Second Mechmate OC 12'x6'x12"
 

Hey all,

Well, I'm back in LA, technically Orange County for a bit, and as I promised, I am going to start building a new Mechmate for my time when I am stateside building sets.

This particular machine is based off my last one, except a tad bit smaller length, but a bit wider width. 12'x6', on 8" Channel. It's a bolt together machine again. I've not ordered parts yet, but am about to start.

It's going to be a rigorous schedule but should be pretty productive seeing as how I have just finished my machine in New Zealand and have a few guys to help.

Cheers,
Chris

Sweet. I'll be watching with interest. Good Luck!!

When you get back to Auckland, fellow #5 builder LEKO is in your neighborhood this year. He too is the movie set building business.

Well the build has begun.

Metal delivery, except main beams, which are coming tomorrow. Most stuff has been drilled or marked today. I'm thinking of doing a Ball screw Zslide this time, does anyone have a plan for that? Guess I could whip one up real quick.

Anyhoo, I've procured a great team of crafty guys helping me.

Cheers,
Chris

http://s7.postimg.org/47e62jcfv/9883...67342622_n.jpg

Well, the first channel came, and was kinked so i sent it back. It was really bad. The next is coming tomorrow. I had to order 10" channel, because the channel here in America is too short on the flange. So it wouldn't mate up to my 3" leg pieces.

All my parts are ordered and trickling in.
went with PK296 B2a SG 7.2 again.
For a BOB, instead of the PMDX products, I opted to try a new Korean bob with 6 axis control, several relays, and ESS support. The board arrived today and looks very clean.

Went with a 600VA PS. Toroidal again, same voltage as my last machine 40, just more amps for one more driver when I expand.
Gecko G203v x4
3kw Chinese Water cooled spindle from Qlandingsatisfaction on ebay. The thing came today, it's huge! He's very reliable and quick.
Went with 16GA wire 4 core for my main wire.
Echain from Chai which is arriving tomorrow, again very reliable.
Control stuff from Automation Direct.
All good stuff, quality machine, very excited. Nearly all holes are drilled, all cuts are finished, Welding begins tomorrow. Well on schedule.

Next week, Table final assembly, and Electrical. I plan to have it finished by end of next week.

Cheers,
Chris
http://s18.postimg.org/9135qfge1/IMG_2336.jpg

http://s18.postimg.org/5wshtmzll/IMG_2337.jpg

http://s18.postimg.org/6xsqirgl5/IMG_2338.jpg

Impressive schedule. I'm in the preliminary stages of a second machine myself, but don't think I could build that fast.
How about a review of the BOB after you've used it a bit?

For the well sorted about machine build, it really only takes about 2 weeks if you have all the stuff in a pile. Great to see you making progress.

Cheers.

Thanks guys,

My goal is to finish the machine before Mike updates this thread to the construction started but not yet cutting yet forum :p. I had a bit of difficulty with my Ycar this time because it was a tad bent, so the roller mount parts didn't line up right and for some reason during welding 2 of the roller holes lost square by 1/8 inch, as in one hole is higher than the other. I'm thinking of grinding out 2 slot welds to correct it as I've not yet turned over to weld the other side yet. Any ideas? Haven't seen what the roller adjustment slot is but I'm sure I'll find it. Is this a slot that is in the hole?

The rest of the build is cake. Second time around is definitely easier.

Here are some pics. I have a great crew helping me. 5 people make it go fast. Very fast. The build will be finished this friday, or sat. It will only be primed but that is ok.

Thanks,
Chris
http://s15.postimg.org/arhv5du9j/IMG_2339.jpg http://s15.postimg.org/ljau6qkc7/IMG_2342.jpg http://s15.postimg.org/4vnxhzeyf/IMG_2344.jpg

http://s15.postimg.org/va85wpit3/IMG_2346.jpg http://s15.postimg.org/84xrapdo7/IMG_2348.jpg http://s15.postimg.org/tijsfjotz/IMG_2353.jpg

http://s15.postimg.org/v6ixu72pj/IMG_2356.jpg

I'm pathetic, you're about to finish your second in the time I turn around:o But this is good news for you, hope you don't run into anymore snags.

:p

Where did you source your laser cut and bent parts?

