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Building a car

Posted: Wed 22. Nov 2017 21:36
by NFBrown
While I wait for Helium frog's new cars I'm working on building a car but I need ideas for the missing pieces. I've ordered one of Ned's Shapeways chassis and I can use 1/32nd slot car parts for wheels and gears. That leaves all the electronics and motor. Has anyone found substitutes for the circuit board? Are the motor specs known?

I have RC gear to experiment with but it's become difficult to buy brushed motor speed controls that are small enough. I can always use a servo for steering and just let the drive motor run slowly so I can run it a test track.

Nick

Re: Building a car

Posted: Thu 23. Nov 2017 15:23
by MagRacer
NFBrown wrote:While I wait for Helium frog's new cars I'm working on building a car but I need ideas for the missing pieces. I've ordered one of Ned's Shapeways chassis and I can use 1/32nd slot car parts for wheels and gears. That leaves all the electronics and motor. Has anyone found substitutes for the circuit board? Are the motor specs known?

I have RC gear to experiment with but it's become difficult to buy brushed motor speed controls that are small enough. I can always use a servo for steering and just let the drive motor run slowly so I can run it a test track.

Nick
I have a post on my site with suggestions for electronics with Neds chassis. Some days ago I uploaded a video for it.
http://magracer.com/site/electronics-ma ... -steering/

Re: Building a car

Posted: Thu 23. Nov 2017 17:07
by NFBrown
Thanks MagRacer, I thought I had looked everywhere for info. I'd looked at your site when I first discovered magracing but it was some time ago now.

Nick

Re: Building a car

Posted: Sat 25. Nov 2017 18:37
by HeliumFrog
@ Magracer
Check PM please

Re: Building a car

Posted: Mon 27. Nov 2017 10:44
by Keld
With such a low price for a controller, i had prefered this instead of the old ones.

controller

speed controller

Re: Building a car

Posted: Mon 27. Nov 2017 18:37
by NFBrown
Can anyone tell me the resistance and wire gauge of the steering coil? If not I guess I'll try "that looks about right"

I have all the major pieces to build a car ordered, now it's time to find magnets and hardware.

Nick

Re: Building a car

Posted: Sun 3. Dec 2017 20:18
by MagRacer
NFBrown wrote:Can anyone tell me the resistance and wire gauge of the steering coil? If not I guess I'll try "that looks about right"
I use 0.2mm wire. 97 OHM

Re: Building a car

Posted: Tue 5. Dec 2017 01:18
by NFBrown
Thanks, Magracer. Now I can wind a steering coil that should work the first try. 0.2 mm works out to 32 gauge here in the U.S.

Nick

Re: Building a car

Posted: Thu 4. Jan 2018 01:31
by NFBrown
My steering coil winding has not worked out. I've made three; number 32 wire comes out at about ten ohms and gets hot at 1.5 volts. The first number 38 wire coil wasn't very neatly done and I broke the wire before the form was full. A second carefully wound #38 coil measures 95 ohms and sort of moves the steering when supplied with 7-8 volts. I don't know what else to try.

So I'm working on a servo steering solution instead. Wish me luck.

Nick

Re: Building a car

Posted: Fri 5. Jan 2018 16:19
by WesR
DSCF0368 (640x479).jpg
DSCF0368 (640x479).jpg (197.52 KiB) Viewed 16773 times
One thing for sure that you do find Nick with magracing steering is that everything is related and, once sorted, cannot easily be altered. So the coil for instance must have the correct wire diameter, the correct number of turns (plus or minus 10 say, and be the correct distance from the steering magnets. Change the steering magnets and you may need a different coil. Change the wire diameter in the track and you may need to change magnets, coil etc.
Like you, I am just beginning to play with servo steering and started a car yesterday. A magnet attached to the servo arm seemed very strong against the two on the track rod so I replaced these, as you can see, with a screw. This, being small in diameter, combined with a small 3mm dia.magnet seems to give a very positive drive and the screw is easily adjusted to vary the gap to the magnet which is probably what will be needed.
The car seems to push around the track ok so I am looking forward to getting it running.
No sure about the very small servo, the slightly larger Turningy one looks better quality and has the correct connector size.
My radio arrived yesterday. The rx is slightly smaller than I expected.
I discovered that there is a throttle reverse switch on the transmitter. I am wondering if it would be possible to use a model aircraft esc (i.e. without reverse) and use the reverse switch on the tx.
Hopefully I will soon find out.