Feeds and speeds. Some tips for a newbie please!

[Dave_stoke]

To me (and the pics arent very clear) it looks like the tool lacked lubrication and/or ability to clear material fast enough. A 2 flute is more forgiving.

I didn't have my coolant running. I doubt it would have made any difference tbh.
I can't slow it down it doesn't get near the stock. It's started acting up again. Losing steps for fun. Certainly doesn't like helix.
I think it's time to give up tbh. The machine is what it is cheap but not cheerful. But £800 isn't cheap.

Thanks anyway buddy

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[Chaz]

I didn't have my coolant running. I doubt it would have made any difference tbh.
I can't slow it down it doesn't get near the stock. It's started acting up again. Losing steps for fun. Certainly doesn't like helix.
I think it's time to give up tbh. The machine is what it is cheap but not cheerful. But £800 isn't cheap.

Thanks anyway buddy

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The issue is, in this world, £800 is not a lot.

[Dave_stoke]

The issue is, in this world, £800 is not a lot.

It is when there's nothing left in the bank lol

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[Chaz]

It is when there's nothing left in the bank lol

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Agreed. Machining is an expensive hobby.

Can any of us help with machining this for you?

[Dave_stoke]

Agreed. Machining is an expensive hobby.

Can any of us help with machining this for you?

Thanks buddy, I have listed it for sale. But also reminded the seller I bought it from that they must provide me with a solution as to why it doesn't do what they promised.

As for parts I might drop it for a while, have a break and finish up all the drawings in fusion. I wanted to make a scale hawker hurricane in its entirety with a 1.5mtr wing span. And then maybe a Lancaster. But watch tools were my main project. Haven't managed one yet.

I'll stay on the boards keep watching, reading and learning. Then maybe if things get better buy a proper mill and convert it to cnc.

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[m_c]

That looks like the cutter has been rubbing more than it's been cutting.

Speeds and feeds nearly always involve some experimentation to find what works best for your machine.
The key thing is tooth loading. Too much and the cutter will snap/spindle stall, too little and the cutter rubs. The smaller the cutter, the more precise the tooth loading has to be.

For most machines, two flute cutters are better, as it allows slower feed rates for any given spindle RPM (double the number of flutes, and you have to double the feedrate to achieve the same tooth loading).

Speeds and feeds calcs (I personally use FSWizard) generally only give you an estimate. If what they're suggesting isn't working, it can be worthwhile to look up the cutter manufacturer's specifications, and work out the figures manually to give you the recommended ranges. First work out the possible spindle speeds (manufacturer's will give a recommended surface speed range), then once you have the min/max RPMs, calculate the required feedrates at those two speeds for the min/max tooth loading.

[Richard]

That looks like the cutter has been rubbing more than it's been cutting.

Speeds and feeds nearly always involve some experimentation to find what works best for your machine.
The key thing is tooth loading. Too much and the cutter will snap/spindle stall, too little and the cutter rubs. The smaller the cutter, the more precise the tooth loading has to be.

For most machines, two flute cutters are better, as it allows slower feed rates for any given spindle RPM (double the number of flutes, and you have to double the feedrate to achieve the same tooth loading).

Speeds and feeds calcs (I personally use FSWizard) generally only give you an estimate. If what they're suggesting isn't working, it can be worthwhile to look up the cutter manufacturer's specifications, and work out the figures manually to give you the recommended ranges. First work out the possible spindle speeds (manufacturer's will give a recommended surface speed range), then once you have the min/max RPMs, calculate the required feedrates at those two speeds for the min/max tooth loading.

Hi m_c, assuming you're looking at my photos, that cutter cut beautifully for the first 5m of the cut (it was a zigzag path 350mm long, moving across 10mm each pass, doing 30 passes in all).

It left a very clean smooth cut then suddenly it seemed to get noisy and the surface finish got worse. I'm assuming this is when the edges went off for some reason....

This was supposed to be carbide, but no idea if it really is, it was a very cheap set, 2mm to 12mm, 8 end mills, for £25! LOL. (Just checked, the carbide bit is almost exactly twice the weight of the HSS one and it much less magnetic, so probably is carbide)

If there was a build up of aluminium on the tips, would that errode the edges like this?

[Snapper]

Thanks buddy, I have listed it for sale. But also reminded the seller I bought it from that they must provide me with a solution as to why it doesn't do what they promised.

As for parts I might drop it for a while, have a break and finish up all the drawings in fusion. I wanted to make a scale hawker hurricane in its entirety with a 1.5mtr wing span. And then maybe a Lancaster. But watch tools were my main project. Haven't managed one yet.

I'll stay on the boards keep watching, reading and learning. Then maybe if things get better buy a proper mill and convert it to cnc.

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What machine is this Dave? Sounds like a chinese ebay special router.

They don't really work well out of the box and need a bit of wiring doing to get them to work fairly stable. Spindle or machine frame needs earthing, a star point earth helps too, and the spindle cable at least pretty much needs swapping for a shielded CY cable, otherwise you will have all sorts of havoc. Doesn't hurt to do the switch and stepper wires either although not really neccesary.

[Dave_stoke]

What machine is this Dave? Sounds like a chinese ebay special router.

They don't really work well out of the box and need a bit of wiring doing to get them to work fairly stable. Spindle or machine frame needs earthing, a star point earth helps too, and the spindle cable at least pretty much needs swapping for a shielded CY cable, otherwise you will have all sorts of havoc. Doesn't hurt to do the switch and stepper wires either although not really neccesary.

It is an eBay special lol. It's the cncest 3040T.
Where do I earth it from to?

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