torch and plasma cutting table

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I have been working on this for a while, been a couple of tricky parts that I would have done different the second time around, but lessons learned. Not finished but getting pretty close. I need to figure out the exactly how I will do the head part and the motor drive but I have a couple of good ideas on how to wrap that up.The last terrible pic is the not finished part to attach the torch arm to plate to the linear bearings (not shown )
Reply:I had a bigger purpose when I put this together, got nothing done on the cutting table, but feed rollers, and a miter setup for my (not) coldsaw. Its was all supposed to fit together, which it does. So when I get the head and motor finished up on the cutting table I can handle 10 ft with door closed or 20ft door open, the table will handle up to 4x4 on a cut. Understand guys my shop is limited in space so bigger just wasn't an option until I expand the building.The miter setup I changed at the last minute, I was going to do this all out of steel, but the 1 1/4 top was just sitting there begging to be used, and it made it easy to place the roller bearing where I wanted, its all steel structural underside though.I have a couple of more tasks to wrap up head and drive for the cutting table, and the lock down on the miter saw in 22.5, 45, and 90 degree positions. But I am just about ready to rock and roll ( after I do some housekeeping )
Reply:Looks good so far. I did wonder about whether you was going to be able to make that screw turn well enough on the cutting table. That's a tricky setup to get running smooth.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:Irsih,I cut bushings ( you can't see it behind the nut ) they are 7/8" bearing on both ends and if it was all welded up rigid it would have worked, the problem is it would need a couple of braces runing down it to hold it all together sqaure and not rack ( I am talking a very small amount just enough to bind the screw, and that screw is heavy probably weighs more than all the rest combined ) Anyway plan "b", which will work. I am going to get a couple more nuts ( not the precison brass shown ) and lock down the ends, then I am going to put a timing belt pulley on the bass nut, and run it off a belt. That screw with nuts on either end acts as a rigid member, thats how I have it mocked up right now. The slider on the linear bearings and the nut moves real freely, so I am talking zip torque. What I am on the hunt for currently is a aluminum timing belt pulley that is big enough ID so I can turn it on the lathe to 1 1/2" and about 2-1/2 to 3 inch OD. And deciding how to do the motor. I am seriously looking at the Metabo 751 drill option ( $125.00 on Amazon ) two speed 0-1000 and 0-3000 RPM, which has a 1/2-20 arbor. The other thought I have is a Nema 34 stepper only concern is the torgue rating, where as on the drill its the weight added to the platform, as its 7 1/2 lbs. both will work. I kind of stepped away from it for a day to get some other stuff done and think ( miter table ) and think about the smart motor setup.I have also left the option to put the pantagragh arm on this later, I don't have a immediate use for it, but think I will eventually.One last thought on the screw, I worked with that a bit, and if it was bolted down and not sitting on the angle it would work ( which means welded rods ) I go it right now so it can be turned by hand mounted as shown but its still binding, clamped down to my fab table its turns real freely.When I said lessons learned if I had made those bushings longer say 2 -3/4 inches this would have worked then I would have had 10% of the length of the rod in a bearing support.Is what it is, its just adapt and overcome a problem,  and I think in the long run just runing the nut will actually be a better option.
Reply:Oh one last thought: When I said lessons learned if I was going to do another one, I wouldn't use angle to slide on my "Y" axis, its sloppy. A better way to do this would have been to use DOM tube or square tube for the bottom structural piece, then use a telescoping piece over the structural. No slop, much more rigid, if I had done this the lead screw wouldn't have a problem now....again lessons learned. I did only tack the angle down, if I was real motivated I could cut those off and put in the tubing. If I can't find the timing belt pulley I still might.
Reply:Ok. Here's a thought on the problem. Instead of bushings on the screw why not use bearings. Like flange bearings which will self align to any angle. They would also allow fine tuning the alignment via the bolt holes holding the bearings.   Just another option to consider anyway.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:Yeah thats a thought, and and soon as you said it makes sense, need to think on that and work costs. I am eaded out to take a picture post in a while.
Reply:Irish,I think these show the issue. Hindsight......telescoping square tube, drilled and tapped instead of the clamps.
