my project is a 4`x 4` plasma table, at the moment I have the Bridge 75% complete with a home made Z axis with 150mm of travel with a Trapezoidal lead screw, and a 3Nm stepper. A 1.4mtr, 25mm linear rail Y axis with a 1mod gear rack and pinion, also with a 3Nm stepper. the X will be 10 cam follower bearings running on and guided by 75x12 cold rolled steel, driven by 2 off 3Nm steppers, one each side. all designed in Auto CAD. the plasma unit is a Thermal Dynamics 75xl with a capacity of 20mm. I dont have any electronics yet, other than a PC with Mach3 on it, I am hoping to get a Candcnc torch head control from America, these are some of the earlier pictures, tomorrow I will take some fresh ones, unfortunately things have came to a temporary stop, I burnt the motor on my miller, The fan stopped working and I cooked it drilling the gear racks for the "X", now I cant find my boring head it seems to have grown legs, I must have lent it to someone but I just cant remember who

Any comments or views will be apreaciated

Thanks for looking

Ste

http://i163.photobucket.com/albums/t311/lleskam/DSCF0649.jpg

http://i163.photobucket.com/albums/t311/lleskam/DSCF0643.jpg

http://i163.photobucket.com/albums/t311/lleskam/DSCF0644.jpg

http://i163.photobucket.com/albums/t311/lleskam/DSCF0650.jpg

All right, A new project to follow. Keep the posts coming. Looks great so far.
DRL

Hi Ste,

Looks like you made a great start to the project. Can I ask you where you sourced the y-axis rail and the rack and pinion? I am located in Ireland an am trying to find components. I like the CandCNC gear too. Good luck with the rest of the build and I'll be looking forward to more pics!

Regards,
Ronan

Hi Ste,

Looks like you made a great start to the project. Can I ask you where you sourced the y-axis rail and the rack and pinion? I am located in Ireland an am trying to find components. I like the CandCNC gear too. Good luck with the rest of the build and I'll be looking forward to more pics!

Regards,
Ronan

Hi Ronan
Thanks, im enjoying it at the moment, not sure how im going to get the torch head control here, may have to send it to my mate in Spain and get him to bring it back from there for me.
I Got the linear rail, all the rack and pinion and the geared pullys and belts als the cam followers came from there, from a company called BML HEYLEY, in Oswerstry, The Manager There Mark is a fantastic help, just dont ask the price

Steve

Hi All

Well the fruits of this weekends work my "Z" axis, just have to put the top bearings in, mount the motor, and Roberts your Fathers brother!! a finished "Z"

Steve

http://i163.photobucket.com/albums/t311/lleskam/DSCF0661.jpg

Hi,
Great looking Project. I have something similar to your project in progress! (Using 3D Inventor) You mentioned that you have CAD drawings for this project. Do you mind sharing your drawings? I would also be interested in more specs of the gears, pulleys,belts and linear bearing that you used.

I would greatly appreciate.

Thanks,

Hi,
Great looking Project. I have something similar to your project in progress! (Using 3D Inventor) You mentioned that you have CAD drawings for this project. Do you mind sharing your drawings? I would also be interested in more specs of the gears, pulleys,belts and linear bearing that you used.

I would greatly appreciate.

Thanks,

Not a problem, enclosed are some cad drawings I have played along the way so not many of my drawings are "clean" any more I have added bits and doodled on them in acad seeing if things work.

I have used metric 1 mod rack and pinion gears and 5mm x 15mm wide belts on 15 and 60 4:1 pullys

as for linear rail I used a 25mm Hiwin witha heavy duty wide car

unfortunately there all metric as in England we are all mixed up with our measurements, some imperial, some metric, some both, I work in either depends what is easier at the time, sometimes both at the same time.

Ste


Ste

Thank you so much. Keep up the great work.

I was just wondering, how will you arrange your gears?

How many inches per minute do you want your machine to work up to?

Do you really have to install 2 motors to drive your X axis?

Thanks Again

Thank you so much. Keep up the great work.

I was just wondering, how will you arrange your gears?

How many inches per minute do you want your machine to work up to?

Do you really have to install 2 motors to drive your X axis?

