A PlasmaCam Table Experiment

[Joe Jones]

I have a crazy experiment in mind. I am going to try to set up a PlasmaCam table to operate without the main wiring harness either swinging over the material, or being controlled by drag chains. The table will not be wireless, however it will not use traditional cables. I ordered some of the parts off of Amazon tonight, and the rest, I will build myself. If this is successful, I will make a video showing the process, and the results. If it fails, well ... at least I will be able to say I tried!

Joe

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[plasmanewbie]

Sounds interesting Joe, I will be following this topic to see what you come up with

[Joe Jones]

I want to create a multi-lead copper contact track along the X and Y axis, and use rolling bearings for the connections in place of wiring harnesses. I BELIEVE I can make a "car" that runs along a track with individual bearings rolling along the copper strips. Think of how our old slot cars worked. Two copper tabs riding along copper strips on either side of a "slot" that the car's undercarriage tab would ride in.

If I can create a X and Y track with multiple copper leads, then the gantry and carriage can run along each axis without any need for a wiring harness.

These are the first things I bought, for the experiment. They are limit switches with roller bearings on the ends. They are rather large, at 2.7" long each. I will not use the NO and NC contacts inside of the switches but rather, the switch bodies will only serve as a base for the teetering rocker arm that is spring loaded, and has a bearing at one end. The rear end has a tab that I HOPE will be ideal either for a paddle connector or to drill a small hole and solder a wire into it. Maybe a terminal block will be needed to draw all of the switch rockers out to a common area.

Since the switches are 3/4" wide, I will need to create banks of switches that allow the narrow wheels to contact the copper tracks which will be spaced very closely together. I am thinking of using round copper wire for the tracks, but then ... I like to think OUTSIDE of the box! So I may route a groove into the base material (PVC board?) and use H.O. Train tracks for the contacts! I can buy them in long lengths, and slip them into a groove IF I can find the correct router bit to create the slots.

Joe

ROLLER SWITCH.jpg

HO TRAIN RAIL.jpg

ROLLER TRACK HO TRAIN RAIL.jpg

[Joe Jones]

I do not know off of the top of my head, how many wires are in each harness. I can go out to the shop to count them.

I figure I can link a row of these switches together and let the wheels ride on the tracks beneath them. The "car" would be attached to the gantry, and another to the carriage. The switches would be wired to the three motors as needed. Maybe I will get lengths of 8020 aluminum extrusion to use as the base for them and design a car to run along the 8020. That is all available already from 8020, so I do not have to reinvent the wheel.

As the gantry moves, the wheels would remain in contact with the tracks and provide the necessary connections. I guess the gantry track will require ALL of the wires to be in contact across the full length of the table, while the carriage will only require those for the Y axis. So the track on the gantry tube will have less tracks to connect. I guess an occasional wipe with a soft cloth would keep them clean enough.

I sure wish I was 25 instead of 65. I have so many things I want to do, and no energy to do them.

Joe

[rdj357]

Let's see - 5 for each encoder, 2 each for x and y motor power, 3 for the limit switches, 3 for the Z motor, 1 for height sense. That'd be 21 plus you'd need a ground/drain to each encoder and each motor that could probably terminate in a single conductor, maybe a good idea for 2 to ensure a good drain for noise. So 23 conductors for the gantry and 12 of those would need to continue on to the carriage.

I'm not sure the connection quality and reliability will be there plus the potential noise from all those conductors bared out that far with no shielding cause me concern.... I dunno - seems like a stretch to me but hey, if you've got the time and the money to play with the idea then should be interesting to see how that turns out!!

[Joe Jones]

Let's see - 5 for each encoder, 2 each for x and y motor power, 3 for the limit switches, 3 for the Z motor, 1 for height sense. That'd be 21 plus you'd need a ground/drain to each encoder and each motor that could probably terminate in a single conductor, maybe a good idea for 2 to ensure a good drain for noise. So 23 conductors for the gantry and 12 of those would need to continue on to the carriage.

I'm not sure the connection quality and reliability will be there plus the potential noise from all those conductors bared out that far with no shielding cause me concern.... I dunno - seems like a stretch to me but hey, if you've got the time and the money to play with the idea then should be interesting to see how that turns out!!