Reply:I think the square tube would give you trouble as well. Tuning in for precision on a job like this is tricky with welds pulling, stock not being straight or precise for that matter makes it hard to do. In a case like this you have to design to allow for adjustment of most aspects of the build. This allows for the fine tuning which is where you are now.   I learned the hard way to stay away from hot rolled stock and pipe when trying to make slides a long time ago. At least if you need to be precise. I spent a week trying to sand and lap in a pair of 2" pipes I used for a slide on a router table build. Never did get that thing to slide properly. It's one reason I work real hard at staying away from parallel bars or anything for a slide. Just to hard to get everything just right even if you machine every component.   Anyway on to your current problem Looking at what you've got I think you need something besides the rods to try and hold you end plates. Something like a x brace, strap, channel, etc run across between the plates to hold the ends square.   Let me see.  Ok here's a crude example of a couple possible methods that I just drew with sketchup. Attached ImagesMillermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:Exactly,My rods or the linear bearings are straight, the thread is straight but the end plates tweak. Thats what I meant by a welded member to straighten it up. I am going to sleep on it, the angle is still the weak link, too much slop. Honestly I would rather get the lead screw turning, a lot less lathe work and trouble.BTW, the plates, and all the aligning were match drilled ( what a pain on a 1 1/4 bore ) and they are with a thou or two. Machining isn't going to fix the rack that you illustrated.I'll leave it at that tonight and ponder my tale of woe.
Reply:Irish,I might get lucky, think I have a line on a pair of 1 1/2"  bore gears, if I get them I will leave the screw rigid. I went and ordered two nuts for that rod...Almost $14 a nut, some expensive hardware that.
Reply:Yep nothing cheap when working with acme threads.   Gears to turn the nuts. Hmm. I'm thinking you're going to need to put bearings on a hollow shaft and mount the gears and nut to it. Otherwise the side force on the gear might make for to much friction on the shaft. Might not but you've got to have some form of bearing for the attachment to the slide.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:The slide I have two linear bearings, and that is running real smoothly, got that finished up today. The gears I am looking at are 2 7/8 thru the bore and that with the brass nut inside should work pretty good. Your point about side pressure is valid though, guess I will McGiver up an adjustment for that so it can be tweaked.With the slide today I was running it back and forth on the bars and its not zero torque but very minimal really won't take much to move it left to right.
Reply:Irish,Thought about the gear idea and scratched it, yes it can ge done but too heavy, and cost is more expensive than need be, it just overkill for this application.Anyway this is what I am going to do:Two Martin timing belt pulleys which I have sourced, one boring bar operation on my lathe to open up the bottom pulley to 1 1/2 inches bore......done deal
Reply:Have you unclamped/released the gantry yet to see how much its going to move on you? Your going to need adjustment between the endplates and the rail for the opposing axis or you'll be fighting it.  You might try bolting and doweling to keep the endplates square with each other.  you might dowel one end and key the other end to allow adjustment on the length, but still keeping it square... You could make a fixture to set the endplates in a mill, locating off the 90deg angle on the bottom where the side plates are riding,  then mill/spotface them at the bushing faces, that would square the sides up with the angle thats riding on the lower rail.. If the sides arent square, you'll be pulling your hair out later..  Add adjustment into the base of the side plates..  might try welding a drilled and tapped plate on top of the piece of angle, and bolting the side plates to that, that way you could shim or adjust side to side if needed..    You need the side plates square and perpendicular with the piece of angle at the bottom..Last edited by brucer; 01-31-2012 at 05:50 PM.tackleexperts.comwww.necessityjigs.comhttps://www.facebook.com/groups/mach...dingequipment/
Reply:" Have you unclamped/released the gantry yet to see how much its going to move on you?"When unclamped it moves front to rear smoothly if thats what you mean. I have pretty much given up on moving the screw I could spend a lot more time on this, but I can just move the nut and use the screw as a structural member. I went and got the nut today.....wrong size its bigger than a 1 1/8 -5 tpi must be a 1 1/4-5, more wasted time. So tommorrow I will have the right nut. I am leaving the option open to remake this stuff later , but right now I need it up and working.
Reply:" You need the side plates square and perpendicular with the piece of angle at the bottom.. "I was going to do this for 2 reasons, first its a square stop, and second to take out the racking, I am holding off on that right now though as I want it to bolt together so its serviceable and right now it is. I will get busy on the brackets for it though.I did get the pulleys ordered, I should have them Thursday.Sides are square I was anal on getting that stuff fixtured up, and the angles were milled and polishedLast edited by fredschrom; 01-31-2012 at 06:31 PM.Reason: comment.
