What 'decent' Milling machine?

[JAZZCNC]

Thanks again all. Problem is no 3 phase at home. I could run a VFD for the spindle. Cant help but get the feeling Im biting off more than I can chew :-(

Mmmmm. I dont know enough about whats good and what bits are good and the potential money pit is big I think, especially if I need to start to retrofit parts.

It's not difficult but does require some knowledge and plenty of research before commiting.

IMO all the machines you have shown so far are cheap (with exception of Denford) chinese imports. They are badged up with someone elses name on but all the same low quality machines.
I think you will be disspointed with the results and you will in the end up either chasing away problems they have and wasting money doing so or selling on.! . . . All cases you'll still Blow money.!!

Old machine and retro fit will serve you better in long run. Also You'll more than likely sell it for more than you payed if you ever do move on or upgrade.

To be honest for your needs with aluminium and plastics which requires higher spindle rpm/feeds I'd build a very strong Fixed Gantry machine and put the money into using good components and ATC spindle before waste on those Chinese Import Milling machines.
The mills will always perform below par for cutting aluminium and plastics compared to strong machine built and spec'd for the task.

Retro fitting a old machine with a high RPM spindle 8k plus would be only choice between building or buying. No way would I consider Small mill for cutting aluminium unless it had high rpm spindle and used Linear bearings.!!

[Chaz]

It's not difficult but does require some knowledge and plenty of research before commiting.

IMO all the machines you have shown so far are cheap (with exception of Denford) chinese imports. They are badged up with someone elses name on but all the same low quality machines.
I think you will be disspointed with the results and you will in the end up either chasing away problems they have and wasting money doing so or selling on.! . . . All cases you'll still Blow money.!!

Old machine and retro fit will serve you better in long run. Also You'll more than likely sell it for more than you payed if you ever do move on or upgrade.

To be honest for your needs with aluminium and plastics which requires higher spindle rpm/feeds I'd build a very strong Fixed Gantry machine and put the money into using good components and ATC spindle before waste on those Chinese Import Milling machines.
The mills will always perform below par for cutting aluminium and plastics compared to strong machine built and spec'd for the task.

Retro fitting a old machine with a high RPM spindle 8k plus would be only choice between building or buying. No way would I consider Small mill for cutting aluminium unless it had high rpm spindle and used Linear bearings.!!

Thanks. I did build my own machine before. It worked 'OK' but not sure Ill do that again. Here is a vid of it cutting a plastic gear with a 1mm high speed endmill.

https://www.youtube.com/watch?v=t_jXTrO0rok

I could not get the rigidity I needed and making centre holes (on a different gear) proved almost impossible.

[JAZZCNC]

Thanks. I did build my own machine before. It worked 'OK' but not sure Ill do that again. Here is a vid of it cutting a plastic gear with a 1mm high speed endmill.

https://www.youtube.com/watch?v=t_jXTