October 23, 2024
Description
Modifications to 3DSets Landy Wagon (and other 3DSets models) to go to metal transmission from gearbox to wheel, using Thumper axles
Use in combination with
UPDATE 10/23/2024 :
- Updated Center of the Chassis to fit the printed pulley gearbox and the GT2/Metal Pulley.
- Added link to GT2/Metal pulleys gearbox
UPDATE 10/18/2024 : added the link for the commonly used 25T Servo horn
UPDATE 10/15/2024 : added a 20mm offset shock adapter, remixed from MWR_Designs and his design on cults (original is 10mm offset)
Assemble front an rear Thumper axles. The only differences from original files are the hub i shortened and the steering rod. You can find the file in attachment.
Note 1: the length of the steering rod may vary. I have for now a short servo horn and designed the steering rod for it. I ordered a “classic” 25T servo horn and will update the steering rod when received
Note 2: the front shocks are 20mm shorter than the rear shocks. I used 80mm shocks for front, and 100mm shocks for rear. You can also bought 4X 80mm shocks and use on the rear the adapter provided
Check from really well made BlackCrow video tutorial on the thumper page : Link
Videos to watch :
For proper front wheels alignment i used the 162mm tie rod from Thumper aftermarket shop page (JTieRod162mm) → Link
You will end with the 2 assembled axles like this :
AR44 gears have a different ratio than original 3DSets differential. Nearly twice. If you do not modify the original gearbox, the top speed will be divided by two. To balance that, i modified the gearbox to remove a 2:1 ratio. The global ratio will be approx the same.
To achieve that, and keep the opportunity to experiment with different ratio, i just modified two pulley (4 and 5) to have the same tooth count. The inner ratio between this two pulley is 1:1 in place of the original 2:1.
As those pulley are bigger, some inner housing of the gearbox have been increased. Those new parts are fully compatible with the original pulley and ratio, and give the chance to design other pulleys with different ratio.
You need to print those parts :
Assemble exactly as described in 3DSets build manual. The difference will be between like this :
Use my other previously published design to modify last pulley to have a metal output : Link
You will end with this :
The Thumper axles need 3 links on front, 4 links on rear. So you need to print and build the modified “center of chassis”. You also have to print the modified links as the length of links vary from original 3DSets model.
Links provided are for Landy wagon. You may have to experiment for other 3DSets models. Original link have been extended by 2 or 3mm to have the wheel correctly fit on wheelbase.
You have to print :
You will end with something like this (the upper front arm is on the left) :
Follow the Black Crow tutorial Assembly Video 8 at 8:15. Different model of rims are available on Thumper aftermarket shop.
If you are lazy like me to unscrew 8 screw each time you need to remove a wheel, you can hollow the center of the rim by 12mm in slicer like this (add a negative 12mm cylinder on center). With that you can directly remove the M4 nut.
I attach the stl of this hollowed rim if someone need it.
Once assemble you will end with 4 wheels like this :
5- Final assembly
This is straightforward.
Don't hesitate to let me know if i forgot something. I tried to be clear, but it can be for me, and not for you.
License:
Creative Commons — Attribution — Noncommercial — NoDerivatives
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Steve Eckerlein
