DIY 6DOF Motion Rig - Bolted to the ground now...

[@johnvenediktov5747]

that might be one of the best DIY designs so far very impressive

[@JuiceSkyy]

Dang that moves quick, nice one fella

[@Unnaymed]

What a massive work !

[@Christopherknauf]

It really was

[@spillredet]

This looks like it would be hella fun in flight sims!

[@De-M-oN]

Dirt Rally

[@bartdereu9267]

@@De-M-oN I have no idea why you'd build a 6DOF rig just for a rally game :-D

[@potatoracer6137]

Brilliantly done 👏👏👏. It will be quite interesting to see how you jump on it?😂😂

[@MotionSimBuilders]

amazing build !! Love it !!

[@Pollock1961]

Best Yet

[@DavidRendekX21hSb5pL79O]

OMG I love it... I wanna try it

[@DavidRendekX21hSb5pL79O]

its possible bubild this only with arduino or raspberry?

[@DavidRendekX21hSb5pL79O]

BTW you got SUBSCIBE ;) its amazing what you build.

[@Christopherknauf]

I used the Arduino IDE, but with a esp32 instead of an actual Arduino board... The esp32 is significantly faster for when controlling all the arms and being able to calculate the inverse kinematic algorithm 1000 times a second. A raspberry pI may be able to do it...seeing that it does have a significant number of gpio.. The cost of an esp32 is significantly less than that of the raspi though...at 10$ ish. This project is all open source.. feel free to ask more questions

[@sushinsong]

WOW. Christopher. Your project is blow my mind. You done amazing job. Thank you my friend. Now I just realize that I need to have one. Do you mind sharing the idea about how much its cost? ;) Thank you very much sir.

[@Christopherknauf]

About 5k USD give or take, biggest cost being the motors/gears ... The chassis and base are just steel from the local supply house, welded in my basement, the project is on GitHub, the main parts are listed.... I know of a few people building their own from my spec,.. one gentleman is nearly complete...github.com/knaufinator/6DOF-Rotary-Stewart-Motion-Simulator

[@sushinsong]

Thank you so much for replying. After researching your project information. I think I need some time to learn electronics and programing:)

[@rumbletorncopper4478]

@@ChristopherknaufSir can you tell me what these 6 engines are and tell me if I can make this simulator like it where can I find the files, the reference source to make them🫶🏻

[@fitchyyboi]

Dude this is so cool haha

[@succulentP]

Incredible, is there a reason you went with such long piston arms? Does it give you a greater angle in degrees you can achieve?

[@Christopherknauf]

Yes, the swing arms are 7.2 inches long giving nearly 14 inches of vertical movement as well greater movement in other angles/ dimensions than simulator rigs with smaller arms.

[@jpjay1584]

great project!! what if every motor had 2 arms? to 'balance the torque on the shafts'? (and with that 2 of everything else)

[@Christopherknauf]

Doesn't need it,... This is more powerful than you can humanly endour.... This video was 1/3 the final top speed. .. it could rip the chassis apart if commanded to do so.... A bit after ripping the human rider to bits.... It's scary fast,... And there really is no need for further modification

[@jpjay1584]

@@Christopherknauf (further down below I saw the links you posted about the source of these motors/gears) how did you find these motors and gears? simply got some "over-speced" parts that will easily handle the load or did you buy these based on other peoples previous experience with these?

