Thanks for an informative and enjoyable video. I enjoy my rubber powered Hangar Rat, but now after seeing the video, I guess i'm going to have to build an electric Rat. Thanks for sharing this fun project.
Thank you! I probably spent as much time editing the video as I did building the plane! I think it's important to try to use music, chapter headings, teach a little something in each video and entertain. This one is definitely worth watching to the end just to see me fall on my behind! (or "keester", the proper aviation term for it!)
Thanks for the footage Steve! Very little video editing needed other than some pan and zoom and cutting out some dead sections (and adding some subtitles for clarity). By contrast the beginning with the plans and build photos took about 4 hours to edit. Your camera has nice high resolution, and I love that the Watervliet Dome lighting doesn't make everything look greenish - the lights at the Chase Sports Center are weird.
Steve, FWIW, I have revised the plans and can give you a set of them to distribute to your club (much better than what I gave you before at the Christmas party). Just let me know how many you'd like to have.
It'll be posted here after the weekend: www.rcgroups.com/forums/showthread.php?3193427-The-E-RATTA-3-channel-Hanger-Rat-conversion-(balsa-indoor) If you don't have a printer than can handle 11x17 Ledger paper, let me know.
Wing is 21" x 4", so wing loading is 0.4g per sq. inch. The Microlite covering (0.6 oz per sq. yard) was tricky and I don't recommend it for this model. I could probably have made it lighter with a couple fewer gussets (they were only added to prevent warping when I ironed on the covering - unnecessary if you go with tissue), a smaller battery (placed further forward) could have been used, and smaller gauge wire for the landing gear (but I was just using whatever I had on hand).
Im thinking of some ways to make it light enough to use my old mini vapor electronics. It‘d have to be under about 12 grams, but I think with very light balsa, and thin Mylar covering, that should be doable.
@Copterdude I'll print a set of plans for you today. I used the standard Champ brushed motor (PKZ3516) and for electronics I used the receiver/servo "brick" from the Night Vapor (3-Ch Rx/ESC w/LED Port: Night Vapor PKZU1152. I could easily add lights someday). I think the servos on the mini vapor brick would be adequate as long as you make your hinges very thin (mine are made from scotch tape - you can see this in the video. I can show you how to make them). The thing I'm not sure about is how many Amps the ESC on a mini vapor brick is. With control surfaces, push rods, landing gear and mounting block for the Rx I'm curious just how light this plane could be built. If it's too heavy, the stock mini vapor motor might struggle to get it airborne. Running a brushed motor at full throttle will burn it out after a couple hours. A bigger motor will add weight in the nose where you probably need it, and will last longer because it doesn't have to work as hard. I found that the ESC in the PKZU1152 is the same as the AR6400, so plugging in a bigger motor (they all use the same plug) was an easy solution.
You can save a good deal of weight with an all-balsa construction (I used basswood for the fuselage & LE of the wing. Also, I made all of my ribs full depth because I wanted a stronger wing. The plans actually call for just the first rib to be full depth. This would save a lot of weight. Also I have a basswood rudder instead of balsa (again I was going for a plane that would be able to survive some bumps and hanger rash). Use .25 wire for the LG (I used .39 which was all I had on hand). Finally you can delete the rear struts if your wing isn't warped like mine was after I covered it with the Microlite. Here is a rubber powered version that came out at only 6.9 grams: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ncruhYv4e2Q.html
@@MasboyRC I was a bit in disbelief, as I'd marked which side of the plug was which with a red marker. But I think the marker ink must have wiped off or smeared at some point. Just goes to show, when doing a maiden like this, bring your tools to the aerodrome! It was quite a thrill to fly it the first time, with my 18 year old son by my side :)
I didn't wait to actually fly it until I was in a big space. I had run up the motor before then, but not with enough thrust to notice it was running backwards. Anyway it was a fun project that I learned a lot from, and that's what matters most. Merry Christmas to you too!
Hi. I'm building one right now! I don't know whether to cover it in litespan or tissue with a very light application of 50 50 thinned dope. What do you think? What did you use?
I used "Microlite" covering. Made by Coverite. I found out about this stuff because it's what Stevens' Aeromodel sells you when you buy the "completion package" for one of their models. It is extremely thin and light. Tissue would work too. I think whichever you have more experience with. Just make sure not to warp the structures. That's why I added gussets to the outer-most wing ribs.
