Machining Aluminum #122 - Sydney, Australia

[racedirector]

Yup.... http://www.mechmate.com/forums/showt...t=2398&page=29

[Tom Ayres]

Ancient Chinese Secret, I asked him for DXF's but he does have a reference in my thread referring to his thread location. For some reason I thought his was #173 or #273 or something like that. Take a look you might find it.

[racedirector]

Milestone today.... construction is done! No more welding, drilling, tapping, cutting, fitting. Garage cleaned, base totally stripped down, up on axle stands all ready for undercoat and paint. All other parts piled up awaiting their turn. Roll on tomorrow!!!

[darren salyer]

Awesome, Bruce!!

[pblackburn]

So Soon?

[racedirector]

Got most of the base undercoated today before I ran out of undercoat! Off to buy another liter tomorrow. I used a small HPLV gun, first time using one and it went very well. Will continue to use the gun for the tricky to get to places but will switch to a foam roller for the flat expanses.

Was trial fitting everything into my control box while I wait for paint to dry and found the 500x500 just isn't big enough, especially since I have 4x AM882 drivers which are a tad bigger than DM drivers or Geckos. A quick call to the supplier and I can swap the 500x500 for a 600x600 by paying the difference .... phew!

While contemplating wiring I have been trying to nut out the 24V circuit supplied by jhiggins7 (John) and don't quite get where the line from the relay to the contactor to shut things off goes 13/14, A1/A2?. John, if you are listening can you clarify that connection please? Also, where are you guys getting the main machine connections from? I found a diagram here http://mechmate.com/forums/showthrea...7&postcount=75 but was wondering if there is anything else.

Cheers

[racedirector]

OK, I am an idiot and should abide by the saying of RTFM. John, cancel that request of explanation, if I draw a little box around your relay drawing it all makes sense.

[jhiggins7]

Bruce,

I'm happy to see the progress you're making. I'm also happy that you worked out the issue you were having. Several people provided diagrams of the control box, early on, that helped me a lot. You might consider posting a copy of the final circuit you come up with for your MechMate. I'm sure it would help any future builders that consider using 24 Volts for the Control Circuit, especially any builders in a 240 Volt environment.

[racedirector]

Thanks John, I'll try and put something together when I work it all out. I am implementing an alarm circuit for my AM882 controllers, they trigger an alarm under certain conditions if a stepper gets out of synch so I want to capture that instead of wondering why things aren't working right. Add to that any alarms coming off my Hitachi X200 plus relay control by the inverter to run the cooling pump. Lost of electrical drawing to do and ideas to "steal" of various people around the net.

I am learning alot about the electric side of things like finding out my decision to use circuit breakers for my controllers instead of fuses. Turns out that running DC through an AC circuit breaker doesn't really work, at least not at the same amps. So they were a wasted purchase and I have since bought some DIN mounted fuses instead for the task.

[racedirector]

Electrical question guys......

I bought a 9VAC toroid to make my 24V power supply. After a few false starts I thought I had stuffed it so I bought a second one from another source. The first one was 20VA, the second one is 30VA.

I built my supply again this time with the 30VA one only to find when it went through rectification it was producing 28.6 VDC, not 24. So I tried the original one again only to find it worked fine. It produced 24.6VDC. Now I am lost - why would one produce more the the other when they are both supposed to be 9VAC. I am attaching the data sheets for each one, the first toroid (that produces 24VDC) is the MT2082 doc, the other is the one from RS Components that produces 28.6VDC. Can anyone see whay this may be so? Should I be sending the RS one back and asking for another? Any ides/help would be greatly appreciated.

EDIT: I forgot to say I am building the 12/24V supply first brought to light by John - the 24V is for my E-stop/safety circuit and the 12V will be for my PMDX 122 so the voltages have to be close to what I expected.

Cheers

[KenC]

Too lazy to go through the pdfs, I presume youu series connect 2x 9Vac secondary terminals.
2x9xsqrt(2)-1.4V=24.052V (1.4V is the ball park voltage drop across the rectifier we use ingeneral but a few V variation won't do any harm,)
If you measure the Vdc without load, its the No-Load Voltage, which is not much use unless you wish to measure the transformer's internal impedance. & the result depends a lot on coil impedence, bigger VA usually reads more.

The useful measurement is made with a load connected eg. resistor or a light bulb between + & - .

[racedirector]

Thanks Ken, yup am wiring in series. My original measurements were with no load so I connected up one of my 24V fans plus put a 24V LED on the 12v side and the second toroid was still showing well above 24VDC. The first toriod however settled down to 24.5 odd on the 24V side. Oh, and I have a 2K2 5W bleed resistor across each of the outputs.

[KenC]

You done well.
BTW, 2k2 bleed resistor 24/2200=~10mA, 22K resistor would be more appropriate. & connect it across the reservoir capacitor is most appropriate.

[racedirector]

Painting has started, base done.

More parts awaiting topcoats - gantry red, rails black.

Control box layout now fixed, most things in place permanently just waiting to be wired.

More elephant disappearing, hopefully soon to be gone

[darren salyer]

Very nice work, Sir.