[@Christopherknauf]

@@jpjay1584 i did a bunch of math up front for good month trying to figure out how much tourques would be required to push up against gravity ~>300lbs of mass. using 6 motors, and with corresponding swing arm lenghts,.. I knew my target was the longer the better... and trying to both find a gear box that could handle the weight and be VERY low backlash... the motor work well the first iteration, I went through 3 different gear boxes to find one with very low backlash where is nearly imperceivable. (i.e less mechanical slop/jolt on quick reverse ) I tested slowly buying one motor, one gear, at a time,... testing it out on a low level,.. testing wieght limits at different swing arm lengths. build many PCBs to get it all connected and talking,... many hours of microcontroller coding to get it moving correct and... ~"SAFE".,,,,

[@jpjay1584]

@@Christopherknauf thanks a lot for taking your time. I really appreciate it. (I have 2 projects with AC servo motors already and stumbled across yours today (totally fallen in love with this idea) I can't thank you enough for answering questions. edit: I just found your project in the xsimulator community.(now I can read that first instead of asking so many questions) cheers

[@Christopherknauf]

@@jpjay1584 www.xsimulator.net/community/threads/compact-ac-servo-6dof-rotary-stewart-platform.14769/

[@guyfrunknown]

Reminds me of a half-life walker thing.

[@Christopherknauf]

equally as dangerous

[@VanisherXP]

flip it upside down, rig it to an inverse kinematic spider model and you got yourself a robotic spider.

[@Christopherknauf]

So you could absolutely dangle this from the cieling, and do some puppet master shit with a chassis,... But the thought of lifing that heeeeaavvyy base above my head is a hard stop.

[@noahnoah4526]

I know this is probably a stupid question but is the difference in load between the "arms"? So if a 180lb person gets in the machine the weight is not always 30lbs per arm right, It would change depending on how the sim is positioned. So what would the maximum difference between load on each arm be, Or rather what is the minimum load any one arm would have given 180 pounds of total load. Sorry if this is confusing, I'm very ignorant on these matters(As I'm sure is apparent, haha). I'm thinking of the idea of using leverage to reduce to load on any given motor. My thinking is if you have a seesaw with one kid weighing 50lbs and one weighing 60lbs you would only have to give the smaller child 10lbs of push to keep them equal, so if you did the same on the levers you could reduce the load by at least that minimum and reduce cost. At least thats how I see it in my head, I'm sure I'm thinking of something wrong. Anyway, sorry for the long comment.

[@Christopherknauf]

I get what you are sayin, the loading is dynamic between the arms depending on the position/speed. The motor/gear combo I chose was to supply enough torque to overcome the worst of the forces. in fact I built enough tolerance into it, that one motor/gear can handle the chassis w/rider at full tilt - see kzbin.info/www/bejne/omOre6SMh8embq8 ... my buddy volunteered to sit in this while it was moving at full speed and it had no issues. the key is also to balance the platform/ chassis over the center of the platform... as much as you can. so if I am not in the seat, the chassis is front heavy,. but with a rider,.. it is almost perfectly balanced over the dead center of the platform, this helps keep things symmetrical PID/control system wise. in that not one direction requires significantly more or less torque requirements. you are thinking of the right things,.. and it is a complex problem,... it took me months to work out the calculations with some mechanical engineer buddies just to get me a ballpark torque requirement for me to feel confident about buying a motor and gear to match. .. While there is overhead in this design,.. I would not feel confident about reducing the torque specifications any lower with different models...

[@davedoyle6835]

It looks like it's been about four years since you got your rug up and running. Is there anything you would change if you had to build it again?

[@Christopherknauf]

Nope, it still holds up design wise.

[@incho80]

Awesome. What is the movement angle?

[@Christopherknauf]

Full heave travel bottom to top of all arms with filtered speed test 11.25 inches in .6 seconds ~21 degree angle offset from home on all rotational axis, pitch roll yaw sway, surge is about 14 inches total, ~7 inches from center home

[@artursjoblom5142]

Chrisopher you're talented! How many degrees of yaw/traction loss can you get? You mentioned 14 inches vertically, how many degrees pitch & roll?. Keep being awesome 😀👌

[@Christopherknauf]

22 + or - for all

[@abrammanoge]

Please share link to the motors you used

[@Christopherknauf]

all the parts are listed in the github link in the description: the motors are 750w ac servos - www.aliexpress.com/item/32844239563.html with 50:1 gears - www.aliexpress.com/item/32967571001.html

[@IAmTheSupremeEmperorOfFails]

I really want to try build one, what moters did you use?

