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Birth of a 4-axis CNC machine #8: Control box enclosure - the machine now has a key!

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Blog entry by DS posted 03-17-2014 07:44 AM 1506 reads 1 time favorited 16 comments Add to Favorites Watch
« Part 7: Early Christmas... Motors and power and drivers -- oh my! Part 8 of Birth of a 4-axis CNC machine series Part 9: Control panel layout and wiring »

Now that I have all my power supplies drivers and controllers, all those electronics need a nice safe playground to hang out in away from the dusty environs that the machine will no doubt foster.

At first I didn’t think I could get a box this nice. These water-tight Nema enclosures are big bucks!
But, I found a guy on eBay with a reasonable asking price, ( his wife must’ve wanted to park her car in their garage again ), and I made an offer, sobbed out my poor man’s DIY cnc router story and he took pity on me and let it go cheap.

The enclosure is 20”w x 24”h x 8”d.

It took a bit of effort to mount this. I had to remove the cable chain tray, insert t-slot nuts into the rails without disassembling the entire machine, revise the cable chain tray and reverse the door hinge.

Keep in mind that the box weighs over 40 lbs, it is low to the ground and I had to support the weight and line up the nuts and the holes with one hand while trying to blindly start the bolt into the threads with the other hand. This left me with an achy back and I took several breaks before it got fully assembled.

One nice thing about the Nema box is that it has a removable back-plane panel for mounting all the electronics.

Next up is planning the electrical layout inside the enclosure.
There is a small chunk of change to spend just in the wires. Still will need terminals, breakers, main power switch and 220vac pigtail.

That all will have to wait until next month before I can afford all of that. In the meantime I might be eating bologna sandwiches to get extra money in the budget.

Thanks for following along.

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251



16 comments so far

View DIYaholic's profile

DIYaholic

13814 posts in 1370 days


#1 posted 03-17-2014 12:47 PM

Electronics enclosure??
You mean these things aren’t powered by hamster wheels??? ;^)

-- Randy-- I may not be good...but I am slow! If good things come to those who wait.... Why is procratination a bad thing?

View Dave's profile

Dave

11186 posts in 1535 days


#2 posted 03-17-2014 12:49 PM

Looking real professional.
Where do the hand planes go?

-- Superdav "No matter where you go - there you are." http://chiselandforge.com

View lightcs1776's profile

lightcs1776

3724 posts in 349 days


#3 posted 03-17-2014 01:10 PM

Interesting project, and well done.

-- Chris ** If there must be trouble, let it be in my day, that my child may have peace. — Tom Paine **

View helluvawreck's profile

helluvawreck

15965 posts in 1562 days


#4 posted 03-17-2014 01:13 PM

This is looking great. It’s going to be a fine machine for the shop.

helluvawreck aka Charles
http://woodworkingexpo.wordpress.com

-- If a man does not keep pace with his companions, perhaps it is because he hears a different drummer. Let him step to the music which he hears, however measured or far away. Henry David Thoreau

View Mainiac Matt 's profile

Mainiac Matt

4202 posts in 1023 days


#5 posted 03-17-2014 02:38 PM

OK…. I’m confused….

220v ? for what? Spindle?

1600 oz steppers? are they NEMA 34s? That’s some serious torque for a small machine.

Also…. I see a stack of power supplies. are you setting up each motor with it’s own dedicated PS?

I’m very intrigued by all of this, as it’s not run of the mill CNC zone hobby stuff, and I know that you really know your stuff.

Inquiring minds want to know….. what is the meaning of all of this :^)

-- Pine is fine, but Oak's no joke!

View Mainiac Matt 's profile

Mainiac Matt

4202 posts in 1023 days


#6 posted 03-17-2014 02:39 PM

and while we’re at it…. what software are you doing your 4 axis g-code in?

-- Pine is fine, but Oak's no joke!

View oldnovice's profile

oldnovice

3806 posts in 2063 days


#7 posted 03-17-2014 03:46 PM

How do you plan to keep the electronics cool as some of with get a little “warm”?

-- "I never met a board I didn't like!"

View DS's profile

DS

2131 posts in 1115 days


#8 posted 03-18-2014 05:28 AM

Wow, lots of questions… Lemme see if I can answer some of them:

Hamster wheels work, but, are less reliable and slightly more messy than solid state circuitry.

The hand planes will live in the tool changer carousel and will be part of the aggregate head (as if)

The spindle will be 220vac 3 phase, but will run with a vfd inverter from single phase 220vac. All told, the machine will pull about 25 amps, which is a bit much for 110v wiring.

