Movement, Logo and CUTTING between the beer cans #39 - Wroclaw, Poland
 

HI folks, do you happen to know anyone who has built Mechmate in Poland? I started reading forum about Mechmate and I have to admit it is a bit overwhelming for me. I hope I will gain more knowledge in time so that I can start building my own machine. You are all great. Keep it up and coming guys.

Starting out, placing orders - Wroclaw, Poland
 

Can anyone tell me if g203v and motionking stepper motor 34hs9801 is possible? Are they both compatible and can I use this driver for that motor?

I've never used a Motion King motor, but the data sheet looks good for the 34HS9801. It is an eight-lead motor, so it can be wired Parallel, Series, or Half-Coil.

The data sheet shows that for Unipolar (half-coil), you would use a power supply of 50 to 65V (maximum). When wired half-coil, the motor would pull up to 4A, so you would use a 62K resistor between terminals 11 and 12 of the stepper driver. The motor is rated at about 780 oz*in.

If you wired the motor parallel, it would pull up to 8A, which is too much for the Gecko G203v stepper driver (7A max.) Wiring parallel would also produce a lot of heat.

If you wired the motor series, it would pull up to 2.8A. The inductance would be 16mH, so the motor would work better at slow speeds if you wired it series. You would use a 31K resistor between terminals 11 and 12. Because of the high inductance, you would not be able to use the proper power supply of 100 to 125V. The G203v is limited to 80V. That also means that you would not get the 1,100 oz*in that you would expect from a series wired motor.

So, if I were considering that motor, I would only consider using it wired half-coil.

Of course, all of those figures assume that the data sheet is accurate.

Hi Martin. Kobus is using that combination of motor and drive on his machine: BBB is cutting #6 - Brakpan, Gauteng, S.Africa

Correction. I have 202's

Starting out, placing orders - Wroclaw, Poland
 

Hi guys, I have spent some time reading the forum and decided i will go for oriental motors. I will place my order tomorrow, it appears that there is one distributor of these motors in Poland. As far as the price is concerned I can get PK296AE-SG7.2 for 212 euros plus VAT per piece. I bought PMDX-122 and four G203V yesterday. I cant wait till they arrive, it is gonna take some time before I receive them. The shipment from the USA. I have started looking around for a supplier of them parts to be laser cut and bend. I am not sure if it would be enough to print the plans and then scan them, email them to the company so that they can produce them. Or do all these parts have to be in DXF format?

Try Kim in Denmark for the laser cuttings. He works at his father's laser cutting company:
Laser cut kits for Europe - out of Denmark

If Kim isn't there anymore, then you should send out only .dxf format drawings. Do NOT print and scan - the accuracy will then be terrible. I have included the .dxf drawings for the laser cuttings in the "downloads" area.

I received my first shipment today. I got it quite fast. I placed my order yesterday and I got it delivered today. 5, 2 meter long M1 rack and Gerald advised me to get two sets of spurgears so I ordered 25 and 35 teeth numbers for my geared motors. Cant wait till I get rest of the stuff.

That is the lot.

Hello everybody, I received email from fedex stating that my standard G203V arrived. They are waiting for customs clearance. They asked me to send them description of what they are and what they are gonna be used for. This is probably to calculate how much customs I am going to pay.
At present I am trying to figure out power supply for the geckos and my PK296AE-SG7.2. Can anyone help me with that issue?
I intend to wire them unipolar which is half coil. Using only four wires gives:
Current per phase, A/phase: 3 ( it is two phase motor, does it mean I have to multiply A/phase by 2 )
Voltage VDC: 1.4
Inductance mH/phase: 1.5 ( same, it is two phase motor, does that mean multiplying mH/phase by 2 )
So, is it gonna be 3 Amps by 4 motors which gives 12 Amps.
Therefore, typically 48 V time 12A gives 576VA so Do I need 570VA transformer? What about them resistors and rectifiers? Do I need any of them?

You take the Unipolar ratings to figure the Voltage and Current requirements for a power supply: MAX Voltage = 32 X SQRT(Inductance), so 32 X SQRT(1.5) = 39VDC. The closest standard size transformer is 35VDC (which is how I have my power supply wired for the PK296B2A-SG3.6 motors that I have).

Current = Amps X number of motors, so 3 X 4 = 12A.

To find the VA rating, you multiply the AC Volts X Amps, but you first have to find out much AC is required to produce 35VDC. The formula for that is: (SQRT(2) X VDC) / 2, so SQRT(2) X 35 / 2 = about 25VAC.

The VA rating is Amps X Volts, so 12Amps X 25VAC = 300VA. A 300VA to 500VA toroidal transformer would work just fine.