[@Christopherknauf]

750w ac servos, documented here - github.com/knaufinator/6DOF-Rotary-Stewart-Motion-Simulator

[@jacobapplebaum3326]

I NEED the music from the video lol

[@patrat6072]

Parts list anywhere?

[@Christopherknauf]

github.com/knaufinator/6DOF-Rotary-Stewart-Motion-Simulator , in the readme, toward the bottom, I go over most of the must have parts, .. gears motors and such

[@patrat6072]

@Christopher Knauf thank you for the reply. Me and my dad are planning on building a 6dof hopefully it goes well lol. 7k is a lot to buy one

[@PaulHappyHutchinson]

You mention the base is "Steel plate ½ inch thick 31” diameter", but what is the size of the chassis? I assume the hexagon is roughly equal to the base or is it shorter and is it a regular hexagon?

[@Christopherknauf]

31.5 inches diameter - you can see my build here in my album - photos.app.goo.gl/6UpUdS5Q1otJAuhEA some dimensions as that one,. ..are shown in various images

[@PaulHappyHutchinson]

@@Christopherknauf Thank you for clarifying that so quickly. I misread the documentation and ended up making a 62" version as I mistook 31.5" to mean the length of each side, oops. Fixed now and I got more practise on the saw xD

[@Christopherknauf]

@@PaulHappyHutchinson specifically that is the diameter of the upper chassis connecting points.... as they are oriented around a perfect circle... I may have misread you the first time,.. either way, :) you have my build album .. i also post here - www.xsimulator.net/community/threads/compact-ac-servo-6dof-rotary-stewart-platform.14769/

[@Panurg81]

very impressive! those logitech pedals (they look like em) are for demonstration I recon? ;)

[@Christopherknauf]

I will upgrade, for sure... :)

[@potatoracer6137]

Sir_Henry_RaceALot 😂😂😂

[@Christopherknauf]

Fanatec set, acquired.

[@WirelessBrain1O]

Wery nice. How much do the parts cost?

[@Christopherknauf]

About 5k usd

[@祖宗-e5o]

in China all the things are cheap@@Christopherknauf

[@michaeldean4362]

does the software know that you are using levers rather than linear actuators?

[@Christopherknauf]

no, my microcontroller code handles the placement of the swing arms. there are complex algorithms that calculate each arm position, 1000 times a second.

[@ДмитрийМиллер-ж4ц]

Сколько будет стоить? Как оформить заказ? Цена под ключ?

[@davedoyle6835]

Can you tell me if you used servos with or without brakes ? Or does it matter?

[@Christopherknauf]

Good question, without breaks. When the power is cut the rig falls. It does not matter, as it's an arc... Goes quick at first, then gracefully stops at the bottom...

[@davedoyle6835]

@@Christopherknauf thank you. We’re getting ready to build a rig .

[@Christopherknauf]

@@davedoyle6835have fun!

[@davedoyle6835]

@@Christopherknauf one more question did you use -80 or -90 servos ? Really can’t tell difference other than size .

[@Christopherknauf]

@@davedoyle6835 80, size is only difference.whatevever u can get+ gear,,, gear is important... Less backlash the better

[@Lets_Race_Gaming]

I will not ride on this rig without a seat belt 😂.. awesome.. better than DOFReality.. complete garbage

[@Christopherknauf]

rule #1: wear the belt... it moonlights as an ejection seat

[@치킨맨-u9t]

DOFReality uses 24v DC motor and this is AC motor. it is uncomparable. it DOFReality is way too expensive for its performance. it is not affordable anymore. and I don’t like their customer support too.

[@kakkol1289]

Plz plz plz plz put this up for sale theres a lot of people who can't set one up and would look to buy one at a good price

[@Christopherknauf]

Effort, ...liability ... its allot of work.. im a busy guy already. i know of someone that is trying to set up a production of them,.. I will post a video about it if it ever gets off the ground. ...