I have seen the photos of the build in the rc group. You had covered the parts using microlite before joining the parts. Did you strip microlite off at the joints during gluing? What glue did you use? I am building one. Thank You.
I used thin CA throughout the build. I didn't strip the covering off to glue the hinges, if that's what you are asking. The rudder and elevator were covered separately. The hinges are made from two layers of scotch tape. I cut slits in the balsa for the hinges with an x-acto knife.
@@altbob For example attaching the rudder to the top of stabiliser.From the photos it looked like entire stabiliser was covered on the top. Did you strip off the covering at the area where rudder meets stabiliser?I will be using ca.Thank You
@@altbobThanks for the info.i was about to cover the stabiliser,rudder and fuselage. I dont know how many times i have seen this video. I have no rc expeience. But I have built the rubber powered hangar rat 2 years back.Your video is the inspiration to try out the three channel rc version.I just completed wing covering job. Its not really pretty. The heating job was a pain. I am planning to use the oversky brick.Joshua Finn from J&H Aerospace helped in providing an oversky brick with a soldered motor connection. Earlier i messed up another oversky brick. i experimented with . 039 carbon fiber rod for the push/pull rod because 0.020 cf rod was bending when pushing. The servo motor in the oversky brick got bricked But later i used shrink tube as a guide for the 0.020 cf which seems to work.
@@johnsamuel10 No need to cover the fuselage. It's just a stick. I painted it red. Covering with micro lite or any of the really lightweight heat films is very tricky. Use very low heat to start out, just to tack the film to the leading edge and trailing edge, bit by bit, starting from the mid-point and working towards the edges, then use only as much heat as necessary to stretch the film taught. Too much and you will warp the wings. Frankly, tissue is easier, but will not give as much strength or durability. Not familiar with oversky, but half the fun is experimenting and learning something new! You shouldn't need much RC experience to fly this - it's very slow and gentle in the air. Just keep everything straight and true during the building process and you should be ok. Good luck!
Not sure which plans you are looking at. The rubber- powered original hanger rat has CG very far back. The RC one that I made has CG more standard 30%+/- back from the LE. My plans are on RC Groups: www.rcgroups.com/forums/showthread.php?3193427-The-E-Ratta-3-channel-Hanger-Rat-conversion-%28balsa-indoor%29/page2
Thanks, I think it's one of my most watchable videos ;) I saw many variations in the different plans available online. The Hanger Rat is highly amenable to tweaking and makes a good student project for this reason. I went with 1/16" wing incidence, and I've seen plans calling for up to 1/8" incidence. The plans are also interesting in that they don't call out a specific position for the LE of the wing. They only show were on the airfoil's the CG should ultimately reside. At first I had the Rx and battery way up front, which would have put the wing almost at the front of the fuselage. I wanted more nose on my plane, so I moved the RX back towards the middle of the stick fuse. The final arrangement: LE of the wing is 3" from the front of the stick (keep in mind however that the prop shaft sticks out another 3/4"). CG is 1.5" from the LE, which is 7/8" forward of what the plans indicated. FYI, wing chord is 4" I put the motor right on the datum. Some build logs looked like they had 1 or 2 degrees down thrust, and I was ready to try that but it didn't seem necessary in the end. Perhaps because I used less incidence on the wing?
I typically use a 1S 70Mah battery. Anything up to 120Mah is probably fine. Bigger than that might be too much weight, but if it gets off the ground, good for you! C rating of 15 to 25 is normal for a plane like this.
@@rva1945 Yeah, the capacity will degrade over time, so old batteries should probably be retired at some point. No sense flying around with extra weight that isn't adding anything to performance or duration.
Thank you! I find I get very good flights with a 70mAh size 1S battery, such as the eFlite 70mAh 1S 3.7V 14C LiPo Battery (EFLB0701S) that is used with the Vapor airplane. I believe this battery weights about 3 or 4 grams. I have flown the E-Ratta with batteries weighting as much as 7 grams with very little effect on flight performance (just have to increase throttle speed slightly).
