microdon2

My Feedback: (47)

Kit - the plane looks good. Good luck on your maiden!

Rodney C

My Feedback: (1)

Yay!! Thanks for posting a pic of the R70 with a DLE20 mounted nice and clean. I've been looking for a pic showing this setup. I've had my R70 up and flyin great with an O.S. 75AX mounted for a couple of months, however, after reading everyone's reviews and watching the videos posted on YouTube showing how well this plane performs with a DLE20 I'm thinking of yanking the O.S. out and slapping in a DLE20. I'm a "Sunday afternoon sport flyer type guy" (3D is cool but I can't do it yet) and have a Funtana 125 and a Phoenix Models Edge 540 both running DLE 20's and I absolutely love this motor. I know a DLE20 will likely make the R70 crazy fast considering my typical style of flying but that's okay. I know how to practice throttle control/management and welcome the short adrenaline rush associated with making a fast fly-by every now and then, LOL.I initially tried to test fit a DLE20 on my R70 but it stuck out waaaay to far at the front of cowl so I gave up and opted for the O.S. 75AX. The new Evolution 15GX gas engine was being considered and it's a direct drop-in where the O.S. 75AX now sits (I have one on my Phoenix Extra 330 right now, which replace another O.S. 75AX I had) but for approximately the same price I'd prefer to go with a DLE20 on my R70. Based on the picture you posted it appears my test fit problem was from the type of engine mount I was attempting to use. It was the type that slides together at the firewall and I didn't feel comfortable cutting it at the time. If I may ask; would you mind posting a picture of your R70 with the cowl on? Or are you running it without a cowl? Again thanks for posting the pic show how your DLE20 is mounted. It really helped me a lot and maybe some others too :-)

microdon2

My Feedback: (47)

Rodney C - The stock mounts work fine, but I did have to cut out the upper cross-members to make room for the carb. The distance from spinner plane to cowl ended up being 1/8th.

ahicks

My Feedback: (2)

Somebody on another forum was talking about how "complicated" the carb linkage was on the DLE20/R70 install. Knowing full well that was not the case, I dug into the photo "Gallery" by clicking on the link at the top of the page in this forum to come up with a couple of examples of just how simple the install really is. Those same pics show both of the mounts being discussed. It's pretty clear the stock mounts are easier to instal, though I believe the "sliding" type may be stronger?

http://images.rcuniverse.com/forum/U...21/Id97282.jpg

http://images.rcuniverse.com/forum/U...51/Jh15558.jpg

Rodney C

My Feedback: (1)

WOW!! Those are even better shots!! I like that throttle and choke control arm setup. I was already imagining the nightmare I might have trying to figure out how to run the rods passed the fuel tank and connect them to a throttle servo inside the fuse. You guys are frickin genious' :-) Thank you soooo much!!! I thing I'll be placing an order for a DLE20 from Tower Hobbies shortly :-) Anybody interested in buying an O.S. 75AX nitro engine w/muffler? Purchased brand new about 3-months ago? Think I'll let it go for $175.

JH313

Quick question on the spinner.  I got the recommended hangar 9 prop adapter, but i noticed it takes a 10-24 bolt.  Should I drill out the hole for the spinner cone.  Also, when I test fit it, it looks like the back groove of the spinner is touching the te of the prop.  Is this normal, can it be remedied?

kcarson

Rodney - Yes, I will run it with the cowl but never do until after a couple of "tweeking" flights. As others have mentioned, there are some options concerning the throttle setup and placement of the servo. I elected to get away from the firewall area. I could do this easily since I did not use the stock fuel tank and have enough "side" room to run a throttle rod. It works very well although I did have to program a throttle curve for the DLE 20 (to me, it has a very narrow band) and it seems to work good so far. I will post a photo with the cowl on. I forgot the cowl today, so I was not able to put it on until we returned from the field.

You will not be disappointed with the DLE 20 in the Rev 70! It performs just great! Plenty of speed and the sound of that DLE 20!!!!! The maiden went well - about three flights in all before the rain came (the last one cut short due to rain). I always program 3 rates and It was flown today on the middlerates - very quick and responsive!

More to come!

