Monday, October 21, 2013

Change of Plans, for the Better

Last post I talked about the jacked-up mill spindle.  My plan was to find a used R8 spindle to replace the bent Kwik Switch 200 spindle.  Well I found a better option.  Midwest CNC is a company right here in Indy, they rebuild Hurcos from this era and are very familiar with my machine.  They sold me a used Kwick Switch spindle in good shape, with the bearings.

When I picked it up Mike at Midwest had the spindle on a surface plate and showed how he measures the run out with a 10th indicator.  Very cool and the run out was only 2 tenths which is within factory specs for a new spindle.  Add to that it has a new nut, so it is kinda brand new to me.  Best of all he showed me the process of removing the old and installing the new.  Turns out to be pretty straight forward, and well, the job is finished and the mill is up and running.  I trammed the head and set the vice last night, then started making chips.

A video just for fun, the replacement spindle going into the quill, lifting it in using the knee.

video




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Thursday, October 17, 2013

Triumphs and Setbacks

I found some problems with the mill, the spindle is out way out, like .008" out.  And not out of round, bent, I think.  See the video of the indicator.  And the problem gets magnified the further down I go on the tool holder.
video

My friend Fazni came Saturday at about 3:00.  Went through the mill and lathe.  Even with the bent spindle it is mostly good news.  He really knows how and where to use an indicator to figure what is out and what is not.  He used it to check the backlash on the ball screws, there is pretty much no back lash.  And he said the ways and screws are in great shape.  And the mill overall is a really nice piece of American iron (even though it was cast in Spain!).  The only thing wrong is the bent spindle.  We are speculating it was crashed hard and that's why it was taken out of service.  They probably didn't want to mess around replacing the spindle, so they sold it.  That just means we get too!

We talked about several hacks to fix the spindle.  But looks like the right way will be to just bite the bullet and replace it.

It has an Universal Engineering Kwik Switch 200 spindle.  A lot of people like these.  But for my purposes I think it will be easier/better/cheaper to replace the quick change setup with a more standard R8 spindle. And I can sell the quick change tool holders I have to probably more than pay for the replacement spindle.

Once all the mechanical stuff is set we can look at adding the cnc stuff back on.  The tight ball screws mean everything, cause we don't need glass scales for position - saving cost and complexity on the controls.  I am betting it will be Christmas, maybe spring before all the mechanical stuff is fixed and everything is setup. So it will probably be next Christmas before I get the CNC stuff added.  But that's OK, just got to keep plugging away.  It was April 2012 when I brought home the first 2 axis CNC table project.  Back then I said it would take six months to get running.  That turned out to take a year, and it is still not much of a usable machine.
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Tuesday, October 8, 2013

Getting Carried Away

I am still getting the shop set up, which has side tracked me from getting the door secured, which has side tracked me from working on the digital control board for the door opener. Life is funny.

What I have been doing is painting, cleaning, running electrical, lights, and such. All stuff that seems a little over the top for what is really a garage, a place to park a car - not a nice car - and a bunch of bikes and plastic kids toys.

 But is there a good reason to do all this, I mean is it better to work in a clean organized room. I hope so, cause it seems like I am spending all my time setting a place to do fun stuff and am never going to get to do the fun stuff.
Small rotary phase converter for powering the 3PH machines
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Thursday, October 3, 2013

Lathe is Finally Home

The lathe I bough way back in February is finally sitting in the garage, right acoss from the mill. Hoping to get power to them this coming weekend. Share on Reddit!!!

Wednesday, September 25, 2013

New Home for New Toys

I have put off work on the door controller for a bit to finish-up the garage.  Exterior is pretty well finished.  Inside is getting dry walled today.  And power company is coming to connect the meter soon, maybe this week.  Soon we'll will have a place to use our new Hurco knee mill, and the lathe that has been waiting in the wings since March.  Not to mention the woodworking machines coming up from the basement.  Nothing else to say, I'll let the pics do the talking.





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Monday, September 9, 2013

Foiled by 3D Space, Again

I etched the first version of my launchpad breakout board.  The etching process is a pain, and the results are not great.  I want to go back to machining the boards - it works well when everything is setup correctly.  But having a physical board in hand and being able to place the components in the real world served it's purpose.


Fig 1 - etched board with components placed

Fig 2 - Lauchpad placed on breakout board

Fig 3 - Kentec touchscreen booster pack place on top of the launchpad

It's hard to see in the photos, and I guess hard to see in 2D, like when designing using EagleCAD, but the stack height is wrong.  The big black relay on the upper left side is to tall, it prevents the touchscreen from seating completely.  I think it is an easy fix, I have room to slide the whole launchpad/touch screen assembly over to give clearance.  Or I can flip the relay to the back side of the board.  I think either will work.  

I guess what I am wondering is how could I have foreseen this? Should I have built a full 3D model?  That would probably have been more work that etching the prototype and finding the error, as I did.  But finding the problem at this stage feels dirtier, like a mistake, versus what could have been finding the problem as part of a robust design methodology.

But, there is another problem, one a 3D model would not have revealed, least not to this novice.  I didn't realize some through hole components like the relays have to be soldered from the opposite side - they sit flush to the board.  So even if I had caught the relay stack height problem I would still be making changes to the board layout and re-making the board.  Lets call it Opus 2.

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Tuesday, September 3, 2013

Quick update and some notes to myself

I was stoked when I got back from the TI training and setup the touch screen for the door controller.  I thought was just about done with my hardware prototyping.  Nope.  Somehow I could not get cheap-o RC receiver to work with the Launchpad.  Did I actually do some damage when I botched the initial touch screen setup?

Let me back up.  I was using the RC transmitter and receiver from a cheap RC kids toy as my garage door opener.  I just connected the 4 pins from the receiver to four pins on the launchpad a BAM, I had a remote door opener.  And it work, no really, there is video to prove it.  But some changed, for some reason the Launchpad cuts in and out when I connect all 4 ins from the RC receiver.  And they are not, I mean they are 0 volts.  When I say cuts in and out I mean the board seems to reset continuously.  I put a amp meter across the power jumper and the current just bounces on and off.  And worse even with only a couple of RC inputs connected I was no longer able to consistently read ON or OFF on the LP pins.  One thing I noticed was the RC rx pins were only reading about 2.5v when they were ON.  This seems weird, and I don't think it use to be this way.

Well I kinda wanted to run this problem down, but I also have to keep an eye towards the bigger picture.  I really think I prefer having my inputs setup with pull-up resistors like the LP buttons.  So just the switch down to ground to read ON.  And the RC toy remote was kind clunking and silly looking.  So I ordered a generic remote control switch with a nice small remote for the car.  It simply trigger a relay, so I will just use that to ground my input.  And it is only 1 button, which will simply the connections, the PCB, and the use.

But note to self, I need to better understand pull-ups, pull-downs, and open drain.  And I need to better understand how to trigger a pin as high, I mean is 2.5v enough?  What happens when you apply 5v?

Anyhoo, I have moved on.  The hardware is working and the basics of the code are there.  I have all my inputs and outputs accounted for and working on the bench.  At this point the project splits in 3 directions:
- Making the breakout board and enclosure for all the controls.  Just generallin wraping up the electrical related hardware.
- Coding the final control program - need to account for all combinations of buttons being pushed, door state, stepper motor acceleration, etc
- And the mechanical side, need to finish the drive train design and get everything mounted, motors, gears, limits, locks/latches.

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