Here is a list of all the postings Frank Skilbeck has made in our forums. Click on a thread name to jump to the thread.
|Thread: ESC help please|
Had a look at the description of the Graupner Elektro Junior S, it comes with a brushless motor for a 7.4v lipo and 30 amp ESC, recommended battery is 2100 to 2200 2s lipo.
So it should be fine with a KMS 30 amp ESC on a 2s lipo (7.4v) as long as the prop has not been changed for a different size.
Your voltage readings are very odd, if it's a 2s battery and its been stored (fully charged) for 4 weeks after charging I'd expect the voltage to be just under 8.4v, if it's a 3s then then fully charged it should be 12.6v.
The voltages you have quoted are for a discharged 3s lipo, if thats the case your charger would reject them if you'd set it to 2s (7.4v).
Also the motor and ESC would not be suitable for a 3s battery unless you fit a smaller prop to limit the amps. Unless you have a means to measure the current then I would not run this motor and prop on a 3s as you could overload the ESC.
|Thread: Multiplex Twinstar 2|
You battery pack is OK, it's as you have said the electronic speed controller is getting to hot and has a thermal shut down protection.
The Nimh batteries will get warm during discharge, and it's made worse by the fact that it's a foam model with very good insulation properites.
What you need to do is make sure you have separated the battery and ESC and have a good air flow over these.
If the TW2 is similar to my original the air is taken in just under the canopy and exits by the rear of the wing, make sure air can flow between these two.
I had similar problems on my Twin Jet and cured it by adding a further air exit. Note the exit should be at least twice the area of the inlet for good air flow.
As anside I put a 3s Lipo in my Twin Star and performance was much improved....................... for several flights, but I can advise they don't fly very well on one motor as I found out after I'd burnt out one of the original 400 motors
|Thread: Ohm's Law?|
|What worried me was that the letter was written by an electrical engineer, I hope he's not designing my ESC's|
|Thread: New type of Li-Po|
|As I understand it A123 cells were developed for use in hand power tools and then adopted by modelers. Power density (i.e. watt/hr per g) is not as good as Lipo's and the voltage drops off a bit more under load, but you can charge them at several C and they will withstand a deep discharge. So a bit more robust than Lipo's. If you look there is another thread on here about them.|
|Thread: The September Grand Prize Draw|
|Thread: New type of Li-Po|
|New generation of cells, are these the Lithium Sulphate cells as used on this http://news.bbc.co.uk/1/hi/sci/tech/7575158.stm|
|Thread: Seagull, Innovator EP|
A Turnigy TR 35-42D 1000kv could also be another good option, I have a Tr42-50 700kv in my e-flite beaver with a Turnigy plush ESC and it's been very good. Good prices on these as well especially from Hong Kong.
Suggest you look at a circa 3,000 mah 3 or 4 s battery to make sure you get a good flight time and are not too hard on the battery. A watt meter will check that the prop you use doesn't overload the motor/esc/battery, but if you go on the hobbycity pages (www.hobbycity.com) you get users posting actual rpm and amps etc for most of their motors, it makes it a lot easier to select a motor.
Your other option would be to go onto the AXI home page www.modelmotors.cz and they have a motor selector program, AXI motors are more expensive but are a very good quality.
Or check out the BRC Hobbies web site they sell the Innovator and recomend two motors which could be usedhttp://www.brchobbies.co.uk/?page=shop&action=additem&item=138
|Thread: Help with Alfa Sabre please|
David, I have a Mig 15 with an inrunner, these fans are really designed for inrunners, there are some other fans which are designed around outrunners. I have seen a design of outrunner which basically uses an extension shaft so the "can" portion of the motor is behind the motor housing tube, like this onehttp://cgi.ebay.co.uk/55mm-Ducted-Fan-Unit-with-Outrunner-Motor-For-EDF-plane_W0QQitemZ220267464730QQcmdZViewItem?IMSfp=TL080811099a10656
I use outrunners on all by brushless prop planes and wouldn't do other wise.
