Hi Dennis,
Thanks for your kind words. ECL is evolving at a fast pace. As more people in CL transfer the E-RC knowledge over to ECL, the pace will quicken. Will, Mike, Bob&Dean, Linhart, Ron King, Kim, and many others have been a big help to many on this list. I think Will's column in SN has been a great help in spreading the word on ECL. You are asking a lot of good questions. I am sure others will chime in with more answers for you.
1. Round Motor planes like WWII fighters and bombers are perfect for shaft forward mounting. Also wide cowl planes like the Extra series, Edges, etc. are very good. I modified my ARC Vector by cutting off the fuselage at the wing LE and completely rebuilding it to look a little like my 35% Extra 300L. With the scale paint scheme I think it looks OK, maybe the middle of row 4 in a 4 row contest?
BTW, it would have been a LOT easier just to make a whole new fuselage than do it the hard way like I did. At least I learned a lot about how NOT to do it next time!
It is very easy to get the E-spinner nut for the shaft. Most hobby stores carry them for RC. Yours is most likely a 5mm shaft. You can also order them form Hobby Lobby, an excellent source for E stuff. I order mine from TruTurn. They make great, light weight E spinners and spinner nuts. The size we use is 5mm x 3/4" or 7/8".
2. I tried the full spinner for the 1st few flights on the P-40 but it seemed to block too much of the cooling air. As strange as it sounds, a cowled in motor gets much better cooling (if done properly) than a motor hanging out in the breeze on a profile gets. This is true in FS also. I use the 3/4" spinner nut on my P-40 and on the E-ExtraVector. If you do want to use the TRADITIONAL CL full spinner, you will have to have a large intake somewhere to bring in cooling for everything. ..... I'm glad I tried the motor both ways in the same plane, I hope it helps others in their quest for the perfect setup.
3. Pls. see #2
4. I proposed this as a cooling solution several months ago. Dean was kind enough to give a very good reason why it will most likely not work well. His detailed ans. is on this E forum somewhere. In a nut shell: "..... the air in the spinner is swirlling around with such force that it would throw the air out the slots and not get to cool the motor ...." When Dean speaks, I listen, he knows his stuff.
5. IMHO: Yes! Cooling Fans were created mainly for the E-Heli flyers. Their motors live in a brutal environment. They draw very high amps with very little air moving over the motor. We in ECL are much closer to Helis than we are to ERC fixed wing planes. We are at high power for 5.5 min. with NO relief for the motor like in E-RC where there is plenty of low TH cooling time during our flights.
One of the reasons Will and I are going to cooling fans is that our E motors like to run as cool as possible for MAX efficiency. They would really like to be closer to 0C than to the temps we run them at. The other reason I recommend fans is that not everyone has the talent and knowledge of the Bob and Dean team to make a very efficient cooling cowl system to move the air where it always does the most good. A fan makes up for our amateur, "less than perfect", cooling duct systems.
6. Yikes! "400F" .... This may be the temp when the magnets stop being attractive to each other and file for divorce, but it is about 260F higher than the MAX recommended temp for our motors. Most Mfg. recommend a MAX operating temp of around 135F to 140F. If you operate above this level your motors life span will be shortend, the magnets will weaken, and the motor will lose power over time. As we approach 170F to 200F the motors life span will be as low as <50 flights. As we go over 250F we start to run the risk that the glue holding the magnets may begin to weaken and fail.
I know that the E speed pylon racers cook a lot of E motors(and batteries) by running at very high temps, but they are going all out to win and look at motors like we IC pylon racers look at glow plugs, one or two flights is SOP.
FWIW When I give you my motor temp readings, they are actual in flight readings from my on board Eagle Tree data logger with a temp probe attached directly to the motor, and one probe to the battery. This unit also gives me real time RPMs showing the changes every 1/10 sec during the entire flight and for each maneuver. it also gives me Watts, mAh, av. and mins/maxs for each flight. It's a cool tool. :-)
BTW: A good rule of thumb recommended by the motor mfg. is that you should be able to touch your motor right after a flight without any pain. If you can't hold on to your motor, it is too hot. This is also the same rule of thumb for our batteries. ..... Our batteries actually like to be a little warm for MAX efficiency. Somewhere between 95F and 110F is where they are happiest and at max power. but they too are sensitive and should not be run at over 130F, or their life will be shortened.
7. Your more than welcome, glad I could help. :-)
Regards,
Rudy: ANOTHER thorough & well constructed post - THANX!
1. Our experiments (that is the only word that really fits) so far have been with the shaft-forward nose-ring mount, got some new motors that came with shaft-aft firewall mount. However, we are also looking at new fuselages that are naturals for firewall mount - I'll have to get some prop adapters for the shaft-forward mounting. I have not tried fitting e-power to a Vector, but I know it has a really snug front end, I can see why a rear mounting would have been the odds-on favorite!
2. Of course your post raised ANOTHER issue that I had not considered - cooling. We are currently flying without a spinner and with the nose ring plate clearing the cooling openings - its about as good as it can get. Your forward versus aft mounting experience with the P40 is golden:
3. *Have you been running with a spinner (2"?) all the time?
4. *Has anyone had any success "ventilating" the spinner to allow some flow to the motor? Seems like a few well place holes should allow some flow directly into the motor. Done right it might even look REALLY cool!
5. * Do you think we should all plan on using fans routinely?
6. * Just how hot is the limit? I thought magnets did not start giving up until 400F or so...?
7. As always THANKS for your feedback & advice!