[asuratman]

Hi anxpert,
You better make a combination with 4 axis rotary tube cutter plasma or OA. Like Millman52 said combination w/router is not good. I wanted to do it before but then decided to make it 2 machine, plasma and router. Its not easy to remove and clean plasma slat and remove router table. Clean it, replace it.

[millman52]

There is more on an upgrade to this table here: http://www.cnczone.com/forums/showthread.php?t=98346

ffelini, I don't know anything about UBcustom. I couldn't advise you there.

[Torchhead]

The most successful Multi-use Router/plasma combo I have seen is a "split" table (part router on one end, part plasma on the other). It requires you design it for both types of cutting. The gantry has to be heavier and a lot more rigid for the contact cutting and have the torque at lower speeds to do routing will still being able to have good acceleration (torque) and speed to do plasma cutting. So you need a table that has both speed AND torque/resolution at the same time (since the linear motion components are the same. To sling a heavy gantry around quickly calls for torque. You can do it with steppers if you gear it correctly but it's a compromise. The best approach is to use servo motors that exhibit BOTH speed (RPM) AND torque at the same time. That will add to the cost and complexity of the table and at some point the idea the savings from having one gantry and one set of controls evaporates. With a kit from http://www.PrecisionPlasmaLLC.com (or their ganty kit) you can built a complete 4 X 4 plasma table (with Torch Height Control) for under 5,000. It uses ultra light gantry construction for plasma/flame only cutting. A separate router table with a more rigid gantry and different final gearing or linear drive type can be configured. On that table you aim is to have torque at lower speeds so the heavier gantry is no as much an issue.

I found when I built my first machine (multi use) that the demand for PAYING jobs was totally lopsided towards plasma. To cut a design in steel that sells for over 100.00 took about 1/3 the total time (or less) that a wood or foam design. The switch over time (because the table was not split) was in the range of 45 minutes. The perceived value of a carved wood piece was less than a simple 2D plasma cutout. It did not take long for us to forget the router part and switch the table to 100% plasma (just followed the money!)

There is always the problem of mixing a process that uses a 30,000 deg arc/flame and generates the nasty volcanic ash of plasma with any cutting process that leaves flammable debris (wood/plastic). With a split table the control is easier by covering one side or the other when not in use but you still need to keep dust and smoke under control on both ends. I have built several tables over the years and two have been mixed use. My first (because I didn't know better and only had money for one table) and the second for being able to quickly setup and test different configurations for our products (CNC Controls). I have a dedicated plasma table but it is used in production of metal only (decorative cutting) and in a different shop and building. The current split table is a 5 x 6 ft with a place to mount a horz rotarty axis and a water tray/grid on the back 28". 95% of the cutting on this table is for production of aluminum plates and milling fiberglass and plastic components. I require the machine be kept clean of debris and chips and we work to block off the non-cutting area. Even with that I would never try to use the plasma side very often. It is just is not compatible in a shop that has electronics production and a machine shop area.

The electronics to do plasma table control if you use an integrated control (where Z is a true third axis) can be used to do any 3 or 4 axis cutting. When plasma cutting the Z becomes the THC. When routing/milling/drilling the Z is the 3rd axis. You could in theory switch the central control between two tables to lower the totally cost , but you would still have to make both of them the same type of motors if you wanted to avoid having separate power supplies and motor drives.

The UBCustom table is an interesting read but it looks like a LOT or man-hours of hard wiring. There is probably 100 man hours alone in just the controller wiring and testing
Lots of soldering and running wires. I don't see any information about what control software they are using and if they have plans for a THC for plasma cutting. In a lot of areas they did things far beyond what they need to and spent a lot of extra time and money they did not need to. If you don't know the real-world numbers it's hard to engineer the electronics to be optimized so builders tend to just use "overkill". While that may give you less things to worry about, it costs you in space and money to buy power you will never use. You can justify a 200 hp motor in a car if you want the added acceleration on rare occasions but it's hard to justify a 600 Hp car for the same use. Just my personal observations. The mechanical part of the build (for which I have lss expertise) is interesting but way overkill for plasma cutting only.

