# CNC plasma cutter build



## DavidR8

I've wanted a small CNC plasma cutter for a while. I can't afford the space to have a permanent table so I scoured the web looking for ideas.
Biggest criteria is size; it had to be small enough to fit on my 2x3 welding table or be portable enough to store out of the way.
Discovered Dacs Garage and his design.





						Portable CNC Plasma Cutter
					






					dacsgarage.com
				






Watched all the videos several times and decided to spend $10 for the plans which include .dxf file so the pieces can be waterjet cut if so desired.
The electronics are an Arduino Duo controller running GRBL and Universal G-Code Sender.
I run a Macbook so no Mach 3 or 4 as they require a PC. I may do that in the future but I need to get my feet wet first.
I bought an import Sungoldpower 60A blowback start plasma cutter to go with it.








						Non Touch Pilot Arc Plasma Cutter 60A
					

Sungoldpower Non Touch Pilot Arc Plasma Cutter 60A Hightlight: ★ Non-touch Pilot Arc: it efficiently cuts though rough, painted, and rusty surfaces and produces minimal slag；the technology allows you to cut without touching the tip to the metal. It provides a better cutting quality and longer...




					sungoldpower.com


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## DavidR8

These are the parts that I had waterjet cut


And the results.


These are the second items that I had cut by waterjet. Man it is impressive. The dimensions are dead on.
I goofed up and only had one of the pieces in the upper left cut so I have to hand cut one to match. When I get the thing made I'll cut a new one


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## DavidR8

Breakout board for the Arduino Uno board.


3D printed base for the Arduino board.


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## DavidR8

All the electronics wired up for a test drive.


I need to figure out a case for this stuff. Not sure what I might use just yet.


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## DavidR8

Made some progress today. 
Did the rough assembly of the X and Y carriages. 
I may have to make some changes because the mounting flange on the V-rail I have is wider than the spec’ed V-rail from McMaster-Carr.
The wider flange pushes the gear rack too far inboard. 

Or I might just order the spec’ed V-rail.

This is the underside of X-axis carriage.


The is the X-axis carriage in the working orientation with the stepper motor mount in place and the Y-axis mount roughly assembled.
I had to bend the tabs over in my vise. 1/8" mild steel is no slouch, took care to make sure that it was dead on 90 degrees.


Stepper mount for the Y-axis in place.


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## cathead

Interesting!  It's a little high tech for me but I am watching along for sure.


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## Braeden P

This is going on my project list I already have the software for my router and I have tons of arduino stuff and steppers


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## C-Bag

cathead said:


> Interesting!  It's a little high tech for me but I am watching along for sure.


Ditto. I could see how a small plasma would have use in my packed shop. But I know better than to do complicated electronics. Watched!


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## Reddinr

I'm curious, how much did it cost to get the water jet cutting done?  This design looks interesting what is the cutting envelope?


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## DavidR8

Reddinr said:


> I'm curious, how much did it cost to get the water jet cutting done? This design looks interesting what is the cutting envelope?



Including the material the cutting was $100.
I’m going estimate the cutting area to be about 18" square.


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## C-Bag

There were several factors that stopped me from getting a full size plasma table. Besides the learning curve and for my parts plasma anneals the steel on my thin parts and makes it too soft, major problem was the air pollution in the shop. This is where I think water jet has plasma and laser both beat. Does the design you are making address that? I've not been around a table with a water tank under it, but I would think that would mitigate the toxic fumes somewhat?


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## DavidR8

Waterjet is a whole different animal to be sure. I've never seen it in action in person though.
Plasma I have seen and the difference between having a water table and not is pretty significant. Without, sparks go everywhere whereas the water table catches much of the sparks. It's still a bit smoky though.
I plan to build a detachable water table that will connect to my welding table.


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## vtcnc

DavidR8 said:


> Waterjet is a whole different animal to be sure. I've never seen it in action in person though.
> Plasma I have seen and the difference between having a water table and not is pretty significant. Without, sparks go everywhere whereas the water table catches much of the sparks. It's still a bit smoky though.
> I plan to build a detachable water table that will connect to my welding table.


Just make sure you let the water evaporate off and don't dump it down the drain. You wastewater district will detect the heavy metals and come a-knockin'. You should be able to sell the remaining slag with your scrap all in one barrel.


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## DavidR8

vtcnc said:


> Just make sure you let the water evaporate off and don't dump it down the drain. You wastewater district will detect the heavy metals and come a-knockin'. You should be able to sell the remaining slag with your scrap all in one barrel.


Thank you, that is a very good thing to know!


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## extropic

I know very little about plasma cutters. I've seen a video where the CNC machine had a Z axis mechanism that detected and controlled the torch height from the stock. As I recall, the torch in the video needed to be very close to the stock to "start" and a little higher during the "run".
Also, the Z sensor maintained torch height over warped stock.

I don't see that type of Z control on your machine so . . .
Are you going to use a torch that "starts" and "runs" at the same height or ???
What are your expectations regarding cutting warped stock. In other words, what is the torch to stock tolerance during a cut?

I like the small portable machine concept. I imagine much larger parts could be made by subdividing the cutting into routines that fit within the X-Y envelope of the machine and re-indexing the stock. Is that part of your plan?

Great project, IMHO.


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## koenbro

I do think torch height control is important. I also would not use my plasma without the water table — building v one is probably the easier part of such a project. 


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## DavidR8

extropic said:


> I know very little about plasma cutters. I've seen a video where the CNC machine had a Z axis mechanism that detected and controlled the torch height from the stock. As I recall, the torch in the video needed to be very close to the stock to "start" and a little higher during the "run".
> Also, the Z sensor maintained torch height over warped stock.
> 
> I don't see that type of Z control on your machine so . . .
> Are you going to use a torch that "starts" and "runs" at the same height or ???
> What are your expectations regarding cutting warped stock. In other words, what is the torch to stock tolerance during a cut?
> 
> I like the small portable machine concept. I imagine much larger parts could be made by subdividing the cutting into routines that fit within the X-Y envelope of the machine and re-indexing the stock. Is that part of your plan?
> 
> Great project, IMHO.


To be totally honest this is my first foray into plasma cutting. I know that bigger tables have torch height controls and how I might add that to this is something that I have thought about but no more than that.
I need to do some experimentation with the plasma cutter to see what kind of tolerances are involved. 
If I have to add a torch height control (THC) I may have to re-engineer the whole shebang as I'm not sure the Y-axis could support a THC as designed.


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## DAT510

Plasma cutters ~<40amps can be used in drag cutting mode, (Typically with a drag tip) so if you leave the amperage lower than <40, you can just leave the tip in contact with the metal.


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## extropic

DAT510 said:


> Plasma cutters ~<40amps can be used in drag cutting mode, (Typically with a drag tip) so if you leave the amperage lower than <40, you can just leave the tip in contact with the metal.


Would 40 Amps equate to about 3/8" thick steel stock (maybe 1/2" slow cut)?


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## DavidR8

My plasma unit is rated at 60A. It's a blowback start because I didn't want the electrical interference issues associated with high-frequency start. Unless I start building bigger stuff, at this point my projects are all using 1/8" stock.


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## C-Bag

vtcnc said:


> Just make sure you let the water evaporate off and don't dump it down the drain. You wastewater district will detect the heavy metals and come a-knockin'. You should be able to sell the remaining slag with your scrap all in one barrel.


Well, there goes another reason I’m just going to keep having my stuff done by a laser company. My stuff is 1/8” mild steel that is more or less a basket. All the structure is 1/8x1/8 so lots of cuts and lots of scrap. When I worked everything out I think it would have saved me $$. But when I had one of my units done on a local machine which was exactly the kind of machine I was thinking about buying it did not come out good. Plus if you’ve ever used plasma it does a wonderful job but there is a lot kerf to figure into your engineering and a lot of slag.  I used a plasma freehand for over a decade in my work as a fabricator. So for my kind of one off manual fab I love my little Hypertherm 35. But in the long run for me a CNC table was not going to save me anything. 

 I don’t mean to throw a damper on your project David. YMMV.


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## DavidR8

C-Bag said:


> Well, there goes another reason I’m just going to keep having my stuff done by a laser company. My stuff is 1/8” mild steel that is more or less a basket. All the structure is 1/8x1/8 so lots of cuts and lots of scrap. When I worked everything out I think it would have saved me $$. But when I had one of my units done on a local machine which was exactly the kind of machine I was thinking about buying it did not come out good. Plus if you’ve ever used plasma it does a wonderful job but there is a lot kerf to figure into your engineering and a lot of slag.  I used a plasma freehand for over a decade in my work as a fabricator. So for my kind of one off manual fab I love my little Hypertherm 35. But in the long run for me a CNC table was not going to save me anything.
> 
> I don’t mean to throw a damper on your project David. YMMV.


