Braiding rubber motors for rubber powered airplanes
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- čas přidán 25. 01. 2019
- Keep your CG set and your noseblock in by braiding the rubber motor. Suitable for any airplane with a freewheeling propeller and some with folders, Peanut Scale all the way to Wakefield and Mulvihill.
Braiding BIG motors: • Ripmax Gipsy Wakefield...
Models in the video:
Blue Ridge Special: volareproducts.com/index.php?...
Maxout IX: jhaerospace.com/product/maxout... - Věda a technologie
so after you've wound some initial cw turns in the loop, then at 11:02 when you hit the reverse button on the winder looks like it unwound ccw , then the motor is ready , is that correct?
stan burdick yes, that's correct.
@@joshuawfinn…...... that's what was hanging me up is I couldn't see what was happening when you un-done the winder, so I had to make a few motors to figure it out...maybe this will help others too...…..o
stan burdick fair enough. :)
...Except that it wasn't really a "reverse" button that was pushed at 11:02, correct? It was just a button to unlock the winder, allowing it to freely rotate. So by unlocking the winder, the rubber then was allowed to release its stored energy (causing the free-wheeling winder to rotate) until the rubber attained its lowest energy state on its own, at which point each of the two prebraided strands of the rubber has braided itself around the other in sort of an "opposing corkscrew" configuration?... Maybe?
Just wanted to make sure I understand the quick rubber action happening right after the button was pressed. Instead of a locking winder thing, you could use say, a nail pushed through a plastic milk jug top and bent into a hook, hooking the rubber onto the hooked nail, keeping it from rotating until ready, then releasing the nail allowing it to freely rotate, thus allowing the rubber to do the final braid action (i.e., equivalent to pushing the winder unlock button).
Or something to that effect. 😁
This is what i just need for my outdoor Senator and my indoor Ota, thank you Joshua .
Greetings from Holland
I just bought some Tan Super Sport rubber for my ultralight Lancer. This is exactly the video I was looking for. Thanks!
-David S.
Very helpful! Thank you for sharing your expertise with free flight. I am really enjoying learning and building again.
Thanks for the info, I've always wanted to know, this is a big help!!
Your videos are a pleasure to watch!
Great video. Obviously from a fellow physics nerd. Just getting back into it. Thank you.
Great video! Thanks to your content and contribution to the community over the years I feel like I can start getting better flights. After braiding I get much better results. Now im looking for the dow 33 and experimenting with different rubbers. Thank you!
I came to your video as a weaver of all things, and it was exactly what I need. You see I am making a special loom out of a wire shelving unit and employing rubber bands to provide reverse-torque as the warp-spools unwind keeping the entire warp constantly tense and straight.
I am no rubber-powered aviation hobbiest, however your expertise has helped a lot with my fiber arts pursuits! Thank you for posting.
ps I also happen to braid my hair c;
And thanks for sharing your knowledge. The only time I tried braiding, I didn't wind in the same direction so it didn't tension and was a waste of time/energy. Now I know. :)
Thank you sir I've watched this video at least a half-a-dozen times and I learned a little something more every time ❤️❤️❤️
You're a huge help I love your CZcams videos buddy thank you
Very helpful,thank you !
Just what I was looking for, Thanks for the great information. I wish I could come over and see it in person, I'm just starting out....
Glad this has helped you! Also, welcome to free flight!
Thanks again Josh 😁
Great beginning:D
Thanks very much for sharing your knowledge I have picked up some useful tips.
This is really cool. In fly fishing we do a similar technique with leaders, we call them furled leaders, I guess you could call this a furled rubber motor, lol.
Nice instructions...thank you
Excellent video! Thanks for the detailed explanation. You are very didactic. Regards from Brazil!
Thank you!
Interview the bird. He/she obviously wants to be internet famous. LOL
Thank you for sharing your very valuable information and demonstration on rubber motors! I have been trying to learn about rubber motors but the info. Is hard to come by, thanks again.
Excellent! Thanks
I'm a big fan of yours I love the way you get a really wide circle with your planes and I love to build them I'm just not quite at the stage of flying them
Thanks for this! Going to give it a try tonight in my Guillows 16" span P40 with 4 strands of 1/8 150% of peg length. Wish me luck! (If I can get this thing to fly well I'll feel like a champ!)
trewheeler let me know how it goes!