Rodney C

My Feedback: (1)

Cool, no rush. I was just curious and wanted to see how much space you ended up with between the spinner back plate and the front of the cowl. With the O.S. 75AX I'm running on my R70 the spacing is very close about 1/16th of an inch, which give a very clean, sleek, flowing appearance. Glad to hear your flight went well today with the exception of the rain out. We had heavy clouds, overcast and some drizzle hear too :-( Hoping tomorrow will be bright and sunny with a light to mild head wind at our field. I need to practice more touch-n-goes to improve my landing skills.

microdon2

My Feedback: (47)

I also shoot for a 1/16th gap between the spinner plate and cowl, for that clean, sleek look. As mentioned, though, 1/8th is the best I could do with the Rev 70 \ DLE 20. Just curious - was anyone able to get 1/16th on this plane \ engine combination? If so, what engine mount did you use? (I used the stock and removed the top cross-beams).

JH313

I've been working on the build modding as I go, and I will be sure to put up all of the pictures at once.  I wanted to ask about the firewall, though.  When I look at mine, there is already triangle stock on the inside wherever it wouldn't interfere with the blindnuts.  Did anybody else have this?  I also noticed that the thickness of the firewall is over 1/4 of an inch, the minimum according to the DLE manual?  So, should I do any modification to it?  I do not know how to fiberglass, though, so any other suggestions would be great.

prr6100

I have upgraded my 70" Revolver with a DLE 20 engine, the combination is great but I am having some concerns with my battery. I installed a Hobbico 3200 mah LiFe, and am currently running both the engine ignition and the servos' etc off of it. I have been slowly getting used to the new plane's power and have been monitoring the battery carefully. I charged it with my computer charger with balancer plug attached. I have a digital capacity controller to check both cells and the remaining capacity of the battery, after two 6-8 min flights the capacity remaining was down to about 55%, this concerned me some, so I charged the battery then. The charger put in about 280 mah into the battery and then gave the full battery indicator, the capacity of the battery was then at 92% according to my checker, Both cells were within .03 volt of each other. My question is, is the percent capacity remaining correct or is the amount of mah that I put back into the battery more correct, should the battery last more than 2-3 flights? or is it normal for a LiFe battery to discharge much lower and still be ok? I am running 2.4 receiver, Futaba 3010 servos, last summer I had a Magnum .91 four stroke and flew at least 5-6 times with a NiMh 2500 mah 6 volt battery with no problems, thanks.

ahicks

My Feedback: (2)

"My question is, is the percent capacity remaining correct or is the amount of mah that I put back into the battery more correct?"

Common usage of your setup is monitoring what you put back in? After doing that for a while, you'll get a feel for how many flights you can go on a charge. I generally fly my Revolver (your setup w/2300mah A123) a couple of evenings (4-6 flights) prior to charging - and it's using some servos that are total pigs when it comes to how much power they use.

"should the battery last more than 2-3 flights?"

Oh yea.....

"or is it normal for a LiFe battery to discharge much lower and still be ok?"

You can drain it down to the point of about 50% of the battery's capacity - though it's a good idea to confirm the battery's capacity on occasion by cycling it?

wjcalhoun

prr
I have a similar setup: DLE20 with ignition running from a BEC, driven by a LiFe3200 mAh single battery. I have Futaba 9452 digitals all around, so they draw current more than standard servos would do.

As ahicks says, just monitor what you put back in. Battery voltage monitors are pretty much useless for LiFe batteries (or A123s), because the voltage (y-axis) / capacity (x-axis) discharge curve is flat for most of the capacity. That is, the voltage of LiFe drops immediately after you begin to draw current from 7.2v or so, to about 6.6 volts, within a few 10s of milliamp hours. The voltage is then stable to within 10-15% of battery capacity, after which voltage can fall off sharply.

My R70/DLE20 set up as above, draws an average of 421 mAh per flight. I keep a detailed flight log, so that is a pretty good estimate for my plane. I would not pull the battery down much below 50%, so for me 4 (or maybe 5) flights would be all I would do on that battery before charging. Were I to go out to the field to fly only the R70 for a day, I would take the charger. I can have the batteries full again within 20-30 min.

I would think it is safe for you to assume a draw of no more than 450 mAh for the first few flights. Fly, measure what your charger puts back in, and get your own empiric estimates of flight capacity. So many things will influence the specific number - length of flight, how hard you maneuver, how fast your engine is turning (increased ignition draw with increased RPM), etc, etc.

8.point.roll

Wow, you guys are using a big battery... I didn't realize they were made that big. I purchased two 2500 Mah LIFE batteries. Do you think that one of these in the Revolver 70 w/ DLE20 will suffice? I will be using Savox 252MG dig. servos.

wjcalhoun

8pr
Battery size is pretty much personal preference and flying style; one 2500 would do if you limit to 3-4 flights, I would think.

