Had a transformer built - Buenos Aires, Argentina

[sailfl]

Pablo,

Thanks for taking and posting the video. Very nice job.

Yes, you can never have a large enough control box. For those in the USA, I purchased mine from FactoryMation, Part #: SCE-30EL2008LP, it is 30" H, 20" W and 8" Deep.

Nice flow meter, Pablo.

[PEU]

Finished it Nils:

Routed the borders both sides, then sprayed black and radioactive yellow/green. On the standing side sprayed grippex spray (grip spray by mmp) and then a couple of layers of transparent coating.



On the bottom I CNC'ed a stencil with my initials




I like it

[Gerald D]

Now we need a photo of you riding that board

[sailfl]

Pablo,

Looks great but the second photo is not showing. Thanks for posting the photos.

How long do you think it will look that good?

The next one lets cut a design into the surface and epoxy with colored resign.

[PEU]

Here is second photo reuploaded, I'm sure this week end even with almost 0C temperature we will go someplace to test it with my son and I will snap a picture of me on top of it



Nils, Im not sure, I was generous with the coatings, only time will tell.

[sailfl]

Pablo,

Looks great.

[PEU]

After seeing Nils Control box I discarded the idea of using the one I got for free, yesterday I purchased an IP65 Box of 45x75x16cm (17.7 x 29.5 x 6.3in) I can dance insede of it if I leave it flat on the floor

So far I added to my previous purchases:

1x Control Box
5x gecko 203v
5x pulleys/belts for Castone reductions
10x Lip bearings for reductions
5x lasercut parts for reductions (5x inside and 5x outside)
1x PMDX 125 BoB
1x PMDX 107 spindle speed control
20x bearings for grinding skate and other purposes
75x DIN rail connectors in five different assorted colors
5x 4mm NPN NO open proximity sensors
5x 9802 Motion King Motors

The reason for going 5X for critical parts is "just in case sh!t happens" being 10000km away from the replacements makes me nervous, so the extra unit is for peace of mind

On the Shop construction, there in not much to be shown, very few advances sadly


Pablo

[PEU]

3rd time I nailed it, the flow indicator works like a charm, instead of using a propeller I used small plastic balls, please don't laugh, the ones that small kids use for making toy necklaces

http://www.youtube.com/watch?v=gCS4V-xS7RM

inside the circular pocket there is an extra groove with the form of a curl that helps make some turbulence around the pocket.

Acrylic is sealed with a small amount of silicone, I will make a few more of these, but next time I will use an oring instead of silicone.


This one is part of a mod I did for the machines I sell.

[domino11]

Reminds me of the ones they use on gas pumps in the US! Nicely done!

[PEU]

Continuing from this post about the microwave transformer.
http://www.mechmate.com/forums/showthread.php?t=2956

Quote was 250 pesos/USD62 (copper wire+labor)for a complete rework of the transformer, the guy will remove the primary also and keep only the lamination, I asked 34v20a 9v2a and 4v2a to get 48,12 and 5vdc, based on the preliminary calculations he did, maybe I can realistically get 34v18a.

When I receive it I will have all my ducks in a row:

transformer+capacitor+diode bridge=power supply
PMDX125
5x gecko
5x motors
contactor
din rails
din connectors in assorted colors
slotted cable guides
meters of 1.5mm cable in assorted colors
proximity sensors

I don't have the door switch but it wont stop me to finally do my control box.

[sailfl]

Pablo,

While you got nothing to do while your MM cuts, you can watch the little balls go around. Almost as good as TV these days.

[MetalHead]

Better

[qroger]

Pablo
Greetings I have been following your progress. Here, (east coast of USA), one can buy out-of-service marine containers, 8' x 8' x 40' water tight, steel etc. for. less than $4000.00 US. If allowed, you could stack these 10 high! Somebody is shipping these to China, turning them into apartments, shipping back to England, stacking up as apartment building! Crazy!

