microdon2

My Feedback: (47)

Thanks for the good wishes, guys.

One more - I also am now tie-wrapping the servo leads together, just above the receiver. I did not used to do this, and my last (bad) crash was caused by the elevator lead pulling out while in the air (total loss!). Not sure why I never thought of it before, but here's the hint for anyone who also has not yet heard of it.

Mike

ahicks

My Feedback: (2)

VictoryRoll - if you go with that alum. sheet mod (that beefs up the firewall to landing gear plate joint) the stock gear works great. I am VERY hard on my gear. I've seen mine hit hard enough to nearly straighten them right out to each side - with no damage.

Mike - best of luck! May the Gods of flight accept your previous sacrifices as dues paid in full for at LEAST one full season!

wjcalhoun

Mike
I'll echo the suggestion to tie the servo leads together with a zip tie just above the receiver. I got that suggestion early on. There is actually a corollary of that suggestion, which is to secure ALL connections; i use zip ties to hold any servo connection (battery-> switch, extensions, etc) aside from the aileron plug ins, and i use a safety clip on those when i assemble at the field to fly.

Having a connection fail in the air almost always results in unwanted consequences.

The forces we put on our models are significant; I'm reading z-axis forces of up to 8g, and fore-aft and lateral forces of 2-3g. I had my instrument pod mounted with 2 #2 servo screws, and last flight with my AW Extra 300 55cc, one of them pulled out. I'll have to re-engineer the mounting to use blind nuts and #2 bolts. Anything that can come loose on board is likely to do so at some inopportune time.

lopflyers

My Feedback: (12)

VictoryRoll

My Feedback: (2)

@AHicks: I love it ! Thanks for the well-wishes and conjuring up the gods of our hobby... they are at work all the time ! .... and unfortunately... MURPHY !!!!! lol !

I "think" I know which post you mean with the aluninum plate(s), but I am not sure... would it be too much trouble to ask you to find it for me and direct me to it, so as I don't incorporate a bad technique, or one that is less than favorable.

Thanks, my friend!

Don

ahicks

My Feedback: (2)

VictoryRoll-
I think this may have been the post that got the flag up for me to look at this joint and consider this idea when I built mine:
http://www.rcuniverse.com/forum/fb.asp?m=11064428

What you're trying to accomplish is to hold the front of that main landing gear plate to the bottom of this firewall - to avoid any possibility of that joint working or pulling apart on a hard landing. What I used is much shorter, does not extend to the rear much beyond the landing gear box (1.5"-2" or so?). I did use about the same as the pics show to fasten to the firewall. I used about 6 screws to hold the alum to the firewall, the landing gear mounting bolts hold it to the plate. Didn't use a lot of glue, maybe enough to just tack it in place. The mechanical fasteners should provide all the strength you need. It's important to match the radius of the bend in the sheet metal to the contour of the plane. Any slack would allow for that joint to flex there, so it needs to fit pretty snug. I used roof flashing to make mine. It's cheap at Lowes or Home Depot. The stuff you buy in a coil is perfect. Stiff enough to be sturdy, and thin enough to work easily. One coil will last many years, 6.00 or so?

This Chinese lite ply is BRITTLE. It doesn't bend, it shatters! -Al

VictoryRoll

My Feedback: (2)

@ahicks: Thank you so much for that link and most importantly, a thorough description of the problem and how to remedy it. Excellent information and a BIG help to me (and I am sure, many others)

Once again, Thank you so much... it is truly appreciated!!

Don

capt1597

i like the looks of the metal plate as it sreads the load nicely and that is the needed for this bird. i did the same thing when i assembled my rev but i spread the load by using fiberglass. i removed the covering and laid in woven glass starting an inch up the firewall then aft 7 in. and went up the sides an in. i then coated the inside of the fus. with resin covering the same area as the cloath on the out side. i the opted for the dubro fibergkass replacment landing gear. i fly off grass fields and have had no issues to date. same theory just different materials. i am a big fan and user of 'west system' epoxy. just my 2cents. happy flying, capt

drube

Hi guys, looking to pick up a R70 and will be running a DLE 20. I'm looking for recommendations on servos, preferably Fataba. I was looking at the S3305's (4.8v) for the rudder and elevator. are these enough? What about the ailerons?
Thanks

microdon2

My Feedback: (47)

drube - the 3305's are plenty for the elevators and rudder, but go with 6v - no reason to go 4.8 (unless you were planning on using the same battery for your EI). I use a seperate 4.8 for my DLE 20's EI - don't worry about the weight, this engine is a BEAST on this plane - it won't even feel that extra battery.

Also, the Futaba 3010's - with 90oz at 6v - are plenty for the ailerons. 6V gives you lots more torque AND speed -and 6v NiMH batteries (if that's how you're going) are pretty cheap. But I'd stay away from Fataba. I'd go with Futaba - a name you can trust~! (a little RC ribbing there...)

Is this your first Rev 70? If so, good choice - I haven't heard anything but raves about this plane from it's owners (including me)

My new Rev 70 \ DLE 20's maiden is tomorrow morning. Can't wait!

