Newbie- Yet another new build

[jjellingson]

First of all I would like to say this forum is great. I find all of the threads very inspirational. I too, have decided to take the plunge and try my hand at this.
I have some experience with fabrication and machine shop fundamentals so I (we) will see what happens in the next few months. To date, I have an order in with Tom at CandCNC for the dragoncut 620-5 package with the remote controller. I am looking forward to that package. Already have decided to use Mach3 and Sheet cam.

I have to admit, I am a newbie at this and can sure use advice from any one. I currently in the table design stage and up for any input here.. I have pretty much decided on a water table and open for input. I seem stuck on just what size to go with. I have been kicking around the thought of a 5'x10' with an aluminum gantry. I need to keep the weight down with the steppers I have coming.

I am also concerned with the gantry extension I need to incorporate for a rotary table off the side for tube cutting. Eventually I would like to add a oxy fuel system and can use advice here also.

All replies will be greatly appreciated

[millman52]

Originally Posted by jjellingson First of all I would like to say this forum is great. I find all of the threads very inspirational. I too, have decided to take the plunge and try my hand at this. I have some experience with fabrication and machine shop fundamentals so I (we) will see what happens in the next few months. To date, I have an order in with Tom at CandCNC for the dragoncut 620-5 package with the remote controller. I am looking forward to that package. Already have decided to use Mach3 and Sheet cam. I have to admit, I am a newbie at this and can sure use advice from any one. I currently in the table design stage and up for any input here.. I have pretty much decided on a water table and open for input. I seem stuck on just what size to go with. I have been kicking around the thought of a 5'x10' with an aluminum gantry. I need to keep the weight down with the steppers I have coming. I am also concerned with the gantry extension I need to incorporate for a rotary table off the side for tube cutting. Eventually I would like to add a oxy fuel system and can use advice here also. All replies will be greatly appreciated

An extention shouldn,t be a big issue as long as the length doesn't add loads of weight or need to be long enough the extension becomes springy. Probably be easiest to incorporate into a dropped side gantry design too.

As far as Ox/Fuel myself & a few others are active here:http://www.cnczone.com/forums/showthread.php?t=98346 I'm sure anyone there will help if we can.

[jjellingson]

I have found so much information on this site, I thought I had better take a moment to thank all that have taken the time to post and help for any one seeking information.

As my build we soon be starting, I will have many questions for all. I will try my best with pics showing the method to my madness. I am sure I will have many of you wondering what this chump is up to.

A lot of you will notice similarities to your builds. I will be using design ideas stolen from several builds here.

Again, thanks in advance for sharing.

John

[jjellingson]

Hey thanks for the link, I see I will be spending countless hours on that thread also. My first thoughts where strictly a oxy fuel table, some how I swayed towards just starting with plasma and then adding the second later. I find I tend to do things backwards from most folks.

Your build has been an inspiration to me. I found your roller system interesting and with a good chance of showing up in my build. I more than likely will be bombarding you with questions on your techniques.

Plain ol Bill, thanks for the pm reply, your build has caught my attention, I am sure many others as well. Quick question for you is... how is the 3m tape working out?

John

[millman52]

Others use is the reason most ppl post their builds here. Feel free to copy anything you see. (at least of my build).

I began posting in hopes others might catch mistakes I was making or about to make before it was to late.

My gantry is pretty heavy. Most items in/on it are from 1/4" steel & some thicker. Although it works great, If I were starting over, I'd strive to build it lighter.

I Had most of the steel on hand (Surplus from other jobs of my shop). Couple that with me not knowing first hand I could ever get one of these things to work. I just didn't want to spend the extra $$$ to buy aluminum & no way at the time to weld it either.

I sort of have the Tim "The Tool Man" Taylor syndrome of "More Power" "Bigger/Heavier Is Better"

The best advice I can give you on building a table that will cut accurately is to avoid anything that may give you backlash (play) in your drive mechanisms. And the rails must be straight & Gantry must be perpendicular to the side rails.

Any slack or being out of square will make circles turn out like eggs. Squares & rectangles will be parallelograms.

