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3D Printing News RC Vehicles

Lynx to F250 Honcho Mods

The LED headlights on the Lynx weren’t that bright and I thought it would be cool to have a light bar so I picked one up off Amazon and attached it to the front bumper with some foam tape. Then I ran into a bit of an issue, I wanted to separate the headlights from the tail-lights as they were wired together and at some point install an FPV camera but I only had one servo Y cable plugged into channel 3 on the receiver so didn’t have enough connections. I thought it would be cool to make a light controller using an Arduino and figured I could control multiple devices connected to it so I dug out an old Pro Mini and after a lot of messing about had a nice light controller that powers the headlights, tail-lights and light bar and takes a signal from the throttle channel to provide working brake lights – all wrapped up in a 3D printed case that attaches to the top of the receiver with hook and loop tape. The FPV camera is connected to channel 3 for now, the Arduino couldn’t provide enough power.

I also finally came up with a spare tire carrier that I’m happy with. It is now screwed into a back plate to provide stiffness and tilts the wheel back to reduce the moment arm and the angle lines up nice with the body.

I posted my Lynx mods to the Carisma SCA UK group on Facebook and found that the Lynx body is no longer being made so is probably worth hanging on to. There were a couple of clear bodies available on eBay in the US so I guess there are still some around but it would be good to find a spare body to use for bashing. Coincidentally a very nice guy posted a Proline F250 Honcho body for free on the GTA RC Crawlers Facebook group. At first it didn’t look as though it would fit because it was fouling on the rear battery tray where I had the ESC and receiver mounted but Carl Craver from Carisma SCA UK pointed out that I could flip the tranny back to the stock orientation and move the ESC and receiver forward over the tranny. So that happened and then I drilled a couple of holes in the back of the new body but there were already 2 sets of holes in the hood neither of which lined up with the posts on the chassis. Several iterations and even more hours of printing later I had some body posts that work and the body was installed.

While flipping the tranny I found that 3 out of the 4 pins in the drive shafts were simple grub screws instead of the grub screws with pins on the end. I prefer the pins and thought about heading down to Great Hobbies to see if they had any but found a set of steel drive shafts on Amazon that seemed decent so ordered them instead. Now that the drive train is upgraded I’d like to get a quicker motor and make it more of a rock racer. I think an adjustable drag brake would be best to go with a quicker motor and found that the QuicRun 1080 has multiple drag brake settings and is in stock at HobbyHobby.

Update: Before I could arrange to get down to HobbyHobby I found a guy 25 mins away selling a brand new sealed one for $50 so I grabbed that and saved almost $20 and a longer trip. Swapped the battery connector to Deans T and found some female bullets that fit the motor and got it programmed, calibrated and installed – wow, what a difference! I had read that the stock ESC was not great but this just seems so much smoother low down and the adjustable drag brake works just how I hoped it would, overall – very impressed.
Then I was doing a bit of reading and came across some tips for increasing the speed of an SCA-1E on the Carisma SCA UK group basically saying that there are significant gains to be had by changing the pinion gear – the recommended range for the stock spur is 13T to 25T and the stock pinion is 17T. HobbyHobby not open today so I went down to GreatHobbies and picked up 21T and 25T from the super helpful lad there and installed the 25T when I got back. Did a quick test in the basement to make sure nothing was binding or slipping and then went on the street and let er rip!! It was much quicker for sure but far from blistering, hard to tell yet whether it has much of an adverse affect on the low end so I guess that means there’s not a huge impact 😀