Thanks for the links Duane! I'll see what I can digest from those. Obviously position accuracy is not ultra critical for a racing motion simulator but velocity might actually be more important.
I doubt anything I posted will be very useful. I was just trying to show some of us are interested in motion control.
I have one prop scanning 2 keyboards and a pedal board from a 1928 Wurlitzer Theater Organ using analog inputs (only 3 required) to implement 2nd touch for both KBs and pedals.
I don't think I've heard of anyone using 2nd touch on a pedals. Very cool.
That prop also scans my stop tabs and a few switches (96) it sends out MIDI to my pipe chamber and to a PC running Hauptwerk & MidiTzer (if you have not used these they can be free and make a very convincing pipe organ.
It's been a while since I've used Hauptwerk. I generally just use the sound module in my Alisis QS6..2.
The entire pipe chamber is controlled by a 2nd Prop controlling over 1100 pipes.
I know I've seen pictures of some of your stuff but do you have your pipe chamber controller documented anywhere?
I'm very much an beginner organ player. Our local church has been desperate enough to have me play a few times but I always have to play the same few songs since there aren't many I can play well. I can only use the pedals with one of the songs (it only has four different bass notes). I don't spend enough time practicing to be very good but it's a lot of fun to be able to play the little I do.
I don't think I've heard of anyone using 2nd touch on a pedals. Very cool.
It's been a while since I've used Hauptwerk. I generally just use the sound module in my Alisis QS6..2.
I know I've seen pictures of some of your stuff but do you have your pipe chamber controller documented anywhere?
I'm very much an beginner organ player. Our local church has been desperate enough to have me play a few times but I always have to play the same few songs since there aren't many I can play well. I can only use the pedals with one of the songs (it only has four different bass notes). I don't spend enough time practicing to be very good but it's a lot of fun to be able to play the little I do.
The original Wurlitzer organ had 2nd touch on the pedals (and both KB)and they are usually used to add a drum, cymbal, etc without the need to turn a stop on and off.
I replaced all the contacts (constantly required adjustment) with small coils and those coils are sequentially grounded and I use the prop counters to measure the time for a given pin to drop to 1/2 Vcc then I just set up a table for 1st touch and 2nd touch trip points. The entire organ can be re-calibrated in less than 5 minutes and it used to take me all day.
I have never documented the Pipe chamber Prop code as it is highly specialized for my application but if you wanted a copy I'd gladly send it. The pipe chamber controller gets sent a copy of all the preset combination action settings upon booting the Console Prop and rather than send a bunch of MIDI messages for every stop which changed when a combination piston was pressed I simply send the actual piston number and the Prop handles the rest. That greatly reduces MIDI messages at a registration change.
The free Haupwerk and St. Annes organ are nice for Church Organ practice. If you have fun playing that is the most important part.
This is obviously a thread drift and if you would like to discuss it further we could take it offline. Glad to know there are other organists on the forum.
When you say Quadrature in the MHZ range how many MHZ are we discussing? I tend to write 90% of my code in PASM which screams and the balance in SPIN just to get things running and so far I have not hit any speed barriers but certainly HS quadrature would be an issue.
My servo motors run @> 6000RPM with 4096-line encoders (16384 quad-counts/rev)
The following is what I would like to implement on the Prop (the "Discrete Time Form" version), along with PID, of course. A sample time of 1ms is typical of many Digital Motion Control systems.
I love PID loops (I have not seen a doctor about this) and used them extensively prior to my retirement. When they are set up right only an engineer could appreciate how well they work.
LOL...I totally understand...For me, no feedback...no control. How would you control the temperature of a room without knowing the prevailing temperature???
There are lots of videos on youtube. This one shows how it should work. ... and this one what happens if you don't use proportional valves but the standard on/off ones. Haha, the racing car sound doesn't fit, feels more like a horse drawn coach.