You'll need lots of capacitance. The formula is: Amps X 80,000 / Voltage, so, 12Amps X 80,000 / 35 VDC = about 25,000uF. Select a capacitor (or several capacitors) that are rated at 125% or more of the voltage. A 50V rating on the capacitor would be the minimum that I would use with a 35VDC power supply. A 63V rating would be even better.

All of the above shows that you should use a 35VDC power supply that is rated to deliver 12A. If you build your own, then use the following:

1 - Toroidal transformer, 25VAC at 300 to 500VA
1 - Bridge rectifier, 25A, 200V
1 - 25,000uF 50V capacitor OR 2 - 12,000uF 50V capacitors OR 3 - 8,000uF 50V capacitors
4 - 36K 1/4W current limiting resistors (I use 33K 1/4w because they are easily found everywhere)

Thank you Mike for your reply, much apreciated. This will enable me to start working on my power supply for the MM. All the best mate.

This is what I received today. Delivery was quite fast. They look awesome.

Where is the little gecko puff toy they sended with their orthers, not anymore?

Hector,

I asked the same question about the stuffed Gecko. They don't include one in every shipment. It is up to the whim of the shipping staff or if they enough to send. I ordered 5 and I didn't get one.

Yet another piece of equipment that brings me closer to building MechMate.
I got it delivered today. As for my previous delivery, I got my G203V sent to me with a sticker that shows a company logo with geckon.

The stuffed gecko toy in this picture:

This is what I found when I got back from work. It does go well with the blue. This is what my wife prepared for me. Nice work.

Martin, have you moved to Croydon now?

Nice file - looks like mine! :)
The Americans will be surprised at having only two rings,
those from the Middle East (eg. Israel) will be surprised that the file opens on the right (upside down to them)

The discussion on motor voltages has been moved here:
http://www.mechmate.com/forums/showthread.php?t=1428

Hi Gerald, I put croydon by mistake. I am from Poland. I am to pick up my laser cut and bent parts for the mechmate on monday. The bloke who is doing it rang me up today saying that after the bending is complete the measurements are slightly different to those on the drawings. There is about 3 milimiters shorter distance between them bent parts. Do you think that could be a problem or is that not much a difference? I have already ordered dualvee rails. They are to be delivered next week together with motors. They should arrive by next friday. The table is to be cut and welded at a local shop. I have no room for that yet. Hope to arrange something soon.

Hi Martin,
Where did you got your rack and gears from, they look pretty nice...?

I think all the bends can accommodate a 2mm error. If the spider is 3mm too wide, that can be a problem. Best is to check the parts one by one and then we can see if they have specific problems.

Hi Hector, the rack and gears come from this website: www.akcesoria.cnc.info.pl. You can get other components needed to complete the build as well.

Martin, I see that website has a busy forum at http://www.cnc.info.pl/ But, when I search their forum, there is no mention of MechMate? Maybe you can fix that? ;)

Hello Gerald, I think the problem might be the language. You will probably agree with me but it is not enough to see pictures. It is essential as well to be able to communicate in the foreign language. As far as I am concerned I have always prefered to use foreign english speaking websites. I personally deem your forum more interesting and informative as well. I aquired the knowledge of english with my effort and the time spent in teachers training college where the faculty was english. Anyhow thats what I think.

Hello Mike, I have a question concerning capacitance. I found a capacitor rated at 22000uF and 63V. Do you think this one would be good for my power supply?

http://www.dewalt.co.uk/attachments/...s/catno/DW627/ Has any one seen this one? Looks quite robust and quite easy to mount as well.

The shaft of that motor has a 12 x 1 mm thread (male) - what tool holder will you use to attach the cutters?

A 22,000uF 63V capacitor should work just fine with power supplies producing up to 50VDC. I commonly use a 11,000 to 15,000 uF capacitor with four PK296B2A-SG3.6 stepper motors. The formula says that I should use 27,000 uF, but I'm not pushing those motors hard enough to draw 3A per motors, so the lighter-duty capacitors work just fine.

Remember that the purpose of the capacitor is to act as a reservoir for electricity. Your power supply will fill that reservoir 100 or 120 times a second (2x the 50Hz or 60Hz that your local power company's AC cycle rate). The stepper motors will draw against the reservoir. If the reservoir is too small, you will see excessive AC ripple on a DC power supply. Having about 5% ripple is okay. If you have more ripple than that, add another capacitor in parallel.

I am back with some photo updates. The box ready to be wired up. Is it really essential to use shielded wire for connecting all the components in the control box? I will do the wiring up during the weekend. I hope everything is gonna be ok. Maybe I will manage to power up the motors as well. We shall see.....