AMAT25LV Basically another PM25 clone :)

[CL_MotoTech]

Cut some parts already!

[dazp1976]

Cut some parts already!

Yeah, I know what you mean
First part will be a small bearing holder for the floating end of the X axis to hold an angular type. After my last teardown the X axis backlash went to 0.035mm (to do with the bearing).
I found out that if I put the bearing tight up to the ballscrew on that end instead of it 'floating' the backlash then drops to 0.01mm rather than the 0.035 as is now.

If I know it'll work I may as well do it.

Then at some stage it's a 17mm head spacer so I can use the extra Y travel. My throat is 183mm allowing the rubber material on the roller some room. The extra 17mm will get me the full 200.

[CL_MotoTech]

.035mm isn't really enough backlash to worry about it, IMO. That's pretty much right on my backlash figures with single nut screws that I repacked. Circles and pockets turn out great. Getting everything to run really reliable with nice tight ways was harder to work out than the backlash. Besides, the machines are pretty flexy, if I lean on the head I can move it .01mm or more, and if you have any play in your z ways then you can easily get more.

What I'm really getting at, is that you need to start making some parts already! But your bearing idea does sound like a good place to start. Bearing pockets are pretty much what I use to judge my machine performance, but I do a lot of them so it's something I spend a lot of time analyzing.

[dazp1976]

First parts off. New mounts for some Nema23 size motors.
Came out ok I think. Head seems dead level using the face mill and the tolerance variation is max of 0.02mm
Sizes: 87 * 63.5mm (Actual 87.02 * 63.48)
86.5 * 66.5mm (Actual 86.51 * 66.48)
Height 15mm (14.98)







Hopefully the smaller motors run as well as the 34's and solve some of resonance the issues.
I hate tapping threads. ugh!

[dazp1976]

Swapped the 1090oz nema34 for a 566oz nema23 on the x axis for a test.
Turned out it runs faster.
It did get fairly warm compared to the 34 which was always cold. I'll double check my driver amp output.

https://www.cnc4you.co.uk/Stepper-Mo...H401-03-Nema23

[dazp1976]

Well. Been experimenting with feeds / speeds etc.
I have been running the same as I was on my old X2 especially with the slotting. Light (1mm deep) cuts at around 700mm/min 2500rpm.
I do get a bit of vibration and higher cutter wear than I did so....

I got a 8mm 3 flute end mill, ran 2500rpm, slowed to 300mm/min (think it was a chipload of 0.6mm / 0.023" ish I forget) and used a DOC of 4mm.
It ate it and was quicker to do.
These type motors are so much better.

Going to order a Lichuan 1.8kw servo + driver rated at 3000rpm in a month or so.
Will fit a 112mm taper lock pulley to it and this will give me 5000rpm at the spindle with a motor speed of 2675rpm. I think I can live with that.
I'll deal with spindle bearings when I blow the stock ones first

I've been holding a tolerance of +/- 0.05mm so far (0.002") which I think is acceptable, yes?
I MUST remember to measure my cutter diameters first, Some of the variation on the cheap Chinese cutters is unreal

[CL_MotoTech]

Those parts came out nice!

For tapping, I’ve taken to power tapping with my battery drill. With a spiral cut tap you can just power through in one swipe. Though thread milling is slowly becoming common practice for me.

That tolerance is quite good. Once you get tool D in order, and continue to tune on the machine some more, you can do a little better yet.

[dazp1976]

Thanks for the comment on those parts CL_MotoTech.

Anyhow. Since then I damaged my spine and haven't been able to get near the machine
With this pandemic an all it's near impossible to get seen to.

I better get my pain injections soon.......
I've just ordered my 1.8kw spindle servo!!!!!!!
(don't tell the mrs!)

Ordered:
https://www.aliexpress.com/item/4000...archweb201603_

[CL_MotoTech]

Good luck! I hope you feel better soon!

[Michael82]

Super badass man I like what you have done . Do you like the amat25lv ? I'm fixing to buy a machine andbhave been looking at the pm25mv but they are out of stock so looking for a different brand . For the price I can buy a bigger machine for the price of the pm25

[dazp1976]

Super badass man I like what you have done . Do you like the amat25lv ? I'm fixing to buy a machine andbhave been looking at the pm25mv but they are out of stock so looking for a different brand . For the price I can buy a bigger machine for the price of the pm25

Hi matey.
Yes. I like these machines so far. Does a nice job of cutting. Still not convinced by the quill design but it hasn't been a problem and it does come in useful when drilling.
I still haven't got on it for a good few months though. Still needs refining.

I've got to adjust / re-make my X ballscrew mounts to get the table moving more level (ballscrew slightly slanting).
Made them on the X2 so they're not perfect.
Next get my limits fitted.
Then, I have a nice big 1.8kw servo to play with fitting to the spindle.

But, yes. Overall these are pretty solid.
I would've liked a 30 size version but I'd have never got it on a bench

[dazp1976]

Just ordered an 80v power supply (to use at around 75v).
Give Z a bit more grunt.

Gripe:
Have to pay VAT to Aliexpress now because of Brexit!!!.
What happened to all these so-called free trade deals eh?
Kick in the nuts!!

[pippin88]

VAT has nothing to do with trade / free trade

It is a tax on consumption (rather than earning)

In Australia the same tax is called goods and services tax (GST).

Aus gov brought in GST for overseas purchases a few years ago. They make the seller / marketplace collect it.