Computerized Index Wheel

[bobbeaupre]

Bob, your experience is the kind of thing that drives me crazy with open source code.

With the Arduino setup I mentioned I was apprehensive. It turned out to be very straight forward with one exception. Of the three computers I tried it worked on my two laptops with no issues. For unknown reasons it doesn't want to work on my desktop.

Which is not much!
I've been trying to compile Bill's software, I've tried two different computers, 6 different versions of Netbeans and three different versions of Java. I get different error messages on each combination!!

I was hoping Bill had a windows version already complied, then I could play with it at my leisure.

I could also feel more confident in ordering parts.

 

[Raul McCai]

do your drivers work for ubuntu?

 

[bobbeaupre]

do your drivers work for ubuntu?

There are Linux driver for the board:
http://www.phidgets.com/docs/Operating_System_Support

 

[billooms]

The Phidgets people change their drivers as they add new products (or as required to keep their stuff working with OS changes). If you install a different version of drivers on your computer than what was used to compile the Indexer software things may not work. When you compile the Indexer software, you need to compile it with the same version of the library file (named phidget21.jar) that matches the Phidgets drivers on your computer.

This is another reason that I abandoned the Phidgets approach.

 

[bobbeaupre]

Good to know I'll have to check what version I have installed
Thanks, Bill

The version I have install is Phidget21 - Version 2.1.8 - Build Feb 22 2016 11:45:54

Name of the drivers is the same but I am sure it is a later version.
Could this be the problem or does it just have to have the same name?

 

[bobbeaupre]

I see they have
windows 64 bit back to version 2.1.6.20090317
windows 32 bit back to version 2.1.6.20090317
and
OS X versions back to 2.1.3.2008114

Can you tell me which version is the one you complied with, or at least which version is installed on your computer

Thanks

 

[billooms]

The last versions I used had a date code of early 2014. I don't recommend using drivers that old. They might not work with current OS versions, might cause other problems, or may not work with the newer versions of the Phidgets boards. I no longer use any of the Phidgets boards so I have not done any updates.

 

[bobbeaupre]

Thanks I may install them just to see if I can compile.
I have back down to version 2.1.8 March 2011 To see if that works.
I'm also going to try version 8.02 of Netbeans

Thanks Bill

 

[bobbeaupre]

Well will wonders never cease. I have been able to create both Windows and Mac installers!!
Not only that but it installs and the program runs in Widows 10, I have sent the Mac install to a friend to see if that works.

Now it looks like it's on to ordering some parts.

Now I'm getting excited!!!

 

[bobbeaupre]

Going all in!! controller, power supply and motor are ordered!

 

[Bill Boehme]

Well will wonders never cease. I have been able to create both Windows and Mac installers!!
Not only that but it installs and the program runs in Widows 10, I have sent the Mac install to a friend to see if that works.

Now it looks like it's on to ordering some parts.

Now I'm getting excited!!!

I'm following along with great interest.

 

[bobbeaupre]

I'm following along with great interest.

Well the programs runs now on my Windows 10 Laptop and on my Windows 7 Laptop. It's a little finicky, there were quite a few warnings during the clean and build but nothing fatal. And there were warnings during the installer build. But most of those were caused by it being built on quite a bit older versions of java. Now that I have it so I know I can at least run it I can take my time and clear out the rest of the bugs. I'll wait on that until the board and motor show up, so I can verify that I can in reality control the motor with the program Then the fun starts

 

[bobbeaupre]

Motor and controller are to be here on Friday.
In the mean time I'm working on the off lathe fixture. I'm making this for open segment bowl and layout for basket illusion, I see Tom Lohman also using it for closed segment.
Drawing it up in Sketchup

 

[bobbeaupre]

Hi Bill,
Looking at your gear reduction on the lathe spindle. Your stepper motor steps 1.8 and you were 20 x 130 on the gear reduction. From your experience was that sufficient with the index program?

The stepper I have ordered steps 0.09 and was wondering if I needed to up the gear reduction?

Thanks
Bob

 

[Bill Boehme]

I'm the other Bill, but, I would guess that torque would be the most important factor regarding the drive ratio. I don't think you could ever have too much holding torque nor step sizes too small. If you still have adequate torque and acceptable step size after reducing the drive ratio then I would think that you're OK.

