CNC machines

[Brad93]

You'll only straighten that with heat.

unless you have a bulldozer to put on it.

 

[James1979]

One thing I did notice is your baffles don’t seem to allow water to flow around. Is that the design or just how the photos show it?

Thinking about draining and cleaning it etc. Assuming you’re going to have another layer of slats on top of that to put the work on?

 

[ned]

Brad I was wondering, yeah not much hope then. I wouldn't know how to approach it with heat. Could I get that much heat into the beams?

I have been looking for a excuse to buy an oxy-acetylene setup for a long time.

James there are small triangles cut out of the lower part of the crossmembers, to allow water to flow around

 

[James1979]

Brad I was wondering, yeah not much hope then. I wouldn't know how to approach it with heat. Could I get that much heat into the beams?

I have been looking for a excuse to buy an oxy-acetylene setup for a long time.

James there are small triangles cut out of the lower part of the crossmembers, to allow water to flow around

Just the way the photo shows it. Thought it was probably something you'd considered

Shame you're not looking for an excuse to buy a bulldozer I'm not one for YouTube but there is a really good video of flame straightening a beam, I will try and find it. He goes right into the theory. Its about little spots but lots of them and dividing it up. Brad knows more about this than I do......

 

[ned]

Cheers James

The thought crossed my mind to put a line of weld on the top beam, similar to the one on the bottom that pulled it.
Use the same pattern and the same heat setting, then grind it off when done.

 

[James1979]

I've done similar but welded large spots about the size of a 50p although on smaller stuff than that. Search 'flame straightening' or 'heat straightening' on YouTube. Theres a few on there if you're prepared to wade through the ****e to find a goodun

 

[MattH]

That is not going to make any difference to your cutting once you factor in a THC.
If you were building a router is would be a problem but not with a plasma.

 

[Brad93]

Heat directly opposite where you have welded and the distortion has occurred.

For the beam to pull back, when it grows, it needs to be restrained.

The effect can be magnified using cooling air or water

 

[Ned__]

Was talking to my dad (welder/fabricator) and he reckons any attempts to right it, could pull it in other directions. So I'm going to leave it be.
As @MattH pointed out, the THC (torch height control) will be able to compensate for the bow, so I'm going to leave it well enough alone and move forward.

Currently I'm waiting on the gantry plates to arrive. I cant really make forward moves until they arrive, so I'll take a short break from this project and prepare my car for its MOT next week.

 

[Hood]

You want to try and get everything as level as possible as even with THC it will cause slight issues. On my first table I didn't worry about the slats being too level, I was in a rush to get it finished so there was probably 5 to 10mm difference.
The reason it can cause issues is the material can be lying tilted to the torch and that will mean a bevel which will be worse on thicker material.

I wouldn't worry about the bow in the frame however, not sure what type of rails you have but whatever it is just keep them level by packing with shims or whatever so that they are straight/level over the length. The slats can then be adjusted level in the tank when fitting the holding plates. The way I did the slats in the last table was just move the torch to one end of the holding plate and zero the DRO in the control, I could then jog along the slat holder and move down the Z to zero on the DRO and bring the holding plate up to the torch and tighten the bolts, I then just repeated for the other two keeping the same Z0 reference.
It made a big difference having a level table compared to the first one.

 

[Brad93]

As robin says pack your rails so they are dead level, parallel and co-planar

 

[Ned__]

Hood a thousand thankyou's. I haven't the time to dwell over everything you've written (in work at the mo) - but I get the gist of it

• The rails can be levelled over the length of the beam

• I can level the sheets of steel using the water

• everything will be fine


hahaaa! wooo


I'll read over the description you wrote about the slats later this evening. Thanks!

Brad vey much appreciate your input also, thank you

 

[Ned__]

small update. The gantry plates arrived, here is one sitting next to the original gantry plates. They are 10mm aluminium and they are beefy, looking forward to seeing them on. I have a distraction for the next week ahead, so cannot start just yet, will be delayed.

Also I painted the interior of the tank with raptor liner, because the hammerite was not happy underwater, it started to fail, break apart, and it smelled bad! Hope this doesn't smell.

 

[ned]

an update. we are still in the process of moving house, and I'm still tapping away at the machine. I bought Open Grid Flooring after seeing a bright spark on youtube using it, I'll link to him later and give him credit for the idea. 200 euros for 6 meters (used). It's priced at around 500 for a 6 meter length, so I did well. It's not quite enough to cover the whole table, but, it's very near.

Also the proximity switches arrived, and the new 48v power supply. Those are the last things I'll be buying from Aliexpress from this address. I hope to fook we find somewhere to live soon.

I now have all the bits I need to complete this. The only things left to get, are some C-beam to make the Z axis longer, and some wheels to make the Z axis lifter.

In the immediate, I plan on finishing the slats and then squaring up my saw to cut the gantry beam. I anticipate that cut will take me a week (I have a job).
It's a pain in the nuts getting the Femi NG160 really square.

Anyways, inching my way there.

 

[Barking Mat]

Looking good, those bits of wood are just to get the heights, not permanent fixtures, I assume.

Assuming that's wood ?

 

[Hood]

You'll love the galvie fumes

 

[MattH]

Great work so far mate.

 

[Barking Mat]

You'll love the galvie fumes

I'm sure he's thought of an extraction system.

 

[Hood]

I'm sure he's thought of an extraction system.

I would be wearing a mask as well, once had the galvie flu bad and definitely don't want it again.

When I built the first table I was considering using some as there was a load going free but not withstanding the fumes issue there are others. The gaps are too small so anything falling through is a PITA to retrieve. Also the grate runs in straight lines so there is a very good chance of the arc running right along a bar, especially as they are quite thick.

 

[James1979]

the grate runs in straight lines so there is a very good chance of the arc running right along a bar, especially as they are quite thick.

that’s the only fault I can find with the xtreme table. Mine are due for renewal so I’m tempted to put some curved ones on there and see how that works