I've watched this multiple times. It has to be one of my favorite design/build vids. Content and presentation are top notch! Inspirational for engineers and teachers alike.
Only found ur channel after catching ur LATHE build. The Mill build to go with the Lathe was phenomenal too my friend. I'm attempting to build my own DIY CNC now. I tried about 18 months ago but didn't really understand the whole process and failed to get it right but now I'm going to have another go .. I haven't watched but 3 of ur videos so far but the ones I have are so interesting to watch. The information is brilliant pal. I hope ur still making these machines today. I will be looing through the channel to see more.. Keep up the great work man..
As I have myself started with designing and manufacturing mechanical systems, I can only imagine the work and experience that was put behind making the system work so flawlessly. Thanks for sharing.
You Sir are brilliant. The design is simple yet seems extremely effective, the perfect engineering solution for a home hobbyist. Thanks for taking the time to share your work, I have spent a few hours at your website absorbing all I can.
Excellent work, and very inspiring -- also a very fine presentation. I am a retired defense engineering programmer/analyst. It's been a while since I've worked on 6 DOF modelling. I don't think I could do the math right off the cuff, but I do understand the control principles. I think it's amazing that the parts for this only cost you $300 - esp the pulleys. The bungee's to neutralize load is brilliant. The only thing I do not see in the design are damping elements. I realize you can control the acceleration via the pot feedback and software - which makes me thin of an elevator, in principle - but in your case, I bet some mechanical damping would cut back jerk and snap for smoother natural operation. I wonder what your thoughts might be on this... It's refreshing to see individuals actually practicing systems engineering on their own projects. A toast to your ambitions, Sir !
Indeed some damping in the system will be needed. It could be added mechanically, but can also be implemented in the servo feedback system by tuning the P/I/D terms to appropriate values with the average load. Thing is that in some flight events you want snappy response while in other events you want slow response. The flight sim data is not all that refined, so a compromise is needed, or active servo PID tuning via software based on flight conditions. Thanks for your comments!
I suggest not using potentiometer unless cost saving is really important. Better to have optical absolute position sensor or simple optical cog-type sensors and zero index (which you already have with your end stop switches). Overshoot can be computed for over various loads if current sensor feedback is used to estimate inertia / mass of load so that servo rapidly slows as destination position is approached. Very cool project - thanks for sharing
@Erich Kaltenbrunner, you can cheat by replacing potentiometers with pairs of LED+LDR (light detection resistors), it'll produce smoother controler inputs than those old crappy mechanical 'pots'. It's a nice and cheap alternative :)
The use of bungie-cord to pre-load the system is an excellent idea to take strain off the motor. I'm surprised it's not used more in robotics for neutral-positioning.
Kudos to your designing and engineering abilities and especially to your mental discipline and energy to follow through to completion. I truly envy your motivation! Had that once upon a time, but lately that spark has greatly diminished...
Very well done! Thanks for putting up a great video and more importantly, for sharing your knowledge. It is appreciated. By the way, don't let the envious trolls get to you.
Very nice implementation, Roland! Isn't it funny how the "haters are gonna hate"? Apathetic spectators of life are full of "better" ideas - but no action. Keep up the excellent effort. I'm off to visit your website now.
Possible considerations for similar designs. 1) I agree with another comment that the potentiometer should be replaced with an encoder to avoid drift and EMI from the motors while reducing oscillations that are likely to occur under high dynamic loads. This can also be addressed by implementing acceleration curves though I suspect the use of belts was intended to suppliment this requirement. 2) By high mounting (instead of under mounting) you run the risk of a collision of your platform with the legs. 3) As you noted, bungees (springs) do not provide constant force at all positions. F = kx, where F is the force applied, k is the spring constant and x is the extension. Further excursion = reduced weight compensation. You will have zero static load at exactly one excursion point, any deviation from this point will result in a required holding force, though this appears acceptable in your tests (probably due the high ratio of the length of bundee to the traversal length of the acutator). 4) You will likely have difficulty maintaining a level platform unless you include belt stretch compensation for holding forces by measuring the load on the motor, either through a load cell or current draw. This is because your center of gravity will shift as the platform is moved around. Any 2 legs should be capable of acceptable actuation with the entire weight of the platform plus an (arbitrary) safety factor above the expected dynamic loads. This seems like a pretty good home setup where minimal excursion and minimal centroid deviation is required however I suspect it will not work well over the full possible traversal (motion envelope will be small especially fore/aft and laft/right). This is mostly due to the high mounting of the actuators relative to the platform. To experience full excursion, your footprint will have to be quite wide (instead of tall) at which point a larger deflection will be required by the actuators to effect the desired roll, pitch or yaw. Vertical motion will be unaffected by footprint width.