[KenC]

Great progress!
No more heavy lifting

[IMMark]

Nice looking machine Bruce....good luck!
Mark

[danilom]

Be sure to report performance with those AM882 drives
I got them too last week and will be testing them soon

p.s. they are a bit too close, and I prefer mounting them horizontal and blowing air from side trough four of them at once

[racedirector]

Thanks guys, more painting completed yesterday and the machine is slowly going together, my wife was actually excited to see things going back on

Danilo, I have tested the drives on my old machine and they work well. In this control box I will have an 80mm fan just above each pair blowing air down the fins. Just gotta figure out a mounting method.

[Alan_c]

Heat rises, so you have them mounted the best orientation, but I would force the air up to help the natural movement of heated air...just a thought

[racedirector]

Alan

I will also have an 80mm fan drawing air into the box through an industrial level filter and exiting the box via another filter. If that doesn't work out I will move the 882's up a little and put the fans for them as suggested.

Cheers

[Bazza]

Hey Bruce
Man thats coming along well!
Moved all our gear up to South West Rocks, settled in now
Purchased all my steel but won't start putting it together until I throw up a workshop (getting quotes this week)
Keep up the great work fulla
Well done
Bazza

[Rapid]

Hi Bruce ... just read your thread. I really like your base with 6 legs and cross bracing that will make the space under the table useful for storage. I also like you combination welded and bolted assembly which can be broken down for easy transport.

That is a cool color... looks like Lipstick red (did your wife help you choose it ?)

[racedirector]

Thanks for the kind words Rapid, appreciated. Funny you should mention storage, thats exactly what I was trying to accomplish. Attached is an updated pic with more progress.

BTW, the colour is called Delicious Red by the Wattyl company here in Aus. It is actually brighter than that pic shows, the lighting washed it out a little.

To progress... as can be seen in the pic the rails are now painted and the fitting of the X has started, spoilboard and the X cable chain shelf attached. More things painted today, motor mounts and brackets in black. Ran out of time to paint the gantry and Y car, that's tomorrows job. While I wait for that pint to dry I'll start wiring up the control box.

Cheers

[Fox]

You must have done that on purpose; but I would flip back 2 of the drives as the heatsinks (where the drive should lose most of it's warmth) are actually warming each other now with their hot air.
Mounting them horizontal is not recommended Danilo, for heatsink effectiveness although with proper forced cooling it can be done.

[racedirector]

Fox, there are plenty of examples of these drives in that configuration with fans blowing down the fins to remove any heat from both drives simultaneously. As stated I have 2 24V 80mm fans yet to install above the drives blowing directly into the fins thereby removing any heat into the flow of a 3rd 240V 80mm fan circulating air within the box itself. In the side of the box beside the drives will be a filtered outlet for the air the first fan draws in from outside, that being locate diagonally opposite to the outlet but again pre-filtered.

Cheers

[pblackburn]

Bruce, nice work on your build. You can mount the drives in whichever fashion you wish, it is your machine build. I am a big believer in not building heat inside a panel intentional so I prefer mounting the heat sink outside the panel box with a cutout for the drives to mount. Filtering air through a enclosure with shop air used to be fairly common with machinery but now most OEMs are moving to larger enclosures with air heat exchangers because filters do not capture the fine particulates and dust still is able to accumulate do to static build up causing premature failure of devices.

You have a nice layout with wire duct. Do be careful on the route that you run your stepper motor wires. Wire duct does allow noise to affect your devices more. I just went through this were I work at. We use steppers to adjust weight dials in a process. The installer used shielded wire and the drain was properly connected. The problem was they stripped the jacket and braid at the cable clamp entrance to the enclosure. The wires were only 18" in length exposed to noise but it was enough to fault out the drive every 10 minutes or less. After trying to isolate which device was causing the problem for about a week we finally found it and standard noise filtering and transient tamers did not work and found the easiest solution was to remove the cable from inside the duct to outside the duct. This stopped the noise generated fault and has be running fine ever since.

[racedirector]

Thanks Pete

These drives are a little different to geckos and every one I have had hasn't actually got that hot. I was running these drives on my old machine at 75VDC and they never even got warm, the fins were still cold to touch. On this machine they will be running at 50VDC so I assume that with the additional fan assist I shouldn't see any problems.

I hope I don't have any issues with the duct. I have sorta planned a major separation of voltages/tasks in the box - the centre vertical duct is for all the low power things and the left hand vertical is for all the 240V routing. There will be very few places where any of the two come in contact so fingers crossed it will all be good. Oh, and I have no VFD wiring coming anywhere near this box, the VFD will be living in his own little house next door to this one.

[Fox]

Ok.

As stated I have 2 24V 80mm fans yet to install above the drives blowing directly into the fins thereby removing any heat

Below or sucking would make more sense as you are now fighting nature (hot air rises). You also placed you drives in the hottest area of your box (top). Not bitching at you just trying to help. Everything is possible with forced air, but strategic thinking already helps with cooling.

[racedirector]

Thanks for the input Fox, I'll take all that under advisement. I did base the layout of my box on multiple examples on other forums and none that I know of had any problems relating to heat. If mine happens to show excessive heat from the placement of fans, drives or positions I will rearrange it.