Semi scale Mig-25 Foxbat, 70 mm - RCCanada - Canada Radio Controlled Hobby Forum
RCCanada - Canada's Radio Control Hobby Forum
Electric Jets Discuss electric jets in Canada.

Reply
 
Thread Tools Display Modes
Old 01-16-2016, 11:32 PM   #1
Dutkoski
RCC Master Contributor
 
Dutkoski's Avatar
 
I am: John D
Join Date: Dec 2002
Location: Toronto, Ontario
Radio of choice:
Spectrum
# of RCs: 10+

Feedback: 3 / 100%
Posts: 1,255
Total Props: 7
Semi scale Mig-25 Foxbat, 70 mm


       Remove this ad - become a site supporter!
So, the red Habu bit the dust Thursday morning, electronic failure of some sort, some of the chaps figured I had a brown out with the ESC. Well, that won't happen again, going to use a separate battery for the receiver like I should have done.

So, I need a plane, fast and I'm cheap, everything but one servo survived the crash. I need a fast build, so boxy fuse, uncomplicated wing and landing gear, big intakes, oh, and military and rugged. So, looked through the various designs and the Mig-25 Foxbat fit the bill the best. Also, I just happen to have a set of three views with me. Had them enlarged so the wingspan was pretty much the same as the Habu. So it worked out to a 36" wingspan and 55" long.

A bit longer than the Habu but most of the nose is thin foam, plus the Mig has more wing area and the bottom of the fuse is wider and will also provide lift.

The Habu's retracts will also fit, but the mains will have to have the strut cut so I can use proper struts. The wheels retract forward not towards the center.

So, with pencil, bristle board, foam board in hand, this evening I designed, made templates and built a full size chuck model to test the CG location. Tomorrow, the foam will get cut and the build will begin. Hope to have it in the air by next weekend.
Attached Thumbnails
Click image for larger version

Name:	image.jpeg
Views:	111
Size:	607.2 KB
ID:	807426  
Dutkoski is offline   Quick reply to this message.

Sponsored Links - Subscribe to remove this ad.
Old 01-17-2016, 08:00 AM   #2
4stripes
RCC Pro Contributor
 
4stripes's Avatar
 
I am: Eric K.
Join Date: Feb 2007
Location: Burlington ON

Feedback: 12 / 100%
Posts: 1,741
Total Props: 10
Re: Semi scale Mig-25 Foxbat, 70 mm

Interesting build!
Nice that it will have retracts too!
__________________
Zen thinking * It's rebuildable till it fits back in the box. **
Cheers
Eric
4stripes is offline   Quick reply to this message.
Old 01-17-2016, 11:53 AM   #3
Dutkoski
RCC Master Contributor
 
Dutkoski's Avatar
 
I am: John D
Join Date: Dec 2002
Location: Toronto, Ontario
Radio of choice:
Spectrum
# of RCs: 10+

Feedback: 3 / 100%
Posts: 1,255
Total Props: 7
Re: Semi scale Mig-25 Foxbat, 70 mm

This morning was a perfect day for testing the glider. A tad tail heavy so taped a steel washer onto the nose. Second toss was perfect. The third toss with more energy was even better, glided straight and level across the front yard and slid onto the driveway as though landing. Very happy, it even crossed my mind to install a couple of 50 mm EDF's to see how it would fly, maybe later on, just for fun.

So, balanced it upside down, the CG is exactly 5" back from the leading edge where the wing meets the fuse. Then flipped it and confirmed it right side up.

Too bad I'm at home alone, could have done a very short video. Maybe later today.
Attached Thumbnails
Click image for larger version

Name:	image.jpeg
Views:	83
Size:	400.1 KB
ID:	807778  
Dutkoski is offline   Quick reply to this message.
 
Old 01-17-2016, 01:29 PM   #4
Dutkoski
RCC Master Contributor
 
Dutkoski's Avatar
 
I am: John D
Join Date: Dec 2002
Location: Toronto, Ontario
Radio of choice:
Spectrum
# of RCs: 10+

Feedback: 3 / 100%
Posts: 1,255
Total Props: 7
Re: Semi scale Mig-25 Foxbat, 70 mm

So, here is a very short video of a hand toss. If I tossed it harder, it goes further at the same attitude. I think I nailed the CG location.

http://youtu.be/FUCdN7tHJbo

Last edited by Dutkoski; 01-17-2016 at 03:58 PM.
Dutkoski is offline   Quick reply to this message.
Old 01-18-2016, 05:44 PM   #5
Dutkoski
RCC Master Contributor
 
Dutkoski's Avatar
 
I am: John D
Join Date: Dec 2002
Location: Toronto, Ontario
Radio of choice:
Spectrum
# of RCs: 10+

Feedback: 3 / 100%
Posts: 1,255
Total Props: 7
Re: Semi scale Mig-25 Foxbat, 70 mm

Even though the Eflite retracts would most likely fit, the struts cannot be removed from the trunnions and since the coil would be facing sideways, which isn't good, decided to order a inexpensive set from HK. So until they arrive, I'll fashion fixed gear on retract size plywood bases. I also ordered another set for my SU-47 as the RC Lander set died, brand new never mounted in a plane, frustrating. To complete that project, I'll mount the crappy plastic retracts and pray for smooth landings.
Dutkoski is offline   Quick reply to this message.
Old 01-19-2016, 07:45 PM   #6
Dutkoski
RCC Master Contributor
 