Yeeeeaahhhh ... The noise issue is the one unknown for me. Still, I am willing to do the experiment. I think
I would begin with my 4x4 table, since the rails are 6 feet shorter than the 510 table. I'm betting Randy Ashdown could set me up. Also, a friend who I met a while ago, who plays with things like robots, autonomous drones and electronics on a level that I can only marvel at, he would probably be able to solve any issues I had. Gosh, I wish HE lived a lot closer to me!

Well, I will build the experiment on my 4x4 table, and if it works, I will replicate it on the 510. I went shopping for model train rails and found three different sizes ... HO, O, and G. I think I will begin with the HO rails, since that will make the contact panel the narrowest. I have to find a T-Slot router bit that will let me slide the HO rails into a plastic base easily. The alternative is to cut grooves for the track, and then lock them in with spacer plates, but that would be a LOT more work.

Joe

ROLLER TRACK ALTERNATE ANCHOR.jpg

[rdj357]

How wide will the ‘car’ be to carry 22-23 conductors using the rail you’re describing?

[Joe Jones]

How wide will the ‘car’ be to carry 22-23 conductors using the rail you’re describing?

I am not sure yet. If I use 3/4" thick PVC board, and space the rails such that they are just far enough apart to prevent a wheel from one rail, crossing over to contact another rail, and I stagger the contacts, with 24 leads, I could get away with a rail board about six inches wide, or even three inches wide if I lay rails on both sides. The switch bodies are 3/4" wide, so that would mean four banks of switches, spaced 3" forward per bank, and offset by 1/4". Or I could interlock the wheel arms with the switch bodies to the outside, and the wheels to the inside between them, alternating left, right, left ... like interlocking your fingers.

The car would be easy to build, and with one glide rail centered and splitting the rails, I could guide the car along the glide rail, with the wheels in tow, each spring loaded against its own rail. Picture a person pulling a wide rake.

I do believe the one factor that may kill this project, is the RF noise that might be coming off of the bare rails. I have no idea (yet) how to control that. Maybe bury the rails deep, so there is a plastic wall between each rail that the wheels roll along? I don't know. Too many unknowns at the moment. It occurs to me that if I do that, I may be able to place the rails even closer together, because there will be a dense (Delron? PVC? Acrylic?) wall between each rail and wheel combination. Then again, the steel bearings would rise above te walls and defeat any shielding gained by the walls. This would merely be a means to prevent one wheel from crossing over onto another rail.

Joe

ROLLER RAILS BURIED.jpg

[djreiswig]

We use this at work. Might give you some ideas.
https://www.cmco.com/en-us/products/pow ... ar-system/

[Joe Jones]

I could get 24 leads on a plank six inches wide, with a glide rail running down the center for the car to ride along.

Joe

ROLLER TRACK 24 ON 6 INCH BACK.jpg

[Joe Jones]

It would be easier to use a ball nose router bit to create round channels in the material that are just slightly deeper than 1/2 the diameter of solid copper wire. I could snap the copper wire into the grooves, and then run the wheels over the top quadrants of the wires.

If I used 3/16" stainless steel round bars as the tracks, I could run one solid length along the 510 table, there would be no rust issues, and the tracks would last longer...

Also, the backing board for the tracks would not need to run the full length of the table. I could make 1" wide strips that hold the rods (tracks) in alignment and only need to provide a mount for the glide rail. HEY! This sounds like a job for my 3D printer!

Thinking ... Thinking ...

Joe

ROLLER TRACK ROUND WIRE.jpg

[Joe Jones]

This is beginning to look like a job for my laser. I can cut the track cradles and set the distance between the rods (tracks) to any distance, and then screw or glue the cradles to a PVC board or another material to create the track with 24 leads spaced exactly where I want them. The cradles would support the rods every (n) inches, sort of like how the bridge on a guitar supports the strings.

Joe

GUITAR BRIDGE.jpg

[weldguy]

It's a clever and cool idea but with plasma cutting dust I would be concerned about connection quality over any length of time without constant cleaning or a very well sealed enclosure but that dust gets everywhere!

[Joe Jones]

It's a clever and cool idea but with plasma cutting dust I would be concerned about connection quality over any length of time without constant cleaning or a very well sealed enclosure but that dust gets everywhere!

I believe a simple bristle brush that runs along the tracks on both sides should be sufficient to prevent a problem with plasma dust. The switches arrive today. All 72 of them! I like options

Joe

[Joe Jones]

We use this at work. Might give you some ideas.
https://www.cmco.com/en-us/products/pow ... ar-system/

That is awesome. I have seen them used on overhead cranes and similar devices.

