The 24 year itch
12-18-2014, 04:57 PM
#101
I have no numbers on the 5-3, mostly because there are so many brands. I wrote down a bunch on the .049's 10% fuel, all same prop. TD 22,900, GZ with Nelson head 17,000, turbo head I made 21,000, CS non piped 27,000, VA 22,900, Stels 23,800, Norvel 22,500, Wen Mac/McCoy 19,500 Medallion 18-19,000 it was getting dark. A different throttled Medallion 13,500. AP .06 16,500 I think it is a dud, got it used. I have a few Norvels, and am not sure which is which since I took these readings. Some are RC, some control line/FF with a smaller venturi-cause I hate bladders. So to answer the question of the 5-3 to the 4 1/4 - 4, it looks like 23,800 to 22,000 on the 5-3. Different motors, different end of the continent... I bet some of the motors would have responded differently to higher nitro, and playing with shims etc.
12-18-2014, 05:38 PM
#102
From my experience with the Mach none and pacers, as well as all the different "Improved" versions I have built. (I probably should have surounded "improved" with question marks instead of quotations as it is sooooo subjective) Anyway, back to the point, I've always found the 5.7X3 to fly these birds much better than a 5X3. That tends to make the motor choice less relevant. I think most AME and Big Mig, revlite or earlier, tend to turn a 5.7X3 withing 500 rpm of each other. That is often within 1000 rpm of a TD. It just loads the motor more and makes porting and venturi differences less relevant. I would run the standard tried and true combo of backplate pressure, galbreath turbo head and no muffler on any of those engines that seem strong and be happy. I think the big mig or ame CL versions will probably pull the strongest. But not by yards. I think this was also borne out in your Thrust-O-Meter thread ages ago. I realy liked that thread by the way.
As to trailers, I still see quite a few on the road. We know a couple from Quebec that tow a small trailer all the way down to Key West from Canada each spring and have no problems. You tend to see them mostly on the big Hondas and occasionally on a full dress Harley. I saw a guy 2 weeks ago with one that looked like a small car hauler with a fiberglass 55 chevy on it. The Car was about 6' long and the whole top hinged up and you stored your stuff inside.
As to trailers, I still see quite a few on the road. We know a couple from Quebec that tow a small trailer all the way down to Key West from Canada each spring and have no problems. You tend to see them mostly on the big Hondas and occasionally on a full dress Harley. I saw a guy 2 weeks ago with one that looked like a small car hauler with a fiberglass 55 chevy on it. The Car was about 6' long and the whole top hinged up and you stored your stuff inside.
12-18-2014, 05:54 PM
#103
Ironically, I've spent most of my "1/2 A Life" either using Cox rubber 5 x 3s or APC 4.2 x 4s. During the past 10 years, APC 4.2 x 4 for sure.
I think they are similar in load. I uploaded a Cyclon powered combat wing powered by a APC 5 x 3 and all I can say is it was a "Happy Camper" with that prop.
Maybe it's time to update the Thrust-O-Meter research thread..?
It's a fun thing to do in the winter.
I did not have a very good "stable" of good, healthy specimens to test. Some of the props I looked at were pretty irrelevant in today's world.
There is much room for improvement with that vertical thrust test rig. What burned me out was how quickly I ruined brand new AP .061s while testing 7 inch props. That was a recipe for disaster, placing an "over load" prop on a new plain bearing engine, then running it as hard as you can vertically.
http://youtu.be/28na2nnbj9E
Last edited by combatpigg; 12-18-2014 at 05:58 PM.
12-18-2014, 07:10 PM
#104
I say good riddence to the AP. I still run 7X3 on Medallions. Low compression mecoa adapter head and a couple extra shims and they run forever on a tank. I used to run the cox 7X3.5 on medallions on a power pod to pull gliders up and never had one complain. I've never used a texaco head either or a heat sink head. And you can run realy stupid big props on the old Enya 09's without complaint. When they started to get too carboned up you run a small prop at around 17k for a tankfull and then clean up all the black gunk that blows out the exhaust. Kind of like running a bristle brush through a cox motor to de-varnish.
Maybe it's time to fire up the Thrust-O-Meter again but instead of using nuts for weights, maybe use old burnt up 1/2a carcases for weights
Maybe it's time to fire up the Thrust-O-Meter again but instead of using nuts for weights, maybe use old burnt up 1/2a carcases for weights
12-18-2014, 09:40 PM
#105
I'll bet you could match the power needs of a glider pretty well that way.
Too bad the APs wore out the crankcases sooner than anything else, because otherwise they were easy and consistent to run for RC Combat. They had enough power to keep a couple 13 oz planes locked up in a tight fur ball while towing 30 feet of streamer.
