Chihai "Distruction of God" Motor

[S Porteous]

I was looking for a high torque motor to put into my R85, so after a bit of research I ordered a Chihai "Distruction of God" motor from AliExpress.  I ordered it at the start of November, and it had an expected delivery date of the 24th of December... well, it actually arrived today!

 

It seemed a little easier to turn by hand than I was expecting, but it gives much more resistance than the stock one from the R85.  I've just fitted it, and it seems to have eased the semi/auto stalling a little - so hopefully once I get a MOSFET in, that'll sort it...

 

I know that @Rogerborg has mentioned using the Big Dragon motors from AliExpress, but wondered if anyone has used the Chihai motors and has a view on how they compare?

 

This one was just under £30 delivered

 

[Rogerborg]

31 minutes ago, S Porteous said:

Big Dragon motors

 

Technically "mortors".

 

Nah, I haven't tried those, but I am intrigued by the potential for deicide.  How's the response and ROF?  My Big Dragon M140s are significantly better at both than any of my stock CYMA, JG, Galaxy or Specna Arms motors.

 

Hmm, I wonder if the 10A circuit on my cheap multimeters would be sufficient for measuring airsoft motors under load.  I've got some project time scheduled, I might wire up a couple of Deans connectors and banana plugs and see if I can blow the bloody doors off my backup meter. 

[S Porteous]

20 minutes ago, Rogerborg said:

How's the response and ROF?

Response seems okay, but with the temperamental nature of the trigger at the moment I'm having to pull it slowly (and not all the way) in order for it to fire consistently.  For RoF it was getting around 8 per second using a 7.4v LiPo.  I'll probably pop the other motor back in to see what that was getting before.  To be honest, I do most of my firing on semi, so not too worried about the RoF.  I'll have a play with pre-cocking once I get the Perun in.

 

26 minutes ago, Rogerborg said:

I might wire up a couple of Deans connectors and banana plugs and see if I can blow the bloody doors off my backup meter

Ha ha, I'm from an electrical engineering background and have learned so many lessons using the "I'll not do that again then" method ?

[Rogerborg]

On 24/12/2021 at 17:30, S Porteous said:

Ha ha, I'm from an electrical engineering background and have learned so many lessons using the "I'll not do that again then" method ?

 

Did you ever learn the right incantation to get the magic smoke back in?

 

Genuinely though, I wonder if 10A would be enough, or have I just found an excuse to buy a clamp meter.

[S Porteous]

8 hours ago, Rogerborg said:

Did you ever learn the right incantation to get the magic smoke back in?

The fact that I'm buying motors from AliExpress instead of getting them custom made would probably answer that already.

 

8 hours ago, Rogerborg said:

I wonder if 10A would be enough, or have I just found an excuse to buy a clamp meter

Quickly looks at fuse... 20A in the R85, so I'd say 10A isn't going to end well.  I then got out my multi-meter to measure the resistance of the motor.  It looks a little too low to get a proper reading with my meter, but was showing at about 0.6 Ohms.  So using basic calculations for DC, you're talking about 12A on a 7.4v and 18A on a 11.1v.

 

I went from electrical engineering to electronics as it didn't hurt as much when I touched the wrong thing.  And then went into IT by accident about 20 years ago, so anything I do with electronics now is just for fun and it's been quite a while since I did any theory.

[Rogerborg]

26 minutes ago, S Porteous said:

It looks a little too low to get a proper reading with my meter, but was showing at about 0.6 Ohms.  So using basic calculations for DC, you're talking about 12A on a 7.4v and 18A on a 11.1v

 

Agreed, that's about what I'm seeing, but that's under no-load.  Under any load, back-emf kicks in and it gets... <animated-equations.gif>

 

There's really only one way to find out, and I do have a spare multimeter.  If you don't hear from me, I burned the house down.

[S Porteous]

10 hours ago, Rogerborg said:

There's really only one way to find out

Good luck, and I'd be interested to see your results (either way ?).  Interestingly, I had to put a new battery in my multi-meter to test the resistance and noticed a BIG fuse in the back of it.  So, it could be, worst case you blow the fuse... 

[Rogerborg]

4 hours ago, S Porteous said:

So, it could be, worst case you blow the fuse

 

Mine are 10A... unfused.  <dramatic-gopher.gif>

[Speedbird_666]

On 26/12/2021 at 21:17, Rogerborg said:

There's really only one way to find out, and I do have a spare multimeter.  If you don't hear from me, I burned the house down.

 

Or you could just but a cheap RC Watt meter - It's what we RC Flyers use to test the power of motors before we commit to chucking our models in the air.

 

And some of our motors are absolute monsters compared to the tiddly little things in the grips of Airsoft guns.

[Rogerborg]

3 hours ago, Speedbird_666 said:

Or you could just but a cheap RC Watt meter

 

That's the ticket.  I'm not sure that I want to know that much, it's more of a passing curiosity.  I'll put it on my watchlist and maybe drunk-buy it later, always in motion is the future.

 

It's been mechanical fixinz today, I haven't got to the wiring tasks yet.  Actually, I might hold out until and unless the cheap Peruns are back in stock at ak2m4, I've got a couple of others that want swapping out for being too big or too weedy.

[ak2m4]

4 hours ago, Speedbird_666 said:

Or you could just but a cheap RC Watt meter - It's what we RC Flyers use to test the power of motors before we commit to chucking our models in the air.

 

Great little bits of kit, come in real handy for testing efficiency of the motors under different setups.  I've also got a tach meter for measuring the RPM and a little heat sensor.  Been running tests the past few weeks on the new 22TPA and 28TPA XT motors

 

@Rogerborg Speaking to Jakub last week and he's still waiting on the chips to arrive for the Perun basic ?

[Rogerborg]

3 minutes ago, ak2m4 said:

Been running tests the past few weeks on the new 22TPA and 28TPA XT motors

 

Oh, neat.  What sort of ballpark amperages are you seeing?  I'm guessing over 10A?

 

 

3 minutes ago, ak2m4 said:

 

@Rogerborg Speaking to Jakub last week and he's still waiting on the chips to arrive for the Perun basic ?

 

Thanks, I figured it was down to the great silicon drought.

 

Hmm, that's a great price on that 150A unit for UK stock, I can only chisel a few pennies off of it on AliExpress.

[ak2m4]

Here's the video from the XT 22TPA earlier in the year, amps came to 12A in the test. 
Another test in the pipeline is measuring the heat build up, those XT motors come with a little plastic fan on top, just never enough time to round to all the cool little tests I'd like to do.

 

 

Build
Rocket 12:1 Gears / Full stroke
Gearparts M110 spring
Perun Basic Mosfet
AOE corrected
RPS 25 - 11.1 25C
Amp 12A (full auto)

 

 

[S Porteous]

Ha ha, I just stumbled on this video and logged in to add it to the thread when @ak2m4 had already done it ?

I've just fired a Perun AB++ to my R85.  It's a great bit of kit, and has stopped the stalling completely.