Thanks Again


Hi I hope this clarifies it a bit, as for speed I have no idea how to even start to work it out, I know what my ratio per step is but am totaly confused as to speed, it has something to do with voltage on motors, which to me seems to be just throw at them what ever you feel like, I know im wrong, but every post I have read seems to say "x times the plate voltage gives so many rpm on the motor" so I will put it together and see

as for 2 motors, im using 23 size motors, 3Nm (425Oz) at the moment and if there not man enough I have drawn replacement plates to take 34s, but in all honesty I just thought 2 motors would help to keep it from dragging and help keep every thing square

Steve

Steve-M,
Do you have any more specs on the spur gear and rack gear. (pressure angle, number of teeth, diameter, width etc.)

Thanks,

Steve-M,
Do you have any more specs on the spur gear and rack gear. (pressure angle, number of teeth, diameter, width etc.)

Thanks,

Hi
There a std "1 MOD" gear form 20 degree Pa, the racks are 2 Mtrs long 15mm wide x 15mm high with a lot of teeth, the spur gears are 16 tooth with a pcd of 16mm and 8mm wide, this way hopefuly if a disaster happens to a rack I have a "second life" by turning it round at least untill I can get a replacement

Hi All

Had a day off so played on plasma table, this is where I got to.. and the non deliberate mistake!!!

one of the X drive units
http://i163.photobucket.com/albums/t311/lleskam/DSCF0683.jpg

http://i163.photobucket.com/albums/t311/lleskam/DSCF0689.jpg

Y drive unit
http://i163.photobucket.com/albums/t311/lleskam/DSCF0687.jpg

http://i163.photobucket.com/albums/t311/lleskam/DSCF0688.jpg

and the "OOPS" that dont work!!
http://i163.photobucket.com/albums/t311/lleskam/DSCF0682.jpg

comments please expecialy if Im going the wrong way

Cheers

Ste

Wow.. great build Steve.. The machine going to be really rigid and professional..thanks for sharing with us..

Good Work
Why is it so close to the bolt heads?
The application of Low head S.H.C.S or Counterbores or flatheads or even hex head bolts might do the job.

Why do you have pictures of the gantry gear racks with counterbore and others you don't? Do you have two gantries or two projects?

Oops, I see. The only problem, I guess, is that the pictures are not in the right order!!!

Sorry,

Good Work
Why is it so close to the bolt heads?
The application of Low head S.H.C.S or Counterbores or flatheads or even hex head bolts might do the job.

Why do you have pictures of the gantry gear racks with counterbore and others you don't? Do you have two gantries or two projects?


HI

Time! the racks with counter-bores are later pictures than the ones with out, the countre bore was my way out

Ste

Hi Steve, Thats a nice looking machine!
Roberts your Fathers brother,Bobs your uncle,
great U.K lingo.

Roger

Hi Steve, Thats a nice looking machine!
Roberts your Fathers brother,Bobs your uncle,
great U.K lingo.

Roger

Cheers, its nice to know there are people out there in net world reading about it, Thanks

Had some more spare time today so I hacked a torch mount out of a chunk of solid Aluminium ( I know we spell It different) It made me realise that I will have to make a 300mm dropper plate, any how heres the pics

http://i163.photobucket.com/albums/t311/lleskam/DSCF0691.jpg

and just to show the torch fits I tried that in as well

http://i163.photobucket.com/albums/t311/lleskam/DSCF0690.jpg

Steve

Hi all

I could do with some other peoples views please,

1/ on my "Z" axis I have 2 ways of mounting motor, one direct on top of the lead screw (12 x 3mm) and drving directly through a coupling PICTURE 1

and

2/ mounting up side down behind the "Z" and belt driving accross the top, PICTURE 2

I cant decide which is better, I have the plates cut for both ways, so thats not a problem. method 2, I will have to loose 10mm of travel for the bearing housing, I will still have 160mm (6"+) I dont have the belt pullys or the belt

What I would like to know is which is better and if metod 2 what belt ratio??

PICTURE 1
http://i163.photobucket.com/albums/t311/lleskam/DSCF0696.jpg

PICTURE 2
http://i163.photobucket.com/albums/t311/lleskam/DSCF0694.jpg

Thanks for your advise
Ste

Hi Steve , what size of gear rack are you using?

