1st and 2nd of april most of us will be at a technical theatre conference in kansas city. we are in session through the end of may.

sean leaves tomorrow, and we are currently scheduling his next trip.

let us know when you will be visiting we will be happy to arrange a tour

Cool, I know where Kansas City is. Maybe we could get together for a beer.

...sounds like a NCSA D&P meet up with the crew traveling is in order. Good luck and have fun in K-city. Eat some good BBQ for me :)

We had our final class of the term today. Made short lists of things left to do for both the machine and the control. Next week is spring break. We may get a little done but are not going to push it. When we get for next term we should be able to polish off the lists pretty quick.

We've done a layout for our cable chain and put most of the finishing touches on the control cabinet. As soon as we get the holes drilled and tapped into the table base we will be able to finish wiring the control cabinet and getting power to the motors.

Ben, I just noticed your rails are mounted on rectangular tubes. Is that more cost effective or just what was available? either way I like the "out side the box" thinking... :)

moco, feel free to jump in with corrections but I think the idea was to build the table base out of the same stock so all our cuts and scrap were of the tame type and also to add weight to the base. I believe we used 2x3" tube. I know the thicker wall of the tube was intentional so there is more material to tap.

We work with tube most of the time, are set up to work with it in our metal shop, and found it easier to source than the channel. We also found it a fairly easy process to build the frames this way and are pleased with how true the frame is with very little adjustment. The tube is 2"x3" 1/4" wall. The thickness let us drill and tap it no problem. We do like having the mass of the base, while it is primarily a torch we will the capable to mount a pindle or router so we wanted the mass. We matched the rest of the tube because themachine is giong to move around from storage in one part of the shop, to use in another. The gantry tubes are 2"x4" 3/16" wall. We wanted the mass of the gantry for the same reason. the 3/16" is still tappable with out a backing strip. Does mean we went with geared steppers for x and y though, x to handle tha mass of the gantry, y to match x. The 2 z steppers are direct drive.

in our business we spend a great deal of time thinking outside the box, to the point that we usually just forget there is one entirely.

nice pictures ben, thanks

What box? :confused:
Well for what it's worth, I like it... what originally caught my attention was the build area,
Winston-Salem
I have family in the Roanoke area...
I would be interested in seeing pics of the dual Z you have... I can see it in my minds eye but its still a little fuzzy... :o
thanks for the in depth reply :)

It's pretty hard in these pictures to see what's really going on in the z-slide but maybe this helps a little. Next time I'm over there I'll get some better shots.

Wiring!
 

Hey moco,

I was just curious about the layout of your enclosure. I was wondering why you are using so many small sections of din rail? Also it looks to me like the control boards you are using are mounted over the power supply transformer? I can tell you from personal experience that you will want to mount it as far away from that as possible.

While i haven't built a mechmate, yet, i have done many electrical wiring projects for some very large installations, and have had BIG problems with things like this. Even with very small control transformers, generate a tremendous amount of noise, which we all know is really bad for electronics.

I think you all need to re-think your control box layout, and distance the PCB's from the high voltage, especially the transformer!

The z-axes are 2 spiders, back-to-back.

engineer, funny you mention that because we actually are a bit worried about it. We did a lot of talking about the layout of the box and finally settled on raising the BOB up over the transformer and shielding it with a steel plate would be okay for a first try. If we get a lot of interference we will move it though.

as for the small sections of din rail: we happened to have small sections so we figured we might as well use it to our advantage and spread things out into places where they fit easily instead of trying to squeeze everything in to one large section. It also helped us a little bit with the "flow" of the box and moving power around it in a way that made more sense.

we'll definitely heed your advice and see what comes once we get power to everything.

shielding
 

A "second try" might involve buying a new bob. Your steel plate under everything will not do much, unless it makes a seamless box around the whole thing and ground it. This will shield the boards from EMI.
In the specific instance that i had a problem with a PCB next to a transformer, much like yours, upon power up the EMI from the transformer actually caused an arc across an opto-isolated part of the board, and fried it and everything connected to it.

Not saying that it will happen to you, but just a word of caution.

Thanks for the pics Ben. I see it better from those pics. But more detail may be of interest to us all... :)

Teacher-of-the-day here.
The Transformer location has been a great topic of conversation in our MOCO (Motion Control) class. Since were in a learning environment, the choice to go ahead with space allotted placement is being taken. The enclosure was a found and repurposed item, so our original requirements were compromised.

The class has located a small NEMA 4/12 Box as a back up solution to "remote" the transformer outside of this enclosure and piggybag on the the bigger box. Thus, rendering the EMF in a box and grounded separately.

Sometimes it's hard to explain EMF and inductance interference until you experience it first hand; Thus, learning :)

Thanks for the comments MM forum - keep them coming!

Regards,
Sean

motors bench tested
 

after being pulled away for some productions, a conference, and a couple other projects the team has been able to get back together and do some nice work on our cnc project.

the motors have all been spinning hooked up on the bench.

the table is in very good shape, awaiting a couple prox target holes and a nice coat of paint.

very pleased with the progress of the team, nice work guys!

In the first picture. you have one radio broadcast?

don't know what you mean by radio broadcast.

The racks (19in?) in the background in the upper left appear to house the type of equipment used for broadcasting radio ... a few years back.

ah
 

ah that would be this. we are in the process of setting this up as a test station for some of our equipment. i am not sure its original purpose, we likely picked it up surplus and are converting to our needs. we do a fair amount of that in our business

...and the best part - all this gear is in perfect working order. Even the tube based freq counting unit on the upper right. Ahhh - surplus. :)
The silver 2U unit that is set vertical in the center of the Rack is a Goddard Controls AWU (automated WINCH unit) Very sophisticated analog limit and position controller. The "essential" basis of theatrical automation and control used on broadway for years. Of course, it's all PLC now, but a great system that is still used today.

Drool ...

getting closer
 

hey all

we have got the frame painted, reasembled and are in progress wiring it all up. we need to ring out all the wiring before we power up. we also need to complete the cutting surface. Images show the overall machine, a close up of the two z slides back to back and a shot inside the tube showing the bolts for x rails.

Great progress class. Can't wait for commissioning day next week!
Cody, I see you got the back-to-back clearance for the proximity sensors worked out.

Note: Since the class decided to make this a 2 z machine, they painted the plasma slide (RED) for FIRE! and the utility z axis black for visual clarity when operating the machine.

Nice work.

Sean

...and the MechTorch machine is cutting. A few bugs, but working pretty well!
Good job class - A+

Congrats to the Class and to Sean! The first MM Plasma. MechTorch! :)
Hey Sean, where are the pictures and logos? :rolleyes:

we are holding off on the logos until sean joins us next week. working right now at ironing out the bugs.i will get more pictures next time i am over in the shop.

getting closer and closer
 

machine keeps getting closer and closer. these are very excting times around here. these are also very busy times around here. we are trying to wrap up this project and a few other ones we have going on to finish up our school year.

I am impressed !!! Congrats ..... Metal Smoke is dust ehhh ? I want to see a video... Sent you a PM as well.