New big CMP Cub.
11-22-2010, 02:12 PM
#26
Junior Member
Join Date: Nov 2010
Location: Pembroke, UNITED KINGDOM
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
RE: New big CMP Cub.
That's right...and both doors have hidden magnets in the panel, and when raised....connects and 'sticks' to the appropriate wing. Very nice and handy when doing anything in the cockpit area.
11-22-2010, 02:46 PM
#27
Senior Member
Join Date: Jan 2006
Location: Lexington,
VA
Posts: 1,556
Likes: 0
Received 0 Likes
on
0 Posts
RE: New big CMP Cub.
Can't help, I'm afraid, Tony. I don't own one. But the CMP is a little larger than 1/5 scale, I think. The full-size Cub has a 36-foot span which works out to 432". Divide that by 5 and you come up with ~ 86". If I remember correctly, the CMP Cub is 91". So 1/5 scale is somewhere between the H9 80" J3 and the 91" CMP.
11-22-2010, 03:44 PM
#28
Senior Member
Join Date: Jun 2008
Location: Laurel,
MD
Posts: 594
Likes: 0
Received 0 Likes
on
0 Posts
RE: New big CMP Cub.
My buddy has the CMP cub that Nitroplanes sells. It' sweet 
Here is what he has:
http://www.nitroplanes.com/j3picub120en.html
Here's a video. He's got a twin OS 4 stroke in it.
[youtube]http://www.youtube.com/watch?v=_iK8uQs2gyQ[/youtube]
Here is what he has:
http://www.nitroplanes.com/j3picub120en.html
Here's a video. He's got a twin OS 4 stroke in it.
[youtube]http://www.youtube.com/watch?v=_iK8uQs2gyQ[/youtube]
11-22-2010, 08:10 PM
#29
My Feedback: (3)
RE: New big CMP Cub.
Tony:
I am assembling one for a customer and I am not sure what dimensions you are asking for so I have a number of them for you. Incidentally, the CMP Cub appears to be about midway between 1/5th and 1/4 scale. I thought the full size Cub (the one at our field) had a 32 ft wingspan. I measured the CMP Cub I have and the wingspan is 87" (including the fuse) so it is between the 80" and 91" mentioned above. My customer is going to use the Zenoah G-20. If you use the Zenoah muffler you will have to cut a large section of the cowling out to fit the muffler. I checked with JTEC/Radiowave and they had a muffler but it would not fit within the cowling (width and height) so I mocked up a inverted pitts style muffler for the CMP Cub with a G-20. JTEC is in the process of manufacturing it. I will let you know how it works out. Incidentally, the model I am doing has the scale gear. It is probably acceptable for the price but I think the tolerances are too wide and there is a lot of "slop" in the entire assembly. Additionally, when assembled and mounted on the plane, I installed the provided "O" rings that act as the "shock absorbers". I left the plane on the gear overnight and in the morning, both "O" rings had broken and the gear had spread out allowing the fuse to sit on the bench. I went to the local hardware store and bought some heavier duty "O" rings and they seem to work well. Instead of using one large O ring on each side I used two smaller ones.
Additional comments. When glueing the wing struts together, assemble the plane and locate the three mounting holes for the strut (two on the wing and one in the fuse). Glue the struts together with epoxy and then bolt to the plane to dry. If you glue the struts together and do not bolt them to the plane, the strut mounting hole spacing on the wing is about 1/8" to 3/16" too close together (becasue the angle cut on the struts at the fuse is incorrect). Also check the mounting hole for the strut where it bolts to the fuse. There was a hole in the fuse bottom and balsa spacers inside the fuse but no plywood and no blind nut for the bolt. If you are going to install the bracing wires between the vertical and horizontal stabilizers, be advised that there are no "hard points" in the stabs or vertical fin. If you tighten the bolts too tigltly, you will crush the balsa.
Also, the instructions say to install the doors and windows near the end of the process, do this because if you install them early in the assembly, they will get in the way and get broken.
When installing all of the electronics, I made a shelf behind the servo mounting plate and this is where I mounted the receiver and the rcvr battery regulator. Ignition and receiver batteries are installed in the bottom of the fuse between the landing gear mounting bolts.
I know that this was not intended to be a "build/assembly" thread but I thought I would post what info I had on the model
Now to the dimensions:
If you are trying to find the dimensions between the "pegs" for the shock absorber "O" rings, that distance is 2.25" or about 60 mm.
Other generla dimensions:
Fuse width at the gear: 6 3/4" or about 170mm
Bolt hole spacing:
front to rear; 4.5" or about 115 mm
side to side spacing (from outside bolt to outside bolt) is 5.5" or 140mm
bolt hole spacing for each pair of mounting bolts (there are eight bolts total, two on each of the front and rear mounting brackets0 is 3/4" or about 20 mm center to center for each pair of holes.
Tony, I hope this is what you were looking for.
Ed
I am assembling one for a customer and I am not sure what dimensions you are asking for so I have a number of them for you. Incidentally, the CMP Cub appears to be about midway between 1/5th and 1/4 scale. I thought the full size Cub (the one at our field) had a 32 ft wingspan. I measured the CMP Cub I have and the wingspan is 87" (including the fuse) so it is between the 80" and 91" mentioned above. My customer is going to use the Zenoah G-20. If you use the Zenoah muffler you will have to cut a large section of the cowling out to fit the muffler. I checked with JTEC/Radiowave and they had a muffler but it would not fit within the cowling (width and height) so I mocked up a inverted pitts style muffler for the CMP Cub with a G-20. JTEC is in the process of manufacturing it. I will let you know how it works out. Incidentally, the model I am doing has the scale gear. It is probably acceptable for the price but I think the tolerances are too wide and there is a lot of "slop" in the entire assembly. Additionally, when assembled and mounted on the plane, I installed the provided "O" rings that act as the "shock absorbers". I left the plane on the gear overnight and in the morning, both "O" rings had broken and the gear had spread out allowing the fuse to sit on the bench. I went to the local hardware store and bought some heavier duty "O" rings and they seem to work well. Instead of using one large O ring on each side I used two smaller ones.
