new 2DoF SCN5 build

Hi, all.
I'm new to motion simulators, but have built full-size arcade cabinets in the past and am excited to add this new dimension to gaming. I'm going to try to document the build here. I've never publicly document a project before... we'll see how this goes.

It's going to be a 2DOF seat shaker. My original concept was a full-frame design, but I'm 6' and 200 lbs and want to see to see how the two SCN5s handle my weight. Once I've confirmed the seat shaker has no issues, I may modify it to full frame... but that's a project for another day.
The build will be welded steel. I've got my 1"x 1" tubing, and am hoping to finish my design and start fabrication over the next few days while I wait for the actuators to arrive.

Here's a design question:
In reviewing other projects, I've noticed that many designs that shake at shoulder height incorporate very long rods, extending from the frame base to the actuator, then from the actuator to the shoulder mounts. Is there a reason for the long rods? Why wouldn't the frame extend up the back of unit with just short rods to connect the cylinders, assuming geometry is maintained?
For reference, here are two possible designs--one with long tie rods, one with short ones:

Long rod:


Short rods:


I appreciate the help and look forward to working with you on this!

I am starting like you, and I have discarded the long pulls for the fact of bringing more lever to the engines, I am heavy and this worries me especially in small engines, I will be attentive to your thread, greeting

If you have the same angles you will not notice the difference much. On the other hand, your rig will be shorter in case you have not a lot of space in the room...

So, I was able to get a little cutting and welding done this past week. Over the next few days, I hope to test mount both the seat and the U-joint to the seat frame, then move on to building the sim base frame.

I received confirmation that my SCN5 150s have also shipped, so those should be here soon as well.
I'm beginning to look at the method of mounting the SCNs to the rods between the shoulder and base frame. I anticipated building something like the SimXperience mounting/damping kits (see image below), but can't seem to find any information on how these work as far as damping goes. Can someone explain this to me? Is the rod that sticks out of the bottom of their SCN5 frame an air shock, or is there a rubber bumper inside it that compresses slightly when impacted?

Those simxperience mountings you see in the photo have rubber bumpers inside. Also simxperience rigs have another 2 of them on the bar attached to the rig (you dont need those IMHO). Take a look at the dumpers FREX uses in their kits, they are easy to build.

Do you mean these bumpers?

I saw those earlier, but I'm not clear how they dampen anything. It looks like a bolt runs right through the bumper from the cylinder to the tie rod end. All the force would be transferred right through the bolt?

If this is really necessary, I'm thinking I could take one of these bumpers:

and then fab up a couple of these bolt w/flange things:

to screw a little way in to each side of bumper to make a sandwich without having the bolt ends touch. The tie rods could then be attached to the flat sides of the flanges.

Have you ever run the SCN5s without damping? This all seems like a lot of extra work. Might be worth trying without damping first to see if it's actually necessary.

MMmmmmmm I see FREX dont sell them anymore, Their website is terrible as usual and I cant find them. The ones you showed me are for SCN6 actuators.
Here is a video with the ones I told you about. They are easy to place in Aluminium profile. I will try to find a better video coz this one is not:
Try not to use SCN5 actuators without bumpers. When used properly, those little motors can last for years and years.

SCN5 Frex

Thanks for the videos! I've never seen a motion sim in person, so I'm relying on photos, videos and the sage wisdom of this community to guide me through this.
It turns out my local hardware store has a rack of "anti-vibration" bumpers of all shapes and sizes (including what I believe are the exact ones in the Frex SCN6 kit I posted earlier). I'll just slide one onto one of the connecting bolts in the arm assembly . Should be easy-peasy. I'll post photos once I get it put together.

You are welcome. there are lots of differents rigs and actuators mountings. You will find easyly the one that suits you best. Good luck!

Update:
I received my SCN5s today! I'm very excited--I think I now have all major components for my build:
- 2 x SCN5s
- USB to RS485 adapters: DTECH 4 Feet USB to RS422 RS485 Serial Port Converter Adapter Cable with FTDI Chip
- Power supply: MEAN WELL LRS-350-24 350.4W 24V 14.6 Amp Single Output Switchable Power
- U-joint (repurposed from a forklift driveshaft)
- Logitech G923 wheel + pedals

As it stands, my seat is now installed in its frame, and frame is mounted to my U-joint. Next steps are to build the base frame, then install seat assembly onto the base frame. During the time that I can't actually get into my workshop, I hope to begin tinkering with the SCN5s (wiring to USB adapter, power supply). At the rate things are progressing, it will be a couple of weeks before I'm able to build my SCN5 enclosures/dampers/mounts, but I think I've at least settled on my design. Here are my current sketches including details for adjustable pedal placement and wheel height.