I used normal AC mains wire for the motor leads. It's normally good for 20A or so. Since average current is low, it is not a problem. The motor controller is my own design, see my website under Motion Platform III and IV "electrical drive" but commercial motor drivers like MD03 are fine too.
That was very, very interesting. Thank you. Also, I commend you for not showing yourself screwing in every individual screw. Some people actually do that...
I noticed some tap holes on the motor front plate. Maybe you could use a bracket to prevent the motor moving forward by utilising those taps. However it would exert a great amount of force on the screws holding the clamp.
I won't be building my own 6dof full motion flight simulator any time soon but it is on my bucket list so I'll definitely be filing this video away for future reference.
Thats impressive and functional. Just a thought: in my experience, bungee cord doesn't last long under load. Most rubber seems to oxidize at a very accelerated rate when left in a stretched condition.
Ya he'd be much better off using gas charged struts like the ones that hold up the rear hatch on an SUV, be tricky fining just the right weight though.
Nevir202 You know, since obviously he's no slouch with electronics, you could use some cheap electronics and air pumps to auto-center some gas struts. (auto-center the linear servo's, I mean) Dunno if you can get gas struts like that that are fillable though. I think the hatch struts on SUV's are just coil springs and have a small hole to use gas as a damper. I know you can get regular vehicle struts that are gas charged (my motorcycle has rear gas struts), but I think you'd have a hard time finding one with enough stroke.
I don't think they have a spring, at least the ones I've known go from fine to totally useless, whereas a spring would slowly get worse but always give some resistance.
Nevir202 Yeah, could well be that quality ones just have piston gasket, compressed air at one end and a hole at the other to act as a damper. Still, I think they're factory sealed. They don't have a Schrader valve or anything for adjustment. Personally, if I were doing this project, I would use a long throw double action hydraulic cylinder and an electric hydraulic gear pump. I don't see why that combination isnt a lot more common.
Ya I've never seen adjustable ones. Might be able to drill and tap to add a valve though. LOL As to why hydraulics aren't more common, it's a lot more expensive and a lot more dangerous. That's why people use pneumatic cylinders for these things generally.
Nice work. You have put a whole lot into your design. Optical encoders can be used in place of the POT. You don't have a proportional feedback control on the shaft. You can add one just my printing it on your printer and an optical interrupter. Also, the groves in the timing belt is deep enough to be used as an encoder. The valleys of the timing belt can be painted white and a forward facing or reflective interrupter can be use. Nice work
Those smaller belt wheels look like ones on car water pumps that are usually discarded when changing timing belts. They can be easily pushed out with shop press. Those would be almost free compared to €14.50 a piece. Also car timing belts could be used for power transmission, even used ones if going really cheap.
Thank you for sharing your project. I will use this as an example of how to document a project for presentation. It is a skill that I need to practice at.
Amazing design, the thing I really like is you can move it very fast or slow, and the materials used in its construction (thick plywood) is actually very strong and easily fabricated and it can move 40kg. This would be amazing in a six axis flight sim.
Have you considered using pneumatics instead ? You could replace all of that with an air cylinder and a proportional valve. If you're lucky you can find some used ones on auction sites
It is rather difficult to control the position of pneumatic cylinders accurately. Electric drive is much easier, and you can use digital PID to tweak the response.
