[Calico]

I want to weld Square pipe 2 meters long, like making a frame of a photo.

I do not have flat surface (table), how to make it really square and perpedicular ?

I have 4 pieces of square pipes, I just want to weld them square with almost 100% square, this is for CNC table.

I can use Dial indicator but not sure how to use for this purpose.

anyone have tricks for this ?

regards
ruddy

[ViperTX]

Do you have a machinist level? If you do then you could temporarily stick (mortar, screw, etc.) 2 post to the floor (ground). Use a couple of clamps and attach one piece of square tubing between the post...use the machinist level to level the tubing...place a third post in the ground.....use another piece of square tubing to go from the third post to the other piece of square tubing....once it's level with the other....tack weld it....continue until you have the rest of the frame laid out...then tack it all...clamp it and weld in short segments.

Don't forget to square the corners......you may have to use the 3-4-5 tringulation method.......

[Calico]

I do not have that machiniest level.

I guess I can't do that without machinist level.

[2muchstuff]

Lay the 4 pieces on the floor like you want them. Use a tape measure and measure diagonally both ways. Adjust the frame so both diagonal measurements are the same. Tack weld the frame, flip over and tack weld the other side. Check for flatness and adjust as needed. Lay back down and finish the welding. Flip back over and finish welding the other side.

[take a cut]

If you really want to use a dial indicator what you need to do is weld a spindle from the junkyard with a hub on to a plate and weld that to something heavy to keep it sturdy. then weld a tube out from the hub to where it will reach the tubes about a foot from the ends in 8 points and dial er up.
Though if you start with good straight material all you really should need to do is clamp the ends to a corner plate on a couple of benches and tap it around to square and shim it level starting with finding your highest point and shimming the rest to it then start tacking in small stiches alternating corners and placement around the tube remebering that your next stitch should be as close to oppisite direction of pull as the last. Tacking in corner to corner stiffeners before welding will help as well. In all likelihood the frame will pull from the drawing of the weld, keep a relatively cool heat setting hope this helps and good luck.

[mxtras]

Calico -

Visit this site - this guy really seems to have his act together as far as getting things damn near perfect without too much machining - I was very impressed with his write up - lots of information.

http://oneoceankayaks.com/madvac/madvac_index.htm

After reading that - come back with questions - what you are trying to do is common.

Scott

[Calico]

Scott,
thank you for that link, very very useful, I have not read all in detail YET.

that guy is a pro. he master everything I guess.

I'm just learning everything from Welding, CNC, molding, electrical etc.

I still need Machinist level, trying to buy from ebay but no luck, cost much to ship to Indonesia.
never giveup though

I will ask later after reading that site.
english is my other problem also, specially when he try to explain thing that I understand 70% sometimes killing me.

regards
ruddy

[mxtras]

Calico -

Personally - I would not get too hung up on the precision level just yet. It is a very useful thing and it is very important for precision work, but as a relative beginner, you may want to keep things simple for now and just do the best you can with the basic tools. Using a regular level, you should be able to get pretty close. Use the level to get a reading, then without changing anything, turn the level around and take the same reading - if the level is accurate, you will get exactly the same reading. If not, split the difference then do it all again.

Yeah - I was pretty impressed with this guy's level of detail - he took the time to create a nearly perfect machine (based on his description) without the use of extensive machining. He had many of the precision tools you would need to accomplish such a task. He also had the knowledge of how to do the best with what he had.

If you dig around this site long enough, you will find all kinds of ideas on how to accomplish what you are trying to do with limited tools.

Keep us posted on your progress!

Scott

[traveler]

What you want to do is not difficult to achieve. Start by making certain the sides are the same length, measure with precision. Then do the front and back the same way. place the pieces on a table or use sawhorses to get them up off the floor. Clamp a flat piece on each corner to align the parts, it takes 8 clamps to do this. Square the weldment by measuring diagonally or corner to corner. When it measures the same each way, back off and look for one corner higher than the other when viewed from the side or end. Place shims to take the twist out. When it measures the same corner to corner, and looks parallel, tack weld each corner on the inside with small welds, check measurements and tack the outside of each corner with small welds. Then carefully apply the final weld. Keep the heat down and work on opposing corners to help control heat distorsion. Take your time and don't hurry. I don't like to hear people talk about "tricks of the trade", I like to think of proper techniques to get the work done. Good luck with your project.