Propeller and SuperMill
Newzed
Posts: 2,503
With the help of SSteve and Mike Green, I have finally finished the Propeller program to run my SuperMill. The program does everything I want it to, and it even has a reset function so that I can reset the X and Y coordinates to 0, 0. Now, I have designed a new PC board to interface the Propeller to the mill. Two boards cost $96.00 from Expresspcb. Since I can only use one, I would like to sell the second board to some one. Here is a description of the board:
Size – 3.8 x 3.0, double sided, PTH, no solder mask, no SS but most parts ID’d with copper.
Chips – Propeller DIP, MAX3232 DIP, 24LC256 DIP
EEPROM hardwired to pins 28 and 29
MAX3232 hardwired to pins 30 and 31
5mHz crystal
Four 8-pos female headers for accessing Propeller pins
5 volt regulator supplying 5VDC to the 8-pos 5V bus and to the 3 volt regulator
8-pos Gnd bus
DB9 female connector for programming
DB9 female connect that accepts a DB9/male to PS/2 female adapter for plugging in keyboard or mouse. Data and clock pins hardwired to pins 24 and 25.· 5V·bus and ground bus hardwired.
RCA connector for TV. The TV resistors R2, R3 and R4, are hardwired to pins 14,13 and 12. R1 is not connected.
Pins 0-7 ported to four 2-pos screw terminals
Pins 16-23 ported to one 8-pos screw terminal
Vin and Gnd ported to one 2-pos screw terminal
Pushbutton with pullup to 3VDC – can be patched to any pin
Reset pushbutton
Red LED for 5V, green LED for 3V. ·R12 – 100 ohms - for 3V LED is guesswork
On-Off switch
Wall transformer input jack
4 mounting holes .125 dia.
You’ll have to accept the layout before I order. If you accept and it turns out that there is an error that can not be fixed, we eat the board. A copy of the Expresspcb layout is attached. Be aware that you are looking at the bottom of the board, not the top, Based on the latest prices from Digikey, parts cost for the board would be about $50.29. Purchase of the board includes the parts list with part numbers and prices.
If I could find three buyers, the board price would drop to $29.00. If interested, please contact me at Newzed@aol.com.
Sid
Comments
Sid
http://www.indoor.flyer.co.uk/millingmachine.htm
I'm very interested in what you are trying to do, can you tell me some more about how you intend to use the propeller with the mill, will you make a g-code interpreter or are you doing something a little different?
I want to use the Propeller to control a micro wire EDM machine I am building:
http://www.indoor.flyer.co.uk/edmwiki.htm
I was going to use a PIC but that would have mean't a very simple user interface and probably a PC sat next to it in the end. The Propeller seems a good solution for me as I can have one processor monitoring the gap conditions another doing the video etc etc.
Love to hear some more anyway.
Cheers,
Graham
Generation of the DAT list is a bit time-consuming but it works very well.· Here is how I do it.· First, as I draw the etch paths in Express. I write the ending coordinate for each etch path on an Excel form - not the distance I want to travel but the ending coordinate.· When I am finished, I type all the data I have written down into an Excel template.· The template converts the data I have entered into a DATA format that my Stamp can use.· This DATA list is then pasted into a special Stamp conversion program I wrote.· The conversion program then converts the DATA list into a format that I can paste into my Propeller program.
When the Propeller program starts reading the DAT list it compares the "coordinate destination" values to the current position.· For example let's take the X table, and let's say the current position of the X table is 500.· If the current instruction is Left 600, the program says:
travel = coord - posx = 600 - 500 = 100.· The actual distance the X table travels is 100, which puts the X table at 600, which is where I wanted to wind up.· If the current instruction says Right 400 then the program says:
travel = posx - coord = 500 - 400 = 100.· The X table travels right 100 and winds up at 400 - again exactly where I wanted to be.· I hope I explained that OK.· I keep the converted DAT files in a special folder, so if I want to make a board I have made before, I just paste that data into my Propeller program and away I go.