IMHO, all that hydraulic stuff is too complicated and expensive. If you only have to lift a seat and a single person electrical servos of <1kW should do. You can overload them by a factor of 3 for several seconds. You could drive ball screws directly with the motor shaft and mount the ball nut at the joints. I have propeller based AC servo drives, but unfortunatelly I don't have the time to build such a simulator.
There are lots of videos on youtube. This one shows how it should work. ... and this one what happens if you don't use proportional valves but the standard on/off ones. Haha, the racing car sound doesn't fit, feels more like a horse drawn coach.
IMHO, all that hydraulic stuff is too complicated and expensive. If you only have to lift a seat and a single person electrical servos of <1kW should do. You can overload them by a factor of 3 for several seconds. You could drive ball screws directly with the motor shaft and mount the ball nut at the joints. I have propeller based AC servo drives, but unfortunatelly I don't have the time to build such a simulator.
Being a retired EE, my first instinct was for an all electric solution and that still my be my final output device. Regardless of the final drive type it will be propeller driven of course. However everyone I have seen/heard are quite noisy and in some of the racing simulators a lot of effort is expended towards replicating the sounds one would expect in the vehicle. I guess headphones could be an option to deaden the noise from the servo drives.
Some sims just move the seat, some move everything except the monitor screens and some like that video move everything so the loads vary significantly with design. The system in that video I believe starts off at ~~$50K US.
I agree hydraulics seem and can be complex to those who do not use them everyday. Pneumatics can offer similar performance in this application using proportional valves or even on/off but like hydraulics require something other than just an electric connection.
Noise from the servos? Modern brushless motors are almost silent. They don't make more noise than the fan of my PC when running at 3000rpm. Cheap ball screws make some noise, though, like a steel wheel rolling on a steel rail. However I think an electric system still makes much less noise than a hydraulic pump.
I also had the idea of making my own proportional valve: Take a steel cube and drill a hole in it. With a reamer you can achive a very tight tolerance so that the shaft of a servo motor fits in with nearly no gap. Drill two more holes in the cube at right angles as shown in the picture. Grind two flat faces to the shaft. It can be sealed with two O-rings.
From full flow to side A to full flow to side B it takes only a 90° turn of the shaft. For a cheap hack it should even work with a model servo. A disc or bell rotor servo can move much faster and does a 90° turn in less than 10ms. Because of the remaining gap this valve might not perform well with industrial hydraulics with >300bar (>4000psi) pressure but I think for a home build simulator 50bar or even less is enough.
There are lots of videos on youtube. This one shows how it should work. ... and this one what happens if you don't use proportional valves but the standard on/off ones. Haha, the racing car sound doesn't fit, feels more like a horse drawn coach.
IMHO, all that hydraulic stuff is too complicated and expensive. If you only have to lift a seat and a single person electrical servos of <1kW should do. You can overload them by a factor of 3 for several seconds. You could drive ball screws directly with the motor shaft and mount the ball nut at the joints. I have propeller based AC servo drives, but unfortunatelly I don't have the time to build such a simulator.
I think my point was missed here: Yes, I have taken "standard on/off" (aka: bang-bang) valves but driven the (DC) coils proportionally using a $10 H-Bridge amplifier, resulting in a flow that is proportional to the coil current. The second video is only an example of valves being all on and all off.
What is complicated about hydraulics? There are two hoses to each cylinder which are connected to the A & B ports of a manifold that distributes the output from a pump. Hydraulic cylinders are silent, ball-screws are noisy.
ManAtWork: Based upon the EXISTING systems for sim racing everyone I have heard exhibits noise significant enough to be heard even with the car/track audio at an appropriate level. Does that mean all servo systems exhibit such noise levels? No of course not! However the systems priced to be attractive for this application, THAT I HAVE HEARD, are not of the "run silent, run deep" variety.
Even that ~~$50 K system in the video link you gave the entire drive system exhibited sufficient noise to be heard over the, yes, rather cheesy car sounds.
