Model Boat Mayhem

Technical, Techniques, Hints, and Tips => BRUSHLESS Motors and Speed Controllers => Topic started by: tizdaz on February 09, 2020, 07:29:30 PM

Title: motor with disc?
Post by: tizdaz on February 09, 2020, 07:29:30 PM
Hi guys,
its a little off topic this in terms of boats! but it is to do with motor & setup!
my partners hobby is Cosplay, she is in process of doing a "Jinx" cosplay, (for those that dont know, jinx is a character from DC Comics!) Anyway my partner is making the "gun" but she wants the end of the gun to rotate (see pic below, this isnt the gun my partner is making but it will be similar in terms of the end spinning) & guess whos been issued with that task! ...mois!
(https://66.media.tumblr.com/02f0c329428d2d0586b878b06963d30e/tumblr_inline_nmkcjugKYi1szgnuy_1280.jpg)
whats best way to do this!? i obviously need a motor! thinking brushless, it doesnt need to spin fast & i will fit some sort of variable speed controller which she can adjust on the fly to alter the spinning speed, But im unsure what or how to attach the spinning part of the gun to the motor shaft?

Any ideas guys!?
Like i say, i know a little off topic but i know you guys are pretty handy when it comes to making things work!!
Cheers :)
Title: Re: motor with disc?
Post by: microgyros on February 09, 2020, 08:55:28 PM

whats best way to do this!?
Power it from a 1 or 2 powerbank from Poundland.

1) A servo hacked for continuous rotation and controlled either by servo tester or
2) dispense with the circuit to replace with low resistance pot. Perhaps 0-22Ω or 47Ω since a 12volt battery calls for 100Ω
3) low power geared brushed with aforementioned pot.

4) Not this:-
Quote
...thinking brushless,...
Title: Re: motor with disc?
Post by: tsenecal on February 10, 2020, 01:10:44 AM
basically what you are trying to do here is build a replica of a gatling gun.  and as microgyros notes, you want something that will NOT be spinning at 40,000rpm, so, the last thing for you to buy is a brushless, or any other high speed motor.  microgyros recommendations of either a gutted servo, or a gearbox on a motor... with some sort of speed control built in,,,

perhaps one could buy and "dress-up" a cheap cordless drill?

to mount the fake barrels... put the fake barrels on a disk, put a 1/4" bolt through the center of the disk, and put the bolt in the drill's chuck.
Title: Re: motor with disc?
Post by: microgyros on February 10, 2020, 01:55:33 AM
A miniature tape deck motor, which you can source, new, on eBay, gives a measure of fine adjustment but not proportional control. They have a shaft torque suited to a spindle.
Title: Re: motor with disc?
Post by: tigertiger on February 10, 2020, 02:14:53 AM

perhaps one could buy and "dress-up" a cheap cordless drill?

 

That would be the easiest.
You could also gut an old cordless drill for its working parts and trigger. Possibly source on with a dying battery in a charity shop, then just wire in your own power-supply. If you use a 6v pack on a 12v drill, it will just run slower.
Title: Re: motor with disc?
Post by: roycv on February 10, 2020, 07:29:46 PM
Hi. What about a Marx gearbox with adjustable the circular rim for gear changing?
Regards, Roy
Title: Re: motor with disc?
Post by: RST on February 10, 2020, 08:20:58 PM
Mfa geared motor. Use a standard raboesh propshaft end bush with a plastic disc araldited to it?
Title: Re: motor with disc?
Post by: microgyros on February 10, 2020, 10:45:30 PM
I'm imagining a small and lightweight costume prop made from readily available materials. Coupling to a cassette tape motor, I'd use a plastic tube from a cotton bud  as they push fit or superglue onto a 2mm motor shaft.
Title: Re: motor with disc?
Post by: malcolmfrary on February 11, 2020, 09:25:32 AM
Using a servo with the electronic card stripped out is probably the cheapest way of getting appropriate rotation.  Maybe an electric screwdriver.  Both are basically a (brushed) motor with a gearbox.  If the end result is not fast enough, more volts will speed things up.  Unless permanent high speed shooting is wanted, motor life should not be a problem.
The big problem is likely to be supporting the rotating mass that might or might not be balanced to stop it wobbling off.
Title: Re: motor with disc?
Post by: malcolmfrary on February 11, 2020, 02:29:15 PM
Thinking a bit sideways, an advert for this - https://www.jolliman.co.uk/item-s-jn165/air-pump-drain-blaster/ - just dropped through my door.
Would need a respray in pale purple, probably a different handle and rotating electric things added.  But was it not the case that the main armament of Daleks was based on a sink plunger?
Title: Re: motor with disc?
Post by: Tombsy on February 11, 2020, 04:37:26 PM
Nerf (and others) make toy gatling guns for their sponge bullets, might be a great source for parts if you can find an old one.
https://images.app.goo.gl/5w1QwuFY64pEfJJy7 (https://images.app.goo.gl/5w1QwuFY64pEfJJy7)
Title: Re: motor with disc?
Post by: Martin [Admin] on February 11, 2020, 06:02:56 PM

 ..... perhaps one could buy and "dress-up" a cheap cordless drill?


 Yes, that's my first line of thinking too, everything in one package, including battery, charger and all VERY strong! - 10
 If you need variable speed, a cheap Chinese cordless drill. - 25
Title: Re: motor with disc?
Post by: tizdaz on February 20, 2020, 01:08:22 PM
Hi guys, some great info here thanks!


I forgot to mention that it has to be built from scratch so to speak as she will be entering a competition with the cosplay, so she wont be able to use a "premade" solution such as a cordless drill etc. Will take some of the ideas here and have a chat with her 🙂 think the biggest issue will be to make sure its strong enough that it doesnt "flop" around or fall off when spinning!
Title: Re: motor with disc?
Post by: Umi_Ryuzuki on February 20, 2020, 07:05:07 PM
You can use a cordless drill, it just has to have the cosplay shell built up around the frame and trigger.

 
 :-))