High angle & Displacement 6DOF

[DoctorD]

Heya Stevant1,

That heim joint of yours looks perfect. It's certainly going to have good strength, tempered with an increased range of motion when compared to a typical rod end bearing.

The only thing that I found with these is that they are typically limited to around 65 degrees total travel (+/-32.5 degrees max). So that's where the custom spacer comes in. This way I can get the most amount of travel, whilst also maintaining enough strength in the part to accomodate a decent platform load. There is a slight chance that mechanical effects like creep/repetitive strain may lead to breakages at the thinnest parts, but I'm quite confident the loads will be quite small relative to the cross sectional area.

Here's a quick snapshot of the CAD screen showing the allowable rotation of my joints:

RotationLimits.jpg (86.19 KiB) Viewed 7322 times

[Stevant1]

I can see that yours will have a greater range of motion. Great that you are able to design your own. I'll be happy with the travel of the ones I am using but will be jealous when I see you hanging on to your platform with a 4 point harness. Your platform is going to be awesome with that kind of movement.

Looking forward to your progress Doc.

[DoctorD]

@Riton from the 4th of September

Firstly, sorry for not seeing your post.
Hopefully I can answer your questions...
The design isn't complete yet, I still have a few design issues to fully document. I have mostly the platform geometry to finish (which I will test with a cheap timber prototype first).
That said, even after the test phase there will be many parts of the simulator that I can modify in geometry:
- The attachment points on the upper frame will allow shifting of the bearing connections
- The gearbox connections to the horizontal base members can be slid along the frame and re-clamped to suit
- The three corner pieces of the base will be drilled to allow different size 'triangles' to be setup
- The vertical rods will be adjustable in height
- The torque arms off the gearbox have four different attachment points (creating four different lever arm lengths)

I am trying to make the project as low cost as possible for my design scope. It's still going to cost around $6000 USD to get it to 100%, but I'm pretty happy with that considering what it should be able to do performance-wise.

[DoctorD]

While I'm waiting on the big stuff to arrive I've been occupying my thoughts with 'important' questions like "what colour should I make the platform"
...lol, very important I know

Anyway, here's what I've come up with:

BluePitched.jpg (71.45 KiB) Viewed 7261 times

BluePitched2.jpg (114.55 KiB) Viewed 7262 times

These images also show off, hopefully, the high angularity of the platform. It's set to a tad over 40 degrees in the images.

[Stevant1]

That angle is amazing Doc, it's more like a thrill ride at that point. Awesome! Blue is my choice, looks great. Make sure you surround the platform with mattresses for those who might fall out.

Keep us posted!

[DoctorD]

All I can say is 'thank crap for 3D modelling!'
...I've spent a great deal of time over the last 3-4 days going over the platform geometry and mechanicals and it's almost comical how many little changes are needed to get the most out of the platform displacement and angularity wise (and keep the damn thing stable!). Here's the latest revision of the platform, now taking into account the high misalignment bearings. You probably can't see, but I have also reconfigured the torque arm travel envelope to improve overal torque curves and to give much better authority to surge, sway and yaw movements.

I'm getting close to the final thing, but I need to spend a bit more time aligning the upper joint carriage with the average rotation centre (and maximise rotation travel).

DeltaConfiguration.jpg (137.76 KiB) Viewed 7235 times

Heave1.jpg (203.25 KiB) Viewed 7235 times

SurgeSway1.jpg (204.1 KiB) Viewed 7235 times

[DoctorD]

I've just finished a run on the CNC machine I designed and built a few years back. This is the 1st of two 1800x900mm MDF sheets to be cut in order to form the Electronics Enclosure.

Here's a pair of photos showing the output:

photo 2.JPG (99.42 KiB) Viewed 7226 times

photo 1.JPG (91.45 KiB) Viewed 7226 times

The panel with multiple rectangular holes will be the enclosure's door. Holes are to allow viewing of the 6 VFDs, the LCD from Thanos' AMC1280USB, safety stop button and a bank of selector switches.
Hopefully I'll get time to do the rest of them tomorrow.

[Stevant1]

Very Nice....CNC machine, awesome. Perfection!!

Looking forward to your build.

[Riton]

where did you do make the mechanical parts?
you have a link?

[DoctorD]

Heya Riton,

Which mechanical parts exactly?
I have had them made from different manufacturers on Aliexpress.

If you pm me I can send you a list.