Motors turning! (under EMC) - Perth, Western Australia
 

Hi All

Have been lurking for .... well years actually but the growing legions of australian builds has convinced me to get my act together and get started. So with this in mind a few months back I ordered a G540 from the run of cheap surplus stock and have now ordered the steppers from motionking, not a perfect match for the G540 but the OM motors would run me around $3000 aussie and with a 3:1 reduction the motionkings should do the trick.

I'm going to start with the control box as I currently have no shed to work in and I figure this'll probably be one of the more complicated bits for me. So hopefully tonight I get to ordering the rest of the associated electrics.

I'll be building the table with a 12' x 4' working area, it's been mentioned before that this is the standard size for aircraft aluminium and yes I'll one day be using this to build an aircraft for those who are curious I'm thinking of a sonex. The table will also have a false spoilboard that can be removed and the extended z slide, the primciple use of the mechmate will be for cutting surfboards.

Anyway I also have a question, what size boxes are people using for the control box as I'm finding it hard to pick the dimensions with all the bits in front of me? any thoughts, I'm thinking 400x600 but not sure if this is too big.

Jed

Hi Jed,

Looking forward to seeing your build. I might have to come over and visit and have a fly in the sonex also ;)

My control box is a parts washer from Super Cheap autos. It has plenty of room and houses the PC, Powersupply and controllers. Having worked on it for a while now I must say the extra room is handy as it makes it easy to work on.

Let me know if I can help in any way.

Jayson.

Hi Jed,

Glad to see you moving into the "builder's group." Welcome.:):):)

I used a 24" X 16" X 10" control box. Very close to your 600X400 mm one.

I did not mount the computer in the control box...I was concerned about heat generated by the computer overheating the Gecko's etc.

I found the box roomy enough, but I would not have wanted it to be much smaller. Also, since the control box is sealed during operation, the air inside the box is circulated and the heat is dissipated through the walls of the steel box. During operation, my Gecko's (measured at the heat sink) run about 10 degrees C above the ambient temperature.

Contactor help
 

So I've been searching through the online catalogues of various local suppliers looking for parts. I'm having problems choosing which contactor to buy as I have never worked with them, was wondering if someone could look at this one and let me know if it's suitable. (hope the link works)

http://australia.rs-online.com/web/s...2437410#header

Just to clarify supply voltage is 240Vac.

Thanks
Jed

Hey Jed,

Great to see more Aussies starting to build.

My control box is 400W x 500H x 200D. Its big enough but extra space is always handy. The one you found should be great.

That contactor looks ok too but it will depend a little on the router/spindle you will use. Its rated to 10A resistive or 6A inductive. A router will be an inductive load so if that contactor will be supplying the router as well as the stepper power supply, you will probably need a higher rated one.

I bought this one
http://au.farnell.com/jsp/search/pro...questid=406046 Its rated to 12A inductive or 27A resistive.

Steppers Arrived
 

Steppers arrived today from motionking :D, impressive, now to finalise my electronics order, getting there.

Electronics on their Way
 

Well after much indecision I have finally sorted my order for the control box.

Following the discussion Here, I have followed Geralds advice and gone and checked over several days and found that we average around 245V, the result of this and a transformer selection for 35V secondary I'll end up running around 52V at this average and should not ever exceed about 62V.

Anyway have gone with the 300VA 35V transformer. Hopefully the delivery man will come soon :)

Jed, if you are averaging 245V then I have a big suspicion that your meter is reading too high. If that is the case, then you will have a lot of problems getting stuff to match your meter readings. Suggest you verify your meter against somebody else's. (There are some bad meters out there)

Maybe your meter is not so suspicious . . . .

Found this on the web: "As of 2000, the mains supply voltage specified in AS 60038 is 230 V with a tolerance of +10% -6%. This was done for voltage harmonisation - however 240 V is within tolerance and is commonly found. Mains voltage is still popularly referred to as being "two-forty volts".

Thanks Gerald

It's good to have someone checking up on us. I've calculated final output voltages and other properties based on supply voltage from 230V through to about 290V as a check though several of the components would smoke (interestingly maybe not the Gecko though) before it got that extreme.

Jed,
Australia has voltage of 240. However on paperwork we have a voltage of 230 +10% - 6% ... This is so we are the same as most overseas countries.