BTW, if you start your post with @billooms then Bill Ooms should receive an email notification of your post.

 

[bobbeaupre]

I'm the other Bill, but, I would guess that torque would be the most important factor regarding the drive ratio. I don't think you could ever have too much holding torque nor step sizes too small. If you still have adequate torque and acceptable step size after reducing the drive ratio then I would think that you're OK.

BTW, if you start your post with @billooms then Bill Ooms should receive an email notification of your post.

Hi there other Bill,
The stepper motor I have ordered has
Holding Torque 12 kg·cm - that relates to 26.4555 lbs at 1 cm (.4 inches)
Rated Torque 11.2 kg·cm
and the Step Angle 0.9° that's 400 steps per revelation.
and the torque is before going thru any gear reduction.

After gear reduction I should have the step angle down to 0.064131° with 5613.636 steps per revelation

The original torque of the motor by itself I thought was sufficient for open segment work, I was just concerned about radial resolution and the cumulative error. Bill was the author of the source code and I did not dig deep enough in the code to see what his is doing in that regard.

 

[Doug Rasmussen]

Hi Bob,

I'm interested in what you're doing here. From your Sketchup drawing it's not clear to me how this off lathe fixture will function. Presumably it's to precisely index/rotate your workpiece in specified increments?

The setup I use for off lathe indexing is similar to the small Sherline motorized rotary table. With the worm gear drive being able to hold position during cutting operations is not an issue. I use a NEMA 23 stepper controlled by an Arduino processor.

http://sherline.com/product/3700-4-rotary-table/


The attached pics are some of the kind of off lathe work I like to do using my indexing fixture..

 

[bobbeaupre]

View attachment 21958 Hi Bob,

I'm interested in what you're doing here. From your Sketchup drawing it's not clear to me how this off lathe fixture will function. Presumably it's to precisely index/rotate your workpiece in specified increments?

The setup I use for off lathe indexing is similar to the small Sherline motorized rotary table. With the worm gear drive being able to hold position during cutting operations is not an issue. I use a NEMA 23 stepper controlled by an Arduino processor.

http://sherline.com/product/3700-4-rotary-table/


The attached pics are some of the kind of off lathe work I like to do using my indexing fixture..

View attachment 21958 View attachment 21959

Hi Doug,
This will be a off lathe setup for open segment bowls. If you look in the center of the flat base you'll see a hole. That is where the axle for the face plate will be set. The axle will be turned by the stepper motor rather than using an index plate. The flat base off the rail will move up and down manually for line up segments.

Hope that makes some sense.

 

[Bill Boehme]

Bob, when you said that the drive train reduction is 20 X 130 does that mean the same thing as 1 : 6.5? I was trying to follow your description of the output step size and torque and couldn't match your results. Does the controller do half steps or full steps?

 

[billooms]

The 0.9 degree steppers (400 steps per rotation) will work just fine. It will give you finer resolution compared to the 1.8 degree (200 steps per rotation) motors. You set the stepper resolution and the gear ration in the Preferences portion of the software.

Yes, 20 x 130 is the same as 1 : 6.5.

You won't have to worry about any accumulation of error so long as the steps-per-rotation of the motor times the pulley ratio is an integer (i.e. not a fraction). So you will have 400 * 6.5 = 2600 which is fine. Your angular resolution will be 360/2600 = 0.138 degree which is close enough for any of our applications.

 

[bobbeaupre]

When I first saw you 20 x 130 gear reduction I though why did he use 20 on the motor end when there were smaller available. That answers that question keep the ratio an integer.

 

[bobbeaupre]

Bob, when you said that the drive train reduction is 20 X 130 does that mean the same thing as 1 : 6.5? I was trying to follow your description of the output step size and torque and couldn't match your results. Does the controller do half steps or full steps?

Hi there other Bill,
As you can see from Bill Ooms reply: Yes, 20 x 130 is the same as 1 : 6.5.
The stepper motor control is a Phidgets 1067_0 - PhidgetStepper Bipolar HC

Here is the link if you want look at it: http://www.phidgets.com/products.php?product_id=1067

The controller proprieties say the resolution is:
Motor Position Resolution 1⁄16 Step (40-Bit Signed)

 

[billooms]

As I recall, the 20 was the smallest I could find at that time on a 1/4" shaft and 130 was the largest I could find.