Reply:I'm still concerned with the nut having to much side load to run smoothly. In fact the belt will put more pressure on it than the gears would since it'll be pulling together as well. Only way to know for sure though is to try it. You might look into getting some moly to put on the screw to help with the friction.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:" some moly " got some. I have actually played with the brass nuts and they are a tad slop ( from a worn out mill ) I can finger spin it and it will walk a couple of thread it moves so freely. What I do need to be careful of on the side load is "NOT " overtightening the belt, which means a fairly accurate means of belt adjustment. One of the reasons I didn't want to initially do this this way.I am waiting on parts so I am going to fab up the arm and the torch holder while I am waiting, I made some progress on that and don't have a whole lot to do to wrap that up.And a last thought other than the angles which are tacked in place this all unbolts or comes apart, so if I get boxed in I unbolt and cut of a couple of tacks and straighten out the end support pieces. But I want to see how I do on driving off the nut first.Should be out working on it now but I was told ( by the big boss wife unit ) not to go out and get dirty as I was walking out the door, which means zip gets done this evening.
Reply:Oh Irish one last thought besides torgue, I am not worried about the screw it is "HARD" the fail point will be the brass nuts, but they have almost 2" bearing, so if I don't overtighten the belt I should be OK. A couple of days will tell.
Reply:fredschrom, have you looked into using v-groove wheels for the gantry? it would eliminate a lot of resistance. Attached Images
Reply:Actually I did but a tad differently with four rollers:And that idea is still not out the window, would definatly slide easier. Going to get left-right working first though then fiddle with a more precise in-out as its working pretty good right now. Besides when I get to fiddling with that more I am going to Nema 34 steppers.Another good way to tackle this is has anyone ever seen a older gun stock duplicator? Pre CNC stuff, cable was used like on a garage door to keep the assembly square so it couldn't rack.
Reply:Forhire,OBTW I got some pretty decent cuts on my Cutmaster 102 using a angle as a guide and following your advice...Thanks
Reply:My worry on the side load is it causing enough friction to make driving it hard. I'm not to worried about that big screw bending though it will flex some from the load. But the friction from the drive might make it hard to maintain a steady speed.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:" My worry on the side load is it causing enough friction to make driving it hard. "Possible , I checked the brass nut this morning and its 1-1/2 inch long so same bearing, the belt is only a 1/2 inch wide so as long as I get the belt centered on the nut I think I should be OK. If not its back to getting those two end plates square.Other than putting the right nut on the end I worked on the torch arm and avoided that, tommorrow I will have parts and I let you know how it works out.Irish,I worked on that screw some today: clamped on end down straight and tight then adjusted the other end, got the screw to move, but still way too much torgue needed, I would need a 3 hp motor to drive it reliably. I think the only way is braces, and a self centering bearings, anything else I am wasting time.I did work with the nuts and a flick of my finger moves the nut 2 threads or about 3/8 inch.I got the drill motor I was planning to use, the "ONE" feature I bought the drill for wasn't there, it was in the marketing crud but it came without the speed control control dial.  Only reason I bought the drill. It is a nice drill beats the snot out of my old milwaukee in fairness but I bought it for a specific reason. Think I am going to just get a nema 34 stepper looking that up as soon as I finish up here.Anyway made progress on the arm and torch holder. Not finished yet but I will finish it up tommorrow, except for trimming the top plate to final size and attaching the motor. The angle on the end which is waiting on my final motor decision is supported by two bushings I cut if your wondering what they are, its to support motor and not rack the linear bearings.
Reply:It's progress. Just have to wait and see about the rest. Sometimes you've got to stay flexible but it hurts when you spend money and it doesn't work.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:One the drill if its costs to return it I will probably keep it, I just checked and they are $45.00 more than what I paid, and my old Milwaukee is getting tired its been rode hard and put up wet more than a couple of times. And being flexible I am kind of like a willow on this one right now. Again there are some lessons learned on this one, in repeat I would never do those end plates and supports the same, playing around with this today I realised besides the square vertical I showed you in the pic's the to plates can be out in out on the angle a touch and cause the same problem. I think I would have used bigger bars than 20mm maybe a 25-30 mm bar it all kind of boils down to the lead screw; heaviest part of the assembly probably weighs more than the rest combined and at least grade 8 so its a pretty rigid member.The encouraging part is the top plate on the linear works great virtually no drag, added a little with those dragger support bushings under the angle but 1/4 to 1/3 hp max to drive the top plate assembly. I also put some thought into the side load comments of yesterday. I am going to watch that, and the nuts might need to be changed once in a while, so I will make it standard and serviceable.
