Adding 2DOF (Seat Shaker) to Aluminum Rig

im really curious how those 3d printed arms hold up. I never thought to even attempt that.

having said that I have printed some stuff at 100% that does feel like a damn rock and I get good layer adhesion so I might just have to give this a go......love the way you printed the arm for your POT with the flex so you could wrap it around. That was creative and a good way to have a little give in any direction.

I imagine you just printed that flat without any bend correct?

I actually printed it with the curvature built in so the part was printed laying on its side, I added the wavy feature to help give it some rotational support while maintaining the off axis flex. I don't know if it will work or not, but it's worth a shot. I will get a couple of pictures of the part sitting on a table so you can see exactly how it was printed. That being said it is really flexible and you could easily induce 90 degrees of bend in it without breaking it.

so far the printed part have held my weight while I force the 50:1 motors to turn so that's a good sign. ultimately I will replace the everything except the pot bracket with aluminum.

I spent a little time working on the updated linkage design. Here are some drawings I created to understand how much movement I will have at the seat base given the angle of the motor and the mounting position of the linkage on the seat base.



I updated the seat base to give me more leverage by extending the connection point about 3 inches further back and out, now at a level position the motor mounting point and seat base mounting point will be directly above each other. that should give me more leverage and also eliminate the nasty side angle I have now.



I don't have enough room to push the motor back without hitting the vibration mount.



I designed a wheel to transfer the motor torque with another linkage set. this is just a quick prototype right now, I will probably start designing parts for printing and try to test in the next few days.
the system will work like an old train wheel, the motor will force the rear wheel to turn which will in turn raise or lower the chair base.

Here are the pot brackets in the same orientation they were printed






Also I did a test where I tightened a bolt in one of my motor arms until I had complete failure. It was a chore to get the nut to pull through, but I was able to eventually destroy the part. I'm still optimistic that these will work for testing and possibly short term use. I think with some redesign and overbuilding the parts it could be a viable solution. if you have a printer why not give it a shot.





This was 100% fill with PLA, 0.2mm layer height. Each arm takes about 1-2 hours on my machine. I really like to crank it up for stuff like this where finish quality isn't that important.

New Goodies
Arduino Mega
2.8" TFT touch screen
Amazon Fire Tablet 7" version

Arduino Mega Terminal Sheild
Old Goodies
Arduino Uno
Arduino Uno Terminal Shield
Sabertooth 2x32
2xDPS-600PB power supplies



I am going to start working on the arduino/sabertooth working with simtools.
im hoping to either use the code by vthinsel
New XPID software for Arduino UNO/Mega and Sabertooth (with LCD !!)
https://www.xsimulator.net/communit...rduino-uno-mega-and-sabertooth-with-lcd.6747/

or this code here by Wanegan
Arduino code : 2 DOF for Sabertooth using Simplified Serial (Working) 1.23
https://www.xsimulator.net/communit...bertooth-using-simplified-serial-working.136/

If anybody else is successfully running arduino/sabertooth and simtools 2.0 and recommend something else let me know.

lastly the amazon tablet is to replace the center tablet in my dashboard, the existing one is a cheap tablet that no matter what I do cannot charge and operate at the same time without draining the battery and shutting down. I will have to disassemble the dashboard and pull the front plate off so I can drill and tap new mounting holes for the new tablet. The amazon tablet is about 1/2" wider then the old tablet. Before I tackle that though I will root the tablet, install the google play store and get the EKsim vdash software functioning. Also if you look closely I made a mistake in my design and put two of the mounting bolts behind the wheel adapter plate. I cannot remove the tablet bracket without disassembling the QD and removing the shaft clamp. If the amazon tablet works out I will be able to fix that issue.

I spent the better part of the afternoon playing with the amazon 7" tablet. I bought the version with special adds ($40 USD)knowing that I would be rooting/hacking it for my needs.
Here is what I did to strip out all things amazon.

The tablet shipped with firmware 5.3.2 and currently only 5.3.1 and below can be rooted, so I had to rollback the firmware.
I downloaded the following files
ABD version 1.4.2 - https://forum.xda-developers.com/showthread.php?t=2588979
amazon firetablet firmware 5.3.1.0 - https://forum.xda-developers.com/showpost.php?p=62986665&postcount=3
rootjunkysdl super tool - http://www.rootjunkysdl.com/files/?dir=Amazon Fire 5th gen/SuperTool
I followed the excellent video by superuser explaining the rollback process and root process -
Then I downloaded the new custom rom - https://forum.xda-developers.com/amazon-fire/orig-development/rom-fire-nexus-rom-lmy49f-t3300714/
Again I followed a video by super user to backup and then install the rom -

End result is a completely bare android tablet that is ready for customizing. I will only be running VDASH-EMU on this device so it will work great. its a really great tablet for the money after you remove the amazon junk.