Hi Steve , what size of gear rack are you using?

Hi

A metric 1 mod with 16 tooth, 16mm PCD pinion

Ste

Hi All

decision made!! There is no going back now "Z" finished apart from a small second floating "Z" to get hight, I have drilled and tapped botom of "Dropper" plate to take a tool holder so I can use table as a router as well by sliding second "Z" up and bolting tool holder on. A few people have asked about the gears I am using so here is a closeup picture (last one below), the ruler is in metric,

Ste

http://i163.photobucket.com/albums/t311/lleskam/DSCF0698.jpg

http://i163.photobucket.com/albums/t311/lleskam/DSCF0699.jpg

http://i163.photobucket.com/albums/t311/lleskam/DSCF0700.jpg

http://i163.photobucket.com/albums/t311/lleskam/DSCF0701.jpg

http://i163.photobucket.com/albums/t311/lleskam/DSCF0703.jpg

Hi Steve,

Could you tell me if there is any play in the y axis truck? Most machines I have seen use two linear guides. If one is quite rigid I might follow you on that design. Does your linear guide truck float in any direction. I would say your rack and pinion will probably stabilize any movement (if there is any) but I am looking at a belt or chain drive which would not stop the play in the truck.

Thanks,
Ronan

Hi Steve,

Could you tell me if there is any play in the y axis truck? Most machines I have seen use two linear guides. If one is quite rigid I might follow you on that design. Does your linear guide truck float in any direction. I would say your rack and pinion will probably stabilize any movement (if there is any) but I am looking at a belt or chain drive which would not stop the play in the truck.

Thanks,
Ronan

No there appeares to be virtualy none on my DTI, even pulling on the top of the "Z" there is none even with out the rack there. I am using the heavy duty wide cart on the rail, dont know if this makes a difference.

Ste

Hi Steeve,
The plasma cutter " Pak Master ". Is it high frequency (HF) start?

Mongkol

Hi Steeve,
The plasma cutter " Pak Master ". Is it high frequency (HF) start?

Mongkol

Hi Mongkol

No its not a HF Start, it has a Pilot Arc, Thats what Thermal Dynamics call it in the manual,

Hi Steve,

" Could you tell me if there is any play in the y axis truck? Most machines I have seen use two linear guides. If one is quite rigid I might follow you on that design. Does your linear guide truck float in any direction. I would say your rack and pinion will probably stabilize any movement (if there is any) but I am looking at a belt or chain drive which would not stop the play in the truck.
Ronan"

Ronan
Had another look at it , If I put my DTI right at top of "Z" (off the beam) I can move it by +- .05mm TOTAL front to back if I push and pull hard, I think it may be bending as there is no free play

Ste

Just a quick update, finished floating "Z" ready for THC, Luckily Jim Cullins from soundlogicus.com will still ship one to England along with a breakout board from Rob Cambell will make a good combination, I hope.

http://i163.photobucket.com/albums/t311/lleskam/DSCF0714.jpg

http://i163.photobucket.com/albums/t311/lleskam/DSCF0716.jpg

Looks like you can counterbore the rack gear to allow clearance for the socket head screws. Or use flat head screws & countersink the holes.

Thanks Millman, thats exactly what I did. it was just one of those things that when it happens you stand back and say "stupid fat boy" well I do any way

Steve

Hi all
Just a bit of a update, I have spent a few weeks collecting bits for the controller, and this is what I have, Campbell Designs excelent Break out board, a Sound Logic Power board with a 500va transformer together they give me 50v dc, and Gecko G203 Vampire drives (Im still 2 short but funds allowing I will order those this week), all in a 2U rackmount case with power and E Stop on front and all plugs on back

having a few problems with speed in Mach3 at moment and struggeling to find where I have gone wrong, so did something different before I scrap the whole lot in frustration

Steve

Well Yesterday I stripped it down and painted it in Blue smooth Hamerite, turned the heater on it and left it to cook for a few hours, then came back this morning and put another coat on it and cooked it again then spent the rest of the day putting it back together. I managed to get the gear rack to within .04mm that works out to about 0.0015" from one end to the other and all bolt points in the middle on my DTI off the linear rail carriage.