@@altbob Thank you. I am still learning rubber power but intend to go into micro rc like the Hanger Rat. I dont yet know the detials of rc components. Do lipos have an in-built protection board on them? Do these small 1S lipos have one, and are they supposed to have one? I am looking at some batteries on Aliexpress and elsewhere and they dont provide such information. I was seeing the 70mah Eflite lipo on Amazon and one query was about the protection board; someone had replied that it doesnt have. www.amazon.com/flite-70mAh-3-7V-LiPo-Battery/dp/B005LH2PPA
No, it's just a simple lithium polymer cell. There are no internal electronics. You should always use a quality balance charger with overcharge protection built in. Max charge to 4.2 volts. You should also use an electronic speed control with a low voltage cutoff programmed into it so that you do not over-discharge your batteries - this will ruin them and could also turn them into a fire hazard. It is recommended that you never fly a batter below 3.6 volts (although some will tell you that 3.0 is the danger line, I stay well away from that!) Store your batteries at 3.8 volts and they will last for many, many years.
@@altbob I was looking around for small servos. What torque does your servo provide and how much does it weigh? How much torque is usualy needed for such small rc planes?
The hinges are just cellophane (Scotch) tape. So little resistance that the pushrods don't flex at all. If they did, I would have added a guide (maybe a small bit of straw - like the kind you stir coffee with) along the pushrod and attached that to the fuselage stick. The pushrods are carbon fiber, FYI.
@@rva1945 The diameter of the rod should be just thick enough that it doesn't flex, and no thicker (because you don't want the tail weight). If it's thick enough it can be CF, steel music wire, bamboo...whatever is on hand. They all weight within fractions of a gram of each other. The key for me with a plane like this is not to stress about anything and just get it flying well and looking pretty. Scale models are a totally different Zen! I love doing both.
@@ollivierhesse7277 Happy to help Ollivier. Much more info here if you need it: www.rcgroups.com/forums/showthread.php?3193427-The-E-Ratta-3-channel-Hanger-Rat-conversion-(balsa-indoor)
You can grab a set of my plans here: www.rcgroups.com/forums/showpost.php?p=40885535&postcount=19 The fuselage is 1/8" x 3/8" firm basswood (you can use balsa to keep it lighter).
Hi Bob, I just found your channel. It's building and indoor flying season again! I like to build rubber power to electric RC conversions too. You did a nice job with the Hanger Rat. I thought the rudder looked small but it does the job. Thank you for the inspiration to build one. Where is your indoor venue?
The indoor venue shown in this video is the Watervliet Dome, in NY. I also fly indoors at the Hudson Falls Chase Sports Complex (see my "FlyJam" videos - such as ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-MFuUJKoMBGA.html) and the Schenectady Armoury (shown in the indoor maiden video of my Chitty Chitty Bang Bang RC flying car ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-vCqQHo-eyWI.html).
Hi Need help I didn't getting any lipo 70mah 14c in India Can I use 100 Mah lipo but they didn't mention discharge rate of that battery. One is available 1s 360mah with 30c Bu I think it will increase wait of plane Also available a 80mah lithium Ion battery can I use it for this ?? Also didn't get micro connector to connect motor with f949 and connector for lipo Planning to solder or connect it correctly ( not good idea but no option ) One more help I need About vibration of motor with propeller
The Mah rating is only the capacity. Bigger number means more "gas in the tank" and longer flights. Anything up to 120Mah is probably fine. Bigger than that might be too much weight, but if it gets off the ground, good for you! The "c" rating is the maximum Amp draw possible with the battery. A higher c rating means a higher quality battery with less internal resistance. Just because a batter has a high c rating doesn't mean you need to fly the plane that way. Keep throttle low with a plane like the Hanger Rat. C Rating of 45 or higher is useful for 3D flying. C of 15 to 25 is normal for a plane like this. If your propeller is vibrating, it could be unbalanced (use a balancer to make sure the blades are exactly the same weight), or your prop shaft might be bent, or the propeller is not mounted properly on the shaft at a perfect 90 degree angle (it should look like a capital "T" from all sides).
I'm looking to get started in the hobby, and maybe leading an afterschool clubs at my school( I teach science to 2-5). Any tips on electronics? Can you share the electronics that you use? I could send my email or something.
I used the servo/receiver "brick" from the Night Vapor and the motor, gearbox and propeller from the Champ. You can get these on ebay or order from Horizon Hobby. Much more information on my build log: www.rcgroups.com/forums/showthread.php?3193427-The-E-Ratta-3-channel-Hanger-Rat-conversion-(balsa-indoor) Best of luck!