I had a local company do it for me in Santa Ana. there are a lot of Laser part places here.

Anyhoo, I'm wiring up the machine now, and have stumbled across a bit of a question. I think I may know the answer, but wanted to confirm prior to melting anything...

My toroidal has two primaries, it's a 625va toroidal. Do I wire them in Parallel, or series? The wires are blue and grey for one side, and Vio and brown for the other.

The other question I had is my motor output only has Stp+, Stp-, and Dir+ Dir- and I'm using G203V which take Dir, Step, Common. Where do I pull the common from the BOB, the Gnd?

Thanks!
Chris

Are the primaries 120V each? If so then if you are using 120V in then parallel, If 240V in then you would want them in series. Make sure to get the phase of the primaries correct.

Hey Heath, the primaries are 120v each. I was just going to wire them parallel but wanted to make sure. It's in order from top to bottom:

Blue
Grey

Violet
Brown

So just to make sure, it's blue to violet and grey to brown?

Thanks

That sounds right, do you have a datasheet for the transformer to be sure?
Or do they show a schematic on the label? parallel would be for 120V source.

Yeah it's as follows:

Blue 120v
Grey 0

Violet 120v
Brown 0

Thanks Heath!
Chris

Ok, I'm having some difficulty with this power supply. For some reason, when I rectify the output of the secondaries, I am definitely getting the same voltage as the AC side (30v), actually 29.8vdc, and I should be getting 42vdc (1.41x). Then when I plug in the caps, which are wired in parallel they are frying the rectifier. The caps are charging up though. Could this be because my primaries are out of phase or something?

Here are the photos.

Thanks in advance for any help.
Chris

[IMG]http://s17.postimg.org/v2m52077j/IMG_2365.jpg

http://s17.postimg.org/j8ee4d8xr/IMG_2366.jpg

http://s17.postimg.org/xxz88vb7j/IMG_2367.jpg


image hosting over 2mb[/IMG]

What is the AC voltage before you plug in the rectifier bridge? Probably a defect rectifier, rare occasion, but it does happen.

its 30v ac, tried with 3 rectifiers, same output, 30v.

Chris, what is the white wire? It looks to be connecting the 2 sets together? You should only have (according to the transformer) violet+blue and brown+grey connected to either side of the rectifer - well that how I understand primaries in parallel.

do you have 30vac on the black red? or orange yellow?
that wiring look fine to me. is rare to see a problem on a "profeccional" transformer this days.

btw.. huge tansformer you can power two mechmates with that..

Shop Space
 

wow I envy the shop space

Hi Guys, Thanks for the response. We still have not figured it out. There is some problem, but not sure what yet. The transformer is 620v a, 30v. 2 primaries at 120v, and 2 secondaries at 30v 10.25a ea. I wanted to get something bigger because I want to add some more axis later.

Anyhow, The white wires are just ac in from the wall as we are testing outside of the control panel.

I haven't yet tested to see if I have 30v on each of the black and red, orange and yellow yet. I suppose half the transformer could be bad and that could account for the loss after rectification. But isn't it rare for the transformer to be bad?

We managed to get another rectifier and the figured that the caps must be shorted somewhere, or not big enough, or something. Not sure, but every time we plug the caps in it fries the rectifier. Any thoughts on this? Today I'm going to get some new caps. A bunch of smaller ones as I can't find bigger ones anywhere in Socal.

Any more suggestions? Thanks for any help on this guys.
Chris

Work
 

What line of work are you in?

I do production design and fabrication.

Are you sure you have your rectifier rating correct?

Chris,
Some stuff to check
Do you have the AC secondaries going to the AC side of the bridge?
Also are you connecting the caps after the transformer is powered up?
I would have them connected first before powerup.
Your wiring of the transformer looks fine. You could also use just one secondary for testing,
that would give you lower amps. What is the rating of the bridge in amps? There will be a
lot of inrush current to charge the caps when the transformer is first powered.
What voltage rating is on the caps?

Not sure here, but I think you may have your caps wired in reverse?
Hard to tell from the pics, but the lite blue wire looks to be going to
a white stripe on the caps, that is usually (but not always) the negative side?
It looked to be going to the pos side of the rectifier.
Again check this as its hard to tell in the pics.