I have finally got it moving at 10,000mm a min, soft limits are fine it stops at 1299.997mm on the DRO, the setting is 1230mm. I do still have a small problem, the "Slow Zone" dose not seem to be working, It stops from full speed to stop instantly

Its time to start making the base table now, Hopefully the other 2 Geckos are on there way and I still need to order 2 more motors

Steve

http://s163.photobucket.com/albums/t311/lleskam/?action=view&current=DSCF0790.flv

http://i163.photobucket.com/albums/t311/lleskam/DSCF0780.jpg

http://i163.photobucket.com/albums/t311/lleskam/DSCF0781.jpg

http://i163.photobucket.com/albums/t311/lleskam/DSCF0775.jpg

Hi All

Just a quick update, (if any one is interested), I have started on the table (will get some pictures tomorrow ) for reasons beyond my control I have made it into a 6`x 4` table, I had 2 off 2Mtr (78") gear racks for the X - A axis and had to buy the cold rolled steel for the runners in 3Mtr (118") lengths so rather than cut a good bit off them and waste it I had another look at the cad drawings and managed to get a 2.5Mtr ( 98") length table with 1950mm (76")travel in the X-A and 1220mm in the Y from the material I had, from 2 full lengths of 7.5Mtr(295") of 60x60x3 (box I only had 2 pieces 40mm (1.5") long scrap, but I do need to buy another length of somthing to carry the material supports and the water trough ( if I fit one)
But standing in the workshop it looks big, and I have yet to put casters on it

I have all the electronics done now, but still need to buy a THC from Jim Cullins but that Will come in time

Steve

Happy Chrismas and a prosperous New Year to all


just a few pictures for those interested, 4`x 4` taple turned into a 6` x 4` table for no extra cost, I did hope to get the 3"x1/2" Bright bar (coled rolled) for the "X" runners before Christmas but missed the stockholders they closed early, so still need to get them yet.but this is how it should sit, I will put jacks on the corners eventualy, when I work out how or even what I want, Any one any ideas??

The control box is now finished for 4 axis and works well I still need to get a THC from Jim Cullins at Sound Logic, and 2 more motors for "X" then I can mount gear racks, slatted bed, and "Roberts your Fathers brother!" finished play time begins

all the best

Steve

HI All

one other thing I am planning is a Bluetooth keyboard, to use as a remote pendant, there is a Keysonic with a laptop style mouse pad on Ebay for £35, unsure yet weather to take it apart and just use the "Hot keys" for Mach3 as buttons in a hand held unit, or just leave it as a keyboard,

I like the idea of a wireless pendant the only problem is I will need 2 because I will probably loose 1

there is another pendant I like around also on ebay but in the US but its not a wireless one
if any one has any views on the Bluetooth I would like to hear

Cheers

Steve

Just a personal opinion but I would not trust anything wireless around a plasma table unless you are VERY confident you have all electrical noise issues under control.

Just a personal opinion but I would not trust anything wireless around a plasma table unless you are VERY confident you have all electrical noise issues under control.

MMMM. Thanks never even gave that a thought, and as this is my first machine I doubt very much if I have it properly suppressed, Thanks. Playing around at the moment its quiet for 10-15 min then it screws my radio in the workshop up

Thanks

Steve

Happy new year to all 12.15 am 1/1/09

Steve if your equipment is messing w/ the radio in your shop just imagine the sort of signals a wireless anything would be picking up out of the air.

Steve if your equipment is messing w/ the radio in your shop just imagine the sort of signals a wireless anything would be picking up out of the air.

Absolutely! I need to look into that now while Im still building it, it could be because I am 2 motors missing on the ends of the wires, as of yet my plasma has not even been on the table, that alone used on it, so I have a problem in the making,

Thanks for the advise and for reading and replying to the post its good to know someone reads them and Im not just wasting my time posting

Steve

I have been following your project since the beginning and everything looks great. That is just the way I am constructing mine... But what is a floating Z head..? I see you have two different sets of rails on the Z axis....