Pretty spiffy. I went ahead and downloaded the file and added a cross bracket to the motor mount to minimize the tilt issue. I will work on it a little more this evening and e-mail you a copy within the next few days. Brilliant configuration, especially for a wooden case as opposed to aluminium.
Chuffing Ale It would be nice as they are free on Craigslist quite often. If and when I tear mine down Ixll let you know and hope you will do the same...sounds like a great diy hack huh?
Excellent! Here is a man of great mechanical mind. If I may be so bold as to offer a suggestion. I noted on the bungycord "Eye Bolts , that an extra force has been applied. I am speaking of the friction between the eye bolts and the bungy cord when it passes through the eyelet. I do wonder what the result would be if you were to add " pullies" where the bungy meets the eye? Hmmmm! Maybe you could achieve a smother operation. I will stay tuned to see if that idea has merit. Good evening and good luck.
It is important If you want to bend the position of a mobile device such as Ball joint of the car Made from ductile cast iron .. the manufacturer is a ductile iron casting factory. Produce a work piece for the furnace to be formed in the form of steel (meaning the order maker has a contract in accordance with the requirements). Step 1. The foundry itself test. Obtain the numerical value according to the requirements ... Step 2, the order maker can get the sample for the furnace steel to be tested by himself .. the test requires👉 the actuators, generally using the hydraulic test. Because it is very broadly defined To the level of frequency cycles caused by aircraft vibrations And three cars can count the number of times, for example, one hundred thousand times, so the yild point, etc.
@Rolandvanroy Do you plan on uploading a video of the completed cockpit? This video was really interesting, I'd love to see the final product in detail.
My father built a linear actuator with chains in a somewhat similar way, except that the output of the actuator was on the side of the cogwheels, rather than on top of them.
Hi Roland, impressive build. I was wondering why you opted for a belt drive and not a ball screw LA type design. Could you elaborate on the reasoning behind this choice?
Great video, inspiring to say the least. However, for the purpose of your flight simulator, you could have used a ball screw coupling instead to reduce space requirement and weight of the actuator, any reason why you opted for this mechanism instead?
To stop the tilting motion just add a 1/8' thick backing plate to the rear or the motor mount. Then use a top half wooden or metal bracket the fits the diameter of the motor and bolt it too the bottom half. Or you could just make the motor support block wider. And then bolt the top half over the motor support block.
Very cool project! Hard to believe you're getting so much power through those skinny wires...50v helps eh? I may have missed it in the video, is it your own motor controller design?
Nice work have you thought of using radial ball bearings for the rods instead of the ones you use now. Love the way you thought it out I will look at doing this my self I will be going to your web site. Again nice work
This is such an inspiring video for someone just starting out. Can I ask some advice please? I am self-teaching control theory and electronics, some 12 years after I graduated with a mechanical engineering degree. Our control lecturer was sadly not the most ... understandable. I have a few projects I would like to create that will require control loops with motors and rotational plus linear movement, and be able to respond to external forces. My maths is now rusty too - do I really need to understand all the integrals of "e to the minus ess tee" laplace / fourier / matrices, or will something like matlab simulink handle all that for me? I am not averse to putting in time on the maths if its truly vital.
No need to know all math of control theory: Some gut-feeling and experience in electronics and mechanics go a long way. It also depends whether you want to make software servo loop or hardware servo loop. For software, more math is involved, while a simple OPAMP is sufficient to make a decent working hardware feedback loop (proportional only, no I or D): just tweak the OPAMP gain until you see oscillations, then reduce for acceptable servo stiffness and response. Its quite fun. Check my website motion platform pages for more info.
I know its probably too late for you, but my degree was heavily control theory based. Since then in the real world I have used nothing except PID control (or P, PD, PI). Unless you want some extreme performance, or you are controlling a particularly nasty system, at most PID is all you need. For professional work you can work out roughly the needed P,I and D gains, but it always then comes down to trial and error to get the system reacting how you want it to. For anything else just instrument everything then go crazy till it works. Adjust the P value till you get roughly the performance you need, then set an I if you get a steady state error, then D to increase the performance (lets you use a higher 'P' without overshoot or losing control).