Mike

drube

Thanks Mike, this will be my first Rev70 and read nothing but good things about the plane. I'll go 6v on the rec/servos and 4.8v on the ignition. This will also be my first gasser. Thanks for the info!

microdon2

My Feedback: (47)

drube - you're welcome. There's also an excellent (and long!) thread here on RCU on the DLE 20. Might be an idea to look it over. Also look at the very first post for a compilation of significant info on the engine. Enjoy your build!


http://www.rcuniverse.com/forum/fb.asp?m=11440365

drube

Thanks for the link! Looks like I got some reading to do..lol

Thanks again

wjcalhoun

drube:

for receiver battery, think strongly about LiFe technology. NiMH are fine for ignition (a 4 cell), but digital servos can draw enough current that NiMH may allow the voltage to sag. Similar concern with a 5cell NiMH; you have the voltage until the servos begin to draw hard (like in a snap roll).

Let me disagree a bit with my on-line friend microdon2 on servo selection. I would think futaba 3305 are adequate, but for my build i would put stronger servos all around, especially at the rudder. Consider Savox 0251 or 0252 which provide more torque, more speed, at about the same price. I try to engineer my builds with servos that have at least 50% more torque than the surface could possilby experience. I don't like to have my equipment working near or at max, but that is just me.

Several hitecs would also work.

Best wishes with your build.

Bill

lopflyers

My Feedback: (12)

Ahrrrrrrr, I did it again , for the third time in 1 yr. 

ahicks

My Feedback: (2)

Drube, I like big servos too. But, I don't like paying the long dollar for them. This is what I have in my Revolver I have them in another gasser as well. Have been flying them for 3 seasons without a single failure.

http://www.hobbyking.com/hobbyking/s...arehouse_.html

This is the servo I'm going to. Not because I'm having trouble with the HXT's, but because they're half again stronger, they aren't digital power pigs, AND quite a few guys have been having pretty good luck with them.

https://www.troybuiltmodels.com/items/HD-1501MG.html

These are both standard size servos.

lopflyers - you mean you stripped them off the bottom of the plane? Did you clobber the bottom of the wings too? Will you be doing the alum. plate thing this time around?

lopflyers

My Feedback: (12)

Wings are fine. This landing was hot but not too hard.

VictoryRoll

My Feedback: (2)

@wjc - Hi Bill !

I agree with you in terms of doubling the OEM suggested values for servos for all my planes... I am going with the Savox that you suggested to me earlier. I love digitals for speed and resolution.
I also agree on a battery other than the NiMH (or NiCD too). I want to go with LiFE but have zero experience and no charger to juice them up.
Can I ask you:
1. What size LiFE would you suggest for the servos that we spoke of (the Savox SC-0252MG's) I plan on five (5) of those servos, utilizing two (2) for the elevators. Plugging a standard Futaba 3001 analog for throttle as I have plenty of them around.
2. Can you give me some suggestions for a charger for them and larger Lipos too? I presently use the Hobbico Accu-cycle Elite, and it has served my needs up until now, but I need to bump up the charger in terms of handling different chemistries and types (the Accu-cycle handles Lipos or LiOns up to 3 cells only). I hear a lot of good things about LiFe's though and also A123's.

I want to use 6v for the servos... is there any issue with using a 6.6v LiFe or a 7.4v Lipo (Do I need to regulate the 7.4's?)


Thanks you in advance.

Don

Anyone else wish to chime in, I would greatly appreciate it !

microdon2

My Feedback: (47)

ahicks - Those servos are certainly inexpensive. How's the centering?

wjc - I do think I'll explore the LIFE technology. Have to check if my Turnigy charger supports it. As Victory Roll asked, does LIFE require a voltage regulator for 6V servos?

btw - the Rev70 \ DLE20 maiden went GREAT today! Holy.. I forgot how much power this DLE20 has! With the APC 16x8 it appeared to have unlimited vertial. Will change to 15x10 soon for some more speed. The DLE 20 ran very well, though a tad rich. Will re-turn. But I'm VERY happy with both plane and engine.

Flying the Rev 701 again tomorrow.

Luchnia

My Feedback: (21)

I switched out to A123s for all my gassers and they are simply the best for my situation. I could not believe how nice they are and how easy they are to maintain - a little pricey out the gate though. No more voltage drops from sitting. They can sit for months without a change. All you have to do is fly them on each plane a couple times and charge, then check how many mah you put back in and you have a idea of how much you use per flight.

I don't use any regulators at all. I am sure regulators are fine if one wants to use them. I run the Taildragger RC 2500 A123s. A single battery on each 30cc and on my 50cc I use two of them, but it is massive overkill really. Another fantastic thing about A123s is that you can blast a charge on them in minutes!

I am also switching out all my ignition batters and using the Ultra IBEC. The only thing is removing the ig batteries may cause a balance issue so I will have to consider that. I think I am OK though as I can relocated some stuff. I really like only charging one battery per plane and being able to have it fully charged in less than ten minutes.

