RC10Talk - The Net's Largest Vintage R/C Community

Did a lot of testing today and had a small issue , it lost drive to the front , I traced the problem to the cross pin that locks the shaft to the second gear in the gearbox and drives the rear sprocket , I'd left too much end float for the gear on the shaft and the cross pin could move out of the keyway in the gear , long story short I made up a shim to fix the problem and modified the gearbox design so future gearboxes won't need the shim .
I'm also going to have to make a modification to the chain guard that fits the side of the gearbox to suit the Kyosho chain and sprocket but that's an easy fix .
Otherwise its going well .

Very cool Dadio!!

By chance are you able to post a running video?

I'm planning on taking it out this evening with a friend and some other cars later so I'll try and get some video then , I don't have a proper video camera but I can take video with our regular digi camera .

New body , first picture is just as it finishes still on the print bed .

Uncut

And fitted

Dadio wrote: ↑Mon Aug 19, 2019 10:39 am I'm planning on taking it out this evening with a friend and some other cars later so I'll try and get some video then , I don't have a proper video camera but I can take video with our regular digi camera .

That should work just fine. Thanks Dadio.
BTW, that printed body appears very smooth, has it received an acetone vapor bath or is just a really high quality print? Either way, it looks great.

I couldn't get the video tonight but I'll try tomorrow , the printer used for the body was a second hand Ender 5 with a couple of upgrades that only cost another £43 , its not that fancy .no acetone treatment was done to the body , its made of PLA a plastic that's unaffected by Acetone , even if I'd printed it in ABS I couldn't use acetone as its only .4 mm thick and the acetone would just turn it to mush almost instantly .

I ordered the new ender 5 plus when it dropped a couple days ago. Can’t wait for it to arrive so I can replace my CR10s. It’s a 350x350x400 machine in the same ender 5 form factor.

That sounds cool, we need to see the beast when it arrives ! , I just don't have space for a printer so large , I was looking at the Tronxy X5SA that's around that size but realistically there was no room for it , as it is I'm going to have to rethink my workshop layout to fit the Ender 5 in a nice place , at the moment its taking 2/3 of my workbench That's got no future so its going to mean a spring clean and redesign of the workshop pretty soon .

I bet you could stack em

GoMachV wrote: ↑Mon Aug 19, 2019 7:00 pm I bet you could stack em

Maybe you should talk to my wife

I finally got some video footage , also had my first part failure , both front suspension top arms cracked at the inner rear mounting , those parts are some of the last parts on the car that are still made of PETG , its flexible but can crack or shatter on impact , not sure weather to print a new set in ABS or Nylon .I also drew up and printed a wing and wing mounts in TPU .




[you-tube]https://youtu.be/o_sKjx9SKao[/youtube]
[youtube]https://youtu.be/JScW4EZ4YZI[/youtube]

Dadio wrote: ↑Tue Aug 20, 2019 4:34 pm I finally got some video footage , also had my first part failure , both front suspension top arms cracked at the inner rear mounting , those parts are some of the last parts on the car that are still made of PETG , its flexible but can crack or shatter on impact , not sure weather to print a new set in ABS or Nylon .I also drew up and printed a wing and wing mounts in TPU .

I'll update once the video is ready

I find it interesting that both arms broke, that they broke in the same location and the break is at the inner rear hinge pin hole. From the photos, the arm's hinge geometry appears to be the same front to rear - to what do you attribute the failure? By chance does your car's drive system overdrive the front wheels? I freely admit that I have zero experience with Yokomos so please excuse the dumb questions.

The top arms are symmetrical , the same front and rear , the gearing in the version I've made is 1 to 1 ratio front to rear ,later models fitted with a slipper on the rear chain sprocket had an overdrive to the front wheels , I'm swinging between two possible reasons for the pivot point failures .
1 the stock mono shock mounting brackets have a built in travel limiter , I'm using some Pargu Store ones that lack this limiter so the travel is now limited to the top arm hitting the bulkhead , that would load up the inner pivots .
2 the arms I printed are an exact copy of the originals and the plastic I used is just not as strong under impact type forces .
Either way I'll go belt and braces , I've slightly reinforced the pivot point in the design , I'll copy the stock mono shock mounts to include the travel limiter and I'll print new arms in nylon a much stronger more impact resistant plastic .
Previous post now edited with video.

First reinforced top arm , I've made it so i no longer need a nut but the crew taps into the rear pivot , its made of nylon as well so much more impact resistant .

I've just had another thought on why I got two of exactly the same failures , there was not quite enough thread on the screws to engage on the nylock part of the nut so I'd used some Locktight to keep them on , Locktight can affect plastics and the layered construction of 3d printed parts might have allowed better ingress into the plastic , I didn't use Locktight on the outer ends but I did use it on the bottom arms on the inner nuts so it should fail there as well but on inspection they look good .