RE: Where can I get a CAD designed engine?
dp44, i don't have a model of the engine just a cad drawing, i do have a model of a fp40 minus carb and muffler.
Posted on: 10/23/2009 12:10 PM by Author "canadagoose" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9196037

RE: Where can I get a CAD designed engine?
I do have a drawing of an OS 61 fx, there's no muffler drawn though.
Posted on: 10/23/2009 12:26 AM by Author "canadagoose" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=9195161

RE: O.S. 49-PI Wankel
The centrifugal force of the rotor spinning, applies more pressure to the apex seals than just what the springs are applying to them. I would rather follow OS's instructions and use fuel with 25% oil. Right now i'm running fuel with an oil content of approx 30% (40% of that castor, 60% synthetic) because i added too much by mistake. Runs great on it though. I'm not saying that maybe there aren't synthetics out there that might be as good as castor when the temps get high but castor has proven itself and i'd rather just stick with using it in these crazy little engines.
Posted on: 8/20/2009 12:19 AM by Author "canadagoose" in the forum "Tachometer Readings"
http://www.rcuniverse.com/forum/fb.asp?m=9029936

RE: Merco 4 stroke??
TFF, it won't be going in any plane at the moment. I should check to see if i have a MA 13x6 to see what rpm it will do with that.
Posted on: 8/14/2009 10:44 PM by Author "canadagoose" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9017340

RE: Merco 4 stroke??
I have been running this engine a bit. Seems to have good power for an old open rocker 60 and idles great. All in all runs really sweet. Propped with an APC 12x8 it managed 8200 - 8300 rpm. This might be a little better than the OS 60 FS could do.
Posted on: 8/14/2009 9:26 PM by Author "canadagoose" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=9017174

RE: Merco 4 stroke??
Here's a couple shots of this engine back together along side an OS fs-60. I looked through my spare engine parts and found a rear bearing that was the right size, don't remember what engine it was for. It's interesting to note that the head port threads are the same in both engines as well as the crank threads. I threaded my spare exhaust manifold into the OS. Rockers and post are different though real similar. The Merco is definitely lighter than the OS. Can't wait to run it but that won't be for a couple days. The reassembly was a snap with this engine, it is quite an oddball.
Posted on: 7/16/2009 9:49 PM by Author "canadagoose" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8939734

RE: Merco 4 stroke??
I was thinking that while i am waiting for some new bearings, maybe i'll measure the parts up with a micrometer and model them in 3d. Maybe Stebro did get some parts from Merco that weren't finished with ports like the crank and sleeve.
Posted on: 7/16/2009 10:47 AM by Author "canadagoose" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8938095

RE: Merco 4 stroke??
Here's a couple pics of the engine torn down and all parts cleaned and laid out. They spent 6 six hours in a hot anti freeze bath. This engine was really gummed up! Some parts like the prop driver, rear bearing and cam box didn't want to come off. I managed to get everything apart without wrecking, bending or marking up too much. The cylinder liner and crankshaft don't have any ports cut in them, i didn't think the liner would but the crank was a surprise. In the upper left corner of the pics is a bunch of spare parts that came with the engine (cylinder head and valve gear, intake and exhaust manifolds, set of rockers and 5 extra pushrods as well as an extra lifter and some bolts). The bearings are not very smooth so i will have to try and order a set before re-assembling.
Posted on: 7/16/2009 2:01 AM by Author "canadagoose" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8937443

RE: 3D Models of Propellers Sought
Chevelle, email sent.
Posted on: 7/9/2009 11:14 PM by Author "canadagoose" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=8920500

RE: Merco 4 stroke??
Ha Ha, didn't even see that Tom.
Posted on: 7/9/2009 10:59 PM by Author "canadagoose" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8920456

RE: Merco 4 stroke??
Hey Kmot, thanks for the bit of info. Where did you get it from? You don't know how many Stebro did, do you? Funny, i can't find anything on the internet about these Merco's.
Posted on: 7/9/2009 12:37 AM by Author "canadagoose" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8917989

RE: Merco 4 stroke??
Thanks downunder for the info that it started as a MK2, i was thinking too that the liner would have to be a new one without ports.
Posted on: 7/8/2009 10:19 PM by Author "canadagoose" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8917555

RE: 3D Models of Propellers Sought
I do have a model of a propellor that i did. It's modeled after a 20" Master Airscrew, the tip is flat instead of rounded though.
Posted on: 7/8/2009 10:14 PM by Author "canadagoose" in the forum "Scratch Building, Aircraft Design, 3D/CAD"
http://www.rcuniverse.com/forum/fb.asp?m=8917536

RE: Merco 4 stroke??
TTF, i have no idea what it uses for a piston, it does use a cam setup similar to the Enya and OS open rocker engines. This cam box bolts in place of the back plate. I don't have the engine yet but i am curious of a few things too like the cylinder liner
Posted on: 7/8/2009 9:57 PM by Author "canadagoose" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8917478

