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02-01-2015 07:37 AM | |
SARPLT |
Re: ESC Recommendation Well I am finally getting a chance to finish this project so I thought I would post the results to rap up this thread. In the end the YEP 120 amp 8S ESC was chosen to handle the power but after the issues that 4stripes had with his YEP ESC on his F86 thread I am questioning my decision. Everything worked fine on the test stand so hopefully I will have no issues in the aircraft. Of interest is that the YEP ESCs come preset for helicopters so you will definitely need the program card to set it up. This is pretty straight forward. After several warnings from Eric about the older version of the CS fan not being able to take high RPMs, I took his advice and purchased a newer CS fan to be safe. This is mated up to a Turnigy SK3 3969-1500Kv 8s for power. The edf/motor/YEP ESC was run on a test stand (DR Mad Thrust Stand) with a couple of older 2 X 4000 mah 25C Turnigy 4S batteries in series. I was getting 2.9kg of thrust at 89amps and 2628 watts. Hopefully some fresh higher C batteries will bring this up over 3kg. Although the motor and ESC were barely warm, I added a heat sink to the motor and will add one to the ESC as well. I am not sure why they don't put one on these higher power ESCs. Thanks for all the input guys. Cheers Marty |
05-01-2014 01:33 PM | |
Dutkoski |
Re: ESC Recommendation Lots of good info on this post concerning the CS 90. I too have them and had trouble getting the adaptor off after loosening the set screws. But I installed it so I knew no glue was used, the adaptor fitted very snugly and the fan spun very smoothly. But I just couldn't slide it off, so I used and old trick, I put it in the freezer for a couple of hours, took it out, used my micro butane torch to quickly heat up the adaptor and the adaptor slid off nicely. The cold basically shrinks both adaptor and motor shaft, and the quick heating expands the adaptor creating ever so slightly more clearance. You could also just heat the adaptor without the deep freeze treatment first to see if that would be enough. This is just a tip.....if glued on, you have to bash it off as you did. Oh, about ESC's I've used Turnigy in the past and present. All but one of the HV Sentilon units blew up, one was used in my Arrow prototype and didn't last the initial flight and caused a forced landing. Totally blew up inside, fortunately the bare battery wires didn't touch. Both were their 100 amp versions. The biggest one I purchased was the 120 amp, it literally blew up on the bench when I plugged in the 10 cell battery. Scared the crap out of me the bang was that loud. I have one left, it will be getting changed this year, using a 10 cell setup with a low Kv motor in a 90 mm fan. I wanted a low amp draw so I believe it's drawing somewhere around 65 amps as the Mega motor is rated for 70 amps. The only reason I am using it is due to the high cell count and I could not afford a better ESC when I assembled the Bobcat 52. I've had good success with the Turnigy Plush series of ESC but I don't use them past 6 cell setups. I'm slowly swapping everything over to Castle Creation ESC's even though the price tag is an ouch at times. Also, being made in the USA, warranty work is actually possible. With Turnigy, you just put them in the trash. This goes for the Turnigy motors, they are pretty and work within their state parameters, but do not push them to get more power. I've had over a dozen, all gone to motor heaven. I believe you get what you pay for when it come to these items. |
04-30-2014 07:09 PM | |
4stripes |
Re: ESC Recommendation Both 5 and 8mm adapters are available for the CS fan. If ordered from HK, it came with both. Your 43g fan can not be trusted at any power level. Buy a new one if you really want a CS fan. I've seen too many light fans self destruct and will not use the lighter version. Its just too dangerous to take a chance. |
04-30-2014 05:17 PM | |
SARPLT |
Re: ESC Recommendation Well after finally weighing the model it quickly became evident that this is going to be a heavy bird at around 9lbs plus. Therefore the option of installing some of the fan packages was only going to make matters worse so I decided to keep the CS fan and try to match it up with a more powerful motor. After reading the good performance Eric's thread had on the Turnigy SK3 3969-1500KV motor matched with the CS fan, I decided to give that a try. Well I just received the motor along with the YEP 120 ESC (another beast). As I sat down to mate the two together it quickly became apparent that the 8mm shaft of the motor would not fit the adapter for the fan, 5mm. The saga continues. Eric help! You indicated in your thread that they matched perfectly so I did not even think to check the adapter. Is there different adapters for the CS fan. I don't want to have to drill out the current adapter as I am sure that will cause balance issues. Looking for further advise. Thanks Marty |
03-29-2014 07:43 AM | |
4stripes |
Re: ESC Recommendation They are Lander fans and are considered heavy due to the chunky shroud. They are reported to be dynamically balanced, but I don't put much faith in mass produced assemblies. They may be fine. A fellow flier at our club had two 70mm lander fans. One was well balanced and sounded great while the newer one wasn't. They are certainly stronger than the CS fan and less prone to fly apart. |
03-29-2014 07:27 AM | |
SARPLT |
Re: ESC Recommendation With the front and rear retainer included the weight is 43g and if I add the main shaft the total weight comes out to 55g. The blades seem pretty stiff though. Any comments on the two fans, DPS Alloy or Dr Madd. |
03-29-2014 07:17 AM | |
4stripes |
Re: ESC Recommendation The weight of the fan minus spinner and adapter is what's important. It includes the retaining washers. The weaker fans also have noticeably flexible blades when you squeeze two adjacent blades together. If it is the light fan I wouldn't use it even for a 6s setup. Had too many failures even at 6s 1800watts. |
03-28-2014 08:01 PM | |
SARPLT |
Re: ESC Recommendation Well I finally got the main shaft out of the fan. I took the four Allen screws out and still no luck so I eventually had to take a small piece of metal rod and run it through the aluminum shaft until it bottomed out on the motor shaft. With that in place I gripped the main shaft with a pair of pliers and tapped the rod with a hammer and eventually the shaft came off the motor shaft. Fortunately no significant damage to aluminum other than a few scratches that should buff out. Once again lots of glue or something solid in there. The process seemed a little excessive but it worked. Having a better look at the motor, it does not have any specs or branding on it so no idea what it is. Reference the fan unit, I weighed the fan blades and they are all 3gs each so 36g total and the fan unit is around 100g give or take with a little silicone still on it. So given the numbers you gave me Eric it appears that this is the older model CS fan with the poor blades. Well they seemed to stay together during my run up on 6S so I guess I will put it all back together and keep it for a future foamy. The shopping trip continues to get more expensive as I now have to pickup a complete fan/motor unit. I see HK does not have the Mercury engine in stock so I am looking at the Alloy DPS or Dr Madd as I want to order something this weekend. |
03-27-2014 09:11 PM | |
4stripes |
Re: ESC Recommendation There are 4 Allen screws holding the adapter to the motor shaft. Sometimes the adapter was drilled slightly too large for the motor shaft. Perhaps it was glued on.... I've done that by necessity but knowing it won't be taken apart. |
03-27-2014 08:54 PM | |
SARPLT |
Re: ESC Recommendation Yup it was glued on. With much prying I managed to get the front retainer off and remove the blades but the shaft is still giving me some grief. Can you confirm whether the three Alan screws behind the rear spacer are holding the assembly on to the motor shaft. I have tried to loosen them but it does not seem to be loosing up. Likely glued as well. I had doubts about tearing the fan unit out of the aircraft but now that I am looking at the inside, there were only two screws attaching the motor to the fan and one was loose so it was a good idea to take it apart to have a look. |
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