I want to mill steel with this machine.

Hey all,

I am looking for some advice before breaking things.

I want to make a 3d welding table like this:



The idea is I cut out the rough form with my plasma machine. Thickness is 10mm steel or 20mm steel . So far I am good but than to get the precision I need I want to put it on my router which looks like this:


Machine weight 3500kg bridge weight 1000 kg. The z axis is made out of cast aluminium. Motors on all axis are 1000w servos. My spindle that I would use is a 4.5kw spindle. I could also do this with a 9kw ATC that I am buying, but don't want to hurt that one.

I would position this plasma burnt metal plate with all holes already plasma burned on the router and than precision cut all the holes.

I would like to know if it would be at all possible to do this. I have a full waterbed with 2 sprinkles on the machine so cooling is not an issue. It can take as long as needed to make it, I just don't want to break any of the motors or guide rails or something like that.also I don't care for tool life.

Could someone recommend me if it can be done and if so how deep and how much I can chip of with this kind of machine. I will use gwizard than for the correct spindle speeds and so on.

Thanks.

I know the machine is not build for it indeed.

I was having in mind to go with 0.5mm down and take 0.1mm from the side with a 6mm carbide mill 4flanges at a slow feed rate.

That was my idea to not hurt the machine. But as I have no experience in steel aside milling the top of my clamps which went surprisingly well , drilling holes in steel and cutting through the occasional mispositioned screw, my knowledge of steel milling is 0.

Secondary option is to make the whole table out of aluminium. The machine doesn't give a flinch when taking 3mm stepover 15mm deep with a 10mm endmill.

I doubt that I can cut with the plasma that accurately on 0.1 through 10mm steel. Plasma is 160A Chinese.

As Tommy said, the plasma cut material will be so hard you won't mill it easily if at all.

I really don't get the attraction of those tables, just use a flat plate and when its required, drill and tap a hole in it where you need to hold something down, leave a 50mm overhang of the top to allow for clamps and include a receiver to accept a 50mm square section that has a vice attached so you can slide it in and take it away as required.

Seeing I have been using it today


I got my laser cutter to cut out the top, gussets and caster mounting plates. Top is 10mm and it would be nicer if it was thicker but then I would never had been able to lift it.

I made this a while ago and don't use it a lot so I've only ever had to drill 2 holes so far

i think the biggest problem with VFD spindles is they are all high speed spindles. the tool paths for aluminum are light and fast cuts for high speed machining applications. why because aluminum is the only type of metal you can get away with running at a high speed with and high feed rates. when you get into steel it requires much lower speeds even when using carbide and the feed rates are a lot slower as well. like everyone else has said the plasma process will case harden every cut made and that is tough to get under before the material is somewhat normal again.

one thing about the moving gantry machines is they are not meant to rough or hog any kind of metal period but with some fancy tool paths you can get away with not destroying the machine because you can limit the load on the tool to fit the rigidity of the machine. you just have to be mindful of tool loads. but like i said before you have to have the right speeds and feeds to even get into trying steel and enough torque at those speeds to get anywhere. HSM advisor will give you a good layout of the load created with your cuts and materials your working with to test out so you can predict what will happen before it even hit the machine.

not sure how much abuse a phenolic table can stand there so that's something to think about as well.

if you use HSC bits and a HELIX toolpath this mashine can do the job easy
if the mashine has the precition you need it will do it

make a SUB that takes the xy of the drill
and does a incremental G2/G3 Zfor helix P for full turns down <0,5mm
www.linuxcnc.org/docs/html/gcode/g-code.html#gcode:g2-g3

its as easy as that

That's funny. 4 times don't do it and than the fifth saying no problem, this machine can do it easily.

I would ofcourse use helix to go down. Not plunge it in the metal.

It's something to think about. The mills I have are HRC60.

i think the first thing you need to figure out is how slow the spindle can run since you want to be working with steel. smaller end mils can run faster but you want to have an end mill with enough rigidity to deal with the hard material your trying to cut. 1/8 inch is about as small as i would even consider and probably won't hold up well since it's on the small side. another thing is the length of the tool. the longer the tool the more trouble you are going to have. so how thick of material do you really need? on small end mills the length can mean quite a bit as far as how well it does with the cuts.

if you run these cutters to fast they will burn up without a doubt. we are not talking about doing one hole here you will have quite a few so tool life is going to be a factor. the only chance of getting a cutter in the right speed range will be with carbide. HHS or Cobalt tooling is not even on the table because the speeds needs are way to low for your spindle to get into most likely. mist coolant would probably be a big help if you can do it.

i agree with a ramping tool path to control the load on the tool. but there are other things you have to consider like i said before. the machine is big and heavy but the spindle is what i would focus on with it's speed range to see how much trouble you could get into.

A HRC of 60 is HSS a 1/8 HSS end mill needs to run around 2800 rpm a 1/4 HSS end mill is running around 1400 rpm in steel the bigger you go in diameter the slower they keep getting. the machine is not the factor the spindle range of speeds are very much so a factor when working with steel. this is why i said you need carbide at the very least it might get you into a range of speed your spindle can do? if i knew what you were working with better i could probably help better with speeds and feeds.