TOM caudle
www.CandCNC.com
Totally Modular CNC Electronics

[DanOSB]

im the guy who owns that ubcustom table..

currently that plasma table i was building a while ago is being used for a router setup.. little more work left on it.. (that controller on it doesnt have thc and the guy who build it was mike laws (i dont see him on the board anymore and he doesnt build electronics anymore too..)

for my other plasma cnc table i use candcnc stuff.. you cant go wrong with candcnc electronics (i'm planning to build another cnc machine sometime soon.. I will be using candcnc stuff for sure..

Cheers
Dan

[Torchhead]

im the guy who owns that ubcustom table..

currently that plasma table i was building a while ago is being used for a router setup.. little more work left on it.. (that controller on it doesnt have thc and the guy who build it was mike laws (i dont see him on the board anymore and he doesnt build electronics anymore too..)

for my other plasma cnc table i use candcnc stuff.. you cant go wrong with candcnc electronics (i'm planning to build another cnc machine sometime soon.. I will be using candcnc stuff for sure..

Cheers
Dan

Oh, Dan, thats' YOU ??

Was not trying to knock the design other than to point out what you have probably already figured out

I know Mike is still around but his business has kept him from having a lot of spare time to do machine builds and post stuff up here.

All his stuff was based on MACH3 and worked with our MP1000 except you didn't need the BOB(s) because all of that was built into the MP1000. The current product still has the BOB (UBOBIII) but technology has allowed us to reduce the number of required parallel ports for doing the Motor drive signals, Homes & Limits, and THC feedback inputs to ONE parallel port.

Regards
TOM caudle
www.CandCNC.com

[anxpert]

Thank you for your comments and suggestions ... I must clarify that the router part of my build is for very soft wood or foam so that we can create models for fiberglass.

Per Tom's suggestion I am convinced that the Plaz Pak 5 System was the correct choice for this project, and will be integrating an adustable water level table to minimize the " dirty " part when utilizing the Plasma.

We have allocated an enclosed " sprinklered " area for our table, painting all surfaces with two part Epoxy Paint for ease of clean-up and a re-conditioned restaurant type extractor.

If anyone has a source for baseline drawings for a 4 X 8 / 5 x 10 Table, it would be greatly appreciated.

Regards,

EM

[millman52]

For the past 3 weeks or so I have been sourcing & building a Gas control for my table.

This allows the preheat gas to be bumped higher to significantly shorten preheat times. Once the pierce happens the flame automatically cut to only what is necessary to maintain cut. This eliminates top edge rounding/beading.

It also allows the pierce to begin at a lower pressure then automatically increase to desired cut pressure. Pretty much completely eliminating metal blow back into the tip.

Have been testing for a couple days now. So far on 3/8" & 5/8" A36. At this point it is working great. Can't wait to get back into 3/4,1, & 1 1/4" plate to see how it does.

[millman52]

Finally got around to installing my new gantry with 25MM rail.

As of right now everything is installed & ready to re align & check for square. I'm sure I'll have to change some settings (working envelope) in Sheetcam to take care of any minor placement changes.

While making these changes I also had the opportunity to inspect wear on the pinions, pinion bearings etc. After 27 months of every day usage & 2 sets of slats completely consumed. I was pleased to find very little wear on the pinions. The double (back to back) flanged pillow block bearings that support the pinion shafts still feel like new.

The Stepper PlazPack from www.CandCNC.com With Mach 3 & Sheetcam has worked flawlessly. Thanks Tom for a great product.

Picture update to follow.

Neil

[millman52]

Here is a few pictures of the new work.

The new rail is 25MM & the bearing cassette is massive nearly as long as the width of a fork on the fork lift. The cassette has (8) sealed needle bearings inside which gives terrific dirt/grit fighting ability along with full scrapers & seals on the bearing.

