Graupner Varioprop 12S
Posted: 07 Oct 2023, 18:37
For those following my Graupner Cirrus build in the models section of the forum viewtopic.php?f=83&t=1415 will have seen that I have been busy converting a lovely condition Tx to 2.4.to drive the Cirrus around when it is finished.
I didnt want to use my original new boxed set and servos for obvious reasons, so found an excellent condition Tx on Ebay that I could play with.
For those familiar with these Grundig built radios will know of their excellent quality, however as I was to experience, there aint a lot of spare real estate inside the case due to their relative thin depth and also the injection moulded is split into two halves. This gives a slight problem when trying to fit 40x40 mm Arduino encoder, in this case a GTS F3A and the Lemon module within the case confines. https://www.ebay.co.uk/itm/133704108565
I used the hard plastic Lemon RF module mount https://www.ebay.co.uk/itm/134615248001 and tapped the mounting holes to M3 which allows it to be screwed to the back panel using two plastic screws. I thought about installing the 2.4 antenna within the original antenna mounting tube but elected to lay it in the back of the case and being as the case is plastic, it shouldnt affect the range adversely.
I also wanted to keep the nice Graupner "twig" which fitted with a sweet little red knob at the end to save poking eyes out and keep the Tx exterior as original looking as possible, so didnt go overboard fitting external rate/expo, bind button and minute minder as yet, in an attempt to maintain the lovely clean lines of the original.
I did replace the DIN charge socket with a JR type socket mounted on a replacement glass fibre board mount and am using a 2S LiPo as power.
After adding new JR plugs to the original stick pot wiring, it soon became clear that the GTS Encoder needed to live near where the two centre aux channel controls are located, but there was no space to accommodate this so a plan was hatched and the encoder and Lemon module have been located on the rear panel of the case and fixed in place with plastic standoff and screws. The battery lives in the original DEAC bay.
I didnt want to use my original new boxed set and servos for obvious reasons, so found an excellent condition Tx on Ebay that I could play with.
For those familiar with these Grundig built radios will know of their excellent quality, however as I was to experience, there aint a lot of spare real estate inside the case due to their relative thin depth and also the injection moulded is split into two halves. This gives a slight problem when trying to fit 40x40 mm Arduino encoder, in this case a GTS F3A and the Lemon module within the case confines. https://www.ebay.co.uk/itm/133704108565
I used the hard plastic Lemon RF module mount https://www.ebay.co.uk/itm/134615248001 and tapped the mounting holes to M3 which allows it to be screwed to the back panel using two plastic screws. I thought about installing the 2.4 antenna within the original antenna mounting tube but elected to lay it in the back of the case and being as the case is plastic, it shouldnt affect the range adversely.
I also wanted to keep the nice Graupner "twig" which fitted with a sweet little red knob at the end to save poking eyes out and keep the Tx exterior as original looking as possible, so didnt go overboard fitting external rate/expo, bind button and minute minder as yet, in an attempt to maintain the lovely clean lines of the original.
I did replace the DIN charge socket with a JR type socket mounted on a replacement glass fibre board mount and am using a 2S LiPo as power.
After adding new JR plugs to the original stick pot wiring, it soon became clear that the GTS Encoder needed to live near where the two centre aux channel controls are located, but there was no space to accommodate this so a plan was hatched and the encoder and Lemon module have been located on the rear panel of the case and fixed in place with plastic standoff and screws. The battery lives in the original DEAC bay.
