Build went quiet for 6 months, now cutting! - Suffolk, UK
 

Hi all
I have been lurking in the forum for some months, gathering information and working on parts lists.First thanks in advance to the forum for providing such a wonderful resource, and in particular to Gerald for producing such a complete set of plans. I am sure I will be asking a lot of questions.
I have a limited amount of CNC knowledge gained some time ago through building two small desktop type machines, the first in MDF, skate bearings and angle iron, the second, a steel framed machine with ball screws and linear bearings, which purely by coincidence is painted Mechmate blue!

Hers my progress so far, comments and suggestions welcome:

Steel ordered, based on a 2400mm x1200mm table, except main x beams. I can get 180x75 or 200x75 any thoughts? For the rails I have ordered 60mm x30mm-hope to save on a bit of grinding.:)

Steppers: - 4x PK296AE-SG7.2 (PK296A2A-SG7.2 not available in UK and I believe 296AE are the same spec?)

PS: - 300VA 2x 25Vac, 25amp bridge rectifier, 1x 10000uf 100v caps?

BOB: - 1x PMDX 126 if available in UK

Drivers: - 5x Gecko 203v

I have noticed several uk start builds but no uk serial numbers?

I will post pictures but at the moment wife and camera both in Australia visiting daughter.

Once again thanks.
Tony

Welcome to the team !!!

Welcome Tony! :)

Tony

Welcome to the Mechmate team.I have just started as well but you have purchased more thean me.

Mick

Uk Build
 

Hi All

Fist apologies for not documenting my build, but there are so many well documented and photographed builds in the forum I am not sure my efforts would have been up to scratch!
I have attached some photos of my build so far, and the first trial cut- sorry for the quality (phone camera and poor lighting).
I have a small laminate trimmer mounted at the moment for set up but intending to mount a spindle and vdf when it arrives.
Thanks to Gerald and his excellent plans plus the wealth of information on the forum the build was relatively straight forward. I still have some configuring to do as I have run out of inputs on the PMDX 126 and the current Mach3 plug-in, to allow extended I/O on a single parallel port, has a few issues at the moment.
I did post a couple of question on Limit switches and eventually followed the PMDX 126 instructions and now have all three axis homing and limits wired directly to the BOB without the need of extra relays.
I hope to be a more active contributor to the forum now the machine is running and the learning curve gets steeper!
Once again thanks you Gerald and all the members of the forum, it would have been an near imposable project without your help.
:o

Sweet build !! Dust, Paint ---- Logos???? Looking forward to posts. Tell us what proxies you are using and how you hooked them to the 126 (Jack# and Pins)

Limits
 

Hi Mike
I spent quite some time reading the proxi-limit thread and posted a couple of questions before deciding on a system. I followed Gerald’s plans to the letter and have “holes” in the x and y axis also decided to drill a relatively small hole in the Z slide support tube, for sensing, after I had tested the x,y sensing. Red and Pablo’s reference to the PMDX 126 manual and the wiring diagram for sensor inputs was a great help, also Steve starlings response to Pablo’s post.
I am using four N/O NPN sensors, one each on x and z, and two wired in parallel for the y axis. I have taken the 12v supply from the 126 (Terminal J12) to the first gantry box and from that to the other sensors. The return signal and ground for each sensor back to J12 pins 11, 12 and 13.
Unfortunately during initial setup I managed to jump the y car off the rails by having Y and A motors running in the same direction! It did prove that the system was working in that everything stopped, but one of the sensors was damaged. I am waiting for a replacement so at the moment I only have one sensor on the y. For the system to work with the single sensor, on the y, the “Home slave with master axis” check box in Mach 3 general config needs to be activated. I have Mach 3 configured with homing and limits for each axis using one input signal per axis.
I can now “reference all” using the single button on mach and each axis references to its home position (z being positive).The x and y limits trigger in both extremes’ + and – the z limit in + only as I have yet to drill a second hole for the z – limit sensing. I did read a post from Gerald about drilling too many holes in the z support tube and loosing its integratory, so at the moment z- is controlled by Mach and “soft limits”
I have posted some pics to show the set up.