Next will be adding the plasma so it can remain mounted full time as well.

[Dustin407]

Millman,

You did a very nice job on the new gantry.... Looks great. I like how you put the rail up top to keep the debris out of the bearings, i know you have sweepers but every little thing helps. Do you think the gantry will be too heavy to acheive the high ipm when you hook up the plasma? If you are mainly cutting thicker plate things should work well for you....

[millman52]

Thanks Dustin,

I did weigh the individual components while I had the gantry assembly tore down Everything calculated but friction, & there is very little everything floats very free with the pinions out of the racks. The entire assembly tallied up at 172#. That's everything including wires,hose etc.

I have dual X (Long axis) drives that are in the 760 oz. in range, 4:1 belt reduction with a 3/4" pinion. I am getting 600+ IPM with mach kernel speed at 35000 If I drop to 25000 I can still achieve over 400 IPM.

I don't do art type work & 95% of what my shop requires is 3/8" & thicker. I probably use 6-8, 4 X 8' sheets of 1/4" per year. & have been farming out a bit of 1/8" or 11 ga. HT cut charts call for apx 100 to just over 200 IPM depending on the size consumable you are using. I should be good for the work I make a living doing.

I guess time will tell how crisp of a corner I can get at 200 IPM range on the acceleration end of the equation. but just watching it run a program without cutting it looks pretty good & I haven't experimented with the acceleration #s to see when I might begin to loose position.

[millman52]

Millman,

You did a very nice job on the new gantry.... Looks great. I like how you put the rail up top to keep the debris out of the bearings, i know you have sweepers but every little thing helps.....

I had the engineering department a Parker/Origa calculate for the rail being on top. For some reason most published information on linear rails is for side mounting.

The engineering department wanted to know things I had never really given any thought. In my case the static load to the bearing cassette is cantilevered off to 1 side, the length of cantilever, weight, maximum speed of travel etc. all these things matter when choosing the correct rail.

Had I had the plasma Z axis installed & the plasma torch it would have balanced out the load on the cassette back to at least near centerline. I could have used 20 MM rail.

I used 25MM because I didn't know how long it might take me to get the 2nd. Z & plasma installed. There wasn't a huge difference in price anyway.
In this case bigger is probably better anyway.

[jjellingson]

Millman, your a pretty sharp fella, on you second gantry now. You gave me some advice not to long ago about using home switches to square ones gantry. I have read, and re read, tried and tried over and over to keep my gantry square. Mind you, your answer about homing was my solution. Even though I have not installed my X or Y switches yet. I did take time to square up my gantry as square as I thought it could be, scribed marks to relocate to when needed. During my learning curve (which by no means is over) I continue to have mishaps that knock the gantry out of square. I used to loosen the bolts and do the long drawn out process of squaring again. I have found that if I let the X float on the two Y bearing trucks (just enough to allow parallelism) I can move the gantry close to my marks, shut the power off and manually turn one drive to square up the gantry and power up again. Basically the same as you do now and I will do when I get my switches installed. My theory is regardless of the amount of time one puts in to engineering and building a gantry the motors have the final say. I need to know your thoughts on this, wouldn't a fella be ahead of the ball game if he designed that into his gantry? let the beam or beams float. (assuming it is a dual drive system) keeping the trucks perpendicular for the drives would be crucial. Seems to me this would be easier on rack and pinion drive systems, allow for any misalignment with welds pulling things out of square, basically allow for mistakes on at least one plane for a builder. This make sense?

[jjellingson]

Millman,
here is a simple concept in autocad 3d.