Merco 4 stroke??
Does anyone have any more info on the engine pictured? All i know (not sure if it's completely right) is that it is a Merco 61 two stroke (duh, seeing it says it on the side) that was converted to a 4 stroke around 1980 by a company called Stebro. Does anyone know if that is right and how many were converted, etc. All info appreciated.
Posted on: 7/8/2009 6:27 PM by Author "canadagoose" in the forum "Glow Engines"
http://www.rcuniverse.com/forum/fb.asp?m=8916978

RE: New twin design project
Hope you had a Merry Christmas too, John. Wish you the best in the coming New Year too. I'm glad i didn't do anything right away with the plane because the more i have just let it sit, the more the wood has dried and now is almost back to the way it was before the dunking. The outer wing panels now look good again where before i thought i was going to have to build new ones. I guess ALL the moisture can take a while to evaporate. I started thinking just a short while ago on a way to fix the landing gear so that it will be strong enough to take anything including strong side loads. I will find a fix for it.
Posted on: 12/26/2007 3:51 PM by Author "canadagoose" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=6807157

RE: New twin design project
[quote]Man, that's gotta be a little disheartening. My heart just sunk when I read your post and its not even my plane so I can only imagine what your feeling right now. I've only followed this post for about a week or so but that has got to be one of the coolest planes I've seen in a long time if not ever. Don't let it set you back, I'm sure I'm not the only one here who can't wait to to see this thing fly.[/quote] It's a little but it is part of trying to build a new design i guess. There's almost always problems to sort out. Sometimes you get lucky and the thing flies right off the drawing board first time around. [quote]Sorry to hear about the mount failure, like you said at least you found the week spot.[/quote] I just hope this was the only weak spot. The wing center section after drying a couple days isn't looking too bad, most off the curling has gone out of the sheeting must be because the sheeting was epoxy glassed. I know how i would build new leg structures if i was building it now, just trying to think of a way to adapt it to this one, then i should be able to fix this wing center section. The outer wing panels look like some sheeting will need replacing, if i try to repair these ones i need to try and keep the washout that was built in otherwise new ones will have to be built. I might need to check if the washout was washed out.[8|]
Posted on: 8/21/2007 12:30 AM by Author "canadagoose" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=6265712

RE: New twin design project
Well i am home from holidays, don't have the greatest news to share. Testing was going good, it weathervanes good in a gentle breeze, taxies good with lots of rudder authority, i didn't have a long enough extension to hook up the water rudder so i mixed differential thrust with the rudder. I had it so an engine would decrease 15% when the rudders were fully deflected, the other throttle would just hold postion. Seemed to work good. The engines were tuned slightly rich and running good. One of my OS 40 fp's is a little different than the other, i think one of them produces about 400-500 more rpm than the other, didn't seem to matter much though when opening up the throttles. Anyways here's where the story goes sour, on one of the runs i had it lift off the water a little then i cut the throttles and landed back on the water, as it was slowing down it hit a small wave pitching up the front with the water rudder going down into the water that's when it cut real hard to the left breaking the front leg mounts on the nacelle undersides, one float tip came up allowing the prop to chew a big hole in the top of the right float. With the right float angling up so that the front portion was up against the cowl underside it looked like the left float tip dug in which must have really helped to flip the plane over on it's back. I had to swim out 50 feet to get it, when i got it back to shore almost everything had water in it especially the wing center section and right float, some water was also in the fuse and outer wing panels. On further inspection I found that the water rudder was turned to the left and was stiff to try and flip up, i should have disconected the linkage to it. The parts that were planked are still good (fuse, nacelles) but sheeting on the wing center section and outer wing panels have curled pretty good. I guess i will have to wait till all the wood is completely dry again before deciding what to do. These tests did reveal a definite weak spot that will need to be redesigned. Here's a pic of the damage.[:(] Next time i'm going to just open up the throttles and let her keep flying. I haven't given up yet as the hop into the air looked promising.
Posted on: 8/20/2007 10:23 AM by Author "canadagoose" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=6260921

RE: New twin design project
[quote]Do you think it'd be a good idea to seal all the wood as a person builds a float plane or do you think it'd add too much weight?[/quote] It's hard to completely seal all the wood, like the wing sheeting and make all parts watertight. Depending on the water damage to the wing, i may have to build a new wing which really isn't that big a deal, the float can be easily fixed. The fuse and tail feathers and left float are good.
Posted on: 8/20/2007 9:59 AM by Author "canadagoose" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=6262051

RE: Props, horizontal or vertical?
[quote]The rule of thumb is always horizontal nomatter how many engines.[/quote] Is there another reason why aside fromthe prop/s more unlikey to strike the ground in the horizontal position? Mine is a float plane so i don't have any worries about that. [quote]I can tell you though that I have had a plane, picture enclosed that will both engines fireing with the props horizontal had some violent reverberations when the motors came up on the pipe and the R's went up. To fix this I had the props offset 90 degrees to each other at compression.[/quote] Good tip.
Posted on: 8/10/2007 12:36 PM by Author "canadagoose" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=6220703