Here are acouple of videos showing the machine homing. Sorry for the quality this is all new to me!
http://www.youtube.com/watch?v=jvKmSW3Tq-Y
http://www.youtube.com/watch?v=0-Ij_VCNpPk

Very nice Tony -congratulations! happy cutting

Are the Proxies wired like this ?

Not to get into a long thread about proxies again. If you did wire like the previous post can you fill us in on why you did it different than the PMDX Manual explains it? I have just been re-reading all the proxy threads this week and want to know particularly all the ways they can be hooked to the PMDX-126 board.

Mike
I thought I had wired them as the PMDX manual shows!Perhaps my explanation was missleading!
Regards
tony

Well I asked because they obviously work fine correct? It would be fine like that if you did not need those connections for any other switches. So you are wired like the diagram in post 10 above?

Mike
Yes wired as post 10 and all works ok. Your last comment about not needing the inputs for anything else has got me thinking! My understanding of mach 3,which is very limited at the moment, was that each limit switch requires a separate input so in my situation I have used three input terminals on J12.On rethinking this I not sure this is necessary or correct. I now have a recollection of a post explaining that you could use just one input for all limits and homes and Mach 3 knows which axis it’s homing in sequence. You may have a better understanding of mach 3 and confirm this? Because if this is correct I do need extra inputs for touch plate etc, as I said earlier still on a massive learning curve so any input welcome.
Regards
Tony

Glad I helped, I also wired many proximity sensors to pmdx-126 per its manual with great results to non mechmate related projects.

I don't use PMDX-126, but from my understanding, disregard of which BOB you may choose to use, you can parallel as many limit switches of what ever type & share a single I/O port on the BOB. The motion control software be it Mach3 or EMC2 will run a logic routine to go about their business. In fact you can find this explained in both the EMC2 & Mach3 manual.
The disadvantage is that the motion control software really don't know which switch triggered when de-railing happens... which IMHO doesn't get in the way in reality... Even if the motion control software knows which switch triggered, what can it do??? :rolleyes: There are only 4 switches in all... how difficult is it to find the offending switch??? :D

I just look at which limit switch light isn't lit (NC when correct), mine have l.e.d.'s where the wire enters the limit, usually caused by one of the axis being positioned over the 'holes'.

I have my machine set up to use separate inputs for the limit /homing and it does use three of the inputs available on the PMDX 126 J12 terminal. I can use the single “Ref All button” in Mach and everything works according to plan. In the Mach 3 manual section 4.6.6 it does say that you can use a single input but you can only reference one axis at a time and to remove the REF All buttons from your screen. So it’s a compromise between pressing one button or three, using one input or three.
As I need more inputs I have installed the PMDX 126 Mach 3 plug in to allow expanded I/O mode which in theory should give me an extra four inputs on the single printer cable, but at the moment it is not working correctly and Steve is working on an updated plug-in for Mach.

All 3 of my limit switches are connected to a single input and I ref all with 1 button at the same time, all homing works fine. I can not use "square the gantry" option.

...Ditto, mine is the same is JR's (Hi sir!)

I am on the first steps of the ladder with MechMate and Mach3 so have you guys got your limits and homing running through relays to allow the single input operation? Or is there a configuration set up in Mach3 that I have missed. I am trying to avoid, if possible, extra relays and circuitry. This may not be possible, but if there is a way of wiring the proxies directly to the PMDX126 using only one input for all three switches any help would be appreciated.

What I have seen done is run the proxy wires to a plastic junction box on the table. Then run a pair (Or use one off the 8 core) to get back to the control box. But since you have already wired all the way back to the control box, you can use teminal blocks and jumper bars. The bars can be cut to bridge the needed blocks together. Then run wires to the 126 off of one of the terminal posts for each leg of the proxy.

I'm using seperate relays.