How did the flight go? I'm working on a Guillow's 16 inch span FW 190 and was starting to consider a motor.
Interesting. I might just try it your way, going forward. I had been following Don Ross' Rubber Powered Airplanes book as a guide. He said that you should wind the one half, then combine the halves, and wind back the other direction. Yours appears to have more tension - although it could be that I didn't follow his technique perfectly. In either case, braiding, at all, has helped significantly since I first started rubber power a few weeks ago.
The biggest issue is that with his method, now you have to keep the ends of the motor secure, separate, etc, and you still have the motor spilling off braiding turns over time. With what I do, keep the motor on a crocket hook and rear sleeve, and the turns never get lost even when taking the motor out for storage. And I don't remember where I learned the method I use...I wish I could so the guilty person could get credit.
Very nice ! Make another video about it
Thank you Sir!
Thanks for the shout out!
VolareProducts anytime! Y'all make the cool stuff!
Hey Josh, Is there a formula or rule of thumb to determine the length of the initial loop for a four strand braid?
This is excellent. Thank you so much for these details. I'm an old guy that likes to build rubber band models on occasion and I can never get the rubber right. I just built a Sr Miss Canada, did a great job, but broke the motor by not winding it properly. I need help like this on the basics. Thanks again.
Glad to help!
I had no idea there was so much involved in a rubber motor.
Interesting video, thank you. One question, how do you determine the maximum winds for any given motor size?
Steve Styx wind a short test piece of rubber of the same cross section and a known length to destruction, then divide by the length of the motor, and now you know max turns/unit length.
Hi, where can I find long rubber bands like that? I cant seem to find some anywhere? Also the whole propeller assembly? Thanks
David Vorbeck faimodelsupply.com is the world distributor for this rubber. Be sure to get some Dow Corning 33 to lubricate it too. :)
Hey buddy! Wouldn't a snug fit on the nose plug solve the problem of the noseplug falling out? This way you won't need to do the braiding so you'll get some extra turns?
PaperFun, they never stay snug. Eventually they get loose, and with enough vibration even a snug plug will fall out. Also when you shim the thrustline, everything gets loose. Perhaps most important, though, is that an untensioned motor will always bunch in the tail. You'll never get the same cg twice with an untensioned motor
PaperFun by the way, the turns lost are pretty insignificant in my experience. Losing 50 turns out of 2000 isn't going to change anything on the stopwatch when flying outdoors. Indoors, you'll never be in glide anyway, so no need to braid there.
@@joshuawfinn Aha I see, CG shifts are indeed very undesirable for a trimmed plane, especially backward shift... Interesting food for thought! I'm empressed how well everything is thought through to optimise efficiency! Thanks for your answer!
PaperFun, there is definitely a lot of work to do when you're trying to get the most out of an airplane. That line "it really is rocket science" definitely applies here.
Hi Joshua.
For the basic 2 strand loop, how many turns to put in for a particular length of motor like you do at 18:45? So I am flying a beginner Squirrel and want to put in a longer 18" motor for a prop hook to rear hook length of 8". How many turns should I put in so that the braided motor come at about 9-10" length?
Ashutosh Bhakuni usually about 10 turns/inch is a good place to start.
@@joshuawfinn Thanks. And the number of inches would be the total length of the strand (eg, 18" in my case) or the length I want to reduce (eg, 8" in my case to get a 10" final length)?
ever try a double braid?? am experimenting with that now
Something Ive had good luck with is use a clear plastic sewing bobbin that holds the rear motor end together to the rear peg and push it back with a "loading stick. then push your rod/tube thru the bobbin center, then pull the loading stick out the front ......the bobbin weights a whopping .79 G
is there a book you can advice ... i want to start peanut scale ... building the model i am ok ... but the rubber motor thing is a miss-tree to me !!!
Great video, though one thing that I wonder about is where you drop the attached rear peg tube through and push a wire through it. The tube is longer than the width across. Everyone else seems to use a stuffer stick and then slowly push the tube through the end of the rubber. Twist ties keep the rubber loop open. That has not worked all that great for me either. Just wondering if you had done your method with say a 20 strand motor?