Great Project ! I will suggest to modify design to be able to tension belts. This will let you avoid tilts on stops. as well will improve longevity of your belts in general. Probably you will need to buy sonic tensioning meter for this and, unfortunately they are not cheap :( .
As always, lots of other things came in between, and I still was not satisfied with the actuator design. In the mean time I have built another prototype. see www.simprojects.nl/diy_motion_platform_v.htm bottom. But then I got my hands on some industrial rollerscrews, and I'm currently checking how I can built a more compact actuator with these.
Hi @Rolandvanroy I'm playing around with a actuator design of my own and also want to incorporate a pre-load force into it. What I'd like to ask is how well the shock/bungee cord has held up over the years. Have you ever had to replace it? Dry-rot? Loss of force/elasticity? Thanks!
Great video mate, super informative. Does the fact that the bungee cords have a very progressive nature, make them less than ideal? It there was a way to have a more linear power curve would it be advantageous?
My random foible is to avoid micro switches, potentiometers and DC motors - in favour of stepper motors with optical encoders (I won't dedicate the motors / drivers - but make them 'snap in' - so I can move them between; simulator, parallel robot, plasma table, etc.)
Not only is the design genius, the presentation couldn't be more clear. Thank you for posting.
I've watched this multiple times. It has to be one of my favorite design/build vids. Content and presentation are top notch! Inspirational for engineers and teachers alike.
Really hidden tallent with so much depth in science yet unrevealed in public. National geographic should approach.
CCM offer belt-driven linear rails which is more efficient and economical, inquiry is welcome www.ccmrails.com
Only found ur channel after catching ur LATHE build. The Mill build to go with the Lathe was phenomenal too my friend.
I'm attempting to build my own DIY CNC now. I tried about 18 months ago but didn't really understand the whole process and failed to get it right but now I'm going to have another go ..
I haven't watched but 3 of ur videos so far but the ones I have are so interesting to watch. The information is brilliant pal. I hope ur still making these machines today. I will be looing through the channel to see more..
Keep up the great work man..
As I have myself started with designing and manufacturing mechanical systems, I can only imagine the work and experience that was put behind making the system work so flawlessly. Thanks for sharing.
You Sir are brilliant. The design is simple yet seems extremely effective, the perfect engineering solution for a home hobbyist. Thanks for taking the time to share your work, I have spent a few hours at your website absorbing all I can.
You are really cool!!! Machines like you building cost a millions of $, but you make it by youself!!! Amazing!!!
Bungee as counterweight is genious idea, but aren't you worried about rubber degradation?
Would same design be possible with springs?
That's what I call superior skills. This video really is super hard to do too.
Excellent work, and very inspiring -- also a very fine presentation. I am a retired defense engineering programmer/analyst. It's been a while since I've worked on 6 DOF modelling. I don't think I could do the math right off the cuff, but I do understand the control principles. I think it's amazing that the parts for this only cost you $300 - esp the pulleys. The bungee's to neutralize load is brilliant. The only thing I do not see in the design are damping elements. I realize you can control the acceleration via the pot feedback and software - which makes me thin of an elevator, in principle - but in your case, I bet some mechanical damping would cut back jerk and snap for smoother natural operation. I wonder what your thoughts might be on this...
It's refreshing to see individuals actually practicing systems engineering on their own projects.
A toast to your ambitions, Sir !
Indeed some damping in the system will be needed. It could be added mechanically, but can also be implemented in the servo feedback system by tuning the P/I/D terms to appropriate values with the average load. Thing is that in some flight events you want snappy response while in other events you want slow response. The flight sim data is not all that refined, so a compromise is needed, or active servo PID tuning via software based on flight conditions.
Thanks for your comments!
I suggest not using potentiometer unless cost saving is really important.
Better to have optical absolute position sensor or simple optical cog-type sensors and zero index (which you already have with your end stop switches).
Overshoot can be computed for over various loads if current sensor feedback is used to estimate inertia / mass of load so that servo rapidly slows as destination position is approached.