Reply:Ok. Good to keep a open mind.   You might need to rig up a bearing to support the nut connected to the motor and slide. You've got to have something connecting it to the slide anyway. I believe you've been talking about the nut being 1 1/2" OD. So maybe you've got room for a 1 1/2" ID bearing next to the pulley. If not you might have to make a hollow shaft that the nut fits in with bearings supporting the shaft.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:Irish,Thats a good idea on the bearing, I will incorporate the its a good idea. I got the head or top assembly and torch holder pretty much wrapped up today, not crazy on the holder I did for the torch cable, I will clean it up a bit. The pics show a couple of details, one the indicator needle which I will put a dial behind so I can dial in bevels. The other dark picture is the support bushings ( open on bottom ) to support the end of the top plate. No the nut is 1.125 ID, I.5 OD, and 1.5 inches long with a flange so putting a bearing on that won't be an issue. I am rethinking the the whole motor setup. What do you think of a 1/4 hp variable speed (1725 rpm ) DC motor? Anyway cutting the timing belt pulley this evening, slow going that its a 1 1/2 inch ID bore.
Reply:Looking good so far. I'm not sure about the motor. To many factors to determine. I'm betting some form of transmission will be needed for a high low at the very least if not more. Otherwise there won't be enough torque at low speed.    Just a 1 1/2" bore. No problem. Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:Got the nut and drive pulley finished up, definately will need a bearing too much slop on the nut.The other couple of pic's are motor mock ups, the round is a 4 1/2" x 5 1/4" piece of A2 tool steel just checking if I have to go a heavy motor if it will have problems. It will work but I will find a lighter motor." Just a 1 1/2" bore. No problem" Your lathe must be bigger than mine.  Once I got the hole big enough to get my boring bar into it it went pretty fast. But getting my morse taper 1 1/8" bit through initially was slow going.Bearing and motor and this baby is ready to cut.
Reply:Looking better all the time.   I figured the bearing would be needed. Looking at the pics I wonder if you could mount the bearing on the pulley shoulder. My next concern is if a single bearing is going to have enough resistance to tilting of the pulley/nut assembly. Might need one on each side or make a sleeve to press in the pulley on the opposite side of the nut to allow two bearings.   Yeah well I drilled a 2 1/4" hole the other day on the drill press. But on my small lathe I've only got a #3 morse so I can only got to a little over 1" with the drill bits I have. But I have both 3/4" and 1" bars and my 1" bar is turned down to 7/8" on the end allowing me to barely get it in a 1" hole to enlarge it.   Fixing to be drilling a bunch of 1 13/16" holes in 3/8" wall tubing starting Mon. I've got a 1 3/4" drill bit but I'm welding 1 3/4" OD seamless tube in them and I've not got the tubing yet. I'm afraid the tubing might be slightly oversized so I'm going to try out a annular cutter out of the batch I just bought a while back in the drill press. We'll see how that goes.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:I have an old Southbend its 13 inch though weren't the common 10 inch. Got a love affair with that old lathe it and my wife of 32 years aren't up for trade.I do want a new lathe ( new to me ) 15 ish gap bed, but not happening for a while, still going to keep the Southbend though.I made up my mind a while back I am never getting a bigger than 1-1/4 twist bit, I am going annulars, still deciding on the brand, Jancy  ( now Fien ), Nitto Kohki, and Metabo is making a new cordless, pretty much either 3/4 or 1 " Weldon. I did just score a Aloris toolholder today, My old Enco toolholder broke a gear inside ( piston type ) and its was an odd ball, took me forever to find a gear, and get it fixed, needed it bad a couple of weeks ago, now that its fixed it sitting on the shelf. I saw the toolholders you made I don't have time to work on that right now, but really good job on those.BTW, thanks for all the encouragement and advise
Reply:I did the bearing and motor hunt today and ended up not good. My shaft diameter on the lead screw is 1.14", I still have another bearing house to call but closest was 1.18 I found. way too sloppy. I also checked on bushings not in stock a week out, still needs to be reamed to size. I think I will run over and get a a piece of delrin rod and cut my last bushing, light strong and gets that problem solved cheaply, done deal.Motor Hmm no good news on that front, biggest issue is speed control in the low rpm range, loss of torque etc. I am looking at using a worm gear in some kind of transmission setup. did a bit of looking on the internet for a calculator but haven't found anything real handy, the sites I found are switching to metric module and couldn't take imperial numbers for the module and even when I converted it are out of range.....HMMAnyway got to go and do some homework on this one I am figuring a 10 to 1 or a 20 to 1 ratio will make the variable speeed motor a lot easier to solve.
