New CNC user mistakes and info

[Zorbit]

Removed.

[Pilsbury]

Zorbit. Interesting about clearance planes. Shall bear that in mind. Also good to hear about HSS being more forgiving. The few bits I have bought are carbide as I thought they were the holy grail.... at least that’s what they said they were on Banggood!

[Pilsbury]

So perhaps my carbide purchases weren’t all that bad. TBH I’ve bought some end mills, ball nosed v bits, flattening bits, v carve bits and still had change out of £20 including postage. Not the end of the world if some meet an untimely end. Think I’ll be more upset about nackering my project.

[Zorbit]

Removed.

[Pilsbury]

If you can use a decent diameter tool then do so, an 8mm cutter is a lot stronger than a 6mm.

You’ve just reminded me about another question! I’ve recently watched a YouTube vid about a bloke talking about the pros and cons of his small 60x90, medium 120x120 and large 120x240 machines. He surprised me when talking about their capabilities. All looked decent expensive machines but he said in the smaller and medium ones 1/4” bits in hardwood would struggle. Only in the big machine can you use them due to rigidity and spindle power. Suppose it depends on the machine, but they were branded gear which wouldn’t have been cheap.

[Clive S]

You’ve just reminded me about another question! I’ve recently watched a YouTube vid about a bloke talking about the pros and cons of his small 60x90, medium 120x120 and large 120x240 machines. He surprised me when talking about their capabilities. All looked decent expensive machines but he said in the smaller and medium ones 1/4” bits in hardwood would struggle. Only in the big machine can you use them due to rigidity and spindle power. Suppose it depends on the machine, but they were branded gear which wouldn’t have been cheap.

How about a link to the vid !!!

[Pilsbury]

How about a link to the vid !!!

Here you go!
https://youtu.be/_YQoOfAm7UU

[Zorbit]

Removed.

[routerdriver]

I don't think you will go far wrong with the bargain level carbide cutters.I haven't even seen an HSS router cutter in twenty years or so although I suspect I have one at the back of a drawer.One thing to watch out for is that not all the TCT cutters have inserts all the way to the centre and consequently won't plunge cut.I bought a few of these myself and it doesn't actually cause many problems as I have the option of a ramp entry tot he cut.As for the holy grail,that has to be Poly Crystalline Diamond and really needs to be experienced once you are confident the cut won't go through a clamp or worse a high tensile bolt head-but if spotted in time and with a control that adjusts feed speed you may be able to machine a nice flat on the edge of the bolt head-not that I'm admitting anything.....

[JAZZCNC]

A good practice exercise that will have all of the above plus more and will be useful is a Collet holder.
If your feeling really confident instead of collet pockets with straight sides make the pockets tapered and use a 2.5D toolpath with a ball-nose cutter. Also, try putting chamfers on the edges.

Why am I getting a DaJaVu feeling here.? . . . If you are going to post at least use your own words.!!

You’ve just reminded me about another question! I’ve recently watched a YouTube vid about a bloke talking about the pros and cons of his small 60x90, medium 120x120 and large 120x240 machines. He surprised me when talking about their capabilities. All looked decent expensive machines but he said in the smaller and medium ones 1/4” bits in hardwood would struggle. Only in the big machine can you use them due to rigidity and spindle power. Suppose it depends on the machine, but they were branded gear which wouldn’t have been cheap.

He's comparing apples with oranges when he's talking about industrial machines and to honest his idea of industrial and sturdy machine honestly isn't. That Sabre machine as so many weak areas in it's design it only just classes as industrial.

You won't have any trouble pushing a 12mm cutter thru most wood or manmade materials on a smaller properly built machine with a decent spindle. How deep and how fast is all that will change between industrial and hobby sized machines.

He's correct when he says most small machines can not cut at the correct feed rates which the manufacturers recommend but that doesn't mean they can't cut perfectly fine within the limits of the power of the spindle.
Yes you won't be churning out the product by the 1000's per day but you can certainly produce enough to start a very healthy business, I've got dozens of customers using my small to medium machines that do just that.

To be honest, to cut correctly at optimum goes beyond just machine size, strength, or spindle power, Dust extraction also becomes massively important because cutting deeper and faster creates more waste material which if not evacuated fast enough becomes a problem quickly so huge dust extractors are required, then you have the explosive side of sawdust to deal with and so on.

Work holding goes to another level, Cutting deeper and faster creates more cutting pressure so holding force becomes massively important. Vacuum holding gets expensive very quickly, for instance, I've just a fit a 10Hp Vac pump that cost £5,500 and that's without the Bed and all the pipework ETC that goes with it. You don't get much change out of £8k for what is a relatively Average Vac setup, it's not uncommon to have 2 x 10Hp pumps working if cutting lots of smaller parts.
Small or large work holding as to be done and you'll often find industrial machines that have undersized Vac systems using just the same work holding techniques that are used at hobby level, ie: Screws and double-sided tape or whatever gets the job done.
I've got a friend who operates a 200K machine in a high volume furniture production environment and it's not uncommon for them to use Vac and double-sided tape because the 2 x 15Hp Vac pumps can't hold everything all of the time and the carnage that is caused if parts lets go and the 20HP spindle slings it across the building is a nightmare health and safety issue.

It's all about levels of Degree.!!.... These things also apply at the Hobby level just to a lower degree, it's still important to get the best from your cutter and machine but no so critical and much less forgiving.
Don't stress over the machine it will do everything you want for a long time before you'll outgrow it and even then it won't be because it's underpowered, it's nearly always the size which people outgrow.