Macgregor Single Channel

[Garththefacebiter]

Today I have aquired another single channel museum piece.

A Macgregor single channel MR200/MR40 Tx/Rx combo with a Ripmax Minimite servo and most of the loom too.

TBH it doesn't look like it's ever been used in anger, although there are signs of it having been fitted to something at some point..

The servo has it's original instruction leaflet, but unfortunately there is no sign of the instructions for the Tx/Rx, and what I assume to be the Rx battery box is missing (loom terminates in a PP3 type battery connector)

If anyone could direct me to a site where I might find the missing instruction sheet, or any other technical data on this R/C relic I'd be most grateful.

I wouldn't mind taking the chance and flying with it, if only I could find somewhere far enough from civilisation for it to be interference free.

[Daithi O Buitigh]

From this thread it looks as if the rx used a 9 volt supply while the servo used a split voltage (2 AA cells, centre tapped)

You could ask there and no doubt someone will fill in the missing info

[Garththefacebiter]

Cheers.

I'll go through that thread in detail when I have time tomorrow (I'm going to work in a few minutes time), and then try a few enquiries.

The reciever mentioned is a MR60, whereas mine is a MR40, but a 9V PP3 battery would be compact and relatively light, so that would make sense for the Rx.

I do have the battery holder for the Minimite, it takes 4x "AA" size 1.5 volts with a centre tapping as described,

There's also an unused lead coming out of the minimite, (3 wires to a plug) which I'm assuming was for a motor control servo.

[Martin Harris - Moderator]

I've got a set of MacGregor Single Channel instructions which I can scan on Friday. There's no mention of receiver model numbers but it covers Minimac and Superhet receivers (relay and relayless) and seems pretty generic for early 70s MacGregor equipment.

I've also got the instruction sheet for the Codamac transmitter if anyone is interested

If anyone's interested PM me with your email address and I'll send you a copy of one or both.

[Garththefacebiter]

Cheers Martin

I'll PM you this weekend with my email address.

Is a Macgregor Codamac the same thing as a Macgregor 1+1 ?

[Martin Harris - Moderator]

I suspect the 1 + 1 may refer to the quick blip throttle - if so, very probably! The instructions say that the Codamac is essentially the same as the earlier version.

The good news is that I've already put the instructions in the car so I shan't forget to take them with me for scanning tomorrow!

[Garththefacebiter]

Cheers Martin

I've downloaded the Macgregor instructions - very useful thanks.

Now I realise that to get the receiver end working with my escapements, I'm going to need Macgregor compatible lead connectors.

Either that or cut up the Minimite servo loom, which I don't really want to do.

Do I have any chance of finding such connectors anymore ???

[Chris Bott - Moderator]

I believe that the Codemac and 1+1 had a single stick for left and right, and a button gave the quick blip for throttle. The difference being that Codemac transmitter just did the press once for left twice for right for you, whereas the 1+1 transmitter pulsed rudder left and right quite quickly, biasing it more one way as you moved the stick giving a sort of proportional control.

[Garththefacebiter]

So the 1 + 1 is a sort of analogue proportional system then?

No digits or integrated circuits lurking within the Tx/Rx ?

The photos I've seen of the 1 + 1 combos up for (online) auction show servos similar to a modern propo one, so I don't think it's a "galloping ghost" system.

If it's of any interest to anyone, I just found the user instructions/handbooks for Macgregors Digimacs on the Macgregor Industries site

Edited By Garththefacebiter on 14/07/2012 16:20:52

[Martin Harris - Moderator]

The Digimac 1 + 1 was a 2 channel digital proportional (on the rudder channel) set - looked very similar to the Codamac transmitter.

Re. the plug/socket - why not use modern parts and save the original bits - you can always solder them back on in the future...

I don't remember them being very good quality - if you're going to use it I'd think you would be better off with new ones anyway.

Edited By Martin Harris on 14/07/2012 20:46:33

[Garththefacebiter]

I just got outbid on a 1 + 1 about 2 hours ago ( Actually I used a sneaky auction sniper while I was down the pub)

Maybe someone on this forum has got it for the princely sum of £26.66!

As for the Macgregor connectors, they seem to be of a reasonable quality, it's the little black heat shrink insulators on the wires which are rubbish (all loose)

Maybe heat shrink tubing was in it's infancy when this kit was built, or maybe just bad quality stuff was specified (unlikely with macgregor I would have thought)

I'm thinking if I can make a suitable tool to relase the metal blades I could replace all the heat shrink with new, tight stuff.

Otherwise it looks like Futaba spec connectors all round.

Efficient, but not really a mod I want to do on a 40 year old museum piece

[Martin Harris - Moderator]

I've dug out my old receivers and one of them has a plug and socket fitted but it's a 7 pin double row connector with flat blades. I really can't say whether it's original - I suspect I might have fitted it when I bought the gear second hand around 37 years ago (how scary is that!)

