Hot temperature after shimming, is this normal?
 

hey guys,

I've recently changed the stock gears in a VFC VR16 to SuperShooter 13:1. Shimmed the new gears using bevel to pinion method. Not sure if I PERFECTLY shimmed it, but its ok in terms of noise and amount of free spin after screwing on the gearbox.

Now after I put the gearbox together with piston/spring etc. and test fire the complete gearbox, the pistol grip gets hot quickly (within 30 shots) and I can feel the wires is hot (unbearably hot if touched) and fairly hot air coming out of the front nozzle.

Some specs of what I am using:
- Lonex A2 motor
- stock wires (connector is changed to Dean)
- SS 13:1 gears
- 7.4 lipo
- no mosfet
- M110 spring

My questions are:
- is the heating up normal with my setup?
- if not, what are some of the most likely causes of the issue? (i.e. shimmed too tight? when I loosen the shim from what I have now, I seem to get more noise from the gearbox, which leads me to think my current shimming is more optimal)

Thanks in advance!

You went from low loading to high loading, so inevitably there's going to be more heat generation.
If ths shimming really is good, then you might want to use a higher torque motor. But motors get hot under load. Its what they do.

I did a similar build in my 417. I used a lonex A1. Got hot as all hell. Went with a high torque and it'sit's at cooler with minimal ROF loss.

Thanks guys!

So it sounds like the heat I'm getting is "normal" and not due to something is installed incorrectly. I was just worried that something will fry if I used this setup for a prolonged period of time.

Lonex A2 and 13:1 should not be generating a significant amount of heat in a mere 30 shots, especially on 7.4. I would suspect shimming, but stock VFC wires aren't that great so maybe that is a contributing factor to the heat output.

So please do yourself a favour, install a MOSFET and use 16 AWG wires. I would also advise you to get yourself a wattmeter and test what kind of current you are drawing. You should be drawing ~20A on that setup.

you were right pestobanana. After putting the gun together for test fire, I had a jam and tiny bit of smoke coming out.... must be shimming too tight?

Did you test your shimming with the mechbox screws tight and the tappet plate installed?

I've tested with gearbox screwed, but did not install tappet plate for the test. Should I also install the cylinder and spring?