[jjellingson]

Here is a scan in case the drawing doesn't open

[millman52]

Millman, your a pretty sharp fella, on you second gantry now. You gave me some advice not to long ago about using home switches to square ones gantry. I have read, and re read, tried and tried over and over to keep my gantry square. Mind you, your answer about homing was my solution. Even though I have not installed my X or Y switches yet. I did take time to square up my gantry as square as I thought it could be, scribed marks to relocate to when needed. During my learning curve (which by no means is over) I continue to have mishaps that knock the gantry out of square. I used to loosen the bolts and do the long drawn out process of squaring again. I have found that if I let the X float on the two Y bearing trucks (just enough to allow parallelism) I can move the gantry close to my marks, shut the power off and manually turn one drive to square up the gantry and power up again. Basically the same as you do now and I will do when I get my switches installed. My theory is regardless of the amount of time one puts in to engineering and building a gantry the motors have the final say. I need to know your thoughts on this, wouldn't a fella be ahead of the ball game if he designed that into his gantry? let the beam or beams float. (assuming it is a dual drive system) keeping the trucks perpendicular for the drives would be crucial. Seems to me this would be easier on rack and pinion drive systems, allow for any misalignment with welds pulling things out of square, basically allow for mistakes on at least one plane for a builder. This make sense?

Yes, As long as there isn't any play in the pivot points. As in rattle, your dual drive motors will square the thing right up with the home switches & hold it square as long as there is power on the motors.

With the pinions disengaged from the racks on my table the gantry isn't rigid at all as far as side to side. In other words if it only had a drive on 1 side the other would lag or trail behind.

I am sorry I haven't answered before now. I have been swamped with work. I read your PM a few days ago & just now have had the chance to be at the computer for a few min.

[WSS]

Very glad to hear it! We had some sprinkles of rain last week and everybody went in to hibernate in So. Cal.

Merry Christmas!
WSS

[millman52]

Well time for yet another update. Started this table in late 2007 has ran over 40 hrs week for last 2 1/2 - 3 years.

CandCNC electronics Flawless. Had a bearing go out in my Z axis NEMA23 motor. Was from dirt contamination not a flaw or defective part.

My home made "X" long axis rails have worked great & still show very little wear. My gantry rail on the other hand, being a single profiled precision rail has wore beyond satisfactory use 2 times & I have installed a 3rd rail.

I think the answer is probably 2 linear rails running parallel. Wear in the bearings & on the rail(s) will still develop but shake or wiggle would still be within good operational parameters. I thing best answer is not use profiled linear rail at all.

The dirt/grit these tables create is impossible to keep out of precision linear rail/bearing. Yes they can be greased which does help. However when any lubricant is left on an exposed surface (every time they move) it's like a grit magnet.

From an economic standpoint for me the table produces apx. $50.00 per hr. running... but is a dead cost when the operator is greasing then wiping excess grease from rails.

When I build again it will be all V rail, runs dry, self cleans, basically 0 maintenance.

[MonoNeuron]

I remember years ago you said there were heaps of dust and soot flying around when cutting so I made some high tensile nylon V guides for my gantry's X axis (long) rails when I built mine. I took the "not always good" cheap path. In hind sight, it would have been cheaper to buy the bearings than the cost of the time and material to make my own, and the bought ones would have been more accurate and functional.

I have cut about 10 meters of cuts in 4 years because every time I use the thing I have something stuff up the THC and the nylon guides have actually worn out the recess where the bearings fit making them a bit sloppy. It doesn't detract from the actual working of the machine though because all the weight is vertical and easily taken up by the THC (about 0.25mm)
I am going to cut my Plasma machine up and do a complete rebuild that will be a lot more stable and use rack and pinion on both sides for the X but I think I will keep the roller chain for the Y axis as it works very well over the short distance with not much load on it. Rack in Australia is so darn expensive. McMaster-Carr used to deliver to Aus but now only ship to large organisations so that is a bit of a let down as their rack is so cheap.