I totally understand and no damper caught 
To be completely honest this is a bit of a lark as my partner wants some yard art made that I cannot freehand. So it's the usual case of building/buying a tool to make something. She is ever more convinced that I have a shop to make stuff....for the shop 
Every so often I'll turn out something that redeems the silly money pit that it is. Though its contribution to my mental health is priceless


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## Cadillac

My good friend has a 5x10 plasma table with a water table. He just cleaned his table was eleven 5 gallon buckets of slag and small cuts. Scrap yard takes it all. The thc is controlled  by resistance between the torch tip and the material. You program that parameter and it’s suppose to follow it. My friend doesn’t use for a lot of stuff. He gets around it somehow. Great machine makes a killing at craft fairs and through his website. Luckily for me he’s more than willing to do my favors. Tolerances are not bad maybe .030, taper edge sometimes seems to cut better .250 and thicker. Gotta get the machinist tolerances out of the head because it doesn’t do that.


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## vtcnc

C-Bag said:


> Well, there goes another reason I’m just going to keep having my stuff done by a laser company. My stuff is 1/8” mild steel that is more or less a basket. All the structure is 1/8x1/8 so lots of cuts and lots of scrap. When I worked everything out I think it would have saved me $$. But when I had one of my units done on a local machine which was exactly the kind of machine I was thinking about buying it did not come out good. Plus if you’ve ever used plasma it does a wonderful job but there is a lot kerf to figure into your engineering and a lot of slag. I used a plasma freehand for over a decade in my work as a fabricator. So for my kind of one off manual fab I love my little Hypertherm 35. But in the long run for me a CNC table was not going to save me anything.
> 
> I don’t mean to throw a damper on your project David. YMMV.



Yes laser is the right solution for that type of geometry. Depending on thickness, there are some pretty sweet CNC punch tooling out there that loves that kind of geometry and makes short work of it. You just need to know a shop that does precision punching so they know how to not warp your basket weave when pressing.


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## f350ca

I built a 4 x 4 unit with a water table, the water makes a huge difference, but you still get smoke/dust in the air, just not nearly as much. I made my own V ways, rollers even cut the racks on the shaper, that was a slow task. Bought the electronics as a package from I think it was called Candcnc in Texas. I uses the arc voltage from the plasma unit to adjust the torch height. Getting the height correct makes a big difference in the dross left on the back side.
The table opens up a whole world of brackets and braces that would be a pain to cut by hand. I've even cut roller chain sprockets for slow speed applications that worked perfect.






Greg


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## DavidR8

Amazing that those were cut by plasma. 
Are you running SheetCAM?


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## f350ca

I'll have to check the shop computer Dave, will get back to you.

Greg


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## C-Bag

DavidR8 said:


> Every so often I'll turn out something that redeems the silly money pit that it is. Though its contribution to my mental health is priceless


^^^This! My SO understands this and is actually jealous as I do have fun making. I’ve made several things around here but the one you have to go through and see constantly is the front gate arbor. It replaced a rickety wooden one and is solid. It has some of my early prototypes built into it as design features, but my favorite is a foot release which really comes in handy when we’re bringing in groceries. You can’t just go down to HomeDepot and buy one.


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## DavidR8

McMasterCarr amazes me.
I decided to order the spec'ed v-rails.
Shipping label created Mar 22 9:48 pm.
On vehicle for delivery Mar 23 8:16 am.
That includes time for customs clearance.


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## DavidR8

I mocked up the rails tonight because well I'm like a kid on Christmas Eve. 
I realized that I couldn't use the other rails because they are about a 1/16" thick so the end of the motor shaft and pinion gear would have been rubbing on the plate holding the rails. The new rails are 1/4" thick which is necessary for there to be sufficient clearance.


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## Ulma Doctor

Very cool project David!!!
looking great man!


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## DavidR8

Thanks MIke, I'm pretty stoked about it. 
Fingers crossed that I can make all the magic pixies do the right thing


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## DavidR8

More progress today.
Built the rails.
Lots of drilling, countersinking and tapping. Ten fasteners in each rail.
Lots of learning too.
On the bottom rail I miscalculated the width of the flat part of the v-rail and drilled the holes in the flat stock too far inboard which meant the holes were to close to edge of the v-rail. All ten of the holes... 
And I thought I could accurately transfer the hole locations from the  flat stock to the v-rails. Not so much...Doh!
So on the second rail I carefully measured the width of the v-rail in decimal inches, divided that figure in half and then scribed marks for the hole locations. I also clampeed the flat stock and v-rail together to drill the holes.