Dutkoski's Avatar
 
I am: John D
Join Date: Dec 2002
Location: Toronto, Ontario
Radio of choice:
Spectrum
# of RCs: 10+

Feedback: 3 / 100%
Posts: 1,255
Total Props: 7
Re: Semi scale Mig-25 Foxbat, 70 mm

Made the wing panels last night and sanded them today. Made from two thicknesses of 1/2" foam and after hot wired to shape, they were laminated together with epoxy. Once the fuselage is constructed, I will cut the slots for the 1/8" plywood spar. I will be installing ailerons and flaps.
The cord is much thicker than a scale airfoil which will help in lift and provides enough wing thickness to install servos.
The templates were made from 1/8" cheap plywood, sanded to shape and the edge covered in aluminum duct tape. In lieu of aluminum templates, this method works really well.
Attached Thumbnails
Click image for larger version

Name:	image.jpeg
Views:	49
Size:	625.3 KB
ID:	812362  
Dutkoski is offline   Quick reply to this message.
Old 01-19-2016, 08:43 PM   #7
Max
Administrator
★ Site Supporter ★★ Administrator ★
 
Max's Avatar
 
I am: Max P.
Join Date: Feb 2007
Location: Aurora, Ontario
Radio of choice:
JR and Spektrum

Feedback: 22 / 100%
Posts: 14,080
Total Props: 156
Re: Semi scale Mig-25 Foxbat, 70 mm

Quote:
Originally Posted by Dutkoski View Post
So, here is a very short video of a hand toss. If I tossed it harder, it goes further at the same attitude. I think I nailed the CG location.

http://youtu.be/FUCdN7tHJbo
Wow! For a chuck glider, that thing flew really nice!!!
Cant wait to see this project come together
__________________
RC Test Pilot; FPV Instructor, Airplane Instructor; Helicopter Instructor

My Aircraft Albums: http://www.rccanada.ca/rccforum/album.php?u=13173

Last Photo added: Dec 15; Warwing Foamy for FPV
Max is offline   Quick reply to this message.
Old 01-20-2016, 02:31 PM   #8
Dutkoski
RCC Master Contributor
 
Dutkoski's Avatar
 
I am: John D
Join Date: Dec 2002
Location: Toronto, Ontario
Radio of choice:
Spectrum
# of RCs: 10+

Feedback: 3 / 100%
Posts: 1,255
Total Props: 7
Re: Semi scale Mig-25 Foxbat, 70 mm

Cut and assembled the main fuselage last night. Basically, a rectangular box, very easy. Today, begins the rough sanding to shape. The top of the fuse was glued to the sides about 1/4" higher than the top of the sides, this is not a mistake, the fuselage top has a slight slope on it so I sanded the top to match the seam. This also gives me an extra 9/16" of depth to the inside of the fuselage.
Attached Thumbnails
Click image for larger version

Name:	image.jpeg
Views:	37
Size:	864.2 KB
ID:	812778  
Dutkoski is offline   Quick reply to this message.
Old 01-20-2016, 02:36 PM   #9
Dutkoski
RCC Master Contributor
 
Dutkoski's Avatar
 
I am: John D
Join Date: Dec 2002
Location: Toronto, Ontario
Radio of choice:
Spectrum
# of RCs: 10+

Feedback: 3 / 100%
Posts: 1,255
Total Props: 7
Re: Semi scale Mig-25 Foxbat, 70 mm

The intakes are pretty large, much larger than the ones on the Habu, so there will be a lot more airflow to the fan. I'm going to laminate some 1/32" plywood to the inside of the intakes. This will allow me to sand the intake lips to an edge like the real aircraft and also make the edges very durable.
Attached Thumbnails
Click image for larger version

Name:	image.jpeg
Views:	43
Size:	528.7 KB
ID:	812786  
Dutkoski is offline   Quick reply to this message.
Old 01-20-2016, 04:02 PM   #10
Dutkoski
RCC Master Contributor
 
Dutkoski's Avatar
 
I am: John D
Join Date: Dec 2002
Location: Toronto, Ontario
Radio of choice:
Spectrum
# of RCs: 10+

Feedback: 3 / 100%
Posts: 1,255
Total Props: 7
Re: Semi scale Mig-25 Foxbat, 70 mm

Intake lips having the 1/32" plywood being glued in place.
Attached Thumbnails
Click image for larger version

Name:	image.jpeg
Views:	49
Size:	874.1 KB
ID:	812834  
Dutkoski is offline   Quick reply to this message.
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the RCCanada - Canada Radio Controlled Hobby Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

Member names may only be composed of alpha-numeric characters. (A-Z and 0-9)

!!ATTENTION ADVERTISERS!! If you intend on advertising anything on this forum, whatsoever, you are required to first contact us here . Additionally, we do NOT allow BUSINESS NAMES unless you are an Authorized Vendor. If you own a business, and want to do sales on this site via posting or private message, you will need to follow the rules. Shops, Stores, Distributors, Group Buys without being authorized will see your account terminated.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Your Name
Your first name and last initial is required if you plan on using the forum.
Location
Which city & province you live in. This is mandatory for classified listings.
Radio of choice?
Which radio is your current favorite to use?
Number of RC Vehicles?
How many boats, cars, planes do you own?

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
vBulletin Message

Thread Tools
Display Modes

Forum Jump


All times are GMT -5. The time now is 02:30 AM.


vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.