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View Full Version : In the design stage CNC Torch X rails



millman52
12-24-2006, 10:40 AM
Getting around to making a few drawings of design thoughts for the X axis rails for my new torch.

First thoughts are to run round rails the entire length (yet undetermined) of my table.

Here is a couple pics. Feedback please.

I will most likely have design sketches similar to this for the entire table by the time I am through. It will not be a complete set of plans but enough to keep my thoughts organised. I will also be keeping a running list of Items I have to purchase. It will not be a complete list either as I have loads of "STUFF" laying around. Leftovers form other jobs, salvaged parts etc.

massajamesb
12-24-2006, 10:57 AM
I would consider having a bearing that will ride underneath the rail as well, to prevent the gantry or carriage from "skipping" or lifting.
If you made something similar to the second drawing, but had one on top, and one on bottom, that would help.

millman52
12-24-2006, 01:22 PM
You think the gantry will not be heavy enough @6' wide overall to keep from rocking up off the rails? Keep in mind this is an oxy fuel table & really not planning on the rapids being lightning fast.

I do appreciate your opinion. & ideas is what I am after.

I don't think there is any way for me to hook another roller underneath the round. I might be able to put something under the main rail somewhere.

massajamesb
12-24-2006, 03:32 PM
well, IMHO, it would be best to overbuild first time around, you never know, you might want to add plasma later??
When my machine was chain driven, I generally only used oxyfuel. Now I use both, and supporting the underside is a must, and the gantry and carriage together weigh about 80 pounds easily. I may also have another solution, I will PM you.

Arie
12-25-2006, 05:06 AM
Very interesting conception, but I think it is rather difficult to calibrate these runners when there is a difference in the middle point of the bearings. Will you making the gantry such that this can handle this? Otherwise it may be a possibility to mount the bearings on strips which can be bolted to the carrier with oversize holes to calibrate the bearings.

arelewis
12-25-2006, 10:03 AM
this design is similar to a heath shape cutter now made by esab. the support rides on bearings 30" apart and the rack and pinion are verticle so the torque won't make it jump

MAS
12-25-2006, 11:58 AM
I build a flame cutter close to 30 yrs. ago with that design. Works very well.
You don't need any bearings underneath. I positioned my rack gear to serve that purpose.

millman52
12-25-2006, 02:05 PM
I was looking at some items in McMastercarr a couple days ago & thought I might have happened on a good alternative for rack & pinion drive for my table. Then today I seen this on here: http://www.cnczone.com/forums/showthread.php?t=16634 post #6 by trevorhinze Figured it would work good on a smaller table but I still question it on a 10-12 foot table. Opinions anyone else????


Driving home from last min. Christmas shopping last evening I had a really original brain storm for my X axis rail(s). Also today I seen this posted on here: http://www.ubcustom.com/cnc/index.php?no=3

So far it seems I'm 0 for 2 on originality. (nuts) but both these ideas look very good to me.

One question I would have on the round linear rail is. Wonder how well 1045CRS would hold up for the rail????

millman52
01-02-2007, 06:19 AM
Holidays are over. Hoping some of the preliminary trinkets I have purchased begin to roll in. Been waiting on a few items to get a better idea of how large overall to build my table. I am wanting to be able to easily position a 4' X 8' sheet of stock without having to squeek it in there with a shoe horn.

Hoping to actually begin the building process soon.

PlasmaGuy
01-03-2007, 07:20 PM
mm52,

Glad to see you are back. My current table is 5x10 and I have roughly 5" X & Y to spare. This is way to small! To do it over again I would allow at least 10".

There is a post somewhere on this forum that suggest linear rail over the round stock.

What is your thinking on that.

Take a look at these guys. http://automation4less.com/

I have not purchased anything from them yet but their web site is nice.

Good luck,

Tom

millman52
01-04-2007, 06:55 AM
mm52,

Glad to see you are back. My current table is 5x10 and I have roughly 5" X & Y to spare. This is way to small! To do it over again I would allow at least 10".

There is a post somewhere on this forum that suggest linear rail over the round stock.

What is your thinking on that.



Tom

I have been working on some preliminary CAD drawings for my table. Right now, allowing several inches on each end of the gantry for mechanical hardware, run off, etc. I still should have a usable area of at least 5' on the "Y" axis. I have the table set at 10' in length, but think I am going to increase the rails to 12'. Once I have a few more things "IN HAND" for my gantry, only then will I actually begin building. I'll probably even gather up & build some of the smaller pieces first. Things like my "Z" axis movement. Determine exactly how I am going to drive the axis(s), Open end timing belt, rack & pinion, etc. All this will then tell me exactly what size the table needs to be.