Very cool project - thanks for sharing
@Erich Kaltenbrunner, you can cheat by replacing potentiometers with pairs of LED+LDR (light detection resistors), it'll produce smoother controler inputs than those old crappy mechanical 'pots'. It's a nice and cheap alternative :)
Your videos are like an open learning program.
your craftsmanship is phenomenal and I enjoyed your thoroughness of design and explanation.
The use of bungie-cord to pre-load the system is an excellent idea to take strain off the motor. I'm surprised it's not used more in robotics for neutral-positioning.
Excellent! While I don't see a Flight-Sim in my future, this opens up a whole raft of possibilities. Thank you, John.
Kudos to your designing and engineering abilities and especially to your mental discipline and energy to follow through to completion. I truly envy your motivation! Had that once upon a time, but lately that spark has greatly diminished...
Very well done! Thanks for putting up a great video and more importantly, for sharing your knowledge. It is appreciated. By the way, don't let the envious trolls get to you.
Very nice implementation, Roland! Isn't it funny how the "haters are gonna hate"? Apathetic spectators of life are full of "better" ideas - but no action. Keep up the excellent effort. I'm off to visit your website now.
Holy crap this dude is some sort of genius
Possible considerations for similar designs.
1) I agree with another comment that the potentiometer should be replaced with an encoder to avoid drift and EMI from the motors while reducing oscillations that are likely to occur under high dynamic loads. This can also be addressed by implementing acceleration curves though I suspect the use of belts was intended to suppliment this requirement.
2) By high mounting (instead of under mounting) you run the risk of a collision of your platform with the legs.
3) As you noted, bungees (springs) do not provide constant force at all positions. F = kx, where F is the force applied, k is the spring constant and x is the extension. Further excursion = reduced weight compensation. You will have zero static load at exactly one excursion point, any deviation from this point will result in a required holding force, though this appears acceptable in your tests (probably due the high ratio of the length of bundee to the traversal length of the acutator).
4) You will likely have difficulty maintaining a level platform unless you include belt stretch compensation for holding forces by measuring the load on the motor, either through a load cell or current draw. This is because your center of gravity will shift as the platform is moved around. Any 2 legs should be capable of acceptable actuation with the entire weight of the platform plus an (arbitrary) safety factor above the expected dynamic loads.
This seems like a pretty good home setup where minimal excursion and minimal centroid deviation is required however I suspect it will not work well over the full possible traversal (motion envelope will be small especially fore/aft and laft/right). This is mostly due to the high mounting of the actuators relative to the platform. To experience full excursion, your footprint will have to be quite wide (instead of tall) at which point a larger deflection will be required by the actuators to effect the desired roll, pitch or yaw. Vertical motion will be unaffected by footprint width.
I used normal AC mains wire for the motor leads. It's normally good for 20A or so. Since average current is low, it is not a problem. The motor controller is my own design, see my website under Motion Platform III and IV "electrical drive" but commercial motor drivers like MD03 are fine too.
That was very, very interesting. Thank you.
Also, I commend you for not showing yourself screwing in every individual screw. Some people actually do that...
I noticed some tap holes on the motor front plate. Maybe you could use a bracket to prevent the motor moving forward by utilising those taps. However it would exert a great amount of force on the screws holding the clamp.
CCM offer belt-driven linear rails which is more efficient and economical, inquiry is welcome www.ccmrails.com /andy@ccm-rails.com
I won't be building my own 6dof full motion flight simulator any time soon but it is on my bucket list so I'll definitely be filing this video away for future reference.
Thats impressive and functional. Just a thought: in my experience, bungee cord doesn't last long under load. Most rubber seems to oxidize at a very accelerated rate when left in a stretched condition.
Ya he'd be much better off using gas charged struts like the ones that hold up the rear hatch on an SUV, be tricky fining just the right weight though.
Nevir202
You know, since obviously he's no slouch with electronics, you could use some cheap electronics and air pumps to auto-center some gas struts. (auto-center the linear servo's, I mean)
Dunno if you can get gas struts like that that are fillable though. I think the hatch struts on SUV's are just coil springs and have a small hole to use gas as a damper.
