An open source Emco 120P lathe tool turret control

Hi Tom,

attached is the costed BoM as of today. I haven't ordered anything yet. Could you look through it and see if anything is incorrect? I am an ME after all so I haven't ever really specified EE components before. I gave it the old college try though Tracking shows I will get the bare PCB's tomorrow.

Scott

Nicely done, looks correct to me. You left C4 blank, I assume you are just going to use 2 of C1?
-Tom

thanx

yes thats right, I forgot to transfer the info down.

I have 10 bare boards coming because that was the cost structure of the board house. I was going to try to build 10 and share those at a little over cost to recoup some of the costs for my PCBA but some of the parts are quite expensive so likely I will get 2 sets of parts and that way I can practice and maybe have a spare. So if someone wants a board I will have some available, I may buy the small discretes for all 10 but the connectors and the driver likely not.

this sounded terrible . not trying to make money. The bare boards were $41/10, the place was minimum 10, so If someone wants a bare pcb then I will be making 5 available immediately for $5 sent in a 1st class envelope (should be safe).

Scott,
In looking a little closer there is one change you should make to the information I gave you, and I should clarify something regarding C6 and R4.

C6 should be 2200 pF (0.0022uF). This is assuming you are using a 20k ohm resistor for R4. The pin on the driver chip that these two parts are attached to labeled "RC" creates a timing circuit. Use EITHER C6= 0.0022uF and R4=20K ohm, OR use C6= 0.0033uF and R4=15K ohm. We used the latter because that is what we had lying around.

This would also apply to C5 and R3 but you have the correct values for these in your BOM.
-Tom

I updated it and moved the 3300pF below with your note. Dropped the price columns because those are only good right now anyway. the part numbers are there for anyone to re-price later

LutzTD wrote: this sounded terrible . not trying to make money. The bare boards were $41/10, the place was minimum 10, so If someone wants a bare pcb then I will be making 5 available immediately for $5 sent in a 1st class envelope (should be safe).

Nice of you to make them available. Making the board is really the primary barrier to someone using this solution. Getting/soldering the parts is easy enough. Now you will be flooded with requests from all those people out there retrofitting EMCOturn 120's :laugh:

-Tom