-
5 Attachment(s)
village idiot builds a plasma table.........
ok to start...this is going to be picture heavy!..anything you see here is how iv done it and it doesnt mean its the right way.....
A year or so ago id seen a few videos on youtube and thought id really love to have a cnc plasma table.....
i had a look on the internet and most seemed mega expensive and made out of pressed tin...
i decided id build my own table to be able to cut an 8x4 sheet of 12mm mild steel.....I HAVE NEVER HAD ANYTHING TO DO WITH CNC EVER,:hypnotysed:
the table is fabricated out of 80x80x6 mild steel box...a few photos of the table
a huge thankyou to julian
Attachment 19662Attachment 19663
-
2 Attachment(s)
Re: village idiot builds a plasma table.........
after welding the table up i mounted some 80x80x6 angle to the side making the base for my y axis 16mm linear rails..i drilled and tapped the three legs of the table and then slotted the angle iron so i had plenty of adjustmentAttachment 19653Attachment 19654
-
5 Attachment(s)
Re: village idiot builds a plasma table.........
next i needed to drive the y axis so after alot of advice i opted for rack and pinion,it came in 2m lengths and i needed two 3m pieces... (lee roberts look away for the next few photos :triumphant:)
Attachment 19655Attachment 19656Attachment 19657Attachment 19658Attachment 19659
-
2 Attachment(s)
Re: village idiot builds a plasma table.........
now having two pieces of 3m rack i needed to attach it to the y axis angle iron i used 4mm counter sunk brass machine screws..iv used these as it was 10pm and thats all i had in the shed.....Attachment 19660Attachment 19661
-
Re: village idiot builds a plasma table.........
How clever are you? Do you actually need any help? Here is a bunch of stuff, feel free to tell me where to go if I am teaching granny to suck eggs.
Joining two bits of racking is easy, you just put a third piece on top an it gives you the perfect spacing while you nut up.
You want to cut 12mm steel, is that a specific job of a theoretical maximum?
An 8 x 4 sheet of 12mm is a fearsome thing. If you are actually going to be slicing 2mm while planning for 12mm, maybe you want a smaller, less vigorous torch to start with, or have you already been on CNC Zone and been convinced HyperTherm is the only option?
Possibly not because you don't have a monster water bed :eagerness:
It might be too late to mention that you do not need huge motors because there are no cutting forces. The only thing you have to push against is the weight of metal in the gantry when you reach a pointy corner. Weight is your enemy.
If you start using the same motor to lift the torch as you use to move the gantry expect derision.
-
Re: village idiot builds a plasma table.........
Quote:
Originally Posted by
Robin Hewitt
If you start using the same motor to lift the torch as you use to move the gantry expect derision.
That's an interesting speculation, HTF would one go about doing that BTW?
- Nick
EDIT: Or did you mean "the same model/specification" of motor rather than "the same motor"?
-
Re: village idiot builds a plasma table.........
Quote:
Originally Posted by
Robin Hewitt
How clever are you? Do you actually need any help? Here is a bunch of stuff, feel free to tell me where to go if I am teaching granny to suck eggs.
Joining two bits of racking is easy, you just put a third piece on top an it gives you the perfect spacing while you nut up.
You want to cut 12mm steel, is that a specific job of a theoretical maximum?
An 8 x 4 sheet of 12mm is a fearsome thing. If you are actually going to be slicing 2mm while planning for 12mm, maybe you want a smaller, less vigorous torch to start with, or have you already been on CNC Zone and been convinced HyperTherm is the only option?
Possibly not because you don't have a monster water bed :eagerness:
It might be too late to mention that you do not need huge motors because there are no cutting forces. The only thing you have to push against is the weight of metal in the gantry when you reach a pointy corner. Weight is your enemy.
If you start using the same motor to lift the torch as you use to move the gantry expect derision.
hi robin,
its in my nature to bite off more than i can chew and blag my way through, bright or stupid?
yes i need help and adviice really, im a first time builder with no expierience of cnc or computers....
iv never even seen r&p until a friend showed me what to order,so yes clamping a piece to the two parts that need joining to get distance right is easy aslong as someone tells you the method of doing it...my original question re.welding rack ...was can i tack it to the frame rather then drill and tapping,its a part that has a sprung loaded gear pushing into it so didnt see any issue??...
iv messed about and built a few narrowboats on the bank without fancy over head cranes or lifting gear so any 8x4 sheet seems easy to handle compared to a 10mm base plate 50ft long.........
everything has always been EYE right as now with this project its 0.5mm is sloppy but ok for a plasma.you never see both sides of a boat at the same time........
i want to be able to cut 10/12mm but also thin stuff like 3mm.....
next part of the build is the x axis gantry..what are the best options for a gantry???iv got some 20mm supported rail and 2m of r&p
thanks in advance for your help..........