Also, I purchased a license for the VDASH-EMU and EKSIM changed the pricing scheme from $10 for the first device and $2 for all devices after to $10 for each device. so if anyone wants to go that route plan on $10 for each device. the license is tied to each device so you cannot transfer.

I would have put some more effort into it had I known you would link it in the FAQ.
Anyone that wants to repeat the process, verify your firmware version prior to attempting. This process with the wrong firmware will result in a bricked device.

I haven't had much time to work on my rig lately, but I did manage to print some parts.
Here is the new motion lever with 10% infill, I was able to print this in about 1 hour.




the print quality is not great at 10%, but I was able to test the fit of the bearings and all was good.

Here are the 100% fill versions, these took about 8 hours to print both parts.



Notice the fill inside the hex nut cavity and the bearing cavity. I make my own supports in the 3d model so that the support material is in the proper location. Once you figure out how to build the support material it works much better then the standard support in the slicer. I use .7mm xy spacing and .15mm z spacing.

I just jam a screwdriver in the gap and the support pops right out.



Here is the backside of the finished parts with hex nuts and the bearing nested.



the next step is to print up some mounting brackets for these parts and update my 3d model to represent the new design.

hrmmm....Suggestion, you need to crank up your mm/min mang, 8 hours to print a Bracket like that proves your going a tad slow. What printer and what speeds you running ? Also what slicer ?

I thought that was pretty good, it was both brackets with raft at 100% fill in 7 hours 36 minutes, the 10% fill version took about 1 hour for a single bracket.
I'm using a Monoprice maker ultimate with the Monoprice specific version of Cura. The printer is a re-branded Wanhao Duplicator 6 and Im running 75mm/s for all settings
Here are my settings in Cura

wow so your up there already in speed. 75mm/s is pretty fast, There's really only 2 places i can think to make up some speed, Giving the Infill some more speed and which ever setting you would consider your Extrusion width, the difference between say .4 and .5 is a pretty big difference in Physical print time. Tho im not 100% sure what setting that is in Cura.

Also 100% fill density in Cura, is that 100% layer height, or 100% infill pattern ?

it's the infill pattern, so at 100% it is a solid part with no air gaps or voids

I think I have the design for the linkages finished up, I will be 3d printing parts over the next day or two to test. The new design is about 3" further back and out for the linkage so I will have a little more leverage then before. Its quite a bit more complicated then a direct linkage, but due to my space restrictions I had to go this route.







The support bracket that holds the rear lever is 5/8" thick, it uses about 50 meters of material for a single bracket. this will probably be the most likely failure point for the 3d printed parts. It will have to support almost my full body weight as well as all the forces provided by the gear motors. of course I will eventually replace with aluminum if I have to.

I updated the model on GrabCAD so if anyone wants to play around with it you can right from your browser.
https://grabcad.com/library/aluminum-racing-simulator-r2-01-1

Infill is a pattern, 100% infill is still a pattern, unless cura handles it differently. to get a 100% solid model, you force 100% solid layers, Not 100% infill.

Not sure about other programs, but cura handles it as a percentage of fill density. At 100% fill density there is only material and no air space. Your right, it is still a pattern, just at 100% fill density the pattern so close together the part is solid.

Take a look at this part, its 10cm x 10 cm x 10cm, pla is 1.25g/cm^3 so it should be 1250g of pla if printed solid. Cura shows the part at 1253 so very close. I have watched the parts print and I can attest they are 100% solid.



Here is a video of the printer running at 100% fill, this is a hand full of layers in so it is not the first couple of solid layers. You can see the print is so close together its essentially solid.

Ah yes, Simplified and Slic3r handle it differently than Cura.

Here is a quick hand test of the new levers and linkages. I'm getting some flex from the rear linkage, but I haven't finished building the new seat base so the rear linkage is still toed in. I'm still optimistic that the printed parts will allow me to do at least a short ride.



I'm a little skeptical of these gearboxes, they are pretty easy to drive by hand. well see once I get them under power, but right now it looks like I will need some sort of lockout for when the rig is used without motion.