Red Dragon update

[Tom Gralewicz]

A bunch of board swapping shows that the problem is the inner circuit board.  We have 2 working ones and 3 bad ones.

We took one apart and found some blown transistors.  New ones are ordered and we can try to fix a board.

The board by itself is listed for $1500 to $1900 on e-bay.  Although I did find one for about 800 euros :-)

Tom Gralewicz

Chronic Maker

(414) 380-1716

milwaukeemakerspace.org

[Tom Gralewicz]

The new parts came in and I swapped all the transistors on the board with the burnt ones.  I also test as may of the passives as I could.

Powered it up with the new transistors and as soon as they were energized they smoked - its been that kind of week.

I have more parts if someone else wants to take a shot at fixing it.

Potential problems I can imagine:

Bad transformers - they don't show shorted or open but its possible that when the high voltage is applied they arc.

Problem on the larger board this ones plugs into:  Power, driver, shorts etc.

I can find a few replacement parts on line:

Module with burnt transistors  $120  http://metalmedixs.com/JH-414CS.html

   If the main board is the problem we would just burn this out again

The whole board we know is the problem  $1500   http://www.ebay.com/itm/Yaskawa-CACR-IRCB-30SB-Circuit-Board-DF8102058-B0-CACR-IRCB-Power-Supply-/140713547567

Buy a complete drive  $2500  http://www.ebay.com/itm/Yaskawa-Drives-AC-Servo-Yaskawa-CACR-AC-Servo-Drive-CACR-IR15SB-PZ4-/131357487392

Get one of ours repaired $1200  http://www.precisiondrives.com/CACR-IR15SB.html

The alternative is we give up on the Mitsuura, sell the boards  and try to buy something newer.

  

Tom Gralewicz

Chronic Maker

(414) 380-1716

milwaukeemakerspace.org

[The Fool]

It sure doesn't sound very promising.

Larry Andersen

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[Joe Rodriguez]

Tom and I have talked and I will take a drive to a shop near me and see what the options are with them.  In the mean time if anyone wants to try or suggest any other options, I would like to hear it.  If we give up on the  red dragon, it may be a while before we could get something with its capabilities we can afford.  If anyone has any leads on where to get a mill for under $5000 I would like to hear about that too.

Thanks,

Joe Rodriguez

[Brent Bublitz]

It may be a crazy naive question, but how hard is it to build out a custom control solution? We have built out CNC systems from the ground up before, is there something about this setup that prevents that? 

[Tom Gralewicz]

Control is easy and the existing control works.  Motors and drives are the expensive part - and the part that is broken.

Steppers won't work, they are just too small.  The existing system uses AC servo motors around 1hp each.

In addition, reverse engineering and controlling the tool changer would take a lot of effort and time.  Without a tool changer we are better off just running the Bridgeport in CNC mode.

Tom Gralewicz

Chronic Maker

(414) 380-1716

milwaukeemakerspace.org

[wwill...@wi.rr.com]

Let me see if I got this correct:

"A bunch of board swapping shows that the problem is the inner circuit board.  We have 2 working ones and 3 bad ones.

We took one apart and found some blown transistors.  New ones are ordered and we can try to fix a board.

The new parts came in and I swapped all the transistors on the board with the burnt ones.  I also test as may of the passives as I could.

Powered it up with the new transistors and as soon as they were energized they smoked - its been that kind of week.

I have more parts if someone else wants to take a shot at fixing it."

So the 2 working boards were in the position that the repaired one smoked in and they survived?

If so then get one of the three repaired.

Bill**2

[Tom Gralewicz]

Yep.  One board is bad.  If I swap it with another working one the error moves with the board.

[Andy Amrhein]

If I find time, l will take a shot at trying to figure out what is causing the transistors to release their magic smoke.  Not sure if I will be in tomorrow though because not feeling good (apparently the transformer smoke was not the cause of my respiratory issues Tuesday night).

Andy

[James]

An open table CNC like the one in the machine shop for a repair project might be a cheaper alternative to a full on machining center.  I ran a newer version of that Partner/Miltronics and it was great!  Tech schools tend to have them due to their small size with both manual and CNC capabilities.  They go up for sale sometimes.
I am almost sure some do have tool changers.
Just a thought.

 

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Subject: Re: [MakerSpace] Re: Red Dragon update
From: bigjoe...@gmail.com
Date: Sat, 14 Nov 2015 16:35:29 -0600
To: milwaukee...@googlegroups.com

[Ron Bean]

BTW: Autodesk's Fusion360 has an option to generate toolpaths using an
advanced machining technique (I've forgotten what they call it,
something like "adaptive machining"?) that is designed to (among other
things) minimize stress on the tooling, which allows machining of steel
on low-end CNC machines.

There's a guy at PS1 who's been using it to machine steel on their
ShopBot, and I've also seen a brief demo of machining steel on an
X-Carve (which is a slightly upgraded version of the Shapeoko2).
Precision is not as good as you'd get on a real machining center, but
it's pretty impressive.

Fusion360 is free for noncommercial use. The guy I mentioned above is
also writing python scrips to generate his drawings in Fusion360 using
it's API. He says that this avoids some bugs in the program when
modifying an existing drawing-- he can just change the script and
regenerate the drawing with the changes. Several of us are practically
begging him to do a class on it.