The old Thrust-O-Meter thread lacked data from a lot of engines like your Medallion, the Enya, etc.
I don't even think any Big Mig entries were done.
The way I did the "pulls"...I would jiggle / tap the sliding engine stand to give it every chance to achieve "lift off" from the starting position. It was just as simple as doing a bench press. I think each steel nut weighed .6 ozs or so.
Back then I had a free online thrust calculator that was in agreement with my results. There were some results that mede no sense, but I repeated the tests when that happened.
Getting repeatable results with these tiny engines is naturally going to be more difficult than if we were looking at what OS .46s can do.
Ideally, an engine collector with nothing but really nice stuff would take this project on.
Too bad the APs wore out the crankcases sooner than anything else, because otherwise they were easy and consistent to run for RC Combat. They had enough power to keep a couple 13 oz planes locked up in a tight fur ball while towing 30 feet of streamer.
The old Thrust-O-Meter thread lacked data from a lot of engines like your Medallion, the Enya, etc.
I don't even think any Big Mig entries were done.
The way I did the "pulls"...I would jiggle / tap the sliding engine stand to give it every chance to achieve "lift off" from the starting position. It was just as simple as doing a bench press. I think each steel nut weighed .6 ozs or so.
Back then I had a free online thrust calculator that was in agreement with my results. There were some results that mede no sense, but I repeated the tests when that happened.
Getting repeatable results with these tiny engines is naturally going to be more difficult than if we were looking at what OS .46s can do.
Ideally, an engine collector with nothing but really nice stuff would take this project on.
12-19-2014, 09:10 PM
#107
Those look like a very good deal..!
I'm curious about how much work was devoted [by the quad copter company] to find the best possible prop. In this case, to develop pusher and tractor props that have identical performance.
No matter how much science is involved, there must be a lot of trial and error.
I'm curious about how much work was devoted [by the quad copter company] to find the best possible prop. In this case, to develop pusher and tractor props that have identical performance.
No matter how much science is involved, there must be a lot of trial and error.
12-20-2014, 12:53 PM
#109
Two left hand and two right hand. A reedy would be able to use the left hand one. I am not sure I like the cloth pattern showing. It should be strands going lengthwise, not a weave. I am sure it sells props, but not sure about strength.
Last edited by aspeed; 12-20-2014 at 12:55 PM.
12-20-2014, 02:05 PM
#110
The Hayes tanks are nippled for medium fuel line. You can force the small tubing over the nipples, but that is an accident waiting to happen. To reduce down from medium to small silicone fuel line I used small hunks of 3/32" brass tubing stuffed inside the small tubing, then lubed the tubing so that it could be pushed inside the medium tubing. The little pieces of brass tubing have their ends rounded by twirling them against a rubber knife sharpener wheel. This prevents these sleeves from chewing the fuel line from the inside out.
With a pressurized fuel system I've used small tubing up to .40 sized engines.
Last edited by combatpigg; 12-20-2014 at 02:08 PM.
12-20-2014, 04:44 PM
#111
Here is a tiny bit of progress on the .049 plane. Actually, this work just brings me back to "even" with where I was with the red plastic tank mount that I ruined.
To replace the tank mount, I cut these mounts out of 1/4" thick plate.
Now both models are ready for the epoxy treatment on their firewalls and tomorrow I'll get both cowls painted.
I've got K&B epoxy paint that dates back to a hobby shop in Seattle that closed over 15 years ago. So far I've found that if it can be stirred up, it will still do the job. I've also got Klasskote that is getting up there in years, but so far has never failed to do the job.
To replace the tank mount, I cut these mounts out of 1/4" thick plate.
Now both models are ready for the epoxy treatment on their firewalls and tomorrow I'll get both cowls painted.
I've got K&B epoxy paint that dates back to a hobby shop in Seattle that closed over 15 years ago. So far I've found that if it can be stirred up, it will still do the job. I've also got Klasskote that is getting up there in years, but so far has never failed to do the job.
12-20-2014, 06:34 PM
#112
Have you sorted out the CG with swept wings and forward engine have you obtained some insights?
Mine is nose heavy at the moment I may have to add lead to the tail arrrggg. I need to finish up to know for sure.
I had some Z poxy new in the box about 16 yrs old it didn't set for 2ish weeks.
Mine is nose heavy at the moment I may have to add lead to the tail arrrggg. I need to finish up to know for sure.
I had some Z poxy new in the box about 16 yrs old it didn't set for 2ish weeks.
