Question 80ST-M02430 voltage

Hi,

I am looking at updating my 2DoF rig from my 24v Jazzy motors to 80ST-M02430 servos. I am in the US and it seems all the drivers use 220v. Is there any alternative as we use 110v in the US.

Thanks

You could use a transformer. You don't need a big 1.5kW one because the average current draw is much lower.

But are you sure you really need such big motors? With 2DOF you don't have heave so the motors don't have to support the weight. I think if the gear ratio and lever arm lengths are calculated correctly, a 200W or 400W servo should be super good enough.

How about this? IHSV60-30-40-48 It only needs an 48V supply (or two 24V in series) and has step/direction inputs. No extra cables required. Of course you have to add a planetary gearbox.

Thanks - This is definitely an option, but I have a question. Why do I need a planetary gearbox? What about a ball-screw actuator?

Yes, of course a ball screw also works. I just thought a gearbox + crank arm + pushrod is simpler.

Does your 2DOF seat have a U-joint in the center? If you use rotary actuators you can position the motors horizontally under the seat which takes less space than vertically aligned ball screws.

There was also a clever design recently which used horizontally arranged ball screws with some sort of hinge kinematic to convert that into vertical movement, but unfortunatelly, I don't find it anymore.

If you post a photo of your rig we could find out what's the best option.

Yes, this is the plan. Here are some pics.

Found it! Theese are the ball screw actuators I've mentioned. But as I said, they are quite complicated, IMHO.

Why do you want to replace your current motors with AC servos? You need more stroke, more speed or you have reliability problems?

Thanks for the info! My current setup is the classic Jazzy Motors, SMC3 firmware with the IBt-2 Controllers. I am not using SimTools as the interface for games. I created my own App to communicate and receive telemetry data from FS2020. When everything is working, its pretty great but I do get a bit of "cogging" or stepping when running as a Flight Sim. I see it more when using slow aircraft like a Cessna 172. I have struggled with the SMC3 configuration for awhile and I can get the occasional motor cut-outs. And that is an immersion killer for me. I am simply frustrated with SMC3 and have chosen to abandon it. I am not bashing SMC3, its proven and a stable for many simmers. I am just struggling with it and reached my limit. I can live with the "coging" but the motors cutting out simply sucks.

I looked at your suggestions. Purely looking at the cost, I am looking at at least $500 - $1000 USD to update my rig. This does not include time and effort, which to be honest is part of the fun. As you know, this hobby is a labor of love. However, at this point I have ordered a DoF Reality M2 and most likely will upgrade to H2 this week.

As I am full time programmer, maker and now a simmer, my plan is to salvage my rig and write my own firmware using the Teensy 4.1 as an alternative to Arduino/SMC3. Either with the jazzy motors or the IHSV60-30-40-48. The Teensy supports the HID protocol which means no more communicating with serial com ports. This is an ambitious project, and perhaps I might not be successful, but for me its a good winter project. Not all my projects end as I expect, but I also learn something new.

With the new Dof rig coming, I can move my homemade rig to the workshop and start coding. Thats the plan!

It's a bit difficult to diagnose from the distance and I have no experience with the SMC3. I saw your motors have spur gear and potentiometer feedback. This works well if the gear has little backlash. But the more backlash you have the more difficult it becomes to tune the control loop. If you keep the gain low you have sloppy response and maybe overshot. With higher gain the motor always dithers forth and back because of the "dead zone" of the backlash.

Servo systems in commercial machines avoid that by using dual feedback, an encoder directly on the motor shaft for speed feedback and a second sensor on the output shaft for position feedback. But that's too complicated and expensive for DIY actuators.

If you decide you want to use the 80st servos the drives have a parameter you can change to lower the low voltage warning and they run fine at 120v.

It's hard to beat these servos in terms of performance and value. When I say these servos I'm referring to all the servos that an aasd15a will drive. Look up the manual there is a list of motors. Everyone from 200 watts to many kilowatts.

[QUOTE="Aerosmith]Servo systems in commercial machines avoid that by using dual feedback, an encoder directly on the motor shaft for speed feedback and a second sensor on the output shaft for position feedback. But that's too complicated and expensive for DIY actuators.[/QUOTE]

Odrive supports dual encoders and the new ones have absolute encoders on board the pcb so you can pop a magnet on the shaft, point it at the encoder and you've got commutation solved with no hunting on power up.

Teensy also will talk can bus which odrive supports.

I don't know a lot about HID. What is the advantage over com ports for our kind of projects?

Ah, good to know. You can then simply use the standard 750W motors. At 115 instead of 230V input they will only run 1500 instead of 3000RPM and the power derates from 750 to 375V (continously). But this should be plenty for a 2DOF rig.

In my experience it's not that simple. Well top speed surely is reduced some but a sim rig will rarely ever get to that point. Rather than go on and on with theory I will post my experience.

I have tried running my pegleg sim rig at both 220 and 110v and I didn't notice any difference in performance. I measured the input with a power meter and the power draw was very close to the same with the current draw being just under double.

I'm no ee but a quick Google search says 120v ac rectified to 170v DC. So maybe you really only loose about 23% of your top speed but not really any torque.

Arguably. there are a couple of benefits, but it does have its cons. You don't have to define a com port. You can assign a name to your device and easily communicate with a bunch of devices on the bus. The HID protocol uses the VID (vendor id) and PID (product id) to find the peripheral on the bus. At a very high level, HID uses "reports" which are 64 bytes in length, not serial. With serial you can send bigger chunks of data, but need to define when to "stop". It's definitely a preference, but can be harder than Serial to work with. Since there are some easy to use libraries, implementing HID in a c# app is relatively easy and I prefer it. I personally find HID more reliable than serial com.