Pi PICO DRO/Quill-Knee combiner

[awemawson]

I feel your pain Bill. I never would have imagined how my little medical issue would affect concentration, yet it still is.

[JamesC]

Hope you can get sorted soon. I know how frustrating forced absence from the workshop can be.

James

[YFelin]

Wow only just read this I hope your recovery continues well Bill, I had a triple 10 years ago please take it easy and do the exercises at the pace they give you don't rush it. It took me a year to recover fully but it is worth it.

[BillTodd]

Thanks for the support guys 

I'm doing fine.  I've built up my walking until limited by my knees . I can do about 2 miles before my right knee says STOP,  sitting on a bike I can do much more.

My pectoral muscles have taken a bashing so I can't ride my ebike for a while , but at least I should be driving again soon .

Six weeks are up on Monday, so I can finally take off the support stockings and get back to my normal fish-nets and suspender belt 

[JamesC]

Six weeks are up on Monday, so I can finally take off the support stockings and get back to my normal fish-nets and suspender belt 

There is a picture I won't easily **** 

[ddmckee54]

Six weeks are up on Monday, so I can finally take off the support stockings and get back to my normal fish-nets and suspender belt 

There is a picture I won't easily **** 

It does tend to conjure up images from "The Rocky Horror Picture Show" doesn't it.  Gonna be hard to un-see that, even if it is only imaginary.

[BillTodd]

[/quote]

It does tend to conjure up images from "The Rocky Horror Picture Show" doesn't it.  Gonna be hard to un-see that, even if it is only imaginary.
[/quote]

I can make it worse...

I didn't tell you about the whole body shave prior to the operation...  (Or indeed, the nightmare of the regrowth!)

[ddmckee54]

"I can make it worse...

I didn't tell you about the whole body shave prior to the operation...  (Or indeed, the nightmare of the regrowth!)"

Nope, body shaving doesn't scare me.  Unless it's a female who chooses to have a shaved head, that just seems wrong.  (Sexist of me I know, but some guys with shaved heads are pretty scary too.)

[BillTodd]

Well, I got the all-clear from Dr Colin today   

On the chest x-ray It looked like they used bailer twine to bind my sternum ! Anyway it seems to have done the job. 

I just have to work my way back to fitness. 

[JamesC]

Excellent new, Bill

Heres to a smooth recovery

James

[BillTodd]

Well only a couple of years break...

I've ported the Knee Quill combiner version of the software to use a cheap display and encoder board, which should make for a tidy little package when finished :

picture here show the KQC version outputting Q+K to the quadrature input of the DRO version. The apparent error is just the DRO's 2dp rounding.

[BillTodd]

I found time to Bird's nest a pcb . Now I just have to box it.

[vtsteam]

That's a pretty cool display, Bill.   

[BillTodd]

Yes, and dirt cheap, the 1.3"  128x64 pixel display board with encoder and two buttons is ?3.50 from banggood ATM. The whole cost of the KQC should be well under ?20.

  it's a pity the higher resolution 256x 64 display is so much more expensive, else one per axis would make a nice unit.

[JamesC]

Good to see you back on this project Bill

[BillTodd]

Thanks James,

I've 3d printed the box in resin and will post process it tomorrow (leaving the print to drip dry makes cleaning up so much easier).

I have yet to fit the knee scale to the mill , and with temperatures dropping here , it may be some time before I do  so , it'll be a while before I can call it done.

Happy new year everyone.
Bill

[BillTodd]

This black resin is really sticky stuff when cold, cleaing it off was a bit of a bugger.

The case clips together, so Im not at all sure if it'll come apart in one piece

[BillTodd]

Braving the cold, Ihad to try it.

[BillTodd]

I can't find my github repository, it's out there somewhere...

In the meantime I zipped up the schematics and micropython code

https://drive.google.com/file/d/10YjkjAzgopwBTsnLx4H4uJlrTUiTRKMI/view?usp=drivesdk

[AdeV]

Bill, that looks superb! When I'm all moved, settled and have my workshop back, I'll definitely be looking at one of those... Are your scales the "standard" Chinesium ones, or something all fancy?

[BillTodd]

The quill is a cheap  Easson one but works ok.
The knee one is just over half of a broken Heidenhain that I was able to trim back and fix.
Both are 5um but the KQC box doesn't care what resolution (adjustable).

There seems to be some interest in making the thing read Mitutoyo SPC quill scales.
I may have to buy one to experiment. It requires an extra transistor to do the REQ output, and a couple of resister changes to sort out the logic levels, but looks easy enough to implement.

[vtsteam]

Pretty neat Bill, and great that you have posted the schematics and code for others!! 

[BillTodd]

Thanks Steve,

looks like I'm a bit premature with the software though: there's a bug in the Z output (actually , less of a bug and more of a whoops, forgot to actually implement the function !)

I finally found it warm enough to fit the knee scale . It was a bit of a PITA because nothing is vaguely flat on the side of the column - I had to print a couple of spherical fitting to allow the scale mounting with just two screws .

Apart from the Z count direction bug , There are a few things that need improvement :

The I2C display is quite slow , compared to the SPI used in the previous dro tests, so the update feels laggy .  I'll have to see how fast I can over-=clock the I2C

The Z output really need to be handled by a PIO . ATM it is possible to move the Quill faster than the Z can output resulting in a off-putting run-on/catch-up of the Z display.