Advise on building a CNC table

[T0rnado69]

hi all, ive for a long time been thinking about a cnc table.

and want to get a list together of what i would need.

been doing a lot of reading different forums, builds and. google searching.

i would say 4ft by 2ft cutting.

steel box frame.

i was looking at making the table so it can be used for plasma cutting with a water table.

or

put thick ply over the top of the emptied water table and use it with a router for woodworking.


cheers

[T0rnado69]

wow nearly 100 views and not one reply with any advice.

[Clive S]

wow nearly 100 views and not one reply with any advice.Hi I don't think you have actually asked a question as to what advice you need. ..Clive

[EddyCurrent]

put thick ply over the top of the emptied water table and use it with a router for woodworking.

If water table was a T slot design the plywood would fasten easily.

[Clive S]

If water table was a T slot design the plywood would fasten easily.Eddy Would the dross or what ever it is called stop the plywood from being flat on the table when fixed down etc. ..Clive

[mekanik]

Hi Clive
Don't know how deep the metal spray would penetrate your tank before solidifying ? but i would cover your "T" slot arrangement with a sacrificial sheet of light gauge Galvanized Steel.When you change to router mode after cleaning and fixing your sacrificial board you will have to skim it to get it flat before you can use the machine.
regards
Mike

[EddyCurrent]

Eddy Would the dross or what ever it is called stop the plywood from being flat on the table when fixed down etc. ..Clive

It's the logic of how I've read the statement;



i was looking at making the table so it can be used for plasma cutting with a water table.

or

put thick ply over the top of the emptied water table and use it with a router for woodworking.


So I read it as ;

Plasma and water table (not router) OR water table and router (not plasma)

in which case I did not take account of the dross from plasma and in fact I thought it would be very difficult to combine all three considering the mess a plasma would make to the bed/table

[Clive S]

Hi Clive
Don't know how deep the metal spray would penetrate your tank before solidifying ? but i would cover your "T" slot arrangement with a sacrificial sheet of light gauge Galvanized Steel.When you change to router mode after cleaning and fixing your sacrificial board you will have to skim it to get it flat before you can use the machine.
regards
Mike Mike Might be wires crossed here my post was indirectly in response to TOrnado69 but yes I get what you are saying.

Eddy Funny I read it one way and you the other:fox: I agree the disciplines just don't mix at all. ..Clive

[EddyCurrent]

Eddy Funny I read it one way and you the other:fox: I agree the disciplines just don't mix at all. ..Clive

Yes, it would have to be an 'and' instead of 'or' for me to think the OP meant combine all three.

Edit: if it helps explain it, I'm left handed and of non mechanical background :abnormal:

[JAZZCNC]

Well I've read it as he want's a router and Plasma with a waterbase.!!

If your going to take this route then think carefully about design because changing from one to the other won't be simple as just throwing a bed on top, you'll need to consider Spindle and Torch location because as anyone who's built a CNC router will tell you setting the spindle up takes a good while and you won't want to be removing in a hurry, then you have skimming the bed everytime you switch which becomes a pain.
You'll also have to consider the affects of heat throwing the accuracy of the frame and bed out, which for a plasma doesn't really get noticed or matter, but a router will see it easily. Also plasma is messy and abrasive compared to router and they won't sit well together.

Personally IME these type of Combi machines never do anything really well and there's always a compromise. Better building one or the other to be best they can be.

[longy]

Personally IME these type of Combi machines never do anything really well and there's always a compromise. Better building one or the other to be best they can be.

I agree totally with Jazz combination machines of any type never do 100% of what you want them to do. You can't beet a purpose build machine any day. Tried a few different combination machines in the past thinking I could save money and then lost money when I sold them.

Mike

[EddyCurrent]

I've just read it again, and not being up on plasma and water tables I assumed that plasma cutting was done on a bed of slats or inverted angle irons and that a water table referred to a T slot type affair for cutting aluminium with flood coolant/lube. Now I realise that the plasma and water table are one and the same thing. :nightmare: I need to lie down for an hour with some Slipknot full blast.

[T0rnado69]

clive S. i guess thats true.
erm i guess all and any advice is good.
for the size of table i want. what size frame would be ideal.
best place to get the steppers. and other electronics.
software ?

Eddy
i guess that would make it easy to fasten.
but the mess the plasma leaves when it cuts would
proberly mess it up, and i thought of another way to fasten the ply to the water table.

jazzycnc
a lot of reading tells me thats it best to have a water table with cnc plamas.. helps keep the metal cool and cuts down on the smoke etc.
changing it over to a router would be fairly easy.
take the torch mount off the gantry and fit the router mount on.
sking any slats that have dross on the top with a soft disc.
fix ply bed onto 4 or 6 tabs that are welded to the water table slats.
i understand that they proberly dont belong together.
but if it turns out they both dont work well together.
then i can leave it as just a plasma table and always look at making a router one.

[Clive S]

TOrnado69--changing it over to a router would be fairly easy.
take the torch mount off the gantry and fit the router mount on.
sking any slats that have dross on the top with a soft disc.
fix ply bed onto 4 or 6 tabs that are welded to the water table slats.
i understand that they proberly dont belong together.
but if it turns out they both dont work well together.
then i can leave it as just a plasma table and always look at making a router one. Please take this in the spirit that it is intended:beer: I think you really need to read JAZCNC's post again and digest what has been said.
You will get all the help you will need on this forum as I and countless others have done:applause:.