Bill Kuhl I use this for everything...even up into the 24-28 strand range. Works great!
I watched this again, so the short tube that the rubber is wound around in the rear stays inside and then you push another tube through it? This is starting to make more sense.
Bill Kuhl bingo!
@@joshuawfinnI thought about this more and this might be brilliant. Trying to keep an open loop with the rubber has not been easy. I tried using twist ties but that did not work well. I ended up cutting in a hole in the covering when working with stuffer stick.
Thanks for that info. I've been braiding but not always successfully, now I realise that I've just not put enough winds on. Bring on Spring! Btw, what is the name of that red,white and blue airplane? It's a beauty!
Crashrr that's a Maxout IX. They're a lot of fun. :)
Is it ok to leave lube on the motor?
Or should it be washed with soap and water after each days flying?
William Dempsey I never wash them or anything unless the get dirt on them. I do relube on a regular basis.
Mantab bang
I knew this method as pre tensioning,back in the day you could buy bobbins which I make by hand now from wood,if you have a Rowan tree in your garden then they are ideal for making rubber model bobbins,the centre of the branch is hollow so all you do is to slice off the required widths and you have a ready made bobbin ! regarding knotting rubber my father taught me to hold the two pieces together and stretch them slightly tieing with wool and cutting off the surplus,your method of a dab of cyno is a good one.
Where can I get brass nose threaded buttons from ? I use these on my rubber scale jobs rather than the plastic buttons.
Stabbing a bobbin is so much easier than placing the bamboo dowel in place.
For a winder I use one made from Meccano that was illustrated in a copy of 'Aeromodeller' magazine it has 3 to 1 ratio which works well,I have yet to make a suitable stooge,do you have details of how to make a simple one ? thank you.
What lubricant are you using on the motors? I couldn't quite see it from the video. Also where did you find that winder?
Matthew Burns Dow Corning 33 from Volare Products. :)
Winder is an old Geauga...sadly no longer available
Ok thanks! 👍
@@joshuawfinn i used (hand powered mechanical) hand drill, before watching this video(not impressive results). I'll surely apply this technique with hand drill in near future. Thank for nice videos.
@@DrPiyushLashkari Make sure you've drilled into the shaft on the hand drill to mount your winding hook. The drill chuck cannot reliably hold a winding hook (Guess how I know).
How much rubber should one use to make rubber motor. Is there any ideal ratio between model and rubber motor weight ? Thank you.
Abid Hussain simple answer, as much as it'll take. Most people find 25-30% of airframe weight is fairly easy and yields a good percentage of max possible performance. Indoors we can get away with 100% and sometimes more.
I can't seem to find any dow corning 33. I keep finding 732 which is a sealant. Any guidance?
Search for molykote 33. Dupont bought out that product from Dow.
Can I do that on my cool new Pinna flyer from you guys?
smokster0604 yes you can!
So forgive me in advance if you explained and I failed to grasp, is there a ratio between the length of the completely unwound single loop and the distsnce between the peg and the prop? Many thanks for your patience
On a stick model like this you can easily braid a motor 3x the hook to peg distance and get it to tension properly when unwound. Enclosed fusages usually end up with bunched rubber motors if you go over 2x.
Many thanks so a sky voyager for example you'd stick with 2x. Sincere thanks
@@nigelhutt9921 sky voyager is a little different. I recommend zero slack in the motors for it unless you're going to pin the noseblock somehow, as the nose tends to pop out if you use longer motors. If you wind good and hard, it goes straight up on 4 strands of 1/8 and does a solid 2 minutes in calm air. Ive pondered making a longer fuselage for one of mine to run really long motors...theoretically would do close to 4 minutes with the right setup.
Many thanks for clarifying things
Josh, you are a great wealth of knowledge, but horrible at keeping a straight face. :) Thanks for sharing your knowledge.
There doesn't seem to be a button on the winder I purchased from you. What do I do?
The red winders are 20:1. You have to count based on that ratio. Unfortunately all of the turns counter winders are pretty pricey.
What make is your winder? Does it have thrust bearings in it.