I know you can get regular vehicle struts that are gas charged (my motorcycle has rear gas struts), but I think you'd have a hard time finding one with enough stroke.
I don't think they have a spring, at least the ones I've known go from fine to totally useless, whereas a spring would slowly get worse but always give some resistance.
Nevir202
Yeah, could well be that quality ones just have piston gasket, compressed air at one end and a hole at the other to act as a damper. Still, I think they're factory sealed. They don't have a Schrader valve or anything for adjustment.
Personally, if I were doing this project, I would use a long throw double action hydraulic cylinder and an electric hydraulic gear pump. I don't see why that combination isnt a lot more common.
Ya I've never seen adjustable ones. Might be able to drill and tap to add a valve though. LOL
As to why hydraulics aren't more common, it's a lot more expensive and a lot more dangerous. That's why people use pneumatic cylinders for these things generally.
Amazing! I think that works like faster as Diadic acotuator but, with 10 times more power and course.
Congratulations!
Great job. Why so many Dislikes - not cool. Never hesitate to share you work!
Nice work. You have put a whole lot into your design. Optical encoders can be used in place of the POT. You don't have a proportional feedback control on the shaft. You can add one just my printing it on your printer and an optical interrupter. Also, the groves in the timing belt is deep enough to be used as an encoder. The valleys of the timing belt can be painted white and a forward facing or reflective interrupter can be use. Nice work
Those smaller belt wheels look like ones on car water pumps that are usually discarded when changing timing belts. They can be easily pushed out with shop press. Those would be almost free compared to €14.50 a piece. Also car timing belts could be used for power transmission, even used ones if going really cheap.
How much would a 6DOF Amusement Machine cost?
Thank you for sharing your project. I will use this as an example of how to document a project for presentation. It is a skill that I need to practice at.
So much better than free to air news thx for sharing
I'm a little bit confused about the bungee cord. What role does it play in the function of the actuator?
Really cool stuff thanks for posting
CCM offer belt-driven linear rails which is more efficient and economical, inquiry is welcome www.ccmrails.com /andy@ccm-rails.com
Looks incredible Roland! I hope this project is still going strong!
Amazing design, the thing I really like is you can move it very fast or slow, and the materials used in its construction (thick plywood) is actually very strong and easily fabricated and it can move 40kg. This would be amazing in a six axis flight sim.
Vintage mechanical keyboard, That's the AGE of keyboard that made me want the one I have today.
Thank you for this video. Where can I source the pulleys? I don't know what to search for...
Have you considered using pneumatics instead ? You could replace all of that with an air cylinder and a proportional valve. If you're lucky you can find some used ones on auction sites
It is rather difficult to control the position of pneumatic cylinders accurately. Electric drive is much easier, and you can use digital PID to tweak the response.
You know you can do the same using air cylinders. Obviously you need a closed loop system so there's a need for position sensing
Pretty spiffy. I went ahead and downloaded the file and added a cross bracket to the motor mount to minimize the tilt issue. I will work on it a little more this evening and e-mail you a copy within the next few days. Brilliant configuration, especially for a wooden case as opposed to aluminium.
Thanks for posting Richard.. We all appreciate it. Pretty cool..
Great inspirational video, now I am so glad I did not throw out that old Nordic Trac ski machine as I want to take it apart and tinker
scott lund de, 4
Samir Hajji ...? do you mean you have 4? if so, congratulations on having that much storage space.
scott lund I have actually wondered if a Nordic Trac would give up any useful parts myself.
Chuffing Ale It would be nice as they are free on Craigslist quite often. If and when I tear mine down Ixll let you know and hope you will do the same...sounds like a great diy hack huh?
This is extremely cool. Way to go on the whole design!
Simply outstanding!👍👍👍👍👍
Excellent! Here is a man of great mechanical mind. If I may be so bold as to offer a suggestion. I noted on the bungycord "Eye Bolts , that an extra force has been applied. I am speaking of the friction between the eye bolts and the bungy cord when it passes through the eyelet. I do wonder what the result would be if you were to add " pullies" where the bungy meets the eye? Hmmmm! Maybe you could achieve a smother operation.