Start by asking specific questions ie what do you want to use the machine for: wood, plastic, alu, perhaps engraving etc. then start a build log and read a lot of the logs on here. Submit a drawing of some sort to get advice on and be prepared to get a bit of flack (most of it is given in good faith and humour on here) don't give up there are some good guys on here willing to help, but they need something tangible to work with.

Sketchup (SketchUp | 3D for Everyone (http://www.sketchup.com/)) seems to be a good package to make a drawing in and it's free.

Don't buy any motors or electronics until you are happy with the frame. Giving some idea about your budget for the build will help. ..Clive

[JAZZCNC]

changing it over to a router would be fairly easy.
take the torch mount off the gantry and fit the router mount on.

Yes sounds easy as chips but I've not seen any commercial machines that do this and believe me they would if it was at all practicle. I've seen less than a couple that have DIY built and that's for good reason.? They don't play nice together.!

Just swapping out torch for spindle isn't simple as you realise or think but you'll find that out the hardway by the sounds of it.! . . . Good luck.

[Robin Hewitt]

If someone asks for advice on their new idea and everyone says, "Don't do it" you might think that would count for something. After years on forums I can assure you it does not.
Confidence is that feeling you get just before you understand the problem. Brimming with confidence the beginner assumes the forum has got stuck in it's ways, isn't prepared to accept brilliant new ideas and needs to be led from the darkness into the light of a new age.
After rejecting all advice he tries to build something. People will still try and help because they know that after a couple of spectacular failures he will become a useful member and willing to shoulder the burden of answering beginner questions.
I think the best introduction to CNC would be...
1: Buy someone else's failure cheap.
2: Identify where they went wrong and fix it.
3: Use your new found skills and the fixed machine to make something better.
I don't think anyone will ever take this advice but there is something delicious about saying, "Told you so" (You would think that somewhere we would have a tongue poking smiley but I cannot find it, please use your imaginations) :playful:

[JAZZCNC]

I try not to say "Told you so" but unfortunatly I Do get to think often. . :whistle:

[EddyCurrent]

(You would think that somewhere we would have a tongue poking smiley but I cannot find it, please use your imaginations)

There's one called 'playful' that might do :playful:

[T0rnado69]

right, it may be a good idea. but not one that will work well.
as jazzycnc has said not seen any others like that.

i relise that all the members that have posted in this thread together proberly
have many years in cnc stuff.
so im going to listen and learn.

so its best to make the table a cnc plasma.

and maybe instead of converting my mill to cnc.
i look into making a cnc table with a spindle.
so it can do metal, wood, plastic etc. ?
would that be the better way around it.

cheers...

[R2Fab]

Hi

Just wondered if your were starting a build log for your plasma table. I'm hoping to make a table of a similar size. But I have no idea what slides motors and bought equipment I need. I really want this information before I start designing to table.

I'm hoping to make a table that can produce products good enough to sell so it has to be reasonable quality.

Any advise on how your going would be great

[T0rnado69]

R2fab at this stage,i havent the time or plans to start the table.
im still reading build threads and taking notes. lol
i have many other things i need to get sorted first.
im also really thinking on doing a cnc conversion on my mill.
i know a round column isnt the best, but as jazzcnc said if you use good electronics they can always be taken off and put onto another machine, or used on another build.
i need to get a DTI stand so i can work out the play in the screws on the mill.
i dont really want to put ballscrews on it, i would sooner put ballscrews on a mill/router or cnc table i was going to build.

take a read of the many build threads on this forum.
ask questions. there are many members that are well clued up on cnc stuff and have build a fair few..

cheers.

[R2Fab]

Building the frame and wiring everything up really isn't a problem for me. Where I'm struggling is I don't know which parts I need. Motors, drives, bearings etc. If I could say I want to make a plasma table that can fit a 1250 x 1250mm sheet. What parts do I need. I could have this built within a week. It's that technical side I'm struggling with.

I'll just keep reading the forums.

[T0rnado69]

there are a fair few on here that could help you with that. but they would want to see a design of the machine, so they can advise you correctly.
start up a build thread ? get a few drawings up and im sure plenty will reply.

theres nothing like buying the incorrect part and having trouble selling it on for a lot less then you bought it.

at that size ( 1250 is a fair width)
i would think your need two screws, maybe driven by one motor with pulleys and belt.

put in your biuld thread your budget ?

good motors with good drivers and ballscrews and good rails aint cheap.
but better to do it right the first time then waste money and time having to buy the good stuff in the end.

cheers.

[R2Fab]

The reason for 1250x1250mm is because it's half of the standard sheet size I use. If I had the room in my shop I'd go for 2500 x 1250mm. But it just won't fit. I'd prefer to get the best parts I can afford. To be honest I don't have a clue about the parts. I've seen so many different set ups it's confusing.

Think I'll sit down and draw up so designs and see what feed back I get.

Cheers for the advise.

[T0rnado69]

yes i understand the 1250 size is half a sheet.
and having a 8x4 table would be nice. but takes a fair bit of room

thats why i was going to do a 4x2 because of space.

yes it can get very confusing about all the different parts that are available.

yes gets some designs drawn up and start a build log...
the help will be no end. and your be glad you did.

cheers.