It's a Geauga 20:1. They were out of production for over a decade until this year when indoorffsupply.com financed the production of a new batch. Very expensive but they're wonderful.
joshuawfinn thanks! If not I will machine one.
Trying to make one of these planes for my kid, where do you get your rubber band material?
The best rubber (correction, the only not awful rubber) comes from faimodelsupply.com and fortunately it's not crazy expensive either. Don't forget to lubricate with silicone oil or armor all to keep the rubber from cutting itself up.
Hello, dear friend, can you sell the aircraft you made? I really want to have a plane for you, I am in Guangzhou, Guangdong, China. Looking forward for your reply, thank you! ! !
When I wind my motor, it unbraids first, then winds. Is that what it’s supposed to do?
Correct. 😀
I'm making a glider and have made all the components. But I am confused as to where to attach the wing to the fuselage. Do we attach the wing to the centre of mass of the fuselage?
For a low ceiling glider, yes. For high ceiling and outdoor, wing needs to be in the first 1/3 of the fuselage, then you add ballast as needed to balance correctly
@@joshuawfinn thank you! Woudn't connecting the wing away from centre of mass, lead the plane to tip forward or backward? What should we do in that case?
@@Kanekighoull add nose weight to move the center of mass. Gliders have to launch at high speed, then transition to a slow glide, so you need a long tail moment to provide adequate pitch damping.
@@joshuawfinn thank you so much! I got it now. So I'll have to shift the centre of mass of required and have a long tail
@@Kanekighoull exactly!
Hello everybody
What rubber lubricants do you use? Here in Switzerland this is not so well known and therefore I do not get any information about it.
I would be happy to receive some product suggestions.
Thanks a lot
Molykote 33 and 55 are excellent. You can also use Armorall, but it tends to spray onto the tissue.
Thank you very much.
Now I am looking forward to thermally active days 👍👍👍
You mention that there's a maximum propeller diameter for each plane in respect to its stability. I'm very curious as to why an outdoor model like this has a much smaller maximum diameter than for example an indoor endurance model, which sometimes have props equal to or slightly greater than its wingspan
Ive always heard prop dia. 1/3 the wing span but am sure thiers more to it
Minimum prop diameter is square root of wing area. A larger prop is always more efficient and turns more slowly, for longer motor run. However, a larger prop counteracts the fin and may affect lateral stability. The proper relationship is between wing area and prop swept disk area. The derivation starts with weight equal to lift, lift to drag ratio to drag, drag equal to thrust, thrust related to swept disk area. The next step goes from thrust to torque and motor cross section.
could this method be used for pistachio or peanut?
Yes, and I've done so many times.
Mantab bang gue dari indonesia salam satu sama lain bang
Which grade of Molykote, light, medium, extreme cold? Would it vary from summer to winter?
Molykote 33, any grade. I've used several over Molykote types and found they either sprayed a lot as the rubber unwound or were so viscous as to impact the unwinding.
@@joshuawfinn Thank you.
is it better than other rubber engines? İm going to try it myself thats why im asking
It's the best way to reliably tension your rubber motors so the models maintain flight trim in glide. As far as rubber, get FAI Tan Supersport rubber. It is by far the best.
@@joshuawfinn ok thank you 👍
Do you braid for all types of free flight planes?
Only for outdoor models with freewheeling propellers.
Thanks. Sent you a message on your website.
I enjoy your vids. Four questions for you: (1) Do you keep the rubber motor with the plane after you are done for the day? (2) How often do you condition the rubber? (3) Do you somehow wash the rubber (I know DC 33 is not washable)? (4) And how do you store rubber strands (of used motors and new ones)? Thanks again for posting. Take care.
On outdoor models I have a bad habit of leaving the rubber in the plane. This is generally not a serious problem as long as the planes are stored in a box in a cool area so they're shielded from sunlight and heat. For indoor models, the rubber gets stored in a freezer and is lubricated prior to each flight. All spare motors, regardless of type, are stored lubricated in a freezer, bagged up to keep them separate.