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## DavidR8

More progress. 
Ends mounted and laying out the gear rack. 











Stepper motor mounted. 






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## rdean

I should have read the beginning  of the thread before asking questions.
Interesting build.

Ray


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## DavidR8

@rdean it's direct drive to the 24 pitch rack via a 15 tooth pinion gear.
The steppers are 175oz/in motors.


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## BGHansen

Nice project David.  Can you imagine taking this on 3 - 5 years ago!  Amazing what a little experience does to build the confidence!

Bruce


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## DavidR8

BGHansen said:


> Nice project David. Can you imagine taking this on 3 - 5 years ago! Amazing what a little experience does to build the confidence!
> 
> Bruce



Thanks Bruce, I really appreciate that. 
As I was working away I was thinking about how I used to see these neat jigs and shop made tools in wood shops and how much I wanted to be to have the skills and tools to make them. 
And so here I am 


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## DavidR8

More progress today. Though I'm not sure that will be apparent from the photos.
Last update I was laying out the gear rack.
Today I drilled and tapped it, counter sunk the holes for the flat head mounting screws.


I had been fretting over how to maintain the .269" spacing from the V-rail. I measured the height of the gear rack at .25" so I decided to use the cut off pieces as spacers. The stepper motor mounts have provisions to adjust the gear mesh so the .019" difference will be made up that way.
The rack is pretty narrow on its face and I was drill and tapping for 6-32 screws. I could only place holes under the gear peaks other wise there wasn't enough material. Needless to say I had my magnifiers on for this 


This is the back of the Y-axis. The top and bottom screws are securing the v-rail. the single screw is for the gear rack.


The bill of materials spec'ed pinion gears without set screws so I had to drill and tap the pinion gears for 10-24 set screws. These gears were $16. With set screws they are a whopping $42. Each. 


Did a trial fit to make sure everything was copacetic.


Definitely a snug fit in there. This is looking down at the Y-axis pinion.


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## extropic

@DavidR8 

It looks like the Y axis rack teeth are facing UP. That is undesirable because any debris will stay there and will interfere with the gear mesh.
Gear wear and possible jamming . . . bad.

I recommend that you go through what ever trouble it is to re-orient the rack so the teeth are down. Let Gravity work for you, not against you.


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## DavidR8

extropic said:


> @DavidR8
> 
> It looks like the Y axis rack teeth are facing UP. That is undesirable because any debris will stay there and will interfere with the gear mesh.
> Gear wear and possible jamming . . . bad.
> 
> I recommend that you go through what ever trouble it is to re-orient the rack so the teeth are down. Let Gravity work for you, not against you.



That’s a good point. I believe the motor mount is symmetrical so I can easily flip the the whole sliding assembly end for end so the rack is on top.


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## DavidR8

Spent a bunch of time cleaning up the shop to day but did manage a bit of progress on the build.
As @extropic sagely noticed, having the Y-axis gear rack oriented teeth facing up was inviting a build up of crud in the gears.
So I flipped the axis end for end and added a tension spring to maintain good gear mesh.
I also milled .05” off the end of the motor shafts as they dragged on the axis plates. Shaft milled like cream cheese as Tom Lipton says.

Though looking at the photo I should probably flip the motor mount so the slot faces down.










I liked how the tension spring worked on the Y-axis so I also added one to the X-axis.





I must be almost done building as the box from McMasterCarr is almost empty


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## f350ca

Looking good David, wise move flipping it, the dust gets everywhere. I have to wipe down/buff my v rails fairly often as the roller pack the grit on them.
Does your spring engage the gear tight into the rack? I made mine that way and it virtually eliminates backlash. 

Greg


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## DavidR8

f350ca said:


> Looking good David, wise move flipping it, the dust gets everywhere. I have to wipe down/buff my v rails fairly often as the roller pack the grit on them.
> Does your spring engage the gear tight into the rack? I made mine that way and it virtually eliminates backlash.
> 
> Greg



Thanks Greg, appreciate the advice on wiping it down periodically. 
Yes adding the spring eliminated any backlash. 
Do you have any pictures of yours?


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## DAT510

Great Project David!  

Do you know what software you plan to run?


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## DavidR8

DAT510 said:


> Great Project David!
> 
> Do you know what software you plan to run?


So far I'm doing CAD/CAM in Fusion 360. Using Universal G-Code Sender (UGS) for the actual machine control. I use a Mac so I can't use SheetCAM as it's PC only.
I recently discovered the Openbuild software though so I'd like to play around with that as a precursor to building a CNC router.




