X-Plane 11 6DOF motion platform

Some nice printing you have done in Orange

After all that measuring and drilling, I tried a dress rehearsal to see if things lined up...and they did!

I still need to file the holes and clean things up but I am happy with the progress

The image doesn't show any of the 3D printed parts - just an alignment test.

Some things that didn't work out:
1. Arduino Uno - dead on arrival
2. Anet PLA filament - far too brittle - switched to eSun PETG
3. The bearing set for the lead screw had two bearings - the top one is not necessary
4. The Bournes pot used for positional feedback will work but not for long - replaced with Vishay
5. The angled wheel nuts for either side of the rose joint are M12 x 1.5 they should be M12 x 1.75 - will need to be tapped
6. The plum motor coupler was the wrong size - rookie mistake - measure everything yourself with a vernier

Edit: It is worth noting that the lower bearing comes with the square lock nut (to stop the lead screw from coming out of the lower bearing) in the sealed green packet. The top bearing packet has the circlip for the top of the lead screw to hold the anti-wobble ring in place (if you want to use it). So if you don't get the top bearing, which is not needed, you will need to find a suitable circlip yourself. The diameter of the circlip slot is 9.1mm

Beginning to set-up for some further construction. Had to re-organise the office again and put things in boxes. The image shows the relative size of the base and how the batteries will be organised. The power supplies and electronics will mount on timber boards on top of each pair of batteries. It will be moved away from the room corner once I get further into the build.

Hey, @SixDegreesOfFlight, are those deep cycle batteries or automotive batteries?

@BondeX
I don't think they fit into either category They were originally designed for brand name uninterruptable power supplies but there was some problem in the manufacturing that caused them to be a few millimeters too big. While it would be ideal to have deep cycle, when you need six the cost is ridiculous. Maybe I should have put all the power supplies in parallel and got two big deep cycle batteries like @SilentChill - only time will tell. These ones were local so I could pick them up and were the recommended capacity of 33Ah for $65 each new. I wanted them new so they were matched in both age and condition.

This is my solution to the rose joint mount that supports the upper frame - car wheel nuts rethreaded to 1.75 pitch on a M12 stainless steel bolt. I chose the female version of the rose joint because I wanted control over the length of the thread which I could then epoxy into the end of the carbon rod in conjunction with a 3D printed sleeve

6 Why in timber, Alloy is very cheap and stronger?

@Ned
Are you referring to the timber frame? If so, it was very easy to make, cheap and light. Once I paint it whether it is timber or metal will make no difference

Morning 6, what is the benefit of building your own linear actuators as opposed to buying them, is it a money saver or is it the challenge to build them? I guess I am asking what is the cost of 1 home made actuator in parts not the hours it took to make? Regards Ned

@Ned
Others will know more about this than me, however, my main reason for building this is the enjoyment / challenge. So far this build is calling upon all my knowledge and skill to solve all the problems (large and small) because that is what this project is - how well can you problem solve. I am sure you would have read the @SilentChill build. Together with @SeatTime they are both masters of creative problem solving. In my build I am not being innovative at all, simply following in the footsteps of the pioneers and mavericks who have demonstrated working systems. To add weight to a self-build is the very high cost of a similar platform built with commercial actuators. Do a web search for a linear actuator that has a 500mm stroke, 400mm/s speed and capable of lifting say 40kg - they are incredibly expensive. If you don't get an actuator with these kind of specifications the dynamics of the rig will be poor and then you are in the territory of motion sickness if you are using VR.

As far as cost per actuator goes - have a look at the cost spreadsheet on page 1 of this thread - it will give you a fair idea

In OZ, suitable aluminium profile is not cheap and for areas of the sim that do not move, its weight is irrelevant. For a base, a bit of weight/mass can be a good thing .

Made some progress this weekend and this will be about it now for the week as my work commitments are about to take a sharp increase.

• The Anet A8 has been printing flat out for the last two days (all parts at 60% in-fill) and there are still quite a few parts to go.
  
• I eventually used stainless steel pan head 12g self tappers rather than M5 bolts for the top plate. @SilentChill used his military grade drill to drive the bolts untapped into the V Slot holes My drill was simply too wimpy
• Finally, the completed rose joint assemblies are shown with the 3D sleeve that will be used to epoxy it into the end of the carbon rod.

@SixDegreesOfFlight
Can I suggest that you use an extra nut to lock those wheel nuts from loosening up or use M12 nyloc nuts instead of the wheel nuts.
Also really consider not using the linear ball bushing as it will wear your CF tube pretty quickly.
I will do a drawing of a elegant solution that you can make or even 3d print.

@OZHEAT
That would be great to see what you could come up with! If the carbon rods wear to a point where they begin to affect the operation of the sim, I would consider other options such as different bearings or even a steel rod. The Igus bearings are prohibitively expensive.

I do have another nut or two to add to the rose joint assembly, I didn't have them handy when I took the photo but thanks for pointing it out.

Edit: thanks for the reminder about nyloc nuts. I just ordered 30xM12x1.75 stainless steel from UK - cheaper and faster than China on ebay. Go figure

Nice

Getting ready to start using the 3M epoxy. All the parts for the rod assembly are now complete.

Still waiting for one of the power supplies. The ebay shop I purchased it from is sending another one. This is the first item that didn't arrive out of the many I ordered

I began by making some groves in the 3D printed collar using a trianglar file as I was concerned at the last minute that there wouldn't be enough surface area for the epoxy to adhere to. The next step was cleaning all the parts with Methylated spirits including the inside of the carbon fibre tube where the rose joint anchor would go. The inside of the tube had a lot of dust. I used a new piece of paper towel to clean each part. Once everything was clean I used a paper plate on the digital scales to accurately measure out the epoxy: 5 parts white (B) base to 7 parts grey (A) accelerator. Confusingly, the white base tube had a black cap. I wore protective gloves and glasses.
Edit: Dec 2017 One of the collars pulled away from the carbon tube. So not only do you have to clean it thoroughly but you should also scrape the inside of the tube with a file to allow the epoxy some sort of key to the carbon

I mixed both parts for about 30 seconds using the supplied wooden paddle then began applying it to the collar, then the lower housing, followed by the rose joint anchor. The epoxy is quite runny and smells and acts like two part Araldite. Because it is quite fluid it will not hold its own weight and tends to run everywhere. For this reason it required quite a bit of concentration and I found myself holding my breath when I was applying it.

At first I tried setting up the rods horizontally but the epoxy began running off. It was lucky I noticed this otherwise I might not have been able to remove them from the shelf where I was going to let them harden. In the end I tied them upright using wire by the top nut.

I wasn't really happy with the result but as I was getting towards the end of the working life of the epoxy I had to leave it as it is. I will take some photos tomorrow once it has cured.

Painters tape is your friend.

Next time, to neaten up the edges use painters tape on the bit you want keeping clean, then just before the glue sets up lightly run a sharp knife around the very end of the tape (using a jig to accurately turn the rod if you want a perfect edge). Then when the glue has almost hardened but is still slightly flexible peel the tape off along with any excess epoxy.

I wouldn't worry about it too much though ...at least it won't be going anywhere.

@DEADBEEF
You are right about the masking tape. By the time it began running it was too late to go and get a roll. I suppose I was surprised by just how runny it was. I ended up having about half of the epoxy left.

When I checked the rods 12 hours later, the epoxy was just soft enough for a finger nail to make an impression. This allowed me to clean up a bit with a knife. Still, lesson learned.

Edit: cure time for full strength is 7 days