I will have upside down angle iron on 1 side only with bought V guide wheels and the other side will be a flat roller or idler. I found you don't need 2 V guides, 1 either side, to keep the gantry aligned. As long as you put a roller underneath the support for the V guide to stop it lifting, there isn't much of a problem with alignment.
I have bought some piano wire to set up the angle iron but I'm not sure if I need it. I just made a small jig out of angle iron to be clamped against the tubing and the rail is pulled back against that and clamped and welded (tacked) in place. You just need to run a straight edge along the tube you are welding it to to make sure it's flat and straight.
When I bought the steel for my table I had it cut and delivered and when I got it the square tubing's sides were 1mm rounded and not flat across them. That stuffed up the entire build. if buying your own steel go there and hand pick it as the steel merchants might think you just need it for a fence post or something. I was disappointed to say the least. $1100 with of steel!

The angle iron is within 0.003" (+0.0015 to - 0.0015) in height after welding in place over the whole length so it is remarkable the tolerances the steel mills can get with mass produced items.
I am yet to fit the Oxy head I got from you but it will go into the next build as well as a plate marker for small hole marking. I have all the stuff and will probably follow your previous thread in fitting the Oxy set up. A lot of good info is in there.
Thanks Millie
Rich.
P.S. Sorry about the ramble. :-)

[millman52]

I remember years ago you said there were heaps of dust and soot flying around when cutting so I made some high tensile nylon V guides for my gantry's X axis (long) rails when I built mine. I took the "not always good" cheap path. In hind sight, it would have been cheaper to buy the bearings than the cost of the time and material to make my own, and the bought ones would have been more accurate and functional.

I have cut about 10 meters of cuts in 4 years because every time I use the thing I have something stuff up the THC and the nylon guides have actually worn out the recess where the bearings fit making them a bit sloppy. It doesn't detract from the actual working of the machine though because all the weight is vertical and easily taken up by the THC (about 0.25mm)
I am going to cut my Plasma machine up and do a complete rebuild that will be a lot more stable and use rack and pinion on both sides for the X but I think I will keep the roller chain for the Y axis as it works very well over the short distance with not much load on it. Rack in Australia is so darn expensive. McMaster-Carr used to deliver to Aus but now only ship to large organisations so that is a bit of a let down as their rack is so cheap.

I will have upside down angle iron on 1 side only with bought V guide wheels and the other side will be a flat roller or idler. I found you don't need 2 V guides, 1 either side, to keep the gantry aligned. As long as you put a roller underneath the support for the V guide to stop it lifting, there isn't much of a problem with alignment.
I have bought some piano wire to set up the angle iron but I'm not sure if I need it. I just made a small jig out of angle iron to be clamped against the tubing and the rail is pulled back against that and clamped and welded (tacked) in place. You just need to run a straight edge along the tube you are welding it to to make sure it's flat and straight.
When I bought the steel for my table I had it cut and delivered and when I got it the square tubing's sides were 1mm rounded and not flat across them. That stuffed up the entire build. if buying your own steel go there and hand pick it as the steel merchants might think you just need it for a fence post or something. I was disappointed to say the least. $1100 with of steel!

The angle iron is within 0.003" (+0.0015 to - 0.0015) in height after welding in place over the whole length so it is remarkable the tolerances the steel mills can get with mass produced items.
I am yet to fit the Oxy head I got from you but it will go into the next build as well as a plate marker for small hole marking. I have all the stuff and will probably follow your previous thread in fitting the Oxy set up. A lot of good info is in there.
Thanks Millie
Rich.
P.S. Sorry about the ramble. :-)

I see nothing wrong with using angle for your "guide rail". I'd probably opt to polish the black off using an 80 or 120 grit flap disc type grinding wheel. Being careful to hold it flat on the surface so not to gouge into the base steel. To me at least, the key to good cuts is very smooth & fluid movement.

The Cold Rolled round I used might have a flat worn into it about 1/8" wide after much use. All this has done is let the gantry "settle" that slight amount

Only reason I'll use the hardened "V" rail is simplicity of installation & then easily replacable if somehow accidentally damaged.