I use a mix of servos, mostly Power HD and Hitec so far with no adverse issues. I don't use LIPOs because with A123 you really don't need to be concerned about anything. BTW, I can fly my 30cc planes 6-8 times easily and more if I wanted to. I sort of set that for my "safe zone".

Hope that is some helpful for anyone considering the A123 batteries.

ahicks

My Feedback: (2)

I'm all A123 (LiFe) now too. Use a single battery pack, but I run the power to the receiver through 2 switches for redundancy and to help feed power (increase available amperage) to feed these big servos when playing hard. Many use the same setup to feed their 50cc planes! Ignition is fed from the same battery pack. I use a 20.00 opti switch made by Rcexl, so I use a 50 cent Radio Shack diode on the output side of the opti switch to drop the voltage going to the ign. module. The Ultra IBEC does that for you, but it's twice as much money.

A123's run at 6.6 volts (about the same as a 5 cell/6v NiMh pack). All my receivers and servos are good to go at that voltage and are run direct - not regulated at all. Regarding ign. module input voltage, many are running those direct now as well (when using A123/LiFe), and reporting no issues. Myself, that 50 cent diode I use gives me some peace of mind. The new ign. modules, the ones that can run on voltage up to 8.4 volts, obviously are good to go as is. Don't need the fancy Ultra IBEC or diodes....

A source for a reasonably priced solid charger that can charge/discharge about anything (including the Lipos I use when flying elec.) until you get up into the exotic stuff. It needs a 12v supply, and if you don't already have one of those handy, there's info around to convert a computer power supply very inexpensively. This same charger is available in an AC/DC version (has a built in AC adapt.) for about 40.00.

http://www.amazon.com/gp/product/B00...ls_o01_s00_i00

My battery packs are home built (I glue 2 cells together and add my own wire/plugs). They are all the older A123 that are 2300mah. The Revolver is often flown 2 evenings on a single charge! Maybe 6-8 10-15 minute flights?

I got my cells from a guy based here in the midwest that sells them on Ebay or direct. He uses them in a business he has, rebuilding power packs for drill motors, etc. I've talked to him a couple of times now. Easy to get in touch with and to talk to if you have the need. Cells sell for 10.00 each, so a battery pack is 20.00 plus your connectors and your time/trouble to assemble (10 minutes?).

http://www.voltmanbatteries.com/serv...LLS/Categories

Finally, here's a link to some reading material that might help when coming up to speed on the A123/Life and LiPO technology. Nicely written in a manner that was a big help when I was coming up to speed not too long ago-

http://www.hangtimes.com/weightcompare.html

http://www.hangtimes.com/a123rxsetup.html

http://www.hangtimes.com/a123_batter...iants_faq.html


Did I mention I'm an A123 convert?

BTW, I need to go up and edit my last post. Those Hextronic servos are digital (no clue what I was thinking when I wrote they were analog!), and they center well enough for me? I don't notice any issue with them anyway. Not going to say I would use them for contest flying, but for sport use I think they're fine.

-Al

wjcalhoun

Hi Don
In answer to your questions

1 - I find that i use ~400 mAh per 15 min flight, and i suspect that your energy use would be similar with the savox. {But note that i use a BEC to power my ignition, wihch accounts for ~125mAh per flight; receiver servos alone are more like ~260-290mAh} Most of us don't like to draw down more than 50% of the rated capacity. I want to have the option of 4-5 flights in an afternoon (1600-2000 mAh), so i have a 3600 mAh in mine. If you are comfortable drawing down further, you could use a smaller battery. For a bigger plane (30cc and up), I install redudant batteries (e.g. 2 1800, or 2 2100), but for a small plane like the R70, i have simply gone with a single battery. How big is mostly doing the arithmetic, and making a judgment about how far down you are comfortable drawing from your batteries.

2 - I bought a Triton II from Tower, which worked fine. I have since upgraded to the Hitec 4-channel, so that i can charge 3 batteries simultaneously in my 50cc birds, and it is great, but that may be more money than you want to spend. I also hear good things about cell pro chargers. As ahicks said, you can save a bit of money if you already have (or can build) a 12v power supply of adequate current delivery; i personally like the convenience of A/C which has informed my choice of chargers.

For the voltage issue, if you are flying LiFe, they hold 6.6 almost entirely throughout the charge/discharge cycle (7.2 for a few seconds just off the charger). No problem with standard servos. If you go with LiPos, then you are dealing with 7.4v and most people recommend either HV servos, or a regulator.

+1 on ahicks recommendation to look at th hangtime website - outstanding information.

Luchnia has articulated some of the main advantages of LiFe technology; i like that i can charge when i return from the field, and have the batteries still ready to go weeks later. After flying, my batteries are generally fully charged after about 20 min on the charger. They can also be safely charged IN the plane, which cannot be said for LiPo technology.

microdon2

My Feedback: (47)

Luchnia \ Ahicks \ WJC - thanks for the great info. These LiFe's sound very attractive. Specially love that they do not lose charge AND that they charge quickly. So with LiFe's I could choose which planes to fly THAT DAY?? Wo...

drube

Double post..

drube

Bill, where can I buy the Savox 0251 and 0252?
Thanks for the info.