Yes, nema34 motors. The machine may be small, but i want it to last. Even these motors are less than half the size of the pro models I am accustomed to. Btw, torque can be exchanged for speed. I won’t likely achieve 1100ipm like the big boys, but I hope I’m not limited to sub 200ipm ranges either.

Each driver has its own PS. 80v 8a peak power per channel. There will be a small 5v PS for the controller as well.

So far, there are a couple of contenders for the controller card. The netduino card would use C# and the .net micro framework. The raspberry pi controller can run Linux and you have your pick of languages if you go that route – including php and a proprietary programming language.

Keeping electronics cool—each ps has a temperature activated fan and each driver has a huge heat sink on one face (which I will strategically place so the ps fan draws air across them. )

The main question is how much heat will accumulate inside the enclosure. Quite a bit will transfer from the back plane panel into the aluminum machine frame and into the air. If that doesn’t bleed off enough btu’s, there is a removable panel in the bottom where I can install a filtered fan to pull in cool air into the enclosure.

I am happy to answer any and all questions. Thanks for your interest.

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251

View oldnovice's profile

oldnovice

3806 posts in 2063 days


#9 posted 03-18-2014 04:57 PM

Just one more for the inquisition, have you selected the spindle or narrowed it done to a few?
On my CNC all the electronics, except for the spindle controller, are in a NEMA enclosure sans fan too.

-- "I never met a board I didn't like!"

View DS's profile

DS

2131 posts in 1115 days


#10 posted 03-19-2014 01:54 AM

There is an ATC spindle I could buy for around $3600 without the VFD or the carousel. I have been seeing some used spindles from dismantled machines going for around $1500, so that kind of sets my range. Minimum 3hp up to 5hp or so is what I am planning for.

When the money is sitting around bored with nothing else to do and a killer deal comes up, that is when I will ultimately select my spindle.

As for the enclosures, the vfd will be inside one. Not sure if it will fit in this one or if I will need a secondary enclosure for it, but protecting electronics from the elements is never a bad idea.

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251

View DS's profile

DS

2131 posts in 1115 days


#11 posted 04-20-2014 08:28 AM

I had a thought the other day that I might sell my truck. Since I have this new job so far away and I bought a new car for the commute (38 mpg Altima) the truck has sat in the garage collecting dust and costing insurance payments.

The plan goes something like this:

So, I sell the truck, use the money to finish the machine, use the machine to make money, buy a newer truck.

Any thoughts?

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251

View DIYaholic's profile

DIYaholic

13814 posts in 1370 days


#12 posted 04-20-2014 01:50 PM

Sounds like a plan….
Of course you could just store the truck, save the insurance money. That may not be enough to fund the finish of the CNC though. It really depends upon the value/condition of the truck and whether it is already paid off.

The most important thing is….
Get the CNC finished, as I NEED to see it working!!! ;^)

-- Randy-- I may not be good...but I am slow! If good things come to those who wait.... Why is procratination a bad thing?

View Underdog's profile

Underdog

547 posts in 730 days


#13 posted 04-20-2014 02:02 PM

Well if you’re not using the truck… and you WOULD use the router, then why the question?

Do you really need the truck?

View oldnovice's profile

oldnovice

3806 posts in 2063 days


#14 posted 04-20-2014 05:31 PM

Sell the truck so you can start trucking on the CNC!

-- "I never met a board I didn't like!"

View DS's profile

DS

2131 posts in 1115 days


#15 posted 04-20-2014 09:31 PM

Thing is, I LOVE MY TRUCK! (It’s been paid off for several years now and that helps me love it even more)

It’s been parked for the last six months now and I have to make excuses to drive it on the weekends just so it doesn’t rot in the garage.

I had a heart attack last September and I haven’t taken on any new projects since, so, it just sits there.

BUT, when I do begin using the cnc machine, I will need to haul wood for projects and perhaps haul finished parts to local shops.

When my truck was approaching the 100k milestone, I looked at trading it instead of doing the major service a truck of that age requires. When I picked one out at the dealership and called my wife to come check it out, she stood right next to me (and the new truck) and asked, “so where is it?”

Turns out I had picked EXACTLY the same truck just a newer model year and she just assumed she was looking at my old truck. That’s when I decided I would drive the wheels off the old one instead of taking on the huge debt of a new one.

-- "Hard work is not defined by the difficulty of the task as much as a person's desire to perform it.", DS251

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