There is one disadvantage to this - the computer in the shop where the mill is has Windows ME, which can not handle the Propeller Tool, so I have the disconnect the Prop board. bring it in here, reprogram it, then take it back out to the shop and connect it up again.··I working on some "quick disconnects" that will make this task easier.· So there you are.
Any questions?
Sid
Sid
Graham
Sid
Sid
Great stuff anyway I hope I can get as far as you.
Cheers,
Graham
Cheerio
Sid
I would like to see a picture of your mill though. Is it already posted in one of the forums.
Signed,
·········· Still Etching.
Sid
For my own personnel use of course!
Sid
That put my dreams in color anyway.
Good luck on your board!
I have a real bug in my Propeller program for SuperMill.· I have a DAT list:
trav2·· WORD··· "L",846
········· WORD·· "I",675
··········WORD··· "O",600
········· WORD··· "Q"
"L", 846 appears to work OK.· If I change it to 847, it goes Left 847,then screen displays an extra line - Going out -73 to 73 - and the program freezes.
If I change it to 848, it goes Left 848, then says "Pausing".· I don't even have a Pause command in this data list.· If I press any key to end the Pause, it then executes the rest of the DAT list
If I change it to 849, it goes Left 849, then says "Done" and ignores the rest of the DAT list.
If I change it to 850, it goes Left 850, then displays an extra line - Going right 777 to 73 - then executes the rest of the DAT list.
Solution, please.
Thanks
Sid
Anyway, I think I've solved the problem.· I changed WORD in the DAT list to LONG, changed the VAR dir to LONG, and changed the WORD in
dir:=WORD[noparse][[/noparse]@trav2][noparse][[/noparse]pntr] to LONGwherever necessary and now it looks like it is working.· I'll have to make additional runs to make sure the problem is solved.
Sid
Sid
Second Class Junior Apprentice Propeller guru.
Sid
Sid, you crack me up.
BTW, first time I have seen picture of "the mill".
Very cool.
Are you using that monitor in the upper right?
Looks like a 9 pin amber monitor.
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- - - PLJack - - -
Perfection in design is not achieved when there is nothing left to add.
It is achieved when there is nothing left to take away.
Sid
I bent up the ends of the aluminum base so it would present a curved surface to the slider surface.· I padded the space between the aluminum base and the stepper frame with masking tape until the stepper shaft was almost aligned with the adapter hole, then I made the final padding with double-sided golf-grip tape to hold everything in place.· The bottom of the aluminum base rests on a sheet of .040 galvanized which is anchored in place.· The top surface of the galvanized and the bottom suface of the aluminum base were polished with 400 grit wet-dry until they shone like a mirror.· I keep a film of white lithium grease from a spray can between the aluminum base and the galvanized to reduce friction to an absolute minimum.· About every month or two, I removed the slider assembly from the adapter and repolish both surfaces.· It really works pretty well.
Sid
Attached is how I did mine, I have had no trouble with droop as the cutter is always directly over the saddle where the bed is held very rigidly.
Graham
p.s. For really small drills stick with the collets, they will spin more truly.
Sid
To attach my assembly to the end of the bed I used the holes that attach the origional plastic ends but I just used much longer screws. They only have to prevent the assembly from turning with stepper torque all the real force is applied to the thrust washers at each end of the leadscrew.
Graham
Sid
Sid
Sid
The nut is important as it prevents axial movement of the screw. The leadnuts in the MF70 are made of delrin and have very little backlash, what backlash there is tends to come from end float of the screw. It is important to get the tightening just right, some grease can help too.
I actually ended up changing the washers that act as thrust bearings at the ends of the screws for normal 6mm ID radial bearings, these are very cheap and the axial load rating is normally about half of the radial. As the radial load is HUGE there is no problem and I can get the screw a bit tighter without it binding. I just hold the bearing with a bit of epoxy around the edge. I can post some pics later.
Graham