I think ultimately I'm going to want a triple-monitor setup, but for testing purposes I'm just going to use my Oculus. Maybe once I try that, I'm going to want to stick with VR--I don't know. But this rig is for entertainment purposes, not hardcore racing. I like the monitors because it will be more fun for spectators.

A few random questions that are rattling around my mind:
- Should I mount the shifter to the moving seat frame, or the static base?
- Should the triple-monitor/TV mounts be attached to the sim base, or should it be completely independent? Being separate from the base would allow for easy positioning and keep it from bouncing and vibrating.

Here's my chair mounted to the U-joint. I positioned it so that it balances perfectly on the U-joint when empty. Upon testing, however, I noticed that when I sit in the chair, the centre of gravity shifts way forward and I have to work pretty hard with my legs to keep upright.
I assume I should move my U-joint further ahead on the seat so that the chair is balanced when someone is seated in it?

Just an update with progress made over the weekend.

I adjusted the positioning of the U-joint under the seat so that it is balanced when I'm sitting in it. Then, I built a base frame out of 1" square steel tubing and laid a 1/8" steel floor overtop. Next up, I'll be mounting the U-joint to the floor and building a frame to support the steering wheel.
There are steel angles running along each side of the frame. These will support my steering wheel frame. I'm going to drill holes at 2" intervals along them so that I slide my wheel frame along them and bolt through them to reposition the wheel fore/aft.
I was able to sit in the seat with my feet resting on the pedals! It's starting to feel like a sim!

I've been struggling to find the time to work on this recently, but was able to squeeze in a few hours last night. Steering wheel is now mounted, but I still have to complete a few welds to make everything stable (ran out of MIG wire last night, but picked more up this morning). I feel comforted knowing that now, if everything went pear shaped and for some reason I couldn't get motion working, I'd at least have a static sim rig. That's something, right?

Next, I'm moving on to building the SCn5 dampener/sleeve/mounting assemblies.

A few questions:

1. I assume that when I mount my SCN5s, they should be positioned so at mid stroke they are holding the seat in the neutral position. That means I would have to get the SCN5s to half-stroke prior to mounting. How do I do this? Currently, they are fully retracted (which makes sense). I figured I would install all the components and then wire it up afterward...
2. I'm going to use triple monitors. Does anyone have any advice regarding using (3) 21:9 monitors? Would I end up with significant stretching/skewing of images at the edges of my FOV? I know this was an issue a few years back when 21:9 monitors were just becoming a thing, but I don't know if software has evolved to correct this.

Good progress yesterday! I built the assemblies that hold the SCN5s inline between the seat and base frame (I'm sure there's an accepted name for this component, but can't think of it at the moment). All the mechanical bits of the sim are more or less complete--I just have to add in a few nuts and washers that I didn't have on hand at time of assembly, and then tighten it all up. Two 3/4" rubber anti-vibration pucks (one to absorb on the push stoke and one for the the pull stroke) are sandwiched at the bottom of the assembly where the threaded rod is connected.

Right now, the seat is at neutral position with the SCN5s fully retracted. When calibrated, the seat should be at neutral position with the SCN5s at half-stroke, so it has equal travel available in both forward and backward directions. To accomodate this, I built 5" of adjustable length into the rods. When I power up the system, I can move the SCN5s to half-stroke (pushing the seat forward), then back off some nuts to shorten the rod assemblies and bring the seat back to neutral.

Next up: wiring!

Hi, guys.
I'm planning how to run the electrical. I expect I'll have my CPU at the front of the rig, on the floor behind the monitors so it is out of sight. The SCN5 power supply will be at the rear, mounted on the rig on the empty space between the actuators. I realize now that I should have run a conduit underneath the floor of the rig to keep cabling tidy running from back to front (I think just an extension cord and 2 x USB cables). I guess I'll be doing a little more fab after all. Sigh.

The only things I'm going to have to mount to the rig are the E-Stop and the power supply.
A couple of question:

1. I don't want exposed electrical wires where they are accessible to little fingers. What is everyone else using as a power supply enclosure?
2. Will I need cooling for my power supply? (Meanwell LRS-350-24-350-4W-Single-Output-Switchable)

Thanks!

1. A 3d printer to make the encloser. Use tinkercad if you dont know about 3d modeling to make your own design
2 Most power supplies have their own litle fan no need for extra