Fitting Graupner Speed 300

[jaseyshef]

Hey guys,

I'm swithcing my Hummingbird V3 motor to a Graupner Speed 300 in preparation for the arrival of some like 90 blades, in a never ending quest to try and fly in slight breezes!

I'm still new to this (3 months and counting) but learning fast, got the basic hover down and flying around is fine (not nose in hover may I add...still practicing on XTR), upgraded to Lipos, but I'm not sure about the motor fitting.

Do I simply remove the standard Hummingbird Motor wires and put them onto the Speed 300, I'm reasonable with a soldering iron so that's fine. just not sure about the wiring (little orange things with U73 on - resistors?) set up.

Any help very much appreciated.

[Raptorite]

Hi Jase,

I would think the speed 300 will be a pretty close replacement for the stock HB motor, the only things you really need to watch out for are the pinion sizes if you intend to use a different one and making sure the motor is fitted correctly with the right gear meshing.

The best way to mesh something like that I have found is to take a piece of paper out of your printer, tear a strip off and place the strip between the two gears. Then push them together as tight as they will go with the paper inbetween, tighten down the motor and remove the paper. The meshing should then be more or less spot on.

I am not sure about the speed 300 per say, you may well have to solder the fly leads that go to the speed controller on to the motor tabs, make sure you follow the markings on the motor casing for + & - and you will be fine.

The resistor things you are refering to are more than likely surpressors which are used to minimise the amount of "noise" generated by the motor and therefore potentially degrading the performance of the radio gear. In most cases you should have 3 of them, one between each of the + & - tabs and the motor casing and one between the two tabs themselves.

I hope this helps.

Cheers,

Pete.

[jaseyshef]

Hi Pete,

that's really helpful thanks.

I am still shaking my head at not working out they were supressors, you'd think stint in the RAF on Tonkas would have served me better than that.

I'll let you know how things go.

Jase

[Jamez]

Burning out ESC

Also, make sure you esc can take the increased current that the speed 300 can draw, my mates spy hawk one lasted about 3 minutes before cooking big time cause it couldn't handle the current.

[jaseyshef]

Im told it can be used as a stick replacement for the 370 motor the HBV3 comes with, using standard mixer board etc, Ill post on this thread if I have any problems with it.

For info Im also trying the wheel collar trick on the flybars to see If I can get a little more stability in slight breezes (wouldnt even want to think about anything more), again Ill drop results onto this thread.

Thanks for the post - Jase

[jaseyshef]

Evening guys,

well I fitted the speed 300 (without Like 90s, not arrived from RC Superstore yet) and it runs really nicely.

However I'm getting seriously reduced flight times (more like 10 than 20 mins). I'm running 2 cell etec 1250s and the twister 4in 1 (esky Honeybee).

Any ideas why - does the speed 300 draw a lot more power than the HBV3 370 motor?

I haver fitted flybar weights (very small, only just fit over the shaft) so this may be part of it.

Cheers for the help,

Jase

[Raptorite]

Hi Jase,

I should think the reduced flight times are down to a number of things, first, the 300 motor may well use more current than the HB 370. Second the additional weight of the flybar weights, although it may not seem like much will have quite a big effect on flight duration due to the extra weight the model is carrying, not to mention the extra power needed by the motor to spin them.

Are there any other differences? I noticed in another post you mentioned that you have changed from a combined RX/gyro/ESC board to separate ones. There will I'm sure be extra weight involved in having separate items on the model, plus all the things you wouldn't normally think of, like the double sided mounting pads to hold the components on with, any additional cable ties, cable connectors and anything else you may have now that you didn't have before. The separate units will also have a higher running current draw I should imagine.

I bet if you put the model on a set of kitchen scales now and got another stock one and weighed it, there would be quite a difference. Having gone this far, if you are finding that the flight durations aren't enough you may need to consider a larger capacity battry pack, something like a 1500Mah maybe.

Cheers,

Pete.

[jaseyshef]

Hi Pete,

thanks for the reply. I haven't actually gone with seperates - I think in the post I said I didn't want to go that far just yet, so was still playing safe with a four in 1 unit.

Tried with the FB weights off and it's better, but still just over 12mins.

Do you think the pinion size may be a problem, I'm currently running a standard 10tooth HB version.

Jase

[Jamez]

Electricaly Speaking

The 300 motor has I believe a lower number of turns (in the windings), therefore a lower reisistance, therfore a higher current draw at the same voltage. This will shorten your flying time as it will drain the current from your battery's quicker. This also explains its increased power as the current draw is directly related to the motors output.

[jaseyshef]

Thanks for everything guys.

Very helpful.

Lets call this thread a day.

Cheers - Jase