Sniper returns

shes back

More POooooowwwaaaaaaaahhhhhhh!!!!

I got the motor ready You got an ESC that will be alright up to about 60Amps plus?

Cheers
Andy

will have soon as i fix marks. my 80amp one and bec are on marks cheesy fan. have had look round and people are running the mega motor on 5 cells with a meaty heatsink getting upwards of 1kw

You will definately need a mega heatsink at that sort of power level! The power dissipation in the motor is going to be huge at those levels... That said, on a 5s pack, they will only be pulling 60 amps or so....

I reckon a nice light setup would be best in the Sniper though. Keep it down to a 3 or 4s 2150mAh pack, and run it at about 40-50 Amps for 400-500 Watts.

I've got an ESC, but it is only rated to 35 Amps. It did tend to limit the current (or just cut out!) when used at around 40A on the MiniFan and a 4s A123 pack. perhaps not the best choice for the Sniper!

Cheers
Andy

andy do u have a couple of capacitors suitable for an 80 amp speedo. ive got some 1200uf ones but there only 14v. marks managed to pull them off his speedo when he crashed his yak. suppose they would be ok upto 4 cells.

I'll have a look around the lab at work, and see what I can find Regarding the voltage rating of ESC capacitors, then generally you want a bit of headroom in them. You have to allow for short-term voltage spikes (I need a blackboard to explain why!), so for an ESC that is to be used with 4s lipos (16.8v freshly charged) I would be looking at using a minimum 20v rated capacitor (25v to be on the safe side)....

Generally, the bigger the capacitors, the better!

Cheers
Andy

getting closer. mark kindly donated a pair of very slim dymond d60 servos for the wing. its sooo thin. Got those mounted up and a hs85mg up its backside taking care up the uppy downy controls. need to make a battery tray for the cockpit can fit a pair of 3 cell 2150s in there to run in parallel should provide the motor with all the amps it can gobble.

only thing is what to do with the grey nose, should i paint it white again with the orange stripe? i do like the look of it all clean and pointy

I would go for the orange stripe, if you can get a paint match. A plain white nose will be a beeeyatch to see against light cloud.

Or, you could go all military on us, and paint the whole thing in grey? Add a few black markings for contrast, and you're laughing.

No luck on the capacitors as yet

Andy

i didnt go with orange and white

here we go had a play with the airbrush. not perfect but was good practice. really needs a transparent or candy blue to give it some depth but i only have opaque.




the layers going on dont show up too well

the last one is with a coat of clear satin.

Blue flames, cool!

I've not got any suitable capacitors for the ESC leigh. the only big uns I can find at work, are rated to 500volts, and are the size of a coke can

It might be worth a trip to maplin or Ebay for some. Thats said, the ones you have will work up to 3s lipos, but I wouldn't risk them with a freshly charges 4s lipo. When you start to over volt a capacitor (especially an Electrolytic one) you risk breaking down the insulation, and causing an internal short. this is usually followed by a small bang, and a bit of smoke! The best case is that the insulation inside holds up, but the capacitance rating drops quite severely. When put on the input of something pulling large current spikes (like an ESC ) you then risk overheating, followed by complete failiure. interestingly, when the caps fail on the input to an ESC, it usually results in the ESC going pop too

If you do buy some, look for 25v rated ones. they will be good for 3,4 and 5s lipos. You may also get away with 6s lipos on them too. I fyou are planning to run a 6s pack, then I would look for 30v or 35v rated ones... As for the size (in µF) you want as much as possible! The big value caps, tend to be rather large though, so you need to choose one that is big enough in value, but not overly large physically.

Cheers
Andy

thanks for havin a look andy. will order some from ebay. you can get em in small numbers without payin silly postage.

Stop the press!

I've found a couple of 1000µF capacitors rated at 25v at work! They are about 12mm diameter and 41mm long.

I'll bring them with me this evening if you want them

Andy

flown on 4 cells last night. getting very quick now

Good stuff!

How's the motor handling it? Hot? I'm not sure I'll be down the field tonight, but will definately be there on thursday. I'll bring me meter with me, and you can measure the juice it is pulling

Andy