This model is base on the Allison 1000 automatic transmission. Is not an exact replica but the basic design and functionality are the same. The most significant difference from the real transmission is the C1 and C2 clutches that I design to work with 3D printed parts and solenoids.
Assembly video: https://www.youtube.com/watch?v=vvhICaIRjOY
I made the lower part of the case quite big so there's room to put solenoids to engage all the clutches and even a parking pawl to control them with switches or even change gears automatically with something like Arduino.
The selector 3D model is here: http://www.thingiverse.com/thing:1214373
For more information about how to make the electrical part to control the solenoids, go to my project page where I show the circuit diagram and arduino sketches: https://interlinkknight.wixsite.com/interlinkknight/automatic-transmission
There is also an adapter to fit this transmission to the Toyota 4 Cylinder 22RE Engine made by ericthepoolboy. This is the adapter: http://www.thingiverse.com/thing:1120974
I don't have a 3D printer so I would appreciate any feedback from people that printed one to improve the model. Still, I check all parts on Cura to make sure all is ready to print, except the orientation. You will have to rotate some parts to print it in the optimum way to have the least overhanging and warp.
A special thanks to the user RobinSwa for helping me improve the model by testing it and giving me useful feedback.
- 1mm rod
- 3mm rod
- 21 self threading screws to fit on a 1mm diameter holes
- 2 self threading screws to fit on a 2mm diameter hole.
- Several washers/spacers for the 1mm and 3mm rod.
- 1 snap ring or E-clip for the 3mm rod.
- 2 ball bearings 608ZZ - 8x22x7mm (inside diameter x outside diameter x width)
- 6 push/pull solenoids with a body size of 30x15x15x30mm (LxWxT). I recommend this one: DC 12V 1A 10mm Stroke Push Pull Type Open Frame Solenoid Electromagnet
The file names are self-explanatory. Print the number of times mention on the file name and assemble like shown on the video.
Use the 3mm rod for the center of the transmission and for the clutch forks.
The 1mm rod is to hold the planet gears to the carrier.
I recommend putting washers in all planet gears and each side of the 3mm center rod.
All the rods have parts where it should be fixed to a part very tight by pressure and another part where it should be lose so it can turn in that axis. For example on the planet gears the 1mm rods should be fixed to the carrier and the planet gear holes should be drilled so is big enough to turn easily.
As I show on the video, you need to put a snap ring or E-clip after the C2 clutch to hold all the planetary gear sets together. To do this you need to create a notch on the rod.
I recommend begin the assemble from output to input, like on the video.
P1, P2 and P3 are the names of the planetary gear set, numbered from input to output. If you don't know the name of the parts of a planetary gear set, here it is:
- Sun gear: the gear in the middle
- Ring gear: the big gear that covers all the gears
- Planet gears: the gears that go between the sun gear and the ring gear
- Carrier: the part that holds the planet gears
- I make a hole on the internal part of the case to put the speed sensor near the parking gear. The parking gear is suppose to interrupt the IR light in the other side, in an angle.
- I divided each fork into 2 pieces to make possible the assembly. The previous forks had an included extension on the bottom to reach the solenoids, but that would prevent the forks getting in to the case in the way is suppose to (from the front). Now the extensions can be added later using a screw with nut. Thanks for the user Hank190 for pointing out this mistake.
- Reduce the angle of all helical gears in all planetary gear sets, so I re-upload all those parts. The reason I change this is because I want to use this transmission with a load and having a high angle on the gears (like before) it creates too much longitudinal force.
- Remove the basic/simpler version that uses buttons to apply the clutches, so now there's only the solenoid version. This is because is harder to keep updating 2 versions of the same transmission, and the solenoid version is after all the way I planned to use this transmission.
- Increase the diameter of the input and output shafts from 8mm to 8.1mm because the inside diameter of the bearing is 8.1mm.
- Put a hole for a nut on each side of the C1 Clutch so there's no need for the screw to cut through the plastic (that was not very strong). I put 1 on each side so is balance. Also I add an included spacer so there's no need to use that many washers between the clutch and the input.