[@nachohaxor]

that's so expensive. 6 nema 34s ($250/(with controllers/with encoders ) with planetary gear casings probably 10:1 or 15:1 $75 a piece the swivel i bolts are $15 a piece at 12 and we didn't even get anywhere else. that's over $3000 for just the stuff that connects a few things and makes the things move. I'm guessing you're 5 grand deep in it at the making of this video? great job and I'm thinking about making it. unless you have access to motors on the cheap or free then this is an expensive project. unless you make more than the average income. I'd have to take a loan out and the wife would be so annoyed at me.

[@Christopherknauf]

$5k USD, was the approximate cost of the platform. its definitely an expensive project... yet significantly cheaper than buying a rig with this sort of performance yet small size. I spaced the cost out over the course of 2 years. only investing as little as I could at first to validate each next step. i.e. ... i bought one motor and verified I could with my microcontroller move it reliably and quickly to a position, once I verified that,.. i bought a gear box (50:1), and made sure that I could lift significant weight with it @ the varying swing arm lengths... once I verfied that,.. I started working on the chassis,.. learned how to weld, steel tubing is not to expensive but there prolly is ~500 in USD in tubing/trial and error cost involved. got another motor, and gear and made the platform into a 2dof unit to completely validate I knew what I was doing, and that the motors and gears could handle the torque load slamming my steel chassis/rider around... then came the next 4 motors and gears,.. this was the expensive part,.. I saved as much as I could, and bought 1 or 2 pieces at a time over the course of the next year,.. until it was complete. I did it as a personal challenge, and as well I am used this as my resume,... I like talking about personal projects in interviews... this one gets everyone excited :)

[@nachohaxor]

@@Christopherknauf I could only imagine. This is my next project after I finish the xray machine.. The steppers are so much quieter than alternatives like hydraulic and much faster than a bunch of linear actuators that break easily. The range of movement seems like it's a lot. Do you think that could have been toned down a little or do you like it as is? I'm sure you'd have to wear a safety harness so you don't fly out of the thing. With 50;1 they seem to still be sufficiently fast. I bought a 100;1 before and that thing is to slow to be of any use. It sure had some torque though. Was an interviewer ever not impressed saying that they have something better in they're garage?

[@Christopherknauf]

@@nachohaxor you can absolutely tone down the movement to your own taste via filtering. The harness is there for safety, along with a few e stops. it has the potential to hurt you. But I have worked to minimize that over the last few years. I did a bunch of calculations to make sure that 50:1 would be sufficient given the max speed of the motor. No one has come close to the same level of at home DIY project. I know those people exist out there,.. they just have not been involved in my interviews... :) .

[@ji3200]

How much is the whole project cost?

[@Christopherknauf]

Somewhere around $5K , hard to say what I actually spent over the last 2 years on this project, but its in the neighborhood of that value.

[@coldhanz1]

What’s it gonna cost me to have you build me a turn key duplicate?

[@Christopherknauf]

Lol,... I don't think I have it in me to do it again :) it took me 2 years! .... Granted others have emulated my design in as little as 3 months... I don't have the time anymore to sink into a ground up rebuild. It's all open source and I have been walking people through their own builds!... If u are interested... It's well within diy territory!

[@bhaskarannanda4791]

@@Christopherknauf that's a nice contribution you made for the racing community, and one question why are motors most expensive despite of very simplistic design.

[@Christopherknauf]

@@bhaskarannanda4791 I feel the opposite!!, until recently these industrial PID controlled AC servo motors cost easily 10 times the amount! these take a large complexity out of the equation and allows for easier control methods .. like what I have designed to drive these motors.

[@mmorrell2007]

Why is everyone compelled to play stupid music over a video? I'd much rather hear you describing the unit.

[@Christopherknauf]

Insightful commentary is reserved for my OnlyFans channel