I think you are going to have problems with the z axis if you have thc... Tom at Candcnc told me to direct drive the z axis motor to acme rod 5-6 threads per inch. The reason for this is the arc voltage and thc will not respond fast enough. I noticed you had a high thread count on your acme around 8-10 TPI and you also pulley that 4 to 1 .. so your motor turns 40 rotations to travel 1" on the z..That gearing is to high... your motor needs to travel 5 rotations for 1"... Just trying to help

I think you are going to have problems with the z axis if you have thc... Tom at Candcnc told me to direct drive the z axis motor to acme rod 5-6 threads per inch. The reason for this is the arc voltage and thc will not respond fast enough. I noticed you had a high thread count on your acme around 8-10 TPI and you also pulley that 4 to 1 .. so your motor turns 40 rotations to travel 1" on the z..That gearing is to high... your motor needs to travel 5 rotations for 1"... Just trying to help

Thanks for the advise, unfortunately Tom dose not seem to want to talk to me, and he definately will not ship to England, something to do with lead content. This is the reason I made the control box the way I did, rather than buy all the CandCNC bits that I wanted, so it is very unlikley that I will get a THC

I will bear it in mind, I can change to drive to 1:1 should i need it, but there is not much I can do about the leadscrew. I did put a post about where I should put the motor, behind or direct drive from above and did not get a single reply, so I went for behind for tidyness

The project is on "Winter Hold" at moment I have a lovley 5000sq ft workshop with no heat, and weather over here is cold and damp so a hour out there and you cant feel your fingers any more, I did build the table to put it on and have photos to post some day soon

Thanks for the advise


Steve

Thanks for the reply steve... I had a previous question I asked but I dont think anyone saw it. What is a floating head on the z axis?

Thanks for the reply steve... I had a previous question I asked but I dont think anyone saw it. What is a floating head on the z axis?

Hi
If you use a THC you will need one, The "Z" comes down and touches the metal that activates a limit switch, it then reverses the distance of the switch activation plus the clearance distance required, as a datum for the "Z" then fires the torch, I have put a floating head on mine, I may have Tom send a THC to a friend in Mexico, who will bring it home when she comes, but I will probably go for a Sound Logic one also designed by Tom, that can be sent into England

I did not answer first question as I thought your second question answerd it, I assumed you had gone far enough int THCs to see. I have posted before then looked back at it and thought "Stupid boy" not that Im thinking your stupid, far from it

All the best

Steve

Posted by steve...."If you use a THC you will need one, The "Z" comes down and touches the metal that activates a limit switch, it then reverses the distance of the switch activation plus the clearance distance required, as a datum for the "Z" then fires the torch...


So what methods do I take to make this floating z head... I noticed you had two rails on the z axis... Is that a floating z to take minor shock when the torch comes down and hits the material the torch rises upward on the secondary rails...?

Steve,
Sorry for the long delay. I've been pretty occupied on something else but now I have to get this CNC machine up and running!!!
Thanks for all the informations, I'm on the point of buying the linear bearing
Product ID: AGW25CB1TxxxxZ1H
Product Name: Combo, 25mm T Rail, 4 Bolt Flange Block
Is this what you actualy use? and, does it seem to be quite sturdy since it is a single rail?
By the way, are you willing to make and sell any parts or assemblies? If so, send me a price list please.
Thanks
Not a problem, enclosed are some cad drawings I have played along the way so not many of my drawings are "clean" any more I have added bits and doodled on them in acad seeing if things work.

I have used metric 1 mod rack and pinion gears and 5mm x 15mm wide belts on 15 and 60 4:1 pullys

as for linear rail I used a 25mm Hiwin witha heavy duty wide car

unfortunately there all metric as in England we are all mixed up with our measurements, some imperial, some metric, some both, I work in either depends what is easier at the time, sometimes both at the same time.

Ste


Ste

Product ID: AGW25CB1TxxxxZ1H
Product Name: Combo, 25mm T Rail, 4 Bolt Flange Block
Is this what you actualy use? and, does it seem to be quite sturdy since it is a single rail

sorry for delay in answering, I dont come to forum often, I always feel like im talking to myself here.

seems to be quite sturdy, but weather it would stand a router on it I have no idea
Here are a few more photos if any on else is interested

Steve,

Everything looks real nice, Do you have it up and running yet?

You could probably use a router if you went very slow...

Thanks for the pics

Looks awesome! I cant wait to see how to lay out the X axis..