@@joshuawfinn Thank you, Joshua. I notice that you lubricate them with DC 33. So, you cannot wash these motors before re-lubricating them, and then storing in the freezer. I like you videos as they are very instructive, especially the one that teaches how to carve wooden props :-))
@@windsurfer3329 you can wash the motors, I just don't see any need for it unless you're planning to salvage them for stripping down to a narrower width (we sometimes do that with collections of old F1B motors made from high value batches).
@@joshuawfinn I meant to say what you do with the motor at the end of the day. You remove it, wipe it off from the grease, re-lube and put it back to the freezer for the future use? I guess I am confused about the process of recycling the same rubber for future use? How many times can you use the same rubber, and long is its lifespan usually? Sorry I wasn't too clear earlier.
@@windsurfer3329 ok got it. First off, I do tend to be lazy about how I handle this stuff. And at $35/lb it's not super expensive (the special batches we hoard for indoor are another matter entirely), so if the rubber gets damaged in storage I just replace it. That said I generally want to get at least 10 solid 80% wound flights from a rubber motor. In general, washing the rubber is fine, and it's something you'll want to do if you blow a bunch of strands and retire a motor but find that there's some of it that's still usable for smaller models. If you're storing the planes in a place where it gets warmer than you're comfortable with or too much sunlight, then you definitely want to remove the motors, label them, and stick them in baggies in the freezer. If they're lubed, just leave them that way, as the silicon actually helps preserve them.
What is the best winder to buy? ❤💕
For starting out, a 15:1 K&P from Volare is probably the best option, at least for small models. Look at the 4:1/10:1 K&P (5x the price) for models up to 16 strands, and for larger you'll need a Sidewinder from faimodelsupply.com.
@@joshuawfinn dont mean to hijack the thread but Ive been using a 4/1 hand drill for a year with no regrets, $11 from fleabay
Were is the cg of our plane collocated?
Damiano Collaone which one? There are several aircraft in this video.
There with the with-blu-red wing which you have on the desk at the beginning of our video. Because I also has built a same plane but i didn't know were the cg is collocated so it not flies wery well. Thanks
Howbout doing one for 3 strands
stan burdick ouch. You had to go there. :P
so, from what i see, is you are making an elastic "rope".
Long video. I still don't know how to braid the rubber motor.
I think I miss the whole idea. I see no actual braiding. Looks like you just wind up the multiple strands. How does it hold those initial windings? Whst kind of tools do you need to wind the bands up? The tubing through the band loops would prevent cutting the rubber but just a wire hook on the props seems like it could cut the loops. I have a plane kit to build but there is really no instructions how you set up the rubber power! Could a Zebco fishing reel be made into a winder? At 76 I only h😢ad fuel motors and then electric. Tissue used dope. I need to watch this several more times. Odd the plane kit with rubber motor parts must assume you know something!
Hi
What size alum tubing is appropriate for rear peg for models like FA Moth, Prairie Bird etc? The 1/16" OD tubing used for prop shaft bearing would be ok for the rear peg too?
And you mentioned using another tubing 2 size larger than the rear peg tubing. So for a 1/16" rear peg tubing, I would use a 1/8" OD tubing, right?
I'd recommend 1/8" aluminum tubing for both. Also, on the prairie bird, move the rear peg forward one bay and extend the nose one bay. They really come alive when you make that change.
@@joshuawfinn So I'll get some 1/8" tubing. Thanks for the Prairie Bird tip! How does the modification affect the aerodynamics to improve performance?
@@ashutoshbhakuni303 the PB mods make it balance better so you can run longer rubber motors. Outdoor flying is as much about power/weight ratios as it is aerodynamics, and sometimes more so.
Ever think of editing?
No.
@@joshuawfinn your dry answers always crack me up 👍
When I was around 9 years old I was very popular with the girls in my school because I could braid their hair for them. I suppose having a popular skill was useful 😜
lol
Sorry, but I wàs not trying to be negative, just mearly letting you know what problems I had understanding your video. Thought you would like to know.
Wayne McNab ok, thank you.
You need someone on the camera. Most of the time ai could not see what you did. Also, some of the explanation was was so fast I did not understand what you tried to convey.
Wayne McNab y'know, I get this response occasionally, yet it's really interesting that not one single person has ever taken me up on the offer to let them do the video work.
Five minutes should have been enough.
Nobody made you watch it.