JMP_blackfoot

This model was given to our club by the son of Eugene Gottschalk of Westerville, Ohio, who passed recently aged 85.
It is very well built and silk covered, looks practically new and came fully fitted with 1959/1960 vintage radio equipment.
Everything seems in really good working order:
- Controlaire tube tone transmitter with Aristo-craft code-a-matic controller.
- Controlaire 3 transistor receiver
- Cobb Hobby Micro 4 motorised servo
- OS(?) 3-position throttle escapement

It was like opening a time capsule.

1 - What is the model? It looks like a DeBolt design, span is 48.5 inches and engine is an OS Pet II R/C, also of 1959 vintage.
The whole radio equipment is mounted in a box which fits in the fuselage.
2 - What voltage was the receiver designed to work with?
I tested it with a lab power supply and a Controlaire Galloping Ghost transmitter.
It works pretty good from 3 to 5V, apparently best around 4.5V and seems to follow pulsing rather well.
3 - Does anyone have the wiring and installation instructions for the Cobb Hobby Micro 4?
4 - What battery voltage is the transmitter designed for (Filament and HT)?

cvint

Looks like a Debolt rebel.

Michaelj2k

Yup - deBolt Rebel and an all original one in excellent condition. Bring it to Toledo and display it in the Vintage RC area.

All Day Dan

My Feedback: (5)

If you need some technical help, get in touch with this organization. Dan.
http://www.vintagercsociety.org/

Truckracer

My Feedback: (19)

Wow, I'm impressed with the condition of that model. Where did he store it, in a temperature and humidity controlled chamber? Very nice!

JMP_blackfoot

Thanks, it is indeed a Rebel, I found it advertised in the April 1956 issue of Model Airplane News magazine.

Thanks for the suggestion, I shall very much try to do that! And I'l definitely display it with the original builder's name. After that, I may build a new radio box with modern receiver and Bonner Varicomp escapement and fly it at vintage meets.

I am a member of VRCS, but I had thought I would try RCU first. VRCS would indeed likely have the answers to the more technical questions.

The model was brought to our club by the builder's son. We have no idea where or how it was kept.
There were other models, such as a well-flown (I would guess literally hundreds of flights) and well-worn but still quite flyable Midwest Esquire fitted with OS Max II 15 R/C engine, Babcock rudder escapement and OS throttle escapement.

HighPlains

My Feedback: (1)

I am struck by how close the Rebel design is to his Livewire Trainer design of 1952. It appears that the wing and horizontal stabilizer are identical, and the fuselage is a slim version with a slightly different vertical tail. Evolution, not revolution.

otrcman

JMP, I have your Cobb Hobby Micro 4 information, but can't figure out how to add attachments on the "New Improved RCU" If you can guide me through that function, I will post the images. Or, you can send me your email address via PM and I'll send the stuff directly to you. It will be 5 images, for a total of about 1 mb.

Dick

PS If anybody from RCU is listening, please note my two thumbs down vote for your revised site. The prior version was far easier to navigate and post to.

JMP_blackfoot

Dick,
Thanks for having found the information on the Cobb Hobby Micro 4.
To add attachments , once in the "Reply window, you first need to click on "Go Advanced", then the "Manage Attachments" option becomes available, much as before...

Jean-Marie

otrcman

Let's see if I was able to post the Micro 4 instructions.

Looks like it worked. I'm using a Mac rather than a PC, and have two different browsers. The one I tried yesterday didn't work. But Firefox did work.

Dick

JMP_blackfoot

Beautiful! Thanks a lot!
I've got the receiver working.
Now to see how it all works together

Jean-Marie

otrcman

I still have the Cobb Hobby Micro 4 and also the Micro Controller that I bought in 1960. Never did get the units to play reliably, but then I was only 17 years old at the time and had no mentor to guide me. I did correspond a bit with Len Purdy (Mr. Cobb Hobby and later Mr. Lanier Models). Len said that they were having some problems with variation between servo motors and recommended that I slow down the controller in order to allow the Micro 4 to keep up with the transmitter signal. I think also the condition of the servo batteries relative to the controller batteries was a factor. Fresh controller batteries increased the signal rate just like blipping too fast with your thumb on a compound escapement.

Please let us all know if you are able to make your system work.

Dick

otrcman

Does the Code-A-Matic Controller use batteries or is it a wind-up ? Seems to me that I borrowed a similar unit when I couldn't get the Cobb Micro Controller to work. The one I used had a wind up spring affair rather than batteries. On a long flight you had to rewind the spring before it ran down all the way. Sounded like an old clock when you made control inputs.

Dick

JMP_blackfoot

The Code-a-Matic is neither battery powered, nor wind-up but it does sound like an old clock .
A spring is tensioned every time the stick is moved and the movement of a wiper drawn by the spring over a pcb track is slowed down and regulated by a rattler, like a compound escapement.
The extent of the movement of the wiper depends on which direction the stick was moved, which controls the number of pulses. Pretty difficult to visualize or describe, but very clever indeed and always ready to operate.
The Micro 4 was working after cleaning the collector and brushes of the motor, checking the wipers and lightly lubricating the gears, but after closing it and tightening the screws, it now does not work too well. More fiddling will be necessary.
I am waiting for a 12VDC-135VDC converter for the transmitter which will be powered by a 3-cell A123 battery, so in the meantime I am using a more recent Controlaire Ghost Tx for preliminary tests.
The receiver seems pretty finicky regarding tone frequency (400 to 600 Hz specified), does not work correctly with the 1200 Hz of a Min-X transmitter, OK with the 700 Hz of the Controlaire Ghost.

otrcman

Yes, the self winding feature of the Code-A-Matic does sound clever. Sort of like the old self winding watches.

I notice that the motor on your Micro 4 is black. Mine is red, just like the rest of the unit. I seem to recall seeing one with a black motor before, which I suspect is a later revision to the early red motor as I have. Probably the black was the "new, improved model".

Electric motors have come a long way over the years and I believe that servos such as the Micro 4 were way ahead of their time. An idea without the mature technology necessary to make it work well.

Dick