[jjellingson]

I have been checking out drive systems on tables and find very informative information. More than likely I will go with the Rack and Pinion drive, it is a well proven concept . I have been impressed with the chain drives and really gave thought to these as well.

To date I have not found any cable drive systems. Has any one used these that I may have missed? Any one kicked this concept around?

Being from the North West and around the logging industry, many of the log delimbers (strokers) are cable driven. Granted these machines are huge, at first many were chain driven. Then the industry seem to sway towards the cable driven carriages. These days they all have highly accurate measuring systems.

Are some of the printers and plotters driven this way?
Any thoughts on this subject?
John

[millman52]

Originally Posted by jjellingson I have been checking out drive systems on tables and find very informative information. More than likely I will go with the Rack and Pinion drive, it is a well proven concept . I have been impressed with the chain drives and really gave thought to these as well. To date I have not found any cable drive systems. Has any one used these that I may have missed? Any one kicked this concept around? Being from the North West and around the logging industry, many of the log delimbers (strokers) are cable driven. Granted these machines are huge, at first many were chain driven. Then the industry seem to sway towards the cable driven carriages. These days they all have highly accurate measuring systems. Are some of the printers and plotters driven this way? Any thoughts on this subject? John

All the printers I have cannibalized have had notched belts.

I can remember reading some posts on here somewhere from a couple guys playing around with the cable idea.

I think you'd be best to stick with R&P. Tried & true.


However if you can design a cable system that will work positively without drift & backlash. Also be able to keep it fairly small & away from flying debris you'd probably be HERO to most all DIY builders. It would most definitely be inexpensive.

[jjellingson]

Update:
Electrics have shipped from CandCNC Now the other side of the coin, time to nut up and order the drive reductions and rack and pinions. Getting enough invested that I have taken millmans advice and sticking with what is known to work. I am about to place and order for 5:1 belt and pulley setups instead of the 4:1. Please speak up if this is a mistake. (keep in mind I will be adding a Oxy fuel torch). Some how I hope to come up with a quick detach for the plasma and oxy/fuel torch to reduce weight. I plan on going with the RKS1.5 rack and 16 tooth pinion from MotionTek. Again speak up if something is a miss. I have decided on going with predrilled T4 rail from Motion Linear, waiting to hear from them on bearing size. I would like to use the VW-2X 52100 sealed bearings (3/8i.d.) Still up in the air on the Z axis. I did however score a ball screw setup on ebay for a reasonable price. I need to design the slides yet.

The design of the table will be more or less Plain Ol Bills. A few changes, a special thanks to him for advice on the side. I will assemble the table with a little different method but basically Bills design.

I hope that I can fire questions to millman, as my milling could be questionable. After looking at his tapping in the Mill, I instantly had visions for my threaded holes with several broken taps. Picked up a nice used tapmatic 50x in hopes of saving some frustration.

I will start posting pics soon.

[millman52]

Originally Posted by jjellingson Update: Electrics have shipped from CandCNC Now the other side of the coin, time to nut up and order the drive reductions and rack and pinions. Getting enough invested that I have taken millmans advice and sticking with what is known to work. I am about to place and order for 5:1 belt and pulley setups instead of the 4:1. Please speak up if this is a mistake. (keep in mind I will be adding a Oxy fuel torch). Some how I hope to come up with a quick detach for the plasma and oxy/fuel torch to reduce weight. I plan on going with the RKS1.5 rack and 16 tooth pinion from MotionTek. Again speak up if something is a miss. I have decided on going with predrilled T4 rail from Motion Linear, waiting to hear from them on bearing size. I would like to use the VW-2X 52100 sealed bearings (3/8i.d.) Still up in the air on the Z axis. I did however score a ball screw setup on ebay for a reasonable price. I need to design the slides yet. The design of the table will be more or less Plain Ol Bills. A few changes, a special thanks to him for advice on the side. I will assemble the table with a little different method but basically Bills design. I hope that I can fire questions to millman, as my milling could be questionable. After looking at his tapping in the Mill, I instantly had visions for my threaded holes with several broken taps. Picked up a nice used tapmatic 50x in hopes of saving some frustration. I will start posting pics soon.