I am quite sure with time "round" linear bearings would certainly wear into a piece of "mild" steel as a rail. If the linear brearing cartriges had the ball bearings inside them fixed into a helical design, as opposed to straight A "soft" rail would probably last quite some time.

I am going to use the design I have posted earlier for one of my rails. I Own a Wood-Mizer sawmil that uses that same design. I have somewhere around 2500 hrs. on it. Eventually the ball bearings will wear small flat spots down the length of the round stock. The wear is very smooth & even though which still allows only a vertical settling effect. Linear movement should still be along the same exact centerline.
In this case the THC should compensate for any wear in the vertical line of movement.

I priced a few sections of steel last week & was a bit surprised to find that 3/16" X 4" strap (to use for the consumable burning bed) is currently $35.00 for 20'. 1/4" X 4" is $30.80 so in this case more costs less. $42.00 more to be exact. for my table as now designed.

PlasmaGuy
01-04-2007, 09:29 AM
Another WM owner Great!

I have a '95 LT40HDG with 1200 hours and the round stock has developed a slight worn spot but not bad. I recall hearing that Woodmizer went through quite a learning curve to find the receipt for their rod. The fixture they use to hold inplace and the weld procedure is unique too. They are very serious about the closed shop policy. I'd love to see a mill but together but I'm getting off topic! Good luck!

Tom

fractaledge3
01-04-2007, 10:58 AM
Hi all,
Take a look to my posts at http://www.cnczone.com/forums/showthread.php?t=29390
I hope it can help.

millman52
01-05-2007, 04:47 PM
fractaledge3, Glad to see your posts & others on the subject of belt drives. I had thought of positive belt drive on my own. First looked in www.mcmastercarr.com to see what they had. Thinking I might find a loop bet long enough to cut. To my amazement they had open ended belting there. Boy was I proud of myself..... The next day I was reading posts on here & found someone else using it. So Much for my original idea!!! LOL.

Anyway I was still worried about being able to tension tight enough to keep out backlash. Especially with the gantry needing to move 10' or perhaps a bit more. For my use, ox/fuel torch I need to motor & belt down both sides of the table. I can keep the belts shielded from as much heat/dust/grit as possible.

Thanks so much for the link(s) to your machine it really helped confirm it's a viable way to drive a table.

millman52
01-05-2007, 05:17 PM
Another WM owner Great!

I have a '95 LT40HDG with 1200 hours and the round stock has developed a slight worn spot but not bad. I recall hearing that Woodmizer went through quite a learning curve to find the receipt for their rod. The fixture they use to hold inplace and the weld procedure is unique too. They are very serious about the closed shop policy. I'd love to see a mill but together but I'm getting off topic! Good luck!

Tom

Yeah all hush hush. Their rail(s) in 1993 are just mild steel. Very easily dressed with a file if nicked.

Well I have a friend that owns a LT30 very early mod. with a gazillion hours on it. His top rail had tremendous flat spots & hourglassing. He asked me to help repair it if possible. I made a clamp much like an overgrown "C" clamp with a "V" block anvil. then used a couple u bolts & a heavy strap. (See attached rough sketch). Anyway started on one end & moved about the same spacing as the rail was originally welded. When finished you couldn't tell it wasn't original & the mill was like new again.

I used a long "V" block on the lower round to clamp against. We replaced both rails. Took us about 40 hours to pull off the project re-paint & all.

PlasmaGuy
01-05-2007, 11:12 PM
What CR did you end up using? 1013?

fractaledge3
01-06-2007, 01:06 AM
For my use, ox/fuel torch I need to motor & belt down both sides of the table. I can keep the belts shielded from as much heat/dust/grit as possible.

Thanks so much for the link(s) to your machine it really helped confirm it's a viable way to drive a table.

Hi millman52,
I agree with "motor & belt down both sides of the table", because my original design was router table modified to CNC plasma table, but if I do it again as a single use plasma table, I will drive it from both sides.

millman52
01-06-2007, 10:42 AM
What CR did you end up using? 1013?

1045

millman52
01-12-2007, 08:19 PM
Been sidelined the past couple weeks on my table project. I purchased several sections of pallet racking. It has taken pretty much all of my time hauling & erecting it. Hope to get moving on the torch again soon.

millman52
01-20-2007, 09:46 PM
I have been wondering if anyone has mounted their electonics, computer, etc. to the "X" axis? Most commercial companys {ESAB, etc} have the controls moving right along with the X axis.