Hi Guys,

We've had it wired up exactly correct and the way that you've told us, once with a 50amp rectifier which blew, then another 50 amp, then a 25 amp. White strip on the caps wired to negative. I think it's possible that the soldering iron was too hot and shorted out one of the caps, dunno.

One detail, the caps are charging up and we're getting a big spark. I just think that the caps are smaller than what they say and mislabeled. They say 63v but are about 1.3rd the size of my 63v caps in Auckland.

I'm getting new caps tomorrow. Will update you for sure then. Thanks again for all the help.
Cheers,
Chris

Ok, we've taken the toroidal wires out and tested the secondaries and they both output 30v ea, so that was not the issue. I plugged in one secondary only into the rectifier and I'm still only getting 1 to 1 on voltage out of the rectifier. So 30vAC in and 29.8vDC out. I can't figure out why this is except that maybe the manufacture of this particular rectifier just doesn't work or is backward or something.

Just to confirm, on the AC side of the rectifier, it does not matter if I hook Neutral or Hot to either correct?
Chris

It is correct that the wiring on the AC side of the rectifier can go either way.

Can you post a photo focused in on the wiring to the rectifier? We can't verify that it is correct.

Also, are there any possible signal paths through that metal mount? How are the capacitors attached? Is the metal case of the rectifier connected to any of its pins?

Does the problem still occur if you get rid of the metal mount and have everything just lying on the table top?

You don't want to connect the caps with the power on. You're gonna get arcing, and ugly spikes that the rectifier won't like.

All your connections looks good to me but looking at the photos, the metal disc between the toroid and capacitors is too big and can be touching the bracket on bottom. if it's the case you have a short and you are lucky that the transformer is still working. take a look at this post: http://www.mechmate.com/forums/showthread.php?t=50

Hey Paulo,

Thanks for the advice on that but it is not that that is the problem. In an attempt, I sawed off the extra flap to make sure. There is nothing touching the chassis from the other side. I'm also for sure getting 30vac out of both secondaries.

I think the problem is that in the US, from the sources I've been going, all they have are half wave rectifiers, yet they say they are full wave. Would that make any difference?

When I rectify, I'm only getting 30VDC out of a 30vAC source. I should be getting 42.5vdc. Pulling my hair out!
Chris

are you measuring that voltage with or without the caps? I think your ripple current is overwhelming your capacitors. if they have arced they may already be damaged.
Have a look at this thread ( post #8 )
http://www.mechmate.com/forums/showt...ight=rectifier

All bridge rectifiers are the same: 4 diodes inside and full wave is rectified. I can't see if the connections on bridge are correct, the AC part can be reversed but not the other part. the way you connect the capacitors, your positive is black and negative is green? (black is normally negative on DC). be careful on that if the polarity on capacitors is reversed for long time they can explode.

Positive on bridge must go to positive on capacitors.

i'm sorry if it seems to primary...

I see 4 wires going to your rectifier from the transformer. Are you sure you do not have a dual output transformer?(yes) Where each pair is 30v?

I think this tranformer could do 2 30 volt or one 60 volt if wired series on the output?

Also I agree those caps look small.

http://www.mechmate.com/forums/showthread.php?t=4057

Specs on that transformer

If your looking for 60 volts out of that transformer you will need to have it wired series I would think not parallel.

What motors are you going to run?

I am slowly answering my own questions as the coffee kicks in :) !!!

Is your input voltage 115 or 220?

Hi Mike,

My input voltage is 120vac. I parred up the primaries. I could unpair them and hook them into 240 and check. I've done everything else, I am still not getting 1.41x my AC voltage... It's the Avel 620VA Toroidal.

I'm only needing the 30v but 20 amps as I want to mount another spindle/plasma later and 4th axis.

Chris

You may have your input hot (120) on the wrong pairs according to the spec sheet. Also make sure your wall plug is wired correctly. In the US most neutrals as also ground and a commen mistake at the outlet is to switch the wires.

I forgot to mention, my machine build is entirely complete.:D

Control Box Complete, everything is complete except one thing. My motor power supply!:(

So hopefully, I can figure this out so I can get it all moving.

I will post pics after I get some sleep.
Chris