More PCB Router Repair

Electronics
#41

J,

I found your Switch Brackets, but no switches. I set up the Optos; maybe use the MicroSwitches at the other end for failure/shutdown. There are a few reasons for this:

  1. Mech switches aren’t repeatable to fine tolerances because they tend to bounce.
  2. Optos are highly repeatable, we’ll see if debris from milling fouls them. If so, I’d say go to Hall Effect transistors.
  3. The “Homing” operation moves into the limit switch, then backs away slowly to repeat the ReferencePoint. This requires precision repeatability.

Unluckily, I found a whole baggy full of Optos on brackets with connectors (scavanged from a copier), about the time I had finished installing the others…I left them in the PCB Mill goody box.

#42

The power supplies, tinyg, fan, and connectors are inside the blue case.

I’m in the process of milling the case to mount all the parts. I have finished the bottom (power supplies and tinyg) and partially completed the front panel (illuminated main power switch, illuminated spindle power switch, spindle speed potentiometer, USB-B panel mount, and cover for all the existing cutouts). I still need to finish the switch mounting and then move on to the back panel. I am waiting for the spindle power connector to arrive from China. Wish I knew it was 100V@500W vs. 24V@300W. It would have made it much easier to purchase the connector (5A vs 12A).

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#43

We should discuss how all the sensors will be cabled. This will affect how many pins we need for the connector. I recommend we keep any components inside the case, preferably on a custom PCB.

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#44

So, apparently we need a 100Vdc P/S that we can modulate. At 24Vdc we’ll only hit about 2k RPM at the cutting bit… This discussion can wait until we’re better versed in TinyG command structure and we’ve achieved Homing and translation with precision.

#45

Connector Pins
(Please put a subject title at the start of responses)

Good idea on the Custom Connector Board! I think the Conn Bd should be attached to the PCB Mill bulkhead, then connected down to the Blue Box on a single cable. This will allow us to run cable track spines across the Axis, and connect nearby. The spines tend to make wires last much longer by minimizing metal fatigue in wires.

The Optos only require 3 pins; power, ground, signal. The motors require 4 (or 6 for better 2 phase motors). If we use a locally mounted Conn Bd, we already have long enough leads.

#46
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#47

Future thought on Translation:

If anyone runs across some Ball Screws, grab them! Also, if anyone runs across some Motor Couplers, grab! This project is begging for precision.

#48

Connector Pins

Art and Walter already have the spindle and servo connectors covered. There is an additional multi pin connector we can use for the limit/home signals. I think we just need to draw out a quick schematic to see how many wires need to exit the case. If it is just 3.3v, gnd, x, y, and z; then no problem. However I’m not sure how you will involve the mechanical limit switches and that’s mostly what I’d like to see drawn out on a schematic. If you’d like to white board something, we could meet this week. I’d be happy to help design any additional circuits and fabricate a board if needed.

#49

Spindle Power

I’ll hook up the existing power supply and spindle then make some measurements. I suspect they are a matched set. Anyone know where I can find an optical tachometer?

#50

I think Automotive has one. Check w/ Tom @TLAR.
Luke @LukeStrickland might know also.

#51

60% sure there’s one in the diagnostics drawer in the black toolchest

#52

Spindle Power

So, we have a separate P/S for the Spindle (router) Motor? This would be 1 less problem to solve. 100Vdc @ 5A selectable?

#53

Debris Extraction

We should probably think about a Debris Vacuum for the Cutting Bit. While not required for initial proof of life test, keeping the flying crap out of this machine will greatly enhance it’s durability.

#54

CPU interface to TinyG

That means you will achieve JSON interface to the TinyG to run the tests. Do we have a Computer that we plan to use to drive the 115K Serial Intf (JSON) to the TinyG? Will this also host the ChiliPepper Web frontend? Please advise…

#55

Optos and flags are in.

We’re thinking a connector board on the side of the bulkhead, and a flexible cable track along the top, and down the side to carry the moving wiring.

We can 3D print the flexitrack.

20171126_203502
20171126_203502.jpg1836×3264 1.08 MB

#56

Cable Chain Track files are attached.

Jump right in and print a cable chain. One for X and one for Y travel.

Cable_Chain.zip (331.9 KB)
Printrbot_Simple_V2_Cable_Management (1).zip (774.5 KB)

#57

Spindle Power

I confirmed the spindle power supply is 100V variable using a 5K potentiometer or 0-10V input. The potentiometer is now mounted on the front of the case.

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#58

Debris Vacuum Cowling

Here is a simple 2 piece Vacuum Cowl that fits our 52mm motor. It’s ABS or PLA, so you know it’s going to get broken. Maybe, make the lower piece from NinjaFlex.

It fits a 1.25" standard vac hose. Looking around, I found 12V and 110V for <$35, OR, we might hook into the Big Sucker next door in Wood Shop, to keep the noise down.

Oops, file too big. Here’s the link:

https://www.stlfinder.com/model/vacuum-adapter-cnc-router/2535131

#59

Just wanted to point out that I’ve been editing the sable wiki page with technical details and a TODO list at the bottom.

CNC PCB Router Sable 2013

BTW, I think the page has the wrong name; I believe that is a Sable 2015; however I don’t know how to rename a wiki page without an add/delete.

#60

As per discussion last nite, here’s the company that make all kinds cable guides, flex chains, carriers, etc. Lots of app notes, guides.

https://www.igus.com/

Also need usb extension cable to bring usb B female on Tiny G brd to front panel. This eliminates the need for a usb pigtail hanging out of the control box. Adafruit (# 907) makes one and is available from Mouser.

https://www.mouser.com/ProductDetail/Adafruit/907/?qs=sGAEpiMZZMsMyYRRhGMFNgTd%2byGTBZEL5O0H3XaFTOE%3D