Sewdhull

I can measure my mag release (cyma mp5) if you want, you measure yours and compare? The TM one has two grub screws the others have one. The TM one is an anodized machined aluminium part ( maybe cast or from a lump) and the others, mim.

I don't know how handy you are but if you epoxy the two parts together, drill it out and sleeve it with brass tube. Or print one https://cults3d.com/en/3d-model/gadget/cm041-sd-silencer-mounting

https://www.patrolbase.co.uk/cyma-cm-041-sd-aeg-silencer-mounting-apparatus It's out of stock here.

Ignore

Currents, 7.4 and 11.1 22tpa xt 17 and 25 BL xt. 15.5 and 20.5. Ah I forgot to take precocking off...wondered why auto was so similar to semi if not a little more. The BL is much faster, esp at 7.4v in comparison, but I haven't sorted my feeding issue. BL motor isn't fitted properly I can tell, I'll have to have look see when I've a bit more time.

You need some sort of electronic commutation and sensors plus a lil computer to work out when to commutate. The main difficulty in making the BL motor like a brushed motor is that the BL needs power to work, MOSFETs have a polarity and the board needs electrical protection that Brushed ones don't. There's a circuit on the board to supply power to the electronics and the tab voltage will go via the MOSFETs to the windings switched at the right time to make the motor spin the right way using the sensors on the endbell. Made the right way you can power the device with PWM, switch the MOSFETs on and let the windings see the PWM signal. It is likely however that fault conditions will be detected if the averaged voltage drops in the PSU. MOSFETs must have enough voltage, from the PSU via the controller not the tabs, to fully turn on or they get hot and magic smoke escapes so this condition is avoided. The PSU should be polarity protected but the MOSFETs can't be because of the diodes protecting the MOSFET from the motor. I noticed the perun load the motor to detect it making it try to turn. If other ETUs don't do this correctly for BL motors that's not the motors fault. ETUs need to bear in mind brushless motors exist. BL motors can brake themselves with a change in timing and probably do, which will always make AB a problem on them. If the AB MOSFET on the ETU shorts the motor it will stop doing things and no braking will occur when the MOSFETs are off. If the motor is shorted in pulses, to lessen the effect of the braking then the MOSFET may remain on if the PSU still has power and there may be braking. If braking is effected by reversing the polarity then this is bad news and magic smoke may escape. BL motors may detect shorts to prevent damage and stop working with any AB. If AB is to be effected on a BL motor the motor should do it, and could with the right programming and circuit. I notice the board has a 78L05 regulator on it and some other PSU bit around the +tab. That reg has a minimum input voltage of 7v (there will be wiggle room) to regulate 5v out.

The motor has to follow the same form factor as existing motors and a single case for long and short motors makes sense, at least for the smaller producers. I don't think there's a case for a reversable motor, unless you can think of a reason why you'd want such a thing. Brushless motors can't be very dumb, they need the controller, the large flat chip, to do the sums to make it turn etc. You need additional wiring terminals to do anything via the ETU because 1, the ETU expects to deliver only voltage to the motor terminals, and 2, the motor expects to see voltage only to the motor terminals. You may find the motor controller already brakes the motor to control the back EMF at motor stop. Given the right message the motor can spin any way you want it to but you'd need some sort of interface to achieve it and the controller programming and it needs power.

As a motor, the brushless is 1mm shorter, compared to the xt brushed, from the motor front to the pinion end, the motor tower has no play in it. Altho I would suggest this dimension could be adjusted as the shaft was probably a bit longer originally. The motor appears to have strong magnets, and the stepping between them very apparent when you rotate the motor. Motor tabs are strong. I notice the tabs are nearer the motor ends, which caused me no issues but may in different grips at the end. There is room to bend the tabs through 90degrees which is an option you don't see usually. Don't bend the tabs lol. I'm really happy with this motor so thank you xt. This weekend I'll run this and the xt brushed through the ammeter and see what that reveals.

I fitted mine to test and it functions just as the brushed motor does. I have a perun. Motor height was different and it needed to be screwed in further. It fit without issue I think perhaps I'll look at bevel height as I've got motor tower play which I removed on the brushed motor. Or shim the tower to fit the hole in the gearbox casing. I haven't fired any bbs through it yet but it fires normally on 7.4 and 11.1 lipo, a 7.4 lion and a 9.9 life.

Yeah diameters of stuff varies from model to model I found.

I think muffs disappeared in the 90s

In the video there is mention of speed tests to come. The actual speed of the motor will be load dependant, but a decent brushless will see higher loaded speeds because of the reduced losses and increased torque usually seen. The brushless motors that allow ab etc need a capacitor to maintain the voltage to the control electronics on the motor. I'm unsure if AK has had a peek to see if such a capacitor exists.

I'll sort out the feed issues running both, but start with 7.4v, then 9.9v then 11v. However the gears are 13:1 and the motor might run too fast with 11s. I wanted a low motor speed, the 22tpa might be too fast on those gears, which I can vary with the perun but I'd rather not have to so I can run with a brushless. At the moment the bbs don't drop into the hop and rely on the mag spring pushing them into the chamber, which is either hop rubber in the way or nozzle, or a combination of the 2. I'm not after RPS so 7.4v would be fine but I think the brushless likes 11.1 so we shall see. I don't think the brushless would like motor speed reduction via the perun.

Mines going in the Mp5 once I sort out the feed issue

No need to worry about too high a C rating. They are unreliable

So you've had no support since 2000s?

Yep

I'll have a close look at the hop bucking nozzle on the morrow, take some measurements.

Yes indeed, I've others I can try

I'm afraid to ask but what is air cocking?

In fairness few dmrs will meaningfully outrange a good aeg. But sniping is a laugh if the site suits it. As far as a dmr goes, good hop nozzle and barrel are really the things. Heavy BBS too and consistentcy OBS a little more joulage for another 10m of range. Tightbore Vs normal won't do much for anything really do long as the barrel is straight smooth and clean.

Numbers, 1 to 4 are semi. 5 to 7 3rd burst, or maybe the 1st 3 are burst ...

I'm not convinced it's feeding quite right, it seems to but the hop rubber pokes back further than I think it should

Ok, so I went with M105 spring from xt. Very consistent at 1.18 and 1.19J on .25 with hop off. I could only find .4g bbs but they gave me 1.17 and 1.18J. I still have to hop it so this is the peak energy and hop will scrub some off.

Hence the need for short mags