Reply:As far as bearings are concerned you can always machine a bushing of some kind to adapt the size.   The motor problem is always the worst on these from my experience. That's why I made the recommendations of the stepper or drill gear box. They're the easiest solutions that I've found. A tachometer feedback on most motors solves a lot of problems. Of course the name for that is servo. Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:Actually looked at the servo option and thats not 100% either the motors that have the speed range usually have zip torque like 3 lbs/inch, and I think I need about 17-35 ish for a resonable safety factor. It did find a on line motor and it has the speed range, torque needed: http://www.osmtec.com/bldc_motor_92bl.htmwith something like this for a controller:http://www.orientalmotor.com/product.../usa_sc_bx.pdfI will get it just not a good progress day.Another option I considered is tying into my three phase if you look at the 400 watt controller above its 3 phase.
Reply:look at keling http://www.kelinginc.net/ they have stepper motors and servos, they have anything you need as far as electronics go..  If your going to use servos be prepared to spend some money, they arent cheap.. I ordered my electronics from hubbard cnc off ebay.. I looked his number up on the internet and called him and ordered, bypassed fleebay..  I used one 425oz stepper with one 425oz stepper slaved  to drive my gantry and i'm going to make a 3:1 gear reduction using xl or htd5 timing belt pulleys with a 3/8dia. d-shaft..  I'm using the 4 axis tb6560 driver board, 24volt 14.8amp power supply and 4 425oz steppers..tackleexperts.comwww.necessityjigs.comhttps://www.facebook.com/groups/mach...dingequipment/
Reply:Brucer," they have anything you need as far as electronics go" I called the today and not quite. They do have stepper motors and have a bunch of contollers but not what I was looking for ( I think, the chinese guy's english was horrible and I had a hard time understanding him ), I did puruse the web site in detail. Decent prices on the Nema 34 motors though.I called a place called Motion Group today also, and they had both the stepper motor and the type of controller I was looking for, still waiting on spec sheets in e-mail.The controller I want has a about a 20K pot as a speed dial and a integrated power supply for the motor, probably has comm ports and other hokus pokus for real step operation, but I just want the forward reverse and speed control, all the rest is just bells and whistles.Looks like this will work, although I need to do a speed increase so I am going to do that with spur gears, a 4-1 or 5-1 will do what I want. Did get my Delrin today to finish up the last bushing which was good news.Not a lot of progress but some, mostly paperwork and phone calls today.
Reply:keling is in illinois, guy might be foreign, i'm not certain as i talked to them several months ago and i decided to order from hubbard.. Are you building just a motorized cutting table thats not using any cnc control? such as plc control?all the cnc controls i've seen are usually based off 200 steps per rev. i'm runing one of the old style tb6560 driver boards and as far as i know its based off 200steps per rev and you have to figure the gear pitches for the thousandths per step figure that you input into the software configuration.. I can also add a pendant control for manual jogging and positioning.. have you looked at baldor motion controllers, good company if you can afford them..   GE also..Last edited by brucer; 02-08-2012 at 12:12 AM.tackleexperts.comwww.necessityjigs.comhttps://www.facebook.com/groups/mach...dingequipment/
Reply:Why don't you buy a controller like http://www.candcnc.com/BladeRunner_Dragon-Cut.html ?