Mickster: As I attempted to say, maybe not well enough, hydraulics can "SEEM" complicated to those who do not use them everyday. You do need a pump but I guess we should also say for servos we need a power supply so even there we have some equality of complexity.I will say, I don't think I will ever be comfortable with the international symbols used to describe [or should I say, attempt to describe] the various valve functions as I have only implemented maybe 4 hydraulic systems in my working career. I eventually figure them out but it sure creates a brain charlie horse.
I also had the idea of making my own proportional valve: Take a steel cube and drill a hole in it. With a reamer you can achive a very tight tolerance so that the shaft of a servo motor fits in with nearly no gap. Drill two more holes in the cube at right angles as shown in the picture. Grind two flat faces to the shaft. It can be sealed with two O-rings.
From full flow to side A to full flow to side B it takes only a 90° turn of the shaft. For a cheap hack it should even work with a model servo. A disc or bell rotor servo can move much faster and does a 90° turn in less than 10ms. Because of the remaining gap this valve might not perform well with industrial hydraulics with >300bar (>4000psi) pressure but I think for a home build simulator 50bar or even less is enough.
Now this is bizarre! Bene, back in the late '90's I travelled from to Detroit to, guess where? Stuttgart, Germany to evaluate something very similar to this. All I remember is that the name of the company owner was Wolf. It worked very well but was relatively expensive and for us was more of a solution looking for a problem. We made controls for a Spanish lathe manufacturer and several of the 8 axes had to be hydraulic for compactness but our existing proportional valves (ATOS) were performing well. I have since toyed with the idea of attaching a servo motor to the spool of a regular spool valve, just for fun.
Sorry, Mickster, My post was never meant as criticism of your work. That racing simulator shaking like a galopping horse was just so funny I couldn't resist commenting it.
And yes, you (and Wurlitzer) convinced me, hydraulics don't need to be complex. The industrial machines with hydraulics I saw were expensive and complex but that's not the fault of the hydraulic technology itself. There are many commercially available electrical servos that are also far to complex and expensive.
We propeller enthusiasts usually do it more the "Mac Gyver way", that is, simple and with "garage shop supplies". Electric servos seem simple to me because I deal with them every day.
Also true, the pump could be put to a remote place or into a "silencer".
Comments
I doubt anything I posted will be very useful. I was just trying to show some of us are interested in motion control.
I don't think I've heard of anyone using 2nd touch on a pedals. Very cool.
It's been a while since I've used Hauptwerk. I generally just use the sound module in my Alisis QS6..2.
I know I've seen pictures of some of your stuff but do you have your pipe chamber controller documented anywhere?
I'm very much an beginner organ player. Our local church has been desperate enough to have me play a few times but I always have to play the same few songs since there aren't many I can play well. I can only use the pedals with one of the songs (it only has four different bass notes). I don't spend enough time practicing to be very good but it's a lot of fun to be able to play the little I do.
The original Wurlitzer organ had 2nd touch on the pedals (and both KB)and they are usually used to add a drum, cymbal, etc without the need to turn a stop on and off.
I replaced all the contacts (constantly required adjustment) with small coils and those coils are sequentially grounded and I use the prop counters to measure the time for a given pin to drop to 1/2 Vcc then I just set up a table for 1st touch and 2nd touch trip points. The entire organ can be re-calibrated in less than 5 minutes and it used to take me all day.
I have never documented the Pipe chamber Prop code as it is highly specialized for my application but if you wanted a copy I'd gladly send it. The pipe chamber controller gets sent a copy of all the preset combination action settings upon booting the Console Prop and rather than send a bunch of MIDI messages for every stop which changed when a combination piston was pressed I simply send the actual piston number and the Prop handles the rest. That greatly reduces MIDI messages at a registration change.
The free Haupwerk and St. Annes organ are nice for Church Organ practice. If you have fun playing that is the most important part.
This is obviously a thread drift and if you would like to discuss it further we could take it offline. Glad to know there are other organists on the forum.
My servo motors run @> 6000RPM with 4096-line encoders (16384 quad-counts/rev)
The following is what I would like to implement on the Prop (the "Discrete Time Form" version), along with PID, of course. A sample time of 1ms is typical of many Digital Motion Control systems.