I will stay tuned to see if that idea has merit. Good evening and good luck.
I would like to see and long-term evaluation of the resiliency of this design
Wonderful!
Very helpful
Waiting to see more from your awesome lab!!
Man there are some clever buggers out there Nice Work
This guy is a genius
I don't understand any of this stuff, but it's just so ridiculously cool!
It is important If you want to bend the position of a mobile device such as Ball joint of the car Made from ductile cast iron .. the manufacturer is a ductile iron casting factory. Produce a work piece for the furnace to be formed in the form of steel (meaning the order maker has a contract in accordance with the requirements). Step 1. The foundry itself test. Obtain the numerical value according to the requirements ... Step 2, the order maker can get the sample for the furnace steel to be tested by himself .. the test requires👉 the actuators, generally using the hydraulic test. Because it is very broadly defined To the level of frequency cycles caused by aircraft vibrations And three cars can count the number of times, for example, one hundred thousand times, so the yild point, etc.
Great thinking and most simplistic execution...Superb..!
@Rolandvanroy Do you plan on uploading a video of the completed cockpit? This video was really interesting, I'd love to see the final product in detail.
you do it like a scientist. thanks
Хорошая работа! Я думаю что при использовании косых шестеренок шума было бы меньше.
Wow, this was a very good quality video.
I like the use of bungee cords. Nice going!
Thanks for choosing components from Taiwan
I was just thinking about designing one of these, cool design but I have yet to finish the video
Very Well, Built - Good Job from Chicago
My father built a linear actuator with chains in a somewhat similar way, except that the output of the actuator was on the side of the cogwheels, rather than on top of them.
Hi Roland, impressive build. I was wondering why you opted for a belt drive and not a ball screw LA type design. Could you elaborate on the reasoning behind this choice?
Great video, inspiring to say the least. However, for the purpose of your flight simulator, you could have used a ball screw coupling instead to reduce space requirement and weight of the actuator, any reason why you opted for this mechanism instead?
Great work thanks for sharing! Where did you purchase the pulleys from? Thanks
CCM offer belt-driven linear rails which is more efficient and economical, inquiry is welcome www.ccmrails.com
Nice job. Clean and Efficient.
Wow! All I can say is ... "BRILLIANT!" Amazing job.
Very cool. How far have you gotten on your simulator. What kind of cost do you have in the actuators
To stop the tilting motion just add a 1/8' thick backing plate to the rear or the motor mount. Then use a top half wooden or metal bracket the fits the diameter of the motor and bolt it too the bottom half.
Or you could just make the motor support block wider. And then bolt the top half over the motor support block.
Why do you need the bungee cords? Don't they slow down the actuation?
Very cool project! Hard to believe you're getting so much power through those skinny wires...50v helps eh? I may have missed it in the video, is it your own motor controller design?
Nice work have you thought of using radial ball bearings for the rods instead of the ones you use now. Love the way you thought it out I will look at doing this my self I will be going to your web site.
Again nice work
This is such an inspiring video for someone just starting out. Can I ask some advice please? I am self-teaching control theory and electronics, some 12 years after I graduated with a mechanical engineering degree. Our control lecturer was sadly not the most ... understandable. I have a few projects I would like to create that will require control loops with motors and rotational plus linear movement, and be able to respond to external forces.
My maths is now rusty too - do I really need to understand all the integrals of "e to the minus ess tee" laplace / fourier / matrices, or will something like matlab simulink handle all that for me? I am not averse to putting in time on the maths if its truly vital.
No need to know all math of control theory: Some gut-feeling and experience in electronics and mechanics go a long way. It also depends whether you want to make software servo loop or hardware servo loop. For software, more math is involved, while a simple OPAMP is sufficient to make a decent working hardware feedback loop (proportional only, no I or D): just tweak the OPAMP gain until you see oscillations, then reduce for acceptable servo stiffness and response. Its quite fun. Check my website motion platform pages for more info.
what program do you use for the animation
Google sketchup
Rolandvanroy Thanks again. I know only that I have an absolute ton to learn!