__





						OpenBuilds Software - FREE Software for CNC Control: OpenBuilds CONTROL and OpenBuilds CAM
					

Download page for OpenBuilds Software / OpenBuilds CAM / OpenBuilds CONTROL




					software.openbuilds.com


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## Papa Charlie

Really great work David. I am impressed with the work and thought you have put into this.


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## DavidR8

Papa Charlie said:


> Really great work David. I am impressed with the work and thought you have put into this.


Thank you sir! I cannot claim much credit as I'm working from a plan.
Most of the credit goes to the good folks who I've learned from!
I have learned a ton of things along the way which I think is the most important outcome. Unless you ask my partner who is anxiously waiting on her yard art


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## Braeden P

we had lawn art in our flower bed one got knocked over buried in weed the hedge trimmer does not like lawn art so now we dont have any but we have a new hedge trimmer


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## rabler

Building a plasma table is on my long term list so I'm watching this closely.


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## DavidR8

@rabler So far I have 3/4 of the cutting part... I still need to figure out the actual table part 
I have a welding table with a 3/8" thick top. 
My napkin-grade idea is to add a couple of square tubes under the top of the table, like hitch receivers.
Then I'll make a frame that will hold a tray and slats. The frame will have arms that slide into the receivers.
Thinking I will add a drain to the table.
Hoping this will let me pull the table off, and store it away. Recognizing that it will be a messy process.


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## f350ca

Guess I've never taken a picture of it finished lol
Cutting the racks with the shaper



The rollers use skateboard bearings



Have a belt drive between the stepper and the pinion



The carriage with height control



Assembled before the electronic arrived



It did get painted finally.
A video of it cutting out a belt guard




And a valentine, boy did that get points.





Greg


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## DavidR8

Wow, that's impressive Greg, 
Did you machine the rails too?


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## f350ca

Yah, nodded the head on the mill and indexed the stock to get the length.
Used the table this morning to cut out the parts for my atv winch mount.

Greg


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## Janderso

f350ca said:


> Guess I've never taken a picture of it finished lol
> Cutting the racks with the shaper
> View attachment 361897
> 
> 
> The rollers use skateboard bearings
> View attachment 361898
> 
> 
> Have a belt drive between the stepper and the pinion
> View attachment 361899
> 
> 
> The carriage with height control
> View attachment 361900
> 
> 
> Assembled before the electronic arrived
> View attachment 361901
> 
> 
> It did get painted finally.
> A video of it cutting out a belt guard
> 
> 
> 
> 
> And a valentine, boy did that get points.
> 
> 
> 
> 
> 
> Greg


What are you, some sort of genius?
Who makes their own CNC plasma table?
I've always enjoyed Kieth Fenner's plasma cam. Very versatile!!
Well done sir. I better start paying more attention.


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## DavidR8

@Janderso I think @f350ca is trying to justify his shaper


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## Janderso

DavidR8 said:


> @Janderso I think @f350ca is trying to justify his shaper


David,
Call me Jeff


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## DavidR8

Janderso said:


> David,
> Call me Jeff



I didn’t know if the system would notify you without a mention


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## Papa Charlie

DavidR8 said:


> Thank you sir! I cannot claim much credit as I'm working from a plan.
> Most of the credit goes to the good folks who I've learned from!
> I have learned a ton of things along the way which I think is the most important outcome. Unless you ask my partner who is anxiously waiting on her yard art



You sell yourself short. You are not following the plan to the letter and regardless, it requires a degree of skill to fab, build and assembly a working machine. 

Not something that is that easy to do right.


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## extropic

Quite a few of us are following along intently.
I don't think I'll ever own a large plasma table but this "portable" option has considerable attraction.
David is blazing that trail for me and I appreciate it.
All credit to the guy doing the work.


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## DavidR8

Thank you sir, it's been an interesting project. I still need to line up the magic pixies in the right order so with any luck that goes without any magic smoke


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## extropic

David will please excuse my off topic question in his thread.

@f350ca , Regarding the use of the shaper to make your racks; can you describe the sequence of operations to create each tooth form?
Did you finish a single tooth form/root (feed table up?) then traverse the pitch dim to create the next tooth form/root?
Or, did you set the traverse auto feed to equal the pitch dim so you could work many teeth before re-indexing the stock on the table?
Or, what ???
Love your work.