Mathematics of Motion Control Profiles
LOL...I totally understand...For me, no feedback...no control. How would you control the temperature of a room without knowing the prevailing temperature???
IMHO, all that hydraulic stuff is too complicated and expensive. If you only have to lift a seat and a single person electrical servos of <1kW should do. You can overload them by a factor of 3 for several seconds. You could drive ball screws directly with the motor shaft and mount the ball nut at the joints. I have propeller based AC servo drives, but unfortunatelly I don't have the time to build such a simulator.
Being a retired EE, my first instinct was for an all electric solution and that still my be my final output device. Regardless of the final drive type it will be propeller driven of course. However everyone I have seen/heard are quite noisy and in some of the racing simulators a lot of effort is expended towards replicating the sounds one would expect in the vehicle. I guess headphones could be an option to deaden the noise from the servo drives.
Some sims just move the seat, some move everything except the monitor screens and some like that video move everything so the loads vary significantly with design. The system in that video I believe starts off at ~~$50K US.
I agree hydraulics seem and can be complex to those who do not use them everyday. Pneumatics can offer similar performance in this application using proportional valves or even on/off but like hydraulics require something other than just an electric connection.
I also had the idea of making my own proportional valve: Take a steel cube and drill a hole in it. With a reamer you can achive a very tight tolerance so that the shaft of a servo motor fits in with nearly no gap. Drill two more holes in the cube at right angles as shown in the picture. Grind two flat faces to the shaft. It can be sealed with two O-rings.
From full flow to side A to full flow to side B it takes only a 90° turn of the shaft. For a cheap hack it should even work with a model servo. A disc or bell rotor servo can move much faster and does a 90° turn in less than 10ms. Because of the remaining gap this valve might not perform well with industrial hydraulics with >300bar (>4000psi) pressure but I think for a home build simulator 50bar or even less is enough.
I think my point was missed here: Yes, I have taken "standard on/off" (aka: bang-bang) valves but driven the (DC) coils proportionally using a $10 H-Bridge amplifier, resulting in a flow that is proportional to the coil current. The second video is only an example of valves being all on and all off.
What is complicated about hydraulics? There are two hoses to each cylinder which are connected to the A & B ports of a manifold that distributes the output from a pump. Hydraulic cylinders are silent, ball-screws are noisy.
Even that ~~$50 K system in the video link you gave the entire drive system exhibited sufficient noise to be heard over the, yes, rather cheesy car sounds.
Mickster: As I attempted to say, maybe not well enough, hydraulics can "SEEM" complicated to those who do not use them everyday. You do need a pump but I guess we should also say for servos we need a power supply so even there we have some equality of complexity.I will say, I don't think I will ever be comfortable with the international symbols used to describe [or should I say, attempt to describe] the various valve functions as I have only implemented maybe 4 hydraulic systems in my working career. I eventually figure them out but it sure creates a brain charlie horse.
Now this is bizarre! Bene, back in the late '90's I travelled from to Detroit to, guess where? Stuttgart, Germany to evaluate something very similar to this. All I remember is that the name of the company owner was Wolf. It worked very well but was relatively expensive and for us was more of a solution looking for a problem. We made controls for a Spanish lathe manufacturer and several of the 8 axes had to be hydraulic for compactness but our existing proportional valves (ATOS) were performing well. I have since toyed with the idea of attaching a servo motor to the spool of a regular spool valve, just for fun.
And yes, you (and Wurlitzer) convinced me, hydraulics don't need to be complex. The industrial machines with hydraulics I saw were expensive and complex but that's not the fault of the hydraulic technology itself. There are many commercially available electrical servos that are also far to complex and expensive.
We propeller enthusiasts usually do it more the "Mac Gyver way", that is, simple and with "garage shop supplies". Electric servos seem simple to me because I deal with them every day.
Also true, the pump could be put to a remote place or into a "silencer".