If only they made a 24-POLE version!

Joe

[djreiswig]

Flip the whole thing upside down and that should help with the dust settling on them.

[Joe Jones]

Flip the whole thing upside down and that should help with the dust settling on them.

I had planned to mount the panel vertically, against the frame, so I don't think plasma dust will be much of an issue.

Joe

[Joe Jones]

This is just too awesome. I figured out how to mount 24 switches in perfect alignment on two cars that ride on the glide rail. Sometimes things just fall into place!

I am waiting for the switches to arrive ...

Joe

[Joe Jones]

They're here! They are awesome. Now to create the car which will hold ... 32 switches! Four banks of eight switches.

Placing 16 tracks on each side of the glide rail will give me options! I might as well have some extra leads available, for things like a powered wireless camera, or a light, or a router power source perhaps, or an engraver, or a laser head, or ... I will use DesignEdge to lay out the car's body and send the file to SENDCUTSEND to have it laser cut to perfect dimensions.

Next, is to create the bridges that will hold the tracks. I will start with stainless steel 1/8" diameter round rod for the tracks. This will eliminate the rust issues, and it will just LOOK bitchin! (The 70's LIVES, dudes!) 32 along the rails, and 16 along the gantry tube... Things are getting interesting.

Joe

BANK OF EIGHT SWITCHES.jpg

NESTED SWITCHES.jpg

[Joe Jones]

Evidently, these round "rollers" are just a barrel on a press rivet. They do not have a bearing. They are NOT smooth, and they will certainly not work to roll along round stainless steel rods in a dusty environment. They hang up just rolling on paper on a glass desk. Granted, they were not designed to ROLL as I intend, so I am not too angry. These are still going to work very well, and the switches were only $1.45 each including tax. I bought 72 of them, just in case I end up doing BOTH tables.

Amazon to the rescue!

I was able to find a quantity of 3mm x 10mm x 4mm stainless steel bearings, M3-.05 x 12mm Stainless Steel Button Head Hex Drive bolts, 3.0 mm ID SS flat washers and 3mm ID SS hex NyLock nuts! I will drill out the cheap rivets on all 36 switches (or 72?) and save the barrel spacers for another project, while replacing them with SS bearings for a smooth roll! Add $160.00 to the project ...

Just checked ... The existing rollers are 4.33mm wide. Whew! Dodged that bullet! "It is better to be LUCKY, than SMART!" - unknown

Still pressing forward ....

Joe

[Joe Jones]

Hmmm... 48 rolling contact switches per table ... 32 on the X and 16 on the Y. I could get by with 24 and 12, for a total of 36 switches, but I figure I want options. The extra contacts can be for a light, or a dry contact for something else. I am one of those, "If four is enough, eight is better!" kind of guys.

I would love to be able to power a router through this system, without needing to have an additional CORD to worry about. I THINK a 1/8" stainless rod and bearing, etc. could maintain a low amperage AC power source... Imagine mounting a small shop vac to a glide rail that parallels the rails to pick up router dust as it is cut.

448 feet of 1/8" stainless steel tracks. $500.00 ? I could always use solid copper wire too. That would probably cost more. 11" X 132" X-axis contact panel. 7" X 72" Y-axis contact panel The ONLY unknown, is the RF interference I may not be able to overcome. Still, I have to try! This is one of those, "If you DON'T do it, you will always wonder if it COULD have worked..." things. Now that I am into this project, there is no turning back now.

Joe

[plasmanewbie]

Cool Joe. I can see your pretty pumped about this! Will be coming back to check your progress

[Joe Jones]

I went to look at the 1/8" steel rod at Lowes. It seems kind of small, seeing that some 60% of it would need to be buried into a holder. So I am going to switch to 3/16" rod, to have more of the crown rise above the retainers.

I wonder what kid of deal I can get on some 500 feet of 3/16" stainless steel rod.

Today, the construction crew will arrive begin building the gable for the elevator. There are other projects also in the works. Thunder and lightning last night ... I hope the bad weather is behind us for a few days until they can close the giant hole they will cut into the FrankenBarn roof. The "Telehandler" with the 42 foot reach also arrives this morning.

Joe

[Joe Jones]

I ordered the two cars from SENDCUTSEND. Now to find a source for the 3/16" stainless steel rod...

Joe

[djreiswig]

Maybe square rod would work better than round. More surface area. I know you can get it in mild steel, so I'm sure it's available in stainless as well.