[Garththefacebiter]

Got the thing up and running today.

Well, almost.

The radio gear is working fine, I've picked up the Tx tone output on my little SW radio set no problem.

The Rx didn't seem to respond at first, but then coiling the receiver ariel around the transmitter ariel got the relay clicking away nicely, so maybe the relay armature was stuck after lying dormant for years.

Looking at the Rx ariel, it's seen better days (the final 3" are bare wire strands), it needs renewing.

As for the Minilite servo, this is 100% dead so far.

Either bad/broken wiring, bad relay contacts in the Rx, or bad contacts in the servos internal switching gear.

My money is on the latter, and as it has it's' own power pack (4x "AA" centre tapped) I'm going to divorce it from the Rx and overide the relay function with a jump wire next.

[Martin Harris - Moderator]

John Dirke - PM sent a few days ago - no reply seen yet....

Edited By Martin Harris on 24/07/2012 10:42:08

[Tony Parkinson 1]

hi just bought a RC baot (sorry not a plane) with a minimac RC 40 per attached. Does anybody have any instrrunation manuals for these - would like to try and get it working.

[Colin Bernard]

Just for info I used a similar setup back in my S/C days. The wires from the Minimite were indeed for a motor control servo which if I remember correctly was called the 'Minimo'.

The servo was fairly simple in that there was simply a set of wipers on one of the gear shafts running over a PC board providing the press/press-press/quick blip decoding, so some contact cleaner should sort out any problems there.

[Jonathan Glass]

This is a message to Garththefacebiter.

 

I was wondering if you still have the Mainstream Autron 2PN. I have one here and I need to see how it is wired inside to get it working. I don't know how to send you a personal message on this forum. If you see this please get in touch by Private Messaging me.

 

Regards Jonathan 

[john stones 1 - Moderator]

17 minutes ago, Jonathan Glass said:

This is a message to Garththefacebiter.

 

I was wondering if you still have the Mainstream Autron 2PN. I have one here and I need to see how it is wired inside to get it working. I don't know how to send you a personal message on this forum. If you see this please get in touch by Private Messaging me.

 

Regards Jonathan 

 

Jonathon I removed your email address, because it could lead to problems for you, to message Garth, hover on his avatar and there is a message option bottom left.

[Jonathan Glass]

Thanks John. That is a very good point, I should have thought of that.

[Simon Chaddock]

My first RC was a MacGregor but a kit of pieces. You had to solder everything to the circuit board yourself.

A tone receiver. It needed a 3V battery.

You had make your own transmitter case.

The big battery compartment was for the 96V HT battery. The lower one for 4 U2  cells for the valve heater.

No frequency control you just "tuned" the receiver to give the best response to what ever frequency the transmitter produced. I never really tested its maximum range. 

It was used in a home designed all sheet glider with a rubber powered escapement working a V tail as a rudder.

 It did glide well enough but I seriously under estimated the effect of the V tail rudder. It simply made no difference at all, either left or right!

Clearly the wrong design of plane for single channel. Even 60 years ago I really should have known better.

I still have both the glider and the MacGregor. 😉   

  

 

 

[Phil Green]

Lovely looking glider Simon, probably a bit more dihedral would help.  My S/C 'Moonbeam' is very responsive, the button really kicks it around turns:

 

 

[Simon Chaddock]

Phil

I note your Moonbeam has both larger rudder areas and aerodynamic counter balance. Such a balance might be necessary to reduce the rudder loads but by adding a slot to each surface when deflected it would significantly improved their effectiveness.

Exactly the sort of thing I should have done on my "MacGregor" glider.

I did convert an A2 sailplane to 2 channel RC but it was not long before I added small ailerons and used the elevator servo to work both the rudder and ailerons simultaneously. It worked just about.

Later with a new fuselage and the poly hederal changed to just keep just the centre line break along with an all moving tail plane it was flown as a powered glider on 4 channels.

 

It certainly flew ever so slowly due to the wing under camber. The all moving tail proved to be extremely pitch sensitive. It was this sensitivity coupled with a twitch from my elevator finger that over loaded the 67 year old balsa spar with the inevitable result.

   

I just could not bring my self to repair it as the whole object of the conversion was to actually fly the 67 year old wing. Such a pity as it certainly looked "interesting". 

[Phil Green]

Ouch!  as I was reading & scrolling I wasnt expecting that!

[Paul De Tourtoulon]

33 minutes ago, Phil Green said:

Ouch!  as I was reading & scrolling I wasnt expecting that!

I flew ( if you can call it that) with my first radio the Macgregor Minimac, and that is how all of my flights ended,,,😨

My 4 channel Macgregor wasn't much better maybe up to 3 flights to destruction,,,

[Andy Stephenson]

MacGregor's own manufactured radios back in the 70s were never regarded as completely reliable. There was a rumour they were using Russian capacitors in their radios. I confronted their sales rep on their stand at a show about this, he went ballistic.