Additional comments. When glueing the wing struts together, assemble the plane and locate the three mounting holes for the strut (two on the wing and one in the fuse). Glue the struts together with epoxy and then bolt to the plane to dry. If you glue the struts together and do not bolt them to the plane, the strut mounting hole spacing on the wing is about 1/8" to 3/16" too close together (becasue the angle cut on the struts at the fuse is incorrect). Also check the mounting hole for the strut where it bolts to the fuse. There was a hole in the fuse bottom and balsa spacers inside the fuse but no plywood and no blind nut for the bolt. If you are going to install the bracing wires between the vertical and horizontal stabilizers, be advised that there are no "hard points" in the stabs or vertical fin. If you tighten the bolts too tigltly, you will crush the balsa.
Also, the instructions say to install the doors and windows near the end of the process, do this because if you install them early in the assembly, they will get in the way and get broken.
When installing all of the electronics, I made a shelf behind the servo mounting plate and this is where I mounted the receiver and the rcvr battery regulator. Ignition and receiver batteries are installed in the bottom of the fuse between the landing gear mounting bolts.
I know that this was not intended to be a "build/assembly" thread but I thought I would post what info I had on the model
Now to the dimensions:
If you are trying to find the dimensions between the "pegs" for the shock absorber "O" rings, that distance is 2.25" or about 60 mm.
Other generla dimensions:
Fuse width at the gear: 6 3/4" or about 170mm
Bolt hole spacing:
front to rear; 4.5" or about 115 mm
side to side spacing (from outside bolt to outside bolt) is 5.5" or 140mm
bolt hole spacing for each pair of mounting bolts (there are eight bolts total, two on each of the front and rear mounting brackets0 is 3/4" or about 20 mm center to center for each pair of holes.
Tony, I hope this is what you were looking for.
Ed
11-23-2010, 03:19 AM
#30
Junior Member
Join Date: Nov 2010
Location: Pembroke, UNITED KINGDOM
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
RE: New big CMP Cub.
Hello Ed,
Thanks for that reply. Fantastic!! Just what I needed. This is the same CUB I have been flying for a few months now. But still, thanks for the building info. I experienced the very same problems you have mentioned.
1. The struts....I had to extend them with alloy pieces to make the meet, but they are fine now.
2. The tail wire struts....I made my own alloy "L" fittings and bolted them right through the tail and elevator. Very strong now. I also used adjustable threaded joints here to be able to alter the tension if needed.
3. For the reciever I put in a plastic...lookalike..suitcase behind the pilot. Batteries etc...I have one for the ignition system also....are where you suggested.
4. The undercarriage....and this was my problem...that you have helped with. The rubber rings supplied, were the same you had. I left them, (assembled), in the workshop, only to find the next morning that they had perished and come apart. I then tried cable ties. No give...which broke on the first landing....no damage but she just 'squatted down' I then tried tent peg rubbers....very strong....but still too flexy. This is where am now with the Cub. I am In the UK for a few weeks and the Cub is in Spain. Hence the call for help. I am going to order now, and then fit when I get back to Spain, strong tension springs to the undercarriage lugs. Maybe just 2 or maybe 2 each side. These springs are 2" without pull and 2.6" fully pulled. It is a bit 'trial and error', but they should work.
I didn't mention the engine. I have put my first petrol engine in the Cub. Its a CRRC 26cc petrol. A bit powerful if anything. I would think , if petrol, a 20cc would be plenty.
Thanks again Ed, and any cross info on the Cub...let me know.
I am currently, (when back in Spain,) putting together an (ARTF), Goldwing Extra 300 LP (DLe 30cc petrol). Fingers crossed on that one......very light and extreme!!
Regards,
Tony...or in Spanish...Antonio
Thanks for that reply. Fantastic!! Just what I needed. This is the same CUB I have been flying for a few months now. But still, thanks for the building info. I experienced the very same problems you have mentioned.
1. The struts....I had to extend them with alloy pieces to make the meet, but they are fine now.
2. The tail wire struts....I made my own alloy "L" fittings and bolted them right through the tail and elevator. Very strong now. I also used adjustable threaded joints here to be able to alter the tension if needed.
3. For the reciever I put in a plastic...lookalike..suitcase behind the pilot. Batteries etc...I have one for the ignition system also....are where you suggested.
4. The undercarriage....and this was my problem...that you have helped with. The rubber rings supplied, were the same you had. I left them, (assembled), in the workshop, only to find the next morning that they had perished and come apart. I then tried cable ties. No give...which broke on the first landing....no damage but she just 'squatted down' I then tried tent peg rubbers....very strong....but still too flexy. This is where am now with the Cub. I am In the UK for a few weeks and the Cub is in Spain. Hence the call for help. I am going to order now, and then fit when I get back to Spain, strong tension springs to the undercarriage lugs. Maybe just 2 or maybe 2 each side. These springs are 2" without pull and 2.6" fully pulled. It is a bit 'trial and error', but they should work.
I didn't mention the engine. I have put my first petrol engine in the Cub. Its a CRRC 26cc petrol. A bit powerful if anything. I would think , if petrol, a 20cc would be plenty.
Thanks again Ed, and any cross info on the Cub...let me know.
I am currently, (when back in Spain,) putting together an (ARTF), Goldwing Extra 300 LP (DLe 30cc petrol). Fingers crossed on that one......very light and extreme!!
Regards,
Tony...or in Spanish...Antonio
