Thanks for the advice. I just came from the metal shop, but they still have not cut it. However the profile seemed normal squarish, nothing unusual, so i believe that will not be a problem.
I wonder guys what are you constructing with 100x100x10 ?
i couldn't help but notice, your gantry is only supported by 1 side plates at each end? Wouldn't it need something stronger, like my design? As profile like support at the sides is stronger from even a thick plate i believe. There is a calculator Excel sheet somewhere here on the forum.
Your table structure looks great, and i have given a lot of thought how to make gantry similar to yours, it looks great also.
The gantry sits directly on the 20mm plates that will hold the rotary nuts, to which another 22mm thick plates with cars will be mounted. There's no gap there. The sides are 12mm thick steel. So there is direct contact of bottom of gantry ends to rail cars. There is no measurable side to side movement possible other than any play in the rails/cars.
I used 100x100x10 SHS for most of the construction as I had to order two 6m lengths and didn't want to throw away too much. Also one 6m length of 140x80x7 was used for gantry and for two table supports, all was used up almost without waste (supports intentionally placed along the table to create space for extra long 4th axis as we'd like to make some gunstocks in the future).
I just realised the pics I posted were somewhat outdated. In the final version I moved the tabs holding rotating nuts/servos of X axis to the rear and turned them 180 degrees so the pulleys are just at the rear plane of gantry. This was done to make possible to add another pulleys so I can belt the two sides together with one long belt. There are schools of thought (especially on our local CNC forum) that they'd better be tied together so if one side will stall or not work properly the gantry won't damage the rails. I believe that this is not necessary as servos have quite reliable feedback and one stepper just wouldn't have enough torgue to damage rails and the other side will stall within few steps from the first side.
Anyways the steppers just stall. Who knows what can happen with servos if stalled, i have no idea. Still not in that league.
At the end i have the profile cut, had to help the guys from the metal shop otherwise it would be next week.
Time to make some sparks and test my recently acquired new toys:
-3 in one plasma cutter, pulse tig , stick 200A
I decided to go with the MIG even as it seems that i do better looking welds with the arc welder. Yes, its strange but is so. Would have Tig-ed it but still no Argon bottle. maybe the Mig welds are more difficult to me due to the fact that i use beer gas. The penetration is perfect, before some days welded 10mm pieces without any problem. I was saving quite some time for the 2 machines, the combi cost 470 euro and the MIg 330eur with shipping to Spain. Both from fleabay. Needless to say the Mig was a great deal for the money.
I was a little worried because my welding is 1h practice at home and watching a lot of videos. But it went extremely well. It seems i weld quite well, the only thing is that my head is not shaped for welding helmets, whatever i did it could not fit properly
First did the gantry. Spot welded it, let it cool, then started short welds, then turn, then weld, then let it cool. I used my IR remote thermometer to monitor the temperature of the gantry to not pass 60C. So at the end i welded it quite precisely in fact, without twisting. However i was quite tempted to do a perfectly looking straight weld from one side to the other , but followed the correct procedure.
Then decided to weld the left and right sides and later connect them. The guys at the metal shop told me first to weld the bead square and then the rest. However i decided what i felt was better, for the purpose of easier adjustment . I decided to weld it precisely, like i would not use epoxy. Wanted to check if i am being able to do this.
Please don't laugh at my welds, at least they are really penetrating. The spatter is from the gas i believe.
Ground the welds where the bed profiles go. Now the thing is that i have only 2 large clamps. I tightened slightly all from both sides on my new acquisition, the welding leg supports i acquired exchanging a vacuum pump for them. using a square and a plastic head hammer started playing around until i finished with square bed on one and the same plane.
To make sure the bead is on the same plane i used Bosch alu profile as my Din 874 straight edge is still travelling
That the bed is square and is on one plane dos not mean that the most important part-the rail support profile is on the same plane, even if you welded properly.
I would epoxy it later, but i tried to make it perfect, so i decided to spot weld only from the upper sides, cause as i said i have only 2 large clamps. later would take off the clamps and adjust the squareness and being in one plane of the rails supports. As the bed is spot welded only from the top, Using the clamps end by end i leveled the rails supports. Then soldered.
Then became dark, and i -tired but happy. I know, its not a big deal, but for me-yes, cause i bought 2 welders and started a build without knowing if i can weld or not. So, now i relaxed a bit. The machine frame stays in front of my small workshop, cause now i can not lift it alone. It seems extremely rigid, much more than i expected. When i am finished, will measure the flex from 90kg on the bed /me/ . The gantry seems indestructible. I underestimated the need for hard stops. back to my first design. Monday will go and by some U profile. I thought of stopping it with bolt. No way, it should be something very strong.
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