Scara

[trev]

Hi.

In my progress with openpnp I came across scara which I think is the coordinate system style the rv uses.

It seems you could use a duet3d xc board which would drive the current stepper drivers and enable the rv to be used with openpnp. The duet board supports scara.

The only thing I think might be an issue is the calibration map the Rv has to do to calibrate itself. I am not sure if that would be easy to implement.

Shame really as it would transform these machines.

Trev

[Mike]

Yes, it is a SCARA type geometry
Aside from the presumed need for calibration, I wonder if it would cope with:
The position-dependent offset between the fid cam and the head
The constraints on reachable area including having to do some moves in two stages
The on-the-fly vision of the RV4.

Apart from a handful of annoyances, the existing software is sufficiently useable that a major change like this would be a ton of work for questionable benefit.

[trev]

Hi Mike

You can set a useable area but I do not know if that is any more than a rectangular size or if with SCARA there is more complex configuration. OpenPNP deals with top and bottom cameras and fully includes them in calibration setup. It even has vision based fiducial homing points to enable perfect starting positions go the machine. This is different to board fiducials

The motion geometry would be taken care of by the motion controller board; the Duet3D XD in this case. You would feed it x and y co-ords and it would move I think.

This is something I found on setting up the board for SCARA. It is related to a 3d printer but the movements are what's important. OpenPNP takes care of the rest.

https://docs.duet3d.com/User_manual/Machine_configuration/Configuration_SCARA

Openpnp would support the on the fly camera but I am not sure if it would support it whilst making movements. It likely just treats it like a second up camera. 

I find the RV so frustrating at times. Today I built some boards and after about 20 the vision on a couple of parts had changed a bit. It started the day fine and the light was constant through out the morning. I just never know when I will get an issue.

Plus the feeders are a pain. Then the waffle trays forget the orientation sometimes and you have to refill and rotate 2 or 3 times before it sorts itself out again. You cant go lower than 0603 and fine pitch is really tricky.

Then the issues with the screen going funny.

There have been days where the machine has really hammered along all day. Then some days I lose a few hours messing around with things I should not need to. I fixed the feeder issue for 0603 leds but then you get tape slip. Then vision sometimes struggles. You cant change the cameras on these easily. Then it relies on old computers. Openpnp works from most laptops and just a control board. No DSP cards. No massive psu boxes.

[Mike]

Hi Mike

You can set a useable area but I do not know if that is any more than a rectangular size or if with SCARA there is more complex configuration.

Scara has an inherently non-rectangular working area - the RV software has some maps in config files somewhere showing valid positions in a 1" grid.
The way the machine is laid out, it is necessary to be able to access pretty much anywhere that's physically reachable, and that adds the complication that some moves need to be split to avoid moving through unreachable areas

The motion geometry would be taken care of by the motion controller board; the Duet3D XD in this case. You would feed it x and y co-ords and it would move I think.

Also, it would need to deal with the very unusual 5-phase steppers that the RV uses - for that reason alone I think you'd be stuck with the original Sanyo drivers and PSU box.
If you can ignore the duet3d onboard drivers and get step/direction signals that took the SCARA stuff into account, you could feed these to the original drivers, it would just have slightly different scaling. 

This is something I found on setting up the board for SCARA. It is related to a 3d printer but the movements are what's important. OpenPNP takes care of the rest.

But what about the fact that the fid camera has an angular offset from the head centre which depends on the position? I think  you'd need to reference the output of the SCARA processing to be able to claculate this.

I find the RV so frustrating at times. Today I built some boards and after about 20 the vision on a couple of parts had changed a bit. It started the day fine and the light was constant through out the morning. I just never know when I will get an issue.

I found that doing the lighting upgrades described elsewhere completely fixed all the vision issues I ever had, particularly the sensitivity to ambient light.  Literally anything from indirect sunlight to artificial light makes zero difference now. It also happily tolerates all the LED tape I've put inside and on the head, which used to cause position-sensitive issues for the flying cam.
Seriously this is the about best upgrade you can do, second only to using the gamepad for manual control.

Plus the feeders are a pain.

no argument there..!
TBH If I were to spend more time improving my machine, I'd be looking at adapting Yamaha or similar "big boy" feeders

Then the waffle trays forget the orientation sometimes and you have to refill and rotate 2 or 3 times before it sorts itself out again.

I've never seen that, as long as you remember to answer "no" to the rotate prompt when refilling, though I don't use trays very often

You cant go lower than 0603 and fine pitch is really tricky.

OpenPnP isn't going to fix that either - I'm certain this is a limitation of the mechanics, though higher-res imaging may make a small improvement. I have done dense 0402 LED arrays on occasion, but that's very much an "on a good day, with the right phase of the moon" sort of thing.

Then the issues with the screen going funny.

Annnoying but minor as there is an easy and quick fix for that without having to go through the homing again - just load any other job file, ignore feeder warnings and reload the original file & you're back in business in a few seconds.

I agree that there are a number of annoyances, but I'm sure the process of getting it to work with different hardware/software would be at least as time-consuming & annoying !

[trev]

You are likely right about the amount of effort it would take to convert.

Regarding feeders having you seen this video? The fella sells the parts as a kit and all that's needed is to print the plastic parts. I think the weak point of it is the life of the servo but the design is excellent.

https://youtu.be/mWer4ytN0Tg?si=IxvxFDR7ZpRtLsQz

[Mike]

Interesting - I've bought a couple to play with

[trev]

I have one here. They come really well packaged in kit form but it takes him a week to ship usually and a few weeks before they arrive. I have not had chance building it yet.

There is a version I am also going to build based on this design by the same company.

https://youtu.be/xfu4Jbbh21I?si=5K80VvTfmLfV7-yk

[trev]

Hi Mike, how did you get on with the feeders? I managed to get one built up. It was quite tricky to get working properly but it seems nice. Have attached a link to it working with 0402 parts.

I will test this feeder some more but I think I will buy more from him.

https://www.youtube.com/shorts/zPJujUt2Y-c


Trev

[Mike]

Received the parts -  was puzzled for a while as they came with no info & took a while to realise what this seemingly random box of bits even was, as it was a while since I ordered!
Having remembered, it then took a while to find any info on assembly as I couldn't remember where I'd found out about it & for some reason it wasn't in my Aliexpress order history.
Haven't got around to doing anything with it since...

[trev]

They are a bit of a faff to put together and then getting them calibrated turned out to be even more of a faff. I got there eventually but I have to say the printed parts I used did not seem to marry with the kit of bits. Few screws did not fit, some left over. Had to use a couple of my own, etc. But it did work.

What did you order? Do you know what you have? lol

Someone also found Yamaha CL clone feeders from a company called https://www.itechsmt.com/ They are 50$ each and appear to be decent. But you need an air solenoid as well and a compressor. But potentially the most straight forward route.

Trev

(Mike : edited to correct link)

[trev]

Mike if you think you might not build them I might buy them off you if you want?