Props, horizontal or vertical?
What is the best position to mount props on a twin where they come up to the engines compression when stopped, horizontal or vertical? I was thinking that if one or both engines quit, the prop blades mounted horizontally would cause disturbance to the leading edge of the wing and that maybe if they are mounted so that they stop against compression vertically, that would help in not causing any loss of lift and drag for that wing being that my cowls are deeper than they are wide. Any thoughts from those with twin experience?
Posted on: 8/10/2007 11:30 AM by Author "canadagoose" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=6220488

RE: New twin design project
Jim, sounds like your twin Hobbistar would make for a good fun float flyer, how well does it handle an engine out? Do you know how far the engine nacelles on the Twinstar are apart, i would like to compare it to mine, i tried keeping the engine nacelles as close as possible for mounting up to 12" props, but 10's and 11's are best on this one.
Posted on: 8/8/2007 8:22 PM by Author "canadagoose" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=6213765

RE: New twin design project
[quote]In terms of flight performance you should be fine at that weight. I'm flying a twin with two 40 FPs at about 10 pounds (wing loading is about 26) and it is a pretty nice flyer once it gets going.[/quote] I know the two 40 FP's will be more than enough power at 8.5 lbs. What plane do you have your 40's on Jim? What a sweet song they sing together! I ran about 3 tanks through the new one that has never been run then tuned it so that it increased in rpm when holding straight up then did the same to the one that has been run before. Sounds like they are insync most of the time and they look to be producing approx the same amount of thrust when increasing the throttles from idle to wide open. This was done with the cowls off to check for any problems with the tanks etc, i'll have to run them again with the cowls on. I can see that i will have to balance the props good because at certain rpm's the engines will vibrate a little on the mounts, might need to strengthen the mounts as well somehow. Can't wait to do some taxi and planing tests.
Posted on: 8/7/2007 4:36 PM by Author "canadagoose" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=6208421

RE: New twin design project
Some more shots outside in the yard. These show the plane much better as it is. Taking pics in my smallish house tends to distort things a little because they are taken close.
Posted on: 8/7/2007 4:23 PM by Author "canadagoose" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=6207595

RE: New twin design project
Thanks Kmot.
Posted on: 8/7/2007 1:06 PM by Author "canadagoose" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=6207667

RE: New twin design project
[quote]What is the finished dry weight? [/quote] I think it is approx 8.5lbs. That would yield a 29 oz/sq ft wing loading. I need to find a good scale because i would really like to know that too. I think quite a bit of weight could be shaved off by using an iron on film, i'm also going to go through the parts on the plans and see where i could make things lighter, i know at least the floats tail fins/rudders could be built lighter.
Posted on: 8/7/2007 12:57 PM by Author "canadagoose" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=6207621

RE: New twin design project
Looks like there might be a bit of algebra involved by looking at this site http://www.basiliscus.com/CaseStudy/hydrostatics.html Probably only the real expensive modeling programs would be able to calculate center of buoyancy for a float/boat model. Using the general rules of float design seem to work alright most of the time. Everything that needed to be done is finished! I did repaint part of the nacelle tops to have a scallop not sure if it will stop there though for the paint scheme but will leave it as is for now. Would also like to add the graphics the i had done in TurboCad to dress it up. I need to find someone that can make me some decals. The balsa cowl mount rings were painted as well, the cowls aren't actually mounted to these but hold the base at the firewall in the right shape. The cowls are screwed to the engine mounts near the front. I now have 2 weeks of holidays to go camping, fishing etc but will aslo be taking the VeeRod with me to tinker with the setup, maybe even try flying it when everything seems ready.
Posted on: 8/7/2007 11:24 AM by Author "canadagoose" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=6207245

RE: New twin design project
Here's some shots of the water rudder. The blade was made from strips of carbon fiber laminated together with epoxy 3 layers thick (2 horizontal 1 vertical), seems to be strong and light. The support is a strip of aluminum from a an old road sign 1/4" wide screwed to the float transom.
Posted on: 8/2/2007 11:47 AM by Author "canadagoose" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=6187557

RE: New twin design project
iron eagle, i have built cowls like that before but i've put too much work in making a mold for the ones i've got to discard them now. Looks good though.[sm=thumbs_up.gif] I was thinking about trying to use differential engine thrust for taxiing instead of using a water rudder. I know twinman has described the practice as being dangerous, but it sounds like it would be dangerous if the programming was to spool up one of the engines. What about programming to decrease rpm on an engine for turning? Any thoughts on this anyone? Some of of the guys i've talked to at the float fly i go to use differential on their twins for taxiing. I will test the plane out without a water rudder or differential thrust to see how effective the rudders are.
Posted on: 7/31/2007 8:22 PM by Author "canadagoose" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=6180777

RE: New twin design project
I was going to do the verticals as well but i want to test fly it first, do you have a bigger pic of the cowl, looks good from what i can see.
Posted on: 7/30/2007 8:16 PM by Author "canadagoose" in the forum "Twin & Multi Engine RC Aircraft"
http://www.rcuniverse.com/forum/fb.asp?m=6176168