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## DavidR8

Bit more progress today. 
Made the bracket that mounts the torch holder bracket. 
Made a start on the actual ring to hold the torch. 
Had an aluminum piece with a hole almost the same dimension as the torch head. Bored it out on the lathe and parted it off at the right length. 
Now I just need to figure out how to attach it to the bracket. 














I’m thinking that I’ll TIG on a rectangular piece to one side of the ring, drill and tap so it can be attached to the bracket.


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## f350ca

extropic said:


> David will please excuse my off topic question in his thread.
> 
> @f350ca , Regarding the use of the shaper to make your racks; can you describe the sequence of operations to create each tooth form?
> Did you finish a single tooth form/root (feed table up?) then traverse the pitch dim to create the next tooth form/root?
> Or, did you set the traverse auto feed to equal the pitch dim so you could work many teeth before re-indexing the stock on the table?
> Or, what ???
> Love your work.


Sorry David for cutting into your project and sorry I never noticed the question till now.
Used 14 1/2 degree pressure angle so a ground acme cutter forms a rack tooth. Cut each tooth to depth with the down feed then advanced over to the next. Added the dro for this project, would have been impossible without. Had pre drilled and reamed the mounting holes using the mill and dro so I could index the material over and start another set of teeth. Did the 3 racks as a set clamped together, when finished I could turn one end for end and they meshed down the length. Think that was more luck than anything. lol

Greg


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## Papa Charlie

Dave, looking good.

I would make the rectangular Al piece the same width as the bracket that you will be attaching it to and at least 1/2" taller than the ring. That would give you sufficient room for two holes to bolt it to the bracket. Also I would add a threaded hole into the ring to put a threaded knob as a locking bolt in to ensure the torch is held firmly.

Here are some examples:








						McMaster-Carr
					

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.




					www.mcmaster.com


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## springer

Wish I knew more about all the electronics stuff, I'd love to have a cnc plasma around the house. 

Very nice job!!


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## DavidR8

Papa Charlie said:


> Dave, looking good.
> 
> I would make the rectangular Al piece the same width as the bracket that you will be attaching it to and at least 1/2" taller than the ring. That would give you sufficient room for two holes to bolt it to the bracket. Also I would add a threaded hole into the ring to put a threaded knob as a locking bolt in to ensure the torch is held firmly.
> 
> Here are some examples:
> 
> 
> 
> 
> 
> 
> 
> 
> McMaster-Carr
> 
> 
> McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.
> 
> 
> 
> 
> www.mcmaster.com



Thank you, thats a brilliant idea!


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## DavidR8

springer said:


> Wish I knew more about all the electronics stuff, I'd love to have a cnc plasma around the house.
> 
> Very nice job!!



Thank you, honestly I know very little! 
I’m learning as I go.


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## hman

I've often discovered that the best way to learn something new is to "need it for a project."  That really focuses your attention.  The down side is that sometimes you only learn one aspect of the "something."  But at least you get a working knowledge.


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## DavidR8

Today’s progress. An iteration or two (eyeroll here) got me to this torch mount. 








See the hole peeking out from behind the torch? That’s a 1/4-20 hole that I made to mount an aluminum plate which had the round holder attached. 
Turned out the screw heads interfered with the torch body so that version was scrapped. 
Second iteration ended up by drilling the steel plate and directly attaching the collar. 

I have been thinking ahead to how I’m actually going to hold the thing down and made a happy discovery. 
The X-axis is exactly 24” wide, the same as my welding table. 
So it fits perfectly across the width. 
I think I’ll swap out end plates for a couple of pieces of square tube. I’ll cut out one side and mount the with the open side facing out so I can clamp it down.


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## Papa Charlie

Couldn't you have removed the torch to install the countersunk machine screw?


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## DavidR8

If only I had some of those in my stock.
My only 1/4-20 fasteners are the round head ones in the third photo.
I have no idea what I did with the correct screws.

Edit: I do have some 1/4-20 screws but the heads are massive so the countersink would have to be very deep. I actually don't know where they came from.
I'm not convinced that the torch holder is the final version but it's got me thinking about how to do it better.


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## Papa Charlie

Couldn't you just move the mounting screws farther out to the sides. If the mounting plate was the full width of the bracket you are attaching to and was a little taller, maybe 1/2" taller than the ring, you should be able to fit those screw heads in to either side of the torch.

Something like this.


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## DavidR8

That would also work. 
Thanks for the suggestion sir!