I used an MXL style of timing belt. Jon Magill has recently begun to use GT2 and GT3 style timing belts and gears. He says that it's easy to make your own gears if you have a rotary stage on a milling machine and a metal lathe. I'll probably look at this option for my ornamental lathe this summer some time.

 

[Doug Rasmussen]

Phidgets is new to me. A little Googling shows they have software drivers in most any language flavor you'd want.

What I'm curious about is the output to the boards regular step and direction signals that could be used with any brand of stepper drive board? Or, is there other communication to the board making the software only usable with Phidgets boards?

My reason for asking is I have a quantity of new stepper drives and motors left from automation projects in years past.

 

[billooms]

The stepper controller board (like the Phidgets 1067) connects directly to any compatible bipolar stepper motor and can drive up to 4 amps current with a supply voltage from 10V to 30V. The connection between the controller board and your computer is not the traditional step/direction from a parallel port, but is a USB cable that communicates with the driver software on your computer.

 

[bobbeaupre]

Well motor, control board, power supply and motor bracket showed up this afternoon. After a little reading to make sure I connected the four wire correctly to the control board, I fired up the control board test program from the manufacturer.
Program accurately identified the board and acknowledged the motor attached. Test program ran the motor successfully.

Next was to fire up the indexer program.
It accurately identified the board. we are in business.
Testing the motor on the arm of my chair here in the living room. Everything looks to be a go.
Index plates load and motor indexes according to the program.
can run the motor / index forward and backward.
Return to zero, and can speed.
Looks like I'm down to the gears and timing belt and building the fixture

 

[bobbeaupre]

Playing with sketchup today, revised the base a little smaller, waiting on some parts to arrive.

Should be looking something like this

 

[Bill Boehme]

Could you describe what the fixture does.

 

[bobbeaupre]

Bill this will be an indexing mainly for doing open segment work, I guess the big thing will be there will be no index plate. That will all be done with the computer and the stepper motor. The two rails on the left side are linear motion rails and the will be linear bearings in the index head. The head will go up and down manual as the rows get added to the bowl.

 

[bobbeaupre]

Base fixture built, waiting on rest of the parts

 

[Doug Rasmussen]

Looks good Bob. Things are coming right along.

I'm still a little confused. Will the fixture be used in cutting segments or is it primarily to mark, like on basket weave bowl patterns?

 

[bobbeaupre]

It's going to be a glue up fixture for open segment bowls.
Can also be used to layout for basket weave

 

[bobbeaupre]

Linear rails and bearings and segment platform are installed. Now I wait for the timing belts and pulleys.
Looking good though. Still need to come up with a way of locking the segment platform in place.

 

[Bill Boehme]

That clamping fixture looks like it might flex. I think that putting a rail on each side would eliminate the bending moment. But, maybe you're not thinking of using it as a vise.

For holding, how about a third bar that is all-thread with a nut to tighten it down. Or, just sit a Vicmarc chuck on it.

 

[bobbeaupre]

Bill,
No clamping. Think big brother to a Driskell Glue Up Jig.

 

[Bill Boehme]

Oh, OK. You have to speak slowly and use simple words when talking about segmenting. I look at it and marvel, but I keep my hands in my pockets and just watch.

 

[Doug Rasmussen]

.............................................. Still need to come up with a way of locking the segment platform in place.

To lock the platform there might be a digital off/on output from your software to a solid state relay that could actuate some sort of mechanical or pneumatic clamping device.

 

[bobbeaupre]

Upper section of the fixture is now complete. Unless I want to get fancier with tray and such, but we'll wait until I'm actually do some work on it.



Tomorrow the timing belts and pulleys will show up so I can finish the drive.
Then I can punch a hole for the motor pig tail, and then I can hook up the computer and see if every thing works.
Bad thing is Tuesday we leave for a week of vacation where it's warm.
I'll be thinking open segment all week!!

 

[bobbeaupre]

We have it working

View: https://youtu.be/Qk-84vqZ9yg

 

[billooms]

Congratulations! Now you can get back to woodturning!