Be very careful with your building foundations, especially if you are still thinking basement. Your neighbors all look like they have masonry walls. Here, any little crack brings out the lawyers. I hope you find buried Inca gold and loose diamonds once you start construction.
http://www.coronadomobilestorage.com...ners-for-sale/

[qroger]

Pablo!
I wanted to make sure you know I was suggesting you use the marine containers for your shop, Not for control box! Containers are 8' x 8', 8' x 10', 10', 20' 40' long, maybe even refrigerated. Most of the load is carried in the corners, you can put doors and windows through the walls if you have a torch. http://www.archicentral.com/12-conta...m-kalkin-7881/

[PEU]

There are plenty of these containers here, but I will build a proper shop

Started with the power supply, the guy that was going to rewind my microwave transformer suggested me that for $10 more (for a total of 300 pesos/ $75) he can build a new transformer from scratch, so thats what I got now: primaries for 210/220/230v and secondaries 24/9.5/4

the idea of having 3 primaries is that I can increase/lower the output if I use 210v or 230v (powerline here is 220v)

Here is my ghetto testing of the transformer, my aim was 48v, so Im pretty happy with 47v (tested without load)

Off topic, I attempted to measure with a digital caliper while the transformer was powered and when I aproached it the caliper began to oscilate/vibrate and I was about one inch away, tried other metals and that did not happen, weird and funny fact.

Now I have a question for MMers with finished control boxes, why the transformer is always on the top side? This thing weights 7kg (15lbs) my common sense says it would be better sitting it on the lower part of the cabinet. The reason is heat?

Thanks

[smreish]

My choice for using the top was I wanted to keep the connnections for the mains and the drivers at the bottom. Thus, easier to route short wires to the terminal strips on the bottom than more wires in the cabinet up the sides.

Heat really isn't an issue with the transformer.

Sean

[riesvantwisk]

Pablo,

that looks like a much better price then the toroid for 170USD, my quote for a transformer here in Ecuador was 130USD + tax.

your 47V will drop a bit with load, but nothing to be concerned of.

I agree with Sean, mostly you need the bottom for all cables and indeed heat is not a issue with transformers, if yours get warm/hot like mine transformer did (build in Ecuador) then it's not a good one and you need to return it.

[KenC]

Connect some light bulbs as dummy load & you can measure the loaded voltage. I recon series up a few light bulbs of ~300W total should do the trick.

[domino11]

A parallel combination would load the transformer better. If they are 120V bulbs.

[PEU]

Got my remaining capacitors and also locally found the cabinet switch, not ensto, the brand is Zoloda.

Im trying to settle on a layout, so far this is my choice:



The drivers are in two rows, the row of three is elevated at about the top level of the row of two.

I need to make a PCB for the multipower supply (48vdc/12vdc and 5vdc) to hold the caps and the regulators for 12 and 5v. Im thinking of adding a thermal switch before the door switch.

Suggestions are welcome

[riesvantwisk]

Pablo,

I am sure you won't forget, but I am not seeing a Cooling Fan for under/around the gecko's.

The layout you are using is the 'standard' Mechmate layout, I use the same.
Except that I could place all Gecko's in one line.
Placing them in one line makes it a tad easer for wiring.

I did run the power of the gecko's all on the left site, and the control lines to the gecko a smutch is possible to the right. Either crossing power and control lines, or in parallel at some distance to minimize cross-over signals from power to control.

Some additional detail. My control lines from Bob To Gecko are shielded, but not connected to GND (GND of the BoB that is). Because the BoB Doesn't have a easy place to add shielding for control cables, at least with my 122 type BoB. SO far, I have zero issues, but I don't have a spindle which are more electrical noisy.

Lastly, and I am sure you know... the Bob + control cables will not get grounded to the case, just through the parallel cable of the PC. The same goes for the power supply of the BoB that will not get grounded to the Chassis.

[PEU]

No, I did not forgot, but Im planning going fanless for the geckos, each one will have a piece of 10mm aluminum bolted to them (photo) and this piece will be bolted to a 25mm chunk of alu, IMHO there is plenty of dissipation there to go fanless, if its not enough I would like to read why.