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## DavidR8

A bit of work last night to make a better torch holder. 
2x2 block, bored to 1” in the 4-jaw. I plan to cut it vertically, parallel to plate so it can clamp the torch head. 
Also need to mark and drill to attach it to the vertical plate and mill recesses for 10-24 SHCS to hold the two halves together. 
I might also break out the rotary table and radius the front 
Ignore those two holes. They are from a prior attempt to make a mount.


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## Papa Charlie

If you are using a torch with a handle as apposed to a machine type config, you may find your new design to be better suited to support the weight of the torch and the cord.


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## extropic

^^^ There you go !!!  ^^^

My recommendation: Don't radius it. Think of it as a spatter shield.


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## DavidR8

Thanks gents, it definitely feels more substantial and fit to task!


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## BGHansen

DavidR8 said:


> Ignore those two holes. They are from a prior attempt to make a mount.


Looks like a job for your TIG welder if they bug you.  I forget about "gluing" patches in mistakes all the time.  Gouged a part on my Bridgeport cutting a slot with an 1/8" end mill, didn't lock the quill when making a pass.  Fired up the AHP AlphaTIG and made the hole go away.

Bruce


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## DavidR8

BGHansen said:


> Looks like a job for your TIG welder if they bug you. I forget about "gluing" patches in mistakes all the time. Gouged a part on my Bridgeport cutting a slot with an 1/8" end mill, didn't lock the quill when making a pass. Fired up the AHP AlphaTIG and made the hole go away.
> 
> Bruce



Yup, I think I’ll do exactly that. Because they do bug me.


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## f350ca

What you have would work as is David. There's no need to clamp the torch. I incorperated a thumb screw to fix it but have never used it. Gravity is your friend. You do need to hold the cable up above the table so the cnc doesn't need to drag it. I use the overhead crane, the torch can swing in the mount as it moves around.

Greg


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## DavidR8

f350ca said:


> What you have would work as is David. There's no need to clamp the torch. I incorperated a thumb screw to fix it but have never used it. Gravity is your friend. You do need to hold the cable up above the table so the cnc doesn't need to drag it. I use the overhead crane, the torch can swing in the mount as it moves around.
> 
> Greg


Thanks Greg, the torch is a snug fit in the block so I might just give it a go as-is.


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## DavidR8

DavidR8 said:


> Thanks Greg, the torch is a snug fit in the block so I might just give it a go as-is.



Torch holder is done. 













Had a rethink on how to attach it to the table. Some 1X tube with openings cut for a C clamp.


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## DavidR8

Hang on to your hats, 
Lock up your loved ones,
The plasma cutter is alive!!!





Nothing special, just a trial of 5"x5" square


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## extropic

You made that look easy.

Congratulations.


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## DavidR8

Thanks very much!
It's a steep curve. Feel like I made it out of basecamp tonight. 
Next I need to build an enclosure for the electronics and fab up the actual table bit.


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## extropic

And soon there will be yard art !!!


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## DavidR8

Indeed, my partner is genuinely excited now!


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## DavidR8

Big progress today. 
Built the removable table. 
1” square receiver tubes under the table. 
3/4” arms with 1” cross supports. 









Made a water tray out of 22ga sheet metal and MIG welded the corners. Watertight (shocking no one more than me)


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## DavidR8

Built the electronics enclosure today. 
Looked at various readymade enclosures but couldn’t find one in the size I wanted. 
So I ventured into my lumber rack and got some sanded 1/2” plywood. 
Had a suitably size aluminum sheet in the scrap bin to mount the various bits. Cut some nylon spacers to raise the mounting plate off the bottom. 
Cut a piece of aluminum for the front to mount the aircraft connectors and the 24v power supply. 
I’ll paint it black and henceforth will be known as “The Black Box” 
















I also sorted the v-wheel tensioning screw problem.


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## DavidR8

All wired up and ready to go. Just need to wire in the torch controller.


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## DavidR8

And it’s alive!
I’m actually completely gobsmacked that it works.


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## Gaffer

Awesome, and great job on a very cool project!


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## DavidR8

Gaffer said:


> Awesome, and great job on a very cool project!


Thanks! 
Some fine tuning to do but the hard work is done


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## DAT510

Great Job!


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## brino

Very inspiring!
Thanks for bringing us all along.

-brino


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## DavidR8

brino said:


> Very inspiring!
> Thanks for bringing us all along.
> 
> -brino


Glad to have all you good folks cheering me on!