As for a contactor... Just go to your local electrical wholesaler and get a 240Volt contactor that is 10A+ (the contactor i used is rated at 27A) The MechMate probably wont draw more than 7A at any time...

Then you just need a transformer to go from 240 to ?V for your geckos. You shouldnt need to worry about voltage beening around 290Volt.

Rob

yep your right on the contactor and not quite right at the same time, mechmate itself won't pull more than the 7A I suspect it won't even reach a couple of amps just running the motors (300VA transformer at 240V means...I'm sure you can do the math) but I'm using a router, that pulls almost 9 on it's own so a standard 10A won't cut it, I've ordered one similar to the one Matt suggested but 24V so i can have a 24V control circuit (I like this for various reasons).

Reason for the 290 was not that I expect it I just wanted to check, if you read my other posts I'm using a G540 so am voltage limited to 50V (you guy's using G203V have a limit of 70V but is using the OM geared motors usually setup at about 35V so don't get this issue) so if I design for 50V to my G540 and get voltage variationI need to check to see that the +10% variation won't kill my gecko, I also back calculated to find out what voltage I'd need to get to result in smoke (that's where the 290V came from and i agree extremely unlikely but worth knowing)

Jed


Good to actually write all this down clarifies it all i think, so thanks for the prompt Rob.

24Volt Contactor? was that a typo or are you droping your voltage before you are going into the contactor...

i would use a 240Volt one so you can use the contactor to switch power to both the router and to the parts in your control box... Like shown on the drawings :)

Rob

Nah 24volt wasn't a typo and yes I have a second transformer for the "control circuit", I prefer being able to do this as it keeps all the 240 stuff inside the box but is essentially personal prefference. I'll be switching the router via the G540 and the existing power supply or can similarly rectify and filter the control voltage for switching the router + prox switches etc. Have a look at the G540 manual from the Gecko website (Here) it has a similar type setup.

The delivery Man has been, Busy wiring
 

Hi all

So the delivery man came the other day and i now have all I need in hand to build the control box, so I have been busy laying out the box and wiring. Will get some pics when I'm a bit further down the track. Now that I have that sorted I'm getting to order the final parts required to have my motors turning, which brings me to my next issue, shielded cable. I can get the Lapp cable but am hesitant to pay the $7.5/m (which is the cheapest quote I've got) so have been looking around and found some Belden cable which looks like it would do the job but I wanted to check with those that are more knowledgable/experienced in this than I. The cable can be found here, has anyone used this cable before? will it do the job?

Thanks
Jed

That Belden cable looks good.

Thanks Gerald,

I now have some on it's way.

Bleed restistors and gecko's
 

Question for those out there who know, I've just completed wiring my control box and am keen to switch it on and see it work. At this stage I don't have my motors wired to the gecko yet and was just wondering that if I turn it on and power it up will the gecko with no load on it drain the capacitor or am I being silly:o and should I just disconnect the gecko and just use a lamp or some other load to drain the capacitor?

Thanks
Jed

Jed,

The Gecko's will drain the capacitors with nothing connected to the motor contacts. Be sure to leave the Gecko's connected to the Power Supply until you have turned off the Power Supply and allowed the Gecko's to drain the capacitors.

I'm assuming you have the Gecko's correctly connected to the Power Supply.

Thanks John I believe I have everything wired correctly but will check again before I actually run it, hopefully tomorrow.:D

Motors turning
 

Haven't posted anything much lately so thought I'd drop in and post that Tonight I got my motors turning:D, I have the motor control side of the control box complete just need to finish off the wiring for the router relay and I'm done.

Can anybody tell me how to setup my a axis to mirror the x axis in EMC?

Got the emc thing sorted set a to receive signals for x axis inverted in stepconfig wizard

Good progress! Wish I can churn thing up this fast... ;)

Thanks Ken, my progress is not as fast as you'd think though. I first stumbled across this site in 2006 (I think) and decided I wanted to build but it took me this long to get a start and approval from the financial controller. Once you get a start though you'd be amazed how fast you can progress, I've just been doing and hour here and there when I can afford the time away from the family (we have a new baby in the house) and a couple of weeks later I have my, motors turning.:D