I can put all the geckos in one line, but the space between them is pretty small, so I went for two rows, one alternative to this layout would be to put the top row with the connectors to the opposite side to allow easy connection.

Regarding control lines, what I did when I made my 1st control box for another cnc router was to braid them, same concept as ethernet cable.

And finally regarding BOB ground, yes, there are big notes on the pmdx125 manual about what to do and what not to do regarding gnds

Thanks for the comments.

[riesvantwisk]

Pablo,

Glad you are up to speed there, expected... just wanted to mention...

About the alu block, it's been a been long time since I had to do any calculations on (mainly power supplies), but her is my theory

The block will cool as long as it's cold, but as soon the block get's warm they cannot dissipate the heat because the surface area is fairly small compared to there size.
Even if you put a fan on it, it will take a lot more time untill the heat is removed from the alu block once it's there, I don't know anymore how well Aluminium transports heat...

That said, I just used a 6mm alu plate with a fan underneath and the works like a charm.
The gecko's don't get to warm because the operate mostly in the digital domain,
but I do noticed they need some cooling.

Ries

[PEU]

Bad heat conductors do what you mention, thats why there are cooking pans made of thick cast iron, they keep the heat very well.

AFAIK aluminum is one of the best heat conductors and in the same price range only surpassed by copper and silver. Regarding the Alu 25mm bars I can help the heat spreading by milling slots on them, less alu more dissipation surface, a good treadeoff methinks... just an idea


Pablo

[riesvantwisk]

pablo,

if you make a tube out of them, then you can put one of these micro fan's in the hole
I am very rusty on these subject.... Hope it's doesn't bug you!

[domino11]

Pablo,
The large mass of alu will give you a large thermal mass. This means that when you couple heat to it it will take longer to heat up. The problem is as Ries mentioned is that once it is hot, it is the surface area that will transfer the heat to the ambient air. That is why heatsinks always have fins, or pins, or some surface treatment like that that will increase surface area to help couple the heat to the ambient air. Airflow, from a fan or whatever, will aid in the heat transfer

[KenC]

Pablo, heat is energy & it can't be created nor destroy, since we don't convert this waste heat to other form of useful energy, we will have to dissipate or dump them into the atmosphere.
Since the heat source is encased within the control box heat will have to pass on to the control box in order to dump into the atmosphere.
Without fan you can only rely on natural air convection current inside the box, conduction through physical metal contact and radiation to "pass-on" the heat to the control box external casing & then "pass-on" to the atmosphere.

Thicker AL doesn't dissipate faster, it only store more heat like a bigger reservoir, to dissipate faster, you need more contact surface. and ideal heat sink is one that is zero thickness with huge surface area. hence you see fins on "real" heat sink. Milling your bar does increase the total surface area.

Also remember that paint is not a good heat conductor so it does contribute heat insulation effect. Having a fan increases the convection heat transfer drastically.

Another note, heat is electronics worst enermy... adding a fan helps... a lot... adding one isn't much trouble to you, I'm sure.

If you must do fanless, alternative is to have the heatsink pertruding outside of the control box or use a heat pipe (just a piece of solid metal such as al or cu)to pipe the heat to an external heat sink. It can just dump the heat to the atmosphere without going through the air within the control box & the control box.

[PEU]

OK OK a good gentleman recognizes when he is wrong will mill slots on the alu bar but also will add a fan below them. Thanks for the input!

[Richards]

Pablo,

1/4" thick aluminum is sufficient, but I use 1" aluminum at my test bench. The Geckodrive G203v are usually used with motors that can pull 4.5A and they hardly get warmer than room temperature. The aluminum bar is about 16" long X 3.5" high (I'm away from the test bench, so I can't measure it). It was just a piece of aluminum that I had on hand.

Thinner is better and fins are best, but unless you really pull some amps through your motors, I don't think you'll have any heat problems.

[PEU]

But you do use a fan or not Mike?