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## f350ca

Congratulations !! Hope the first cut wasn't the deepest. lol

Greg


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## DavidR8

f350ca said:


> Congratulations !! Hope the first cut wasn't the deepest. lol
> 
> Greg



Hah! 
Naw, Rod and I are tight. 
It was just 22ga. I’ll try some thicker stock when I get the slats for the water table done.


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## extropic

Excellent project.

The cutter is starting and running OK without an active Z axis height control, yes?

There seems to be some error between when the cutter is moving away from the camera vs toward camera. I noticed what looks like (nearest the camera) a flat (cord) on the round hole and the two short segments of the square don't converge. Are those intended or mechanical backlash or software tuning? My question is, if those observances aren't intended, where do you expect to implement the fix?


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## DavidR8

extropic said:


> Excellent project.
> 
> The cutter is starting and running OK without an active Z axis height control, yes?
> 
> There seems to be some error between when the cutter is moving away from the camera vs toward camera. I noticed what looks like (nearest the camera) a flat (cord) on the round hole and the two short segments of the square don't converge. Are those intended or mechanical backlash or software tuning? My question is, if those observances aren't intended, where do you expect to implement the fix?


It's a blowback start torch so as soon as I pull the trigger/activate the torch it fires, even if it's inches away from the stock.

I'm not sure what happened on that square as I re-ran the file and it cut just fine. I have a hunch something got hung up and caused it to skip a tooth on the x-axis gear rack.
@extropic I figured out the problem. The torch cable moved the sheet slightly as the X-axis moved toward the camera.
Starts at :07s in the video. You can see the edge of the sheet move about an 1/8"+.


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## rwm

So cool...
R


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## DavidR8

rwm said:


> So cool...
> R



Thanks!
It’s pretty amazing to watch run. 
Full disclosure: the first time the torch fired I jumped back because I was so startled.


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## jwmelvin

Lol, I can imagine your reaction. Nice work on the table; it looks like fun.


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## DavidR8

Used my metal shear to cut strips for the water tray. Not perfect as I need to add a couple at the near end. 
I was going to use the plasma cutter to cut them but the torch switch is wired to the black box. 
I have some new connectors coming so I can also use it as a handheld torch.


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## BGHansen

Just curious how the water tray works in use. I have a cheap inverter plasma cutter and recall cutting 1/8" steel using whatever current and air at 30-40 psi. Does the air tend to blow the water out of the tray? Seems like all nice tables have them, the design must be sound.

Bruce


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## DavidR8

BGHansen said:


> Just curious how the water tray works in use. I have a cheap inverter plasma cutter and recall cutting 1/8" steel using whatever current and air at 30-40 psi. Does the air tend to blow the water out of the tray? Seems like all nice tables have them, the design must be sound.
> 
> Bruce



It serves a couple of purposes: the water absorbs the sparks that blow out the bottom of the cut and the water helps cool the metal.


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## koenbro

BGHansen said:


> Just curious how the water tray works in use. I have a cheap inverter plasma cutter and recall cutting 1/8" steel using whatever current and air at 30-40 psi. Does the air tend to blow the water out of the tray? Seems like all nice tables have them, the design must be sound.
> 
> Bruce



The water bubbles and cools the metal, traps the smoke and does not splash out except when cutting at the very edge of the tray. Evaporation is a bigger concern, I drain mine into a drum (with a lid) at the end of a day and use a small pump to refill in the morning. 


Sent from my iPhone using Tapatalk Pro


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## Boswell

I have seen video's where the water level is raised under CNC control so that the metal to be cut is touching the water. even seeing wetness on top of the target metal. This does not seem to interfere with the cutting.


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## Tmate

Another consideration is selecting a space for your small CNC plasma table is the tremendous mess it creates.  Plasma dust goes everywhere and settles on everything, not to mention in your lungs.  Sparks fly everywhere, and debris falls out the bottom.  Water tables help reduce plasma dust, but create a mess of their own.  

The solution that I have used over the years can be found here:  https://www.hobby-machinist.com/threads/cnc-plasma-cutting-when-you-have-no-space.85935/


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## DavidR8

Tmate said:


> Another consideration is selecting a space for your small CNC plasma table is the tremendous mess it creates.  Plasma dust goes everywhere and settles on everything, not to mention in your lungs.  Sparks fly everywhere, and debris falls out the bottom.  Water tables help reduce plasma dust, but create a mess of their own.
> 
> The solution that I have used over the years can be found here:  https://www.hobby-machinist.com/threads/cnc-plasma-cutting-when-you-have-no-space.85935/


I did make a water table but it's a hassle to be sure.


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