I know its probably too late for you, but my degree was heavily control theory based. Since then in the real world I have used nothing except PID control (or P, PD, PI). Unless you want some extreme performance, or you are controlling a particularly nasty system, at most PID is all you need. For professional work you can work out roughly the needed P,I and D gains, but it always then comes down to trial and error to get the system reacting how you want it to. For anything else just instrument everything then go crazy till it works. Adjust the P value till you get roughly the performance you need, then set an I if you get a steady state error, then D to increase the performance (lets you use a higher 'P' without overshoot or losing control).
Why do you add those rubber bands? It just makes it much harder for the engine no?
Great project, look forward to seeing the final build!
very cool but why did you not youse a normal pneumatic system? i think it would be cheaper or did you wanted the challange ? :)
a pneumatic system isn't variable, it's only in or out (or in out and middle if you want multi-step pistons at the cost of power).
ok ty i thought with modern pistons and some electroniks it wouzld be no problem
What a great job Sir. I'm amazed about the construction
This is a wonderful, well explained and well thought out video.
I enjoyed seeing the current during testing ty!
Great Project ! I will suggest to modify design to be able to tension belts. This will let you avoid tilts on stops. as well will improve longevity of your belts in general. Probably you will need to buy sonic tensioning meter for this and, unfortunately they are not cheap :( .
CCM offer belt-driven linear rails which is more efficient and economical, inquiry is welcome www.ccmrails.com /andy@ccm-rails.com
Should a DC motor with or without a gear box be used, for optimal performance?
Mercurial Mann Most DC motors have a very high base RPM which is unsuitable for these applications. So I think a gearbox has to be used.
Couldn't finish to understand what is it about, and what is it for.
Could explain?
pure genius! very well done - thx for sharing.
Excellent vedio, the highlight for me are the socks.
Amazing concept. Keep up the good work.
CCM offer belt-driven linear rails which is more efficient and economical, inquiry is welcome www.ccmrails.com /andy@ccm-rails.com
if you've got all six of these holding 50 kg does that mean the seat and all that weigh 300kg?
Very nice, would love to see the final simulator setup in action with these actuators in motion.
impressive, beautifull, and AWESOME actuator. congrats !
Did you ever finish the 6dof platform?
As always, lots of other things came in between, and I still was not satisfied with the actuator design. In the mean time I have built another prototype. see www.simprojects.nl/diy_motion_platform_v.htm bottom. But then I got my hands on some industrial rollerscrews, and I'm currently checking how I can built a more compact actuator with these.
awesome! very good design/insight
How is this project going, would love to see an update?
Hi @Rolandvanroy I'm playing around with a actuator design of my own and also want to incorporate a pre-load force into it. What I'd like to ask is how well the shock/bungee cord has held up over the years. Have you ever had to replace it? Dry-rot? Loss of force/elasticity? Thanks!
Fantastic video! Very informative. Very well designed.
I am sure i can come up with a better design...but i am glad to know intricacies of other people's design.
What happens when the limit switches break? Exciting things.
What is "six degree of freedom (6DoF) motion platform"... and where did you get the software for the motor from; did you create it?
+Stephen Balogh: for software see bffsimulation.com/6DOF-Motion-Software.php
So how much can this thing lift like that? Is it suitable for a simulator platform?
Great video mate, super informative. Does the fact that the bungee cords have a very progressive nature, make them less than ideal?
It there was a way to have a more linear power curve would it be advantageous?
Thank you for the video Roland.
Enjoyed it.
I like your work, quite a lot.
So Roland, how’s the 6 dof platform coming along ? I reckon that the mermaids of multirotors have kept you in shackles too long. 😊
Thanks a lot for this explicit video !
Nice!, my compliments!, uit nederland?
My random foible is to avoid micro switches, potentiometers and DC motors - in favour of stepper motors with optical encoders (I won't dedicate the motors / drivers - but make them 'snap in' - so I can move them between; simulator, parallel robot, plasma table, etc.)