My First 2DOF Joyrider Flight Simulator

Hi,

I have been looking through some of the amazing simulators posted on the sight. They are a real testament to hard work and nohow. I am not nearly as skilled in fabrication to build some of the things that you all have. My goal is to build a pretty generic joyrider for flight simulation. Below is an idea I have for my simulator build, based on inspiration I have gotten from the great ideas I have seen in the community. I was wondering if anyone could give me some guidance, pointers or pitfalls to try and avoid after you take a quick read of my very high level [build] ideas.

My plan is to build the simulator according to the Joyrider specs I have purchased, using the same materials defined in the specs [pvc and casters at the pivot points]. The modification I was planning on doing was the following:

Two worm gear motors, one to control the pitch axis and one to control the roll axis. One motor would be positioned in the back behind the seat at the end of the Gimbal frame. Using this motor the roll could be controlled by using a belt sprocket and a belt, with one side of the belt opened [so it is an open ended belt]. I would then connect each side of the [open ended] belt to the ends of the gimbal frame [with possibly a toothed belt clamp] and have the motor and associated belt sprocket control the pitch when it turns one way or the other [the configuration of the belt when attached to the motor and the gimbal frame would be a "V"]. The second motor would have the same configuration for the pitch axis, positioned on the side near the pitch pivot point. After researching a bit I think the "Worm Drive Motor, 12V DC, 150-160RPM 25", that was mentioned on the DC motors shopping list on the site, would be good for this.

Fundamental things I still need to figure out:
There are many things I still need to figure out, some of which I am sure I don't even know I need to figure out yet. Below are some of the questions I have gotten up to:

• what type of belt sprocket should I use?
• what type of [keyed] shaft can I use to connect the belt sprocket to the motor?
• what type of belt [I was thinking one with teeth]?
• what is the best way to fasten the belt to the pvc frame [ I was thinking a toothed belt clamp]?

I am still sketching this on paper and just wanted to start to share some high level ideas to see if they make sense. Hopefully I was able to explain it enough for you to get a general idea of what I am trying to do. I hope to soon post some diagrams and eventually some pictures of my progress.

Any guidance or pointers you all could give would be greatly appreciated.

Thanks,
Michael.

I'm very early on with my Joyrider style build, so I don't have a lot of direct experience yet. I'm just starting assembly this coming weekend.

Mine isn't strictly a Joyrider, so I have some flexibility with the design. Following the advice of others on the forum, I am using a lever assembly instead of a belt or chain drive. I think that should cut down on the backlash to give more precise movements and less bouncing. It is also a simpler setup, although I had to make my sim a bit larger to accommodate the drive levers. I want to make sure the motors can make a complete revolution in case of a malfunction, so I needed room for a 10" lever bar to make a full 360.

That being said, I've had success with belt drives on my homemade CNC router. The key is to have an good way to easily adjust the tension. Also a belt drive allows you to easily adjust the speed of the movement by changing sprocket sizes. With my lever drive that is quite a bit harder to do.

If you use a belt, you definitely want one with teeth, and with very low stretch. Make sure it is plenty strong enough. On a quick change of direction you can put an awful lot of force on it.

Hi @cgodwin,

Thanks for the information and such a quick response! Being my first build, I am looking for simplicity. I thought the worm drive and belt scenario would give me better range of motion if I needed it but if a lever system is what is recommended, I should research this a bit more.

I hope you don't mind, I had a few questions:

• Does the lever system scenario you are planning to use work similar to an actuator [up and down motion]?
• I am not sure how much range of motion a flight simulator would need, is there a concern on the range of motion a lever system can produce or is this a non-issue?
  
• Have you settled on a motor and shaft assembly design?

I would love to get some more information on the lever system you are putting together. The belt scenario that I had sketched up for my build was the only way I could think to get a large range of motion [if I needed it]. I did not realize that there would be issues with backlash and precision. Certainly willing to redesign using levers if it will simplify and enhance the experience.

Thanks again,
Michael.

Hi,

Thinking about this power supply:
http://www.ebay.com.au/itm/500W-Uni...cal_Test_Equipment&hash=item256fb4a8bf&_uhb=1

... and this worm drive motor... now that I can post urls

http://www.ebay.com/itm/GEAR-MOTOR-...384?pt=LH_DefaultDomain_0&hash=item51bd392f00

All found on other builds in the community...