The fuel tank for gas is huge; the DLE 20 burns ~1/2 - 2/3 oz / min at WOT, so 25-30 min flying time is possible. A smaller tank would make some of the linkages more easy to install.

8.point.roll

Yeah, I guess it is huge. That would be a 24 to 32 min. flight. My fingers would break off!

I hear people using a Fiji bottle or something like that. Do you have any suggestions for manfacturer and size of tank (maybe 8-12 oz ???)

prr6100

Thanks for all the input, I will continue to monitor the battery and how much it takes to replace the used mah, so far I had two flights one evening and replaced about 280-300 mah into the battery. I am used to NiMh and watching the voltage drop as to when to recharge.

kcarson

Jacob - I did some beefing of the firewall although I really do not think it is required (as my pics above show). I tend to beef first and ask questions later! So far, no problems. I shot this video today of the (actually) second maiden flight. I flew it 5 times today - just cannot get enough of this bird and engine!

https://www.youtube.com/watch?v=F_QXu8XFqKM

kcarson

8-point - I would suggest these:
http://www.aero-works.net/store/detail.aspx?ID=488

Fortitude are the best in my opinion. This is what I have in the Rev 70 and the Rev 50cc. With a 16oz in the Rev 70, one can fly for a good 15 minutes plus there is lots of room for linkages and the such.

kcarson

I would agree with everyone else. I can get 3-5 flights out of the Rev 70 with DLE 20 and the same out of my Giant Big Stik with an OS GT33. That is, I also do not let the batt's go under 50 percent - not worth it to me! In both aircraft, I have 2000mah MIMH's - one for the ignition and one for the receiver.

ahicks

My Feedback: (2)

Enough newbies here to make this worth going over this again. Regarding beefing the firewall, I think there's a place on it that does need reinforcement. It's at the bottom. The joint where the firewall and landing gear mounting plate meet. There are those that will reinforce it there before it pulls apart, and there are those that will fix it (and the bottom of both wings) after you've pulled it apart. It's a well known issue among those of us that have been flying this plane for a while, especially from grass. Keep in mind Chinese plywood has very little strength internally. It might just as well be sawdust between the inner and outer layers. It's brittle!

Here's what it looks like if you wait (assuming you are lucky and get a clean break):
http://images.rcuniverse.com/forum/U...05/Am73883.jpg

Notice the almost total lack of structure holding the front of the landing gear plate to the firewall. This is a REALLY highly stressed area in the case of a slightly less than graceful landing. That plywood plate is going to pull loose at that joint and twist right out of there unless you do something significant to stop it.

I saw these pic's and used this plan - slightly modified - as I was doing mine. I decided to go a little smaller (lighter), and just concentrate my reinforcement on the stress at the firewall/landing gear plate joint, so my reinforcement stops at the rear of the landing gear plate, but uses the same width as shown. It does not continue to the rear like the pics do. You can do as you like. I made mine from alum. roof flashing available in rolls for about 5.00 at Lowe's and Home Depot. It's just the right thickness to be easy to work with (cuts easily with tin snips), and pretty stiff, but not too stiff. The angle bent into it easily done by hand by sticking one end into a vise and just bending it over neatly. If you get one of those rolls, you'll have enough material for about 10 of these, so if you mess the first one up, just make another!

http://images.rcuniverse.com/forum/U...68/Ge95595.jpg

http://images.rcuniverse.com/forum/U...68/So42657.jpg

I just used the landing gear mounting holes to hold it in place on that side. On the firewall side I drilled 8-10 holes pretty much randomly and used small short sheet metal screws to get a good mechanical connection on that side.

This reinforcement, as installed on mine has held up to a terrific amount of abuse! I have seen the landing gear flex to the point they've been straightened right out, with no apparent damage!

Best of luck!
-Al

8.point.roll

I thank everyone who chimed in on my questions regarding fuel tank replacement possibilities and battery size.

JH313

Ahicks, thanks for the answer.  Is this reinforcement for the gear only or also for the firewall?  I have already reinforced the gear with a ply block behind it, pictures will come when its done, but if this is necessary for the firewall I will need to do this too.

ahicks

My Feedback: (2)

Firewall is beefy enough as long as it's glued well. It generally stays together pretty well? This is just about holding the front of the gear in place. Without it, the block holding the gear will pull right out of the firewall. -Al

8.point.roll

In reading some of the more current postings, I am curious:

microdon, how did you make out with the repair? just curious if there was something(s) that you may of found that would lead you to suggest we R70 newbies should know in the building process.

Thanks,

8pr