Only thing I can tell you about tapping in a mill especially small holes.

(1) I buy spiral point taps. The will push 90% of the chips out ahead of the flutes.
(2) Use fluid designed for tapping/cutting. NOT motor oil.
(3) Shift the back gear on the mill to neutral & back tap out by hand (still in chuck) for small taps, most anything near 1/4" or larger I power thm back out.

I suggest you practice a few holes on a piece of scrap material the same thickness to get the hang of it. A tapping head is nice but thy will still break taps if not properly adjusted. Plus you will have to drill all the holes you can reach, change to the tapping head then tap.

I usually drill hole, & then tap while still over the location to prevent having to hit same spot again. When tapping I also start the mill & turn off & tap the hole with the spindle coasting. Again small taps. Allows a free hand for the brake.

[plain ol Bill]

John I use a tapping head in my old pc. of crap drill press when making folding knives. Screw size is 2-56 and I power thru and out in titanium. I get a BUNCH of holes out of a single tap.
I am flattered you are going to use my build as a primary model. I think you will be very happy with the 5:1 gear reduction. I cut out some 14 ga. today for a roof rack I am building for my Jeep. I will throw up some pics when I get a chance.

[jjellingson]

Here is the latest:
Picked up steel yesterday, Shell shock, seesh steel is horrible for prices. Okay, we are trying to get past this. I Really don't have that great of access to a facility to bend, I kicked it around and thought what the hell just have it sheared and weld the joints. A couple of extra hours at the most. Well I order up three sheets of 11 guage, two sheared to my specs. Order up my 4 in square tubing and angle iron. I am a happy camper, got up early and I am first to load out....hehehe... In the mad rush for do it your selfers on Saturday morning I run off and left my angle iron, order was not all together....

Keep in mind I don't know this until later in the afternoon. After a cautious drive home with the steel, nothing banded. Every time I hit the brakes for steet lights I had movement. Okay, I managed to make it home with all intact and thought we are in good shape.

Measure up my square tubing and wow every thing is pretty much cut to length. I had one long piece that I thought I would cut my own up rights out of. The six 8" pieces on both sides. I had an extra few inches to play with (lucky). All of the saw cuts are out of square. I guess getting mileage out of their saw blades. I am pissed (don't realize just yet how lucky I am).

Start to set up my jig to weld up the cross members and uprights when I realize this ain't gonna happen. I think to myself how the hell am I gonna weld six units and keep everything true. Cross members are all cut pretty close to length. The out of square won't hurt me here.

I get the brian storm I will go about this just the opposite of what I had intended to do. I back the trailer (work table) back into place and proceed to get after it. I am laying out my six cross members on the trailer and get all of them so so and throw the 5' by 10' sheet down. Centering up, I get to looking and the sheet is 61" x120". What next.

Lucky I already have a plasma, made quick work out of that. Okay, all is good, I had already cut all the uprights, things are really looking good. You have to realize I am really anal about my saw. These 12 pieces are all lined up and not 0.010 difference.

[jjellingson]

Okay, getting things layed out again, and I think what the heck, set the uprights in place and see how things look. I think what the hell, set the 12 footers up and see how things look. Every thing is going great. I thought what the hell set up the sheet metal sides.

Tap things around a tad here and there. Hey, I have 90% of this table mocked up and every thing is really square and true. I double check, triple check. I had better start tacking things in place.

Keeping an eye on things I get after it. I have all the uprights and the top rails all tacked up, check it all and think this is easy. Keep in mind my bottom sheet and two side sheets are sitting in place to keep my spacing accurate. I figure I might as well tack these in place. I had two clamps on each of the sides. I start tacking.

I am two thirds down the first side, I notice a gap in my sheets on the bottom, impossible I think, the sides are sitting flush with the cross members.
How or why this happened is beyond me. I missed something moving. Starting to get cranky.