-
Re: village idiot builds a plasma table.........
I tried and failed, my gantry was 2.75m of 4" square aluminium box section and it did the long axis. I started out by taking a 4m length of the stuff, supporting it at the ends and dumping weights in the middle to see how far it bent. Hardly at all. You don't need to swing huge amounts of iron just to move a torch. It had a 15mm profile rail along one side, screwed from behind so the black dust could not sneak in past the wipers.
I threw the towel in when I discovered the T5 belting and pulleys I had bought were unbelievably slack.
If you have pinions at either side of the gantry connect them with a low inertia shaft. Thin walled aluminium tube perhaps.
I could ramble on all day, it was fun.
-
3 Attachment(s)
Re: village idiot builds a plasma table.........
not a huge amount done today, anchored the table to the floor and adjusted it for leval and true,,,iv gone with 80x80x5mm box for the x axis....the brackets are just 2" of 50x6 angle welded to the legs still need to round the brackets off and repaint....
Attachment 19685Attachment 19686Attachment 19687
-
Re: village idiot builds a plasma table.........
Slats, you will support the work piece on slats. Think how you will support your slats. If they have to flex a bit to fit they are more likely to behave themselves.
If it is a small piece of metal you will need the slats close together with more support from below. If it is a large sheet the slats can be further apart. Why not put slats close together in one corner and further apart over the rest of the table?
The other slat function is the tilt. You cut a complete part and instead of resting flat on two slats or falling through it tilts and jambs itself at an angle. The tool slams in to it on a rapid transit and does hideous damage to itself. You would need vast numbers of slats to avoid this but it is quite predictable. You can put a bumper ring around the tool tip to spot them and apply the brakes.
-
Re: village idiot builds a plasma table.........
i quite like the mixed slat idea!...im going to use 100x50x6 angle to support the slats which will be spaced 20mm away from the main frame so i can eventualy turn it into a water table with down draft air extraction...im planning to use magnets to hold the torch to the z axis so if it hits anything it will break away.............
-
5 Attachment(s)
Re: village idiot builds a plasma table.........
had an evening of drilling tonight..managed to secure the first linear rail..then started fabricating the gantry
Attachment 19699Attachment 19700Attachment 19701Attachment 19702Attachment 19703
-
5 Attachment(s)
Re: village idiot builds a plasma table.........
-
Re: village idiot builds a plasma table.........
-
Re: village idiot builds a plasma table.........
Quote:
Originally Posted by
Lee Roberts
Looking smart.
thanks lee.
iv got a bit of time,so hopefully this is the last big push to getting it finished
-
3 Attachment(s)
Re: village idiot builds a plasma table.........
only managed a few hours in the shed today...managed to mount the linear rails to the x axis gantry....lots of m5 tapping
Attachment 19726Attachment 19727Attachment 19728
-
4 Attachment(s)
Re: village idiot builds a plasma table.........
iv managed to get the x axis painted..and the z axis pretty much finished. iv gone for two short lengths of 16mm linear rail and and old piece of ball screw..
Attachment 19835Attachment 19837Attachment 19838Attachment 19839
-
1 Attachment(s)
Re: village idiot builds a plasma table.........
reduction box ..
iv ordered 15mm silver steel to build the shafts,15mm pillow block bearings (look very cheap) and the t5 pulleys are coming pre bored and grub screwed, by doing this hopefully the only bit of engineering will be to bore the 24t rack gear...
Attachment 19842
-
5 Attachment(s)
Re: village idiot builds a plasma table.........
iv managed to build the x axis reduction box today..iv mounted the stepper upside down, im not sure i really like it like this,my plan is to make a cover to hide the motors and wiring...Attachment 19936Attachment 19937Attachment 19938Attachment 19939Attachment 19940
-
Re: village idiot builds a plasma table.........
Looks really good. What is your plan for tensioning your pinion gear into your gear rack?
-
Re: village idiot builds a plasma table.........
Quote:
Originally Posted by
1Jumper10
Looks really good. What is your plan for tensioning your pinion gear into your gear rack?
hi, im going to use spring to hold the pinion against the rack,im using stainless steel to make the bush to pivot the reduction box (scrap prop shaft from a boat).........
-
4 Attachment(s)
Re: village idiot builds a plasma table.........
managed a few hours today,
Attachment 20012Attachment 20013Attachment 20014Attachment 20015
for the (hopefully)final assembly iv drilled the shaft for the grub screws to bite into and for the pinion gear iv sweated the gear onto the shaft and used a roll pin,which im sure is very stable and wont come loose but now if i have a bearing faiure im going to have to pull the shaft back through the 60t gear and the other bearing,so im not sure iv gone the right way...
-
2 Attachment(s)
Re: village idiot builds a plasma table.........
iv had a few hours spare so iv finished the slats for the table....iv used 80x3 flat...