12-20-2014, 07:12 PM
#113
I haven't tried my Hobbypoxy for a good few years. The colour seem to settle and harden. I used the K&B hardener on it when the hardener was not available any more. I just got some tub repair epoxy hardener that I may try some day, as the K&B is no longer available. I just hope some cans will mix up. I can still get the thinner. Klenks brand. Not many colours, white and bone pretty much.
12-20-2014, 07:39 PM
#114
I've been using lacquer thinner for the epoxy paints. I was told that it isn't an exact substitute for the "official" name brand thinner, but most importantly it cleans up the spray gun just fine. My Badger air brush finally died, so I'm just using a $12 HF touch up gun now.
The CG was "loosely" established when I was figuring out the wing's placement on the fuselage. The relatively huge AAA pack ought to take care of any issues once the time comes. I think the plane will need the weight up front.
Having the .049 mounted on a long mount gives me the option of switching to a .074 without too much effort...[I reckon].
The CG was "loosely" established when I was figuring out the wing's placement on the fuselage. The relatively huge AAA pack ought to take care of any issues once the time comes. I think the plane will need the weight up front.
Having the .049 mounted on a long mount gives me the option of switching to a .074 without too much effort...[I reckon].
12-21-2014, 01:51 PM
#115
It weighs 25.4 ozs, no thanks to the fully sheeted wing that came out a little heavy.
I didn't use any primer under the cowl paint, so it isn't as good a match with the covering as it could have been.
I shot the .049 model's cowl this morning so that plane will be RTF after the paint cures.
I tried out some automotive pinstriping tape on both models and uhhh....never again. It just doesn't stay put or tolerate any heat.
So far everywhere I've looked for a ASP.12 [from a US dealer] they are out of stock. I see there is an outfit in England that sells them, plus they sell P/L sets. It might be worth contacting them, they look like a customer service oriented business judging from the looks of their website.
12-21-2014, 02:00 PM
#116
Nice shiny wing. These guys are out of stock too. They have the AP .15, but it is a bit more $ than other places.http://www.himodel.com/engines/ASP_1...Airplanes.html Hobbypartz seems to wait till they run out of parts, and then order everything at once. The most popular ones go quick, and then the least popular ones sit forever.
Last edited by aspeed; 12-21-2014 at 02:18 PM.
12-21-2014, 07:18 PM
#120
Thanks for the compliments and for the leads on another .12..!
It is odd how this engine seemed fine the last time I ran it and now it's junk. Taking it apart probably disturbed any sort of life it was clinging on to. I'll see if my Enya .11 will work for the time being.
I'll try it with a 7 x 3 APC and look through my stuff for a 6 x 4.
The CG Calculator says this plane has 268 sq inches and at 25.4 ozs a stall speed of 18 mph.
It is odd how this engine seemed fine the last time I ran it and now it's junk. Taking it apart probably disturbed any sort of life it was clinging on to. I'll see if my Enya .11 will work for the time being.
I'll try it with a 7 x 3 APC and look through my stuff for a 6 x 4.
The CG Calculator says this plane has 268 sq inches and at 25.4 ozs a stall speed of 18 mph.
12-21-2014, 10:13 PM
#121
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18mph? Sounds like a *****cat. One day I need to resurrect my CX-11. Ran it once about 48 years ago, on a 7x3 something or other. I have a Baby Birdie fuselage from sometime in the 80's, with the nose modified to wedge in the Enya in upright position. Perhaps if I finish that,
12-22-2014, 09:03 AM
#124
Klord, when I first saw that sticker, I thought it was the THRUSH emblem [it was].....but it looks like Clay Smith Cams owned it at one time.
Clay Smith is still in business, as well as some other small cam and valve train makers that date way back.
Clay Smith is still in business, as well as some other small cam and valve train makers that date way back.
12-22-2014, 06:16 PM
#125
I even flew it today, but botched the video.
The first flight was with the Cox .5 x 3 prop and the plane seemed too slow in roll and slightly twitchy in pitch. After resetting the controls it was much improved, but it's naturally a slow roller. The CG was set OK based on the glide. The trims were set pretty close, well within flyable range for RC.
I flew a few more times with the 5 x 3 then switched to a standard Cox 6 x 3. The model flew just as well and for a plane like this the much lower noise with the 6 x 3 was a nice change of pace. After 8 flights the plane feels pretty comfy, but having only a 1 oz tank is a nuisance for a relaxed flyer like this. I'll see if a 2 oz tank will fit.
I think the video SNAFU was not "formatting" the disk, so I'll work on that as well. This plane really needs a .074 to put it "over the top", but it's not bad with the AME .061.
I like the outline of the plane and would like to build a smaller SWR version of it later.
Last edited by combatpigg; 12-22-2014 at 06:20 PM.