#121
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Gantry and X Cable Wrap
Thanks for the warnings Fox, I'll keep them in mind when I do my start up. It will be a little while. I need to get cable and hose.
The gantry didn't move out of square on final weld. It rolls with very little effort. You really don't appreciate Gerald's design and documentation until you build and it fits and works. I sized up the X-Cable Wrap and installed the support brackets. |
#122
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Control Box Stuff
I recieved my spindle and need to test it. I got side tracked when looking into connecting it and ended up working on the control box.
Went to a surplus store looking for multiconductor wire and found these gems for mounting my spindle. They will get a little machining for a better fit but are solid right off the shelf. Drilled and mounted my components on the back plate. Still need to drill the hole and mount the fan for the geckos. Drilled the plate for a 5th gecko since there was room. Decided to go with the PMDX-106. I should finally get my Y-car body back today and can start that assembly. Question: Do the 203V Geckos need the 470uf Cap on the power input or is that for other models? |
#123
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The Gecko 203V don't need the 470u cap, from https://groups.yahoo.com/neo/groups/...s/topics/10780
Although it cannot hurt to add one. Just make sure the cable length between the gecko and your transformer is small, use thick enough cable and don't bundle them tight. I never had issues with the 203V's, they are a bot $$$ but work well. I cannot clearly see it, but are you actively cooling your gecko's? I have a ventilator below the heat sink of the gecko's to make sure they keep below 50c-isch... I don't uses fuses on the DC wire of the gecko (looking at your picture, are they fuses??), I figured (looking at the warnings) that if they blow while in normal operation I might break the gecko. I kinda trust the internal fuse of the gecko's. |
#124
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I did not know they were internally fused. That will eliminate one more external component to cause problems. I just read the manual and it is a little clearer. I have only been using it to determine connection points so far. Thanks for the info.
I have not drilled the hole for the fan yet, but do plan on actively cooling the geckos. |
#125
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Fitted and welded the Y Car last night. Need to pick up some all thread tonight to prep for the final weld.
Twisted up some wire for the power supply to gecko harness. Replaced the fuse blocks with wire tie holders. Picked up an LED Halo light for the spindle. Really small wires and connector. Question: When doing the final weld on the Y-Car, what alignment is important? I see granite surface plates, glass plate, I-beams being used. The inner plates need to be parallel to each other. Next I assume that the inner plates need to be 90 degrees to the plane of the Y rail. Is 90 degrees to the top of the Y Car close enough? Or am I just keeping the plates from becomming a parallelogram? Maybe I'm just over thinking it. |
#126
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Side plates that hold the rollers parallel and square to top surface (keeps vee rollers in plane)
Center spider holder frame needs to be consistent gap so spider fits without too much shimming. |
#127
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Thanks Sean,
So as long as I keep everything square and parallel I should be fine. Didn't want to finish the welding and then find out I missed some important alignment. John |
#128
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That halo light is cool. Where did you find it?
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#129
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Amazon
Amico Auto Car 100mm Dia White 33 SMD LEDs Angel Eyes Ring Light Headlight. Dirt cheap too. Have not tested it yet but assume it will be bright for the spindle. |
#130
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Thank you, Sir!!
So, I just went to check them out ......and ordered two of them....Gotta stop impulse buying. lol. Last edited by darren salyer; Wed 21 May 2014 at 09:23.. |
#131
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Quote:
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#132
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You are correct, Fox.
I've ordered from them before. Didn't see this particular light on their site, but didn't get too in depth looking. |
#133
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These are in car lights on dx, search for 'angle eye'. I ordered a few different sizes in the past for my mill drill etc..
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#134
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Finished welding the Y-Car and its idler.
Still need to install stops, prox hole, gear rack on Y-Rail. Picked up a 24VAC doorbell transformer (HomeDepot) for my E-Stop Circuit (pdf File). |
#135
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Don't you also want to include an on_off switch (in your low voltage e-stop circuit) ? I did. With the main breaker I energize the box, with the on off switch I put power to the VFD (spindle) motors etc. An E-stop trigger everything off again (except my control card, which also receives an e stop signal as input ).
Last edited by Fox; Fri 23 May 2014 at 08:08.. |
#136
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Fox,
What do you think of this? Added on off switch for the latch circuit. Added main power disconnect. Added separate 12VDC supply always on (not latched) to power PMDX-122 and PMDX-106. Added contacts to e-stop relay to connect PMDX J6 GND to E-Stop. VFD and Gecko Power Supply supplied by the same latch. John |
#137
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My only comment is the Gecko amplifiers don't need to be on a fused circuit. They are fused internally on the board.