Attachment 20047Attachment 20048
-
Re: village idiot builds a plasma table.........
looking very nice.
Have you thought of making a scraper/cleaner for the supported rails carriage?
In the past I have used pot scrubbers ( cheap scotch-brite nock-offs)
the flat ones .. Like these https://www.youtube.com/watch?v=kAv-pKD0Eug
profile to suit the rail section.. Green side out. sandwich between to alu plates.
I soak them in sewing machine oil prior to installation
Paul
-
Re: village idiot builds a plasma table.........
hi paul,
iv been thinking about some sort of scraper/gaurd for the linear rails..im ging to put an hour meter on the table so i can get an idea of how long parts last and cost of running.then i can work out if the for instance if the 16mm bearings will last a year and cost x amount and then they become a consumable? Or if its just a bad design and i'll need to rejig it....is plasma dust evil stuff?
-
Re: village idiot builds a plasma table.........
Just wanted to say, I've enjoyed reading this thread, I'm trying to learn as much as i can, so your lots of pics approach is great.
-
Re: village idiot builds a plasma table.........
Quote:
Originally Posted by
ned
Just wanted to say, I've enjoyed reading this thread, I'm trying to learn as much as i can, so your lots of pics approach is great.
thanks for your kind words..i'm back on the cnc today...pics to follow :chuncky:
-
Re: village idiot builds a plasma table.........
cool, following with interest.
Can I ask you, if you were to guesstimate, how much you reckon the build is going to cost you?
Speaking in euros, to buy an 8x4 table seems to be around 11 - 12 thousand, so maybe 9 - 10 thousand GBP.
At the moment I'm trying to familiarise myself with the different mechanical parts of the machine, I'll concentrate on that first and when I've that built, I'll scratch my head and think about the next hurdle, the electronics and software.
-
Re: village idiot builds a plasma table.........
Quote:
At the moment I'm trying to familiarise myself with the different mechanical parts of the machine, I'll concentrate on that first and when I've that built, I'll scratch my head and think about the next hurdle, the electronics and software.
Welcome to the forum Ned. The two are sort of related but when you are ready start a build log and try and get some cad drawings up then ask away.
Also keep away from kits of electronics as they are never matched.
-
Re: village idiot builds a plasma table.........
Cheers Clive, appreciate the welcome.
I cant use CAD. I will have to learn. I'm pretty handy with photshop though, so I can illustrate well enough to explain what I mean, hopefully that will do till I learn. Oh its all in front of me... )
http://i.imgur.com/K2e03AV.jpg
ill bow out of this thread so as not to distract, regards all.
-
Re: village idiot builds a plasma table.........
loving this thread. keep the photos coming warwick.
-
5 Attachment(s)
Re: village idiot builds a plasma table.........
evening chaps....iv built the one side of the y axis drive.....not sure if iv got the pivot on the right place? there is enough travel to disingage from the rack if needed..Attachment 20329Attachment 20330Attachment 20331Attachment 20332Attachment 20333
the shape of the gearbox is awful,but ill make some more when the tables up and running, iv had to run the steppers inboard because of the x axis moving off the table.......
-
Re: village idiot builds a plasma table.........
Very envious of the space you have in your workshop and that enormous welder! Looking good, I quite like the weird looking gearbox!! Subscribed.
Sent from my iPhone using Tapatalk
-
Re: village idiot builds a plasma table.........
good progress. the gearbox might look more in keeping with the machine if it were more angular, like below. Its functional though, who cares, it works.
http://i.imgur.com/KKNf08e.jpg
-
2 Attachment(s)
Re: village idiot builds a plasma table.........
managed to get the rack bolted upto the gantry tonight, im going to re design the y axis gearboxes because..theres to much pressure on the rack and pinion gear because the pivot it to close...i can get 3m cut on the y axis..and it looks awful...
photos of the rack bolted to the gantry
Attachment 20344Attachment 20345
-
Re: village idiot builds a plasma table.........
How about turning the motor the other way up so that it can't get fowled from below
-
10 Attachment(s)
Re: village idiot builds a plasma table.........
-
5 Attachment(s)
Re: village idiot builds a plasma table.........
this is the final design for the y axis drive,the motors will be tucked away under the table, it doesnt take alot of spring pressure to hold the pinion into the rack.i can now get full travel accross the whole table...
Attachment 20414Attachment 20415Attachment 20416Attachment 20417Attachment 20418
-
2 Attachment(s)
Re: village idiot builds a plasma table.........
iv managed to finish the reduction gearboxes and mount them today,have ordered the cable so i'll be wiring very soon!!
Attachment 20469Attachment 20470
-
2 Attachment(s)
Re: village idiot builds a plasma table.........
iv got the cable drag chain carrier fabbed up,just the ends of the x axis linear rails to support and im finished the fabricating...
Attachment 20501Attachment 20502