- Now the 2 sliders use the intermediate shaft as axis for more stability. Also the contact part to the forks was moved.
- Remade the two forks because they not longer need to support the sliders, so they now have a smaller contact surface with the sliders, and also fit with the new sliders position.
- C2 Clutch is a bit longer to fit better.
- Input and output now have dipper holes for the intermediate shaft, so the shaft can work to stabilize the input and output (avoid side play).
- I made the shaft for the P2 Carrier - P3 Ring a bit longer.
- Before, the P2 Sun - P3 Sun had 1 hole for a screw. Now there is one on each side so is balance. There is no space for nuts, but a good option could be glue this part to the intermediate shaft, using this 2 holes so the glue has something to hold on to.
- A bit bigger support for the fork rods in the Solenoid Case. Also those supports were moved a bit forward to avoid touching the spring of C3 clutch that is near by.
- A little better hook for the spring on C3 clutch.
- Add a dipstick. Is optional, but I think is a nice touch.
- Both cases were improve with more cosmetic details and there's a hole to make space for the bearing on the output side so the bearing don't touch the wall. Also, now there is a place for 2 magnets to hold the top cover, and put tops/limits so the cover stays better in place.
- Add the 2 holes for the magnets on the top cover.
- Fix a minor aesthetic detail on the oil pan.
- Add some included spacer on the bottom of the P2 Sun - P3 Sun to fill the space to the output.
- Now all the 3 planet carriers have the holes for the planets going all the way through so is easier to remove the 1mm rods.
- Now all the ring gears have an included spacer so they now all touch each other in the outside part. Before, I tried to make the contact part on the inside to reduce friction, but I realize that is better to have stability, and friction don't seem so bad because those parts print much smoother than the inside.
- New hook for spring on C3 clutch, fixing a mistake of the direction of the spring.
- Add C-Clip that goes on the C2 clutch.
- Increase the internal hole in C2 clutch so is easier to fit in the tube.
- Edit the front cover so it has a space for the inside part of the bearing to prevent it from touching the wall. I will later do the same for the output part.
- The input and output has a included spacer so the outside of the bearing don't get in contact to the input and output.
- Fix the P1 Carrier - P2 Ring so it has thicker walls in the carrier part, so the small rods of the planet gears have better support.
- Small fix to P2 Carrier - P3 Ring, but mostly irrelevant.
- All planet gears were reduce in size to 98% so everything turns smoother.
- Convert all the parts to have only one shell. Before, I made the mistake of making each part with multiple polygons join together, but later when someone tried to print them it broke off where each polygon touch to each-other. Now is fixed.
- Change the place for the screws on the oil pan, so I had to update both cases and the oil pan.
- I remove the extra support of the rods on the front cover to give more space to the clutches.
- I had to increase the internal hole of "P2 carrier - P3 ring" to be able to insert the sun gear.
- Add C1 and C2 clutch forks for the solenoid version.
- Improved C3, C4 and C5 clutches for the solenoid version.
- Further improve the parking pawl to engage better with a solenoid, calculating using a solenoid model with the correct measurements.
- I change all the ring gears exterior so the end of the notches where the clutch engage is vertical to avoid the solenoids clutches from disengaging if the force is stronger of what the solenoids can give. This don't affect the default version since it uses buttons.
- Redesign C3, C4 and C5 solenoid clutches to a lower position and the edges now are vertical.
- For the solenoid case I lower the holes for C3, C4 and C5 clutches.
- I improve a little the parking pawl so is easier to engage by a solenoid.
- Add 2 realistic cases: one for using with buttons to engage C3, C4 and C5, and another case for using with solenoids.
- Add buttons to engage C3, C4 and C5.
- Add clutches for C3, C4 and C5 to engage with solenoids.
- Better clutch fork with more support.
- Longer shaft for the input.
- Longer shaft for the output.
- Add parking pawl for the solenoid version.
- Improved C2 Clutch to prevent the P1 Sun Gear from moving forward.