Otherwise, I don't see anything abnormal at all! Cheers, Sean |
#138
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Thanks Sean,
Here is REV B eliminated fuses in Gecko power. |
#139
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Made some progress. Two of the three days anyway.
Made my rail stops for both X and Y. Welded them in. Installed the Y-Cable support. Ground and drilled my Z-Plate. Cleaned up. |
#140
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Almost there. good work.
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#141
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You are really zipping along. You will be done before you know it.
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#142
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There is no way I could make this kind of progress without all the previous builds to guide me.
Last night I found out I didn't have the 1x2 tube for the z-slide so I disassembled the controller back plate to cut the hole for the fan and other items to mount. Ended up making standoffs for the Gecko power distribution. Someone said a star connection was the best. |
#143
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Properly execute a stare point should only be one point.
The good practice not treating the casing as a conductor. |
#144
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A single point source.
Not daisy chaining the connections. |
#145
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Good practice is later on to actually ground the casing of your box, but to isolate the control box from your frame ( rubber mounts - if you mount it on the machine / hang it on the wall) ?
Cause the trick is just to avoid to create a ground loop (you already have the thick ground wire going to you machines frame ). The better starground would indeed be to create one point ( take a longer bolt ). You will notice when you mount your regulated powersupply to the same plate like that, ground will already run from that casing to your starpoint, so you are already creating a groundloop right there ... it get's confusing really quick. I have 'heard' from a local electrician that a solid metal backing plate will often already be accepted as a good ground by machine builders, cause there can be so many parts that you mount in there that will create a ground when you mount them... Still it's a good idea to keep connections as local as you can. Especially with Mach ( I am using Eding CNC CPu5b on Ethernet) which is much less prone to interference. Disclaimer: I am no electrican Last edited by Fox; Wed 28 May 2014 at 14:03.. |
#146
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Fox and ken,
My picture may have caused confusion. The two bolts are completely insulated from the base plate. One post is + Positive and the other is - Negative. The posts will connect to the Power Supply + and - connections. Nothing is touching ground. John |
#147
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But the NEC here in the US requires that all control boxes and enclosures and equipment must be grounded. NEC and NPFA 79 are the two you have to comply by if State side. If you have followed the proper grounding procedures in your business or dwelling, you should not have a problem. A chassis ground and earth ground should be followed. Most all OEM equipment have a central grounding point. NEC does have a requirement of the amount of termination at a single point based connection type. Most now use a bonding bar to give multiple termination points at one central point (your star point). Isolating the enclosure, panelboard is not required as long as it is a central point and you did not inadvertently create a loop. Metal conduit cannot be used as a path to ground any more so a wire must be run for the power supply with sizing appropriate for arc flash requirements. Proper grounding is not that hard if you think of the path of flow.
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#148
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A star distribution is not needed on the power side as long as it is parallel connections and not series. The only benefit, at times, of running individual power cables is for removing a device from a circuit without affecting the other devices. In this case, it would not be feasible to remove a drive out of the machine and run on the remaining drives. With all that being written. That is a nicely done binding post setup.
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#149
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This is for MY installation in a US supplied power source and is not a recommendation for anyone not knowledgeable in electrical power wiring. This is a disclaimer of sorts.
Safety ground, signal ground, and ground loops are different issues. The box must have a safety ground and that comes in to my box with the power from the electrical panel. I will be bolting my control box to the frame. There will be a bond wire from the box to the frame. I will also be sending a ground wire from the control box to, the gantry, the Y-Car and the Z-Plate. These items will be connected to ground to prevent the ground from trying to pass thru the bearings. Ground loops occur when there is an alternate path to ground that is lower or equal resistance to the safety ground. This lower resistance ground is usually the shield of a signal cable. The ground current flowing through the shield induces a current into the signal wire that appears as noise (usually 60 Hz hum). If everything is operating correctly there is no ground current. Ground current typically comes into play when someone connects the neutral to ground in the device. Neutral and ground are only connected at the power distribution panel. A lot of people get confused when they see them connected together in the panel and think they are the same. They are not. The neutral does carry current. If the neutral is connected to ground downstream of the breaker panel some of the neutral current will flow through both the ground and the neutral wires based on their resistance. If you have shielded cables with the shield connected at both ends then some of the current will flow through it as well. To reduce the chance of current flowing through the shields it is recommended that you only connect one end to ground. Preferably the best ground (control panel ground). Hopes this helps. |
#150
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John,
You are right, I was confused by the photo. Now that you cleared the air, That is a nicely done star point. |
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