A belt drive is certainly better if you want a vary large range of motion. I'm not really sure how much range I need yet, but others here have indicated it doesn't take as much as you might think to provide a good feel. After all, when flying if you make a coordinated turn, even with an extreme turn there isn't any lateral motion and hence no movement of the simulator. In my case, I think I'll end up with about 20 degrees of pitch and 35 degrees of roll/bank.

Here is a crude drawing of my planned lever setup. But by the time I'm done with this thing I wouldn't be surprised if I modify that or even change to a belt or chain drive. One nice thing about the level setup is my gear motors can run away and turn continuously without causing a problem. A belt drive would need limit switches to prevent that. But it would be awesome to make one that could handle a full 360 degree movement of the rider!

I'm building something similar to a joyrider...Trial and error is a way to learn, but an expensive way to learn. Research, research, research, and when you're ready to click "buy now", wait and research some more. If simplicity is what you're going for cut out the chain, sprocket, pulley system as this will add to backlash, and slow your rig down (in some cases this is a good thing), and make movement seem jerky and unflight like. I recommend a direct drive. Something where the force is applied directly to the drive shaft.Torque is key. 200nm-2100kgcm is roughly what you would need to rotate a 400lbs payload, and overcome the directional change forces. Worm gears are the way to go, almost the only way to go actually. When choosing a power supply it is ABSOLUTELY crucial to choose one that exceeds the rated current. If you have a 24v 15amp motor, you want a power supply that can provide at least 45amps (this compensates for Inrush current, and will keep the power supply from clicking off, or blowing up). The more amps, the more expensive the power supply. I recommend Server PSUs. You can find a modified 1500w PSU for like $60 (granted these are usually built by middle easterners...maybe they're used in IED construction or something..). OR you can cut out the jihadi and make them yourself..This can be dangerous though if you're not familiar with power supplies. THESE CAN KILL YOU EVEN WHEN UNPLUGGED. Some people on here have built flight sims using AC current as these motors are cheaper, but I dont recommend this as the current these consume is extreme. One short and your flight sim, chair, or platform becomes an electric chair. Some countries even require a license to mess with AC circuits. I've started to rant, hope this helped out though man.

Thanks for all of your support and great advice!

@cgodwin, thanks for uploading the sketch! It really helped me visualize a seemingly better alternative to the belt system I was thinking about.

@kimballfount, thanks for your advice on avoiding the belt system and really digging into the analysis... you really nailed my personality, I love the idea of hitting that buy button [it's so easy... and unfortunately costly!]. Luckily I have not done that yet on this build but I am struggling with it daily!

Based on both of your advice I am going change my design to a lever assembly instead of a belt assembly and am going to really dig into a bit more research on the appropriate motors and power supplies to make sure I don't make a costly mistake.

Thanks again for taking time out from your own builds to give me tips and advice. It is wonderful to have a place to get this type of help!!!

Michael.

What about Michael Pettenato's original idea but using steel cables instead of timed belts.
One or more turns on a barrel attached to the motor will provide enough friction to move the seat.
It will also reduce the speed and improve the torque for wide angle motion that is not possible with a lever.

When one side has tension the other side will be flopping around with cables...Ive always seen levers, belts, or chains...less serious builds seem to use cables, ropes, etc

There is always the option of direct driving each axis. The output of the gear motors has to be slow, or you need high power motors. My motors are only 41 RPM, but that is still screaming considering the entire machine would roll in 1.5 seconds. Having limit switches is critical with a direct drive system if you can't handle a 360 degree movement.

41 rpm!! That's really fast..Are you doing a racing sim or flight sim?

started on the rig. I have not been able to get much time. This all that I have done so far. Just wanted to keep everyone posted to make sure things look ok

Thanks,
Michael.

The caster photo above represents how I plan on fastening the caster to the pvc. I have used 2 1/2 inch screws, washers, lock washer and a nut to attach the caster. I still need to put a few more washers to even/level the caster.

This is a photo of the fasteners I used to fasten the pvc parts.

Thanks,
Michael.

Building is going a bit slow. I was able to find a little more time to work on the rig. Built the other support structure and secured the casters by sandwich-ING the bottom. I have uploaded two photos to give a better idea.

I finally got a bit of time. Wanted to show a couple of the components I purchased. Attached is a picture of the power supply.

Attached is a picture of the pololu jrk 12v12 USB motor controller with feedback I purchased. I have a little bit of soldering to do.

I was able to do a little bit of work on the rig. I mounted a motor to the joyrider frame. I have attached a photo of the assembly.

Posted another photo of the joyrider rig for a better look (Please excuse the mess in my basement ).