Reply:Brucer:"Are you building just a motorized cutting table thats not using any cnc control"Yep just a straight line cutting machine, one axis. Plan was from begining that, if you notice I put the ends resting on angle supports. That is so I can lift the head off the table and use it off of my truck if I need to ( and that bright idea on my ppart introduced a lot of pproblems which are nw solved )  Another item not really noticable its the holder for the plasma torch, I made that interchangable so I can switch the head and put a machine torch head on this,  probably truck application as right now I am not planning on a compressor on my truck ( that could change but for now thats the plan.I do like the stepper option, as if down the road I want to get this into a three axis machine one axis is done."   I can also add a pendant control for manual jogging and positioning.. " What is that?I know that the control set up for a pot are made, oriental motor has one, but the one that has the right watts is set up for three phase which kills the truck use, I have 3000 watts 110 and 220 on my welder, but no three phase.I should get the manual on the controller today, I am sure it will have the computer interface, but for now I am just looking at just a small part of the capability.I didn't blow the whole day on phone calls I spent a bunch of the day doing drawings on the gearhead assy, a little bit of cutting and a lot of precision drill work on that, going out today to get the aluminum to get started up on that, and will knock out the last bushing and finish off the nut on the lead screw assembly.And guys to date, I am around $300 ish into this table and ton of labor, so if I need to drop another $500-700 to finish up the motor, and another ton of labor I will still be ahead. The bushings, the whole head assembly I all did on the mill and lathe, so I had about $20.00 in materials, that didn't count the linear bearings or the rods which were a big dent on the $300.Once I have the motor assy wrapped up, its pretty much the downhill slide to finished up. But think I am going to switch over to a couple of other projects while I wait on parts.Forhire thats pretty nice setup but way overkill for me right now.
Reply:I got the link to the controller manual today: Not cheaphttp://motiongroup.com/download/manuals/smd1man.pdfIf you scroll down to the wiring diagram it shows the run/stop,  speed contol, and the direction switch.And I thought I was all on track till I did a design verification and checked all the numbers....wrong I donked it up I had been working on a 4 to 1 ratio and I need a 7 to 1 so I guess I am back to looking at the worm gear option, or a real big spur gear Anyway back to the drawing board as they say.
Reply:Irish,I finally figured out how to get the leadscrew to work right, drew up prints, sourced parts: motor, controller, gears, bearings. The gearbox was tricky worm gear driving spur gears. Anyway took it through a design verification ( used to do those when I was a engineering manager ).Let it sit for a day and thought on it.AND the offical answer is, I am dumping the lead screw ( maybe I'll cut it up and make a couple of vises out of it ). Too complicated, screw is too heavy, and the 5-1 ratio is making the motor a lot more expensive and complicated than it needs to be.So I am have a pretty good idea how to do it right, with a rack gear, but I am thinking that through before I jump.I didn't touch the table today except to cut some stuff and pull the leadscrew out. Worked on my lathe, and a flange rollout wheel.
Reply:I think that's probably a wise decision. I wasn't sure about the screw when you first brought it up. To many problems in that approach with several other easier ways to do it. Rack is one as well as toothed belt drive, cable drive, or even friction drive.   Personally I've always thought that the toothed belt system was pretty slick for a low budget setup.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:" Personally I've always thought that the toothed belt system was pretty slick for a low budget setup."I looked at that but wasn't getting much joy on belt length, the ones I found were too short, a timing chain is another option. Do you have a source for longer say 100+ inch belts?We shall see I am working on finishing up my rollout wheel weld positioner tommorrow, I have hit the walk away and think about it for a day or so stage, and I still have plenty of projects to get wrapped up. Took me days to sort out the mechanics of the gear mechanism to get the screw working, and I need to clear my head on this for a day or so.
Reply:[QUOTE=fredschrom;790531]Do you have a source for longer say 100+ inch belts?I've been buying timing belts and pulleys from http://www.bbman.com/. They also stock gears. Catalog states up to 270 inches. Have you considered a garage door belt? Same construction and you can likely pick one up local.
Reply:Forhire,Thanks yep they have long belts, puts the timing belt option on the top of the heap design wise.Thanks again.
Reply:McMaster Carr is listing belts to 10' though I didn't narrow it down to which series.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:Irish, In light belts McMaster stops under 100 inches. I always check Mcmaster when chasing parts good place to start.Anyway its finish my rollout wheel (or get close) today. Going to clear my plate of projects and come back to the table, it cuts right now and I used it yesterday, and I think I want a tad more cutting time on it to work out a couple of refinements anyway.