It's an AXI 1215 in my Mig, it's been there two years, including when I transplanted the fan after crashing my first Mig 15 and it has not given me any problem at all and I've fitted the rear fairing so there is really no cooling air flowing through the motor.
|Thread: Alfa A4 Skyhawk|
|I use 1500 mah 3s in my Mig 15 and have my timer set for 6 mins. Keep it light|
Just thought, the motor could be the one that CML sell to go with the plane.
|Thread: Brushless motors|
Just swap round any two of the three wires between the motor and ESC. Changing the battery wires around is a sure fire way of releasing the magic smoke.
Some brushless ESC's do come with an arming switch, but if you are using lipo's you must always unplug them as they will still be supplying some power to the ESC and will eventually be drained below the 3v per cell limit and irrevocably damaged.
|Thread: Power loss?|
|Have you still got 100% travel set on the throttle.|
|Thread: Alfa A4 Skyhawk|
I have an AXI 1215/12 in my Mig 15 (2nd one) been used for around 2 years with no problems. But it's probably the pricy option, but when I got my 1st Mig 15 there were not too many options.
I'm assuming your Alfa is the 3 blade fan? if so my Axi's a 4750 kv motor good for 20A and pulls around 16a on a 3s lipo, so I would think something similar.
They have the instructions on the web site www.alfamodel.cz for assembly and say for disassemble then reverse but without the model they were not too clear.
Not sure which motor is in yours but getting the wires threaded through the fairing is a bit fiddley and I bet one has snapped hence the motor's not working.
If you have to change the motor then the difficult job is taking off the fan driver which is bonded to the motor shaft (you get glue in the kit), a bit of heat, i.e. soldering iron or heat gun, seems to help here.
You now know why it only had two flights.
|Thread: Brown outs and Grey areas - the truth!|
|Tom - when changing back to 35, don't forget to extend the aerial|
|Thread: What next|
Alfa Sabre and Mig come with the fan but no motor.
£65 for all that, bargin
I'm using one of these in my Alfa Mig http://www.modelmotors.cz/index.php?page=62&kategorie=12 4750Kv, I have a Fantom but I'm not sure what the motor is in that but the fan dia and no of blades is similar to the Alfa.
Note on the Alfa's the area where the battery goes is quite shallow (approx 22-24mm) so you need a thin battery, I use 1500 mah 3s Lipo's and the 2100's I use in my Fantom wouldn't fit.
Alfa's are great fliers though and the detailling is excellent.
Few reviews here
Seriously had mine for just about a year now and even though mine was recalled (it was back within 10 days with two free servo's) I've been very pleased with it. The asthetics are not as good as the Far Eastern designed radio's but even though I bough a Spektrum 6Xi to check out 2.4 I still use the Sx for my glow models and larger electric models and put more hours on the Sx.
Downside on the price is that you have to buy the charging lead separate and you will need a charger capable of doing 6 cells (note though the battery is a 6 cell 1800 mah pack so you get a long flying time).
|Thread: Comparing Costs|
I have some Jeti and Hobby Wing/Turnigy ESC's, they all have been very good.
I also have some AXI motors (small size 250 watt max) and some cheaper motors (inc a 700 watt Turnigy), the AXI's are definitely a better quality, the Turnigy is a bit rough round the edges. But I can't complain about the power the Turnigy gives plus it runs well and quite cool.
Not had it long enough to comment on longevity, but my AXI's are all over 12 months old and one of them has been "planted" but it shrugged this off as though nothing had happened (shame I can't say the same for the plane )
Multiplex Tx will operate any 35 mhz ppm Rx, the only thing you might find is that the channel assignments are different so you may have to swap over a couple of servo leads.
I've used mine with a Futaba DP138, no problem, plus several other makes of Rx. Multiplex IPD Rx's also work with Futaba Tx's. It won't work a Futaba PCM Rx if you have any of those though.
Programming is a bit different to Futaba, but after a short while you'll realise how good the programming is. If you are into 3D helis then it may lack a couple of features, but for planes and gliders its got some excellent features.
Tx is also synthised so no crystals required.
Have a look at one first though, they are not as blingy as the Futaba sets and might appear a bit plasticky but I changed from a Futaba FF6 and wouldn't go back know even though mine was one of the sets subject to the recent recall. You can download the manual from Multiplex's web site
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