batteries before I trim to length and solder on the plugs.

The bolt for the negative side is almost ideal. Just a tad short. Found a better one in my bolt bin. Need two though.

Shorted myself a few connectors so have not yet made crossover connectors. Left side waiting for a switch.
Everything will get taken apart and cleaned up with sandpaper before final connection.

Any suggestions for insulating and mounting the DC 2 DC converter/supply for the main board? Does it get hot? Can I just encase it in that foam rubber and strap it to something?

I put heat shrink tubing on it and fix it just with velcro…


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Perfect. I was over thinking it.

Back at it for an evening. Recieved a spark arrestor knob. Thank you very much @maymayday
First step, disassemble the provided switch. Four screws on the back. One more holding the red knob from the inside. Four major parts plus a spring. Do not loose that spring!


Next, spend an hour digging through my junk to find a scrap of solid core wire. Came up empty so just used some well sized stranded. Strip at least three cm.

Yeah that wire has to go out the other way. Drilled out a thin layer of plastic left from the print. Stuffed the wire through. Both wires installed.

Assembled. Added got glue to stabilize the wires and hold them in place. I also used a drill bit in my fingers to clear out the holes for the spring to save some frustration there.

Tested it with a multimeter. Reassembled the switch with my new knob. Hmmmm what’s wrong with this situation. Doh!

Disassembled switch again, reassembled with the mounting plate in place.

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I ordered the second switch from banggood. Cheaped out on shipping. :roll_eyes::tired_face:. Man I hope that ETA is a conservative estimate.


Btw that spark arrestor switch knob fits amazingly, perfectly, precisely.
Also, got a track on my Bonkas. They should be in Sumas next week for me to pick up. Seems I may be waiting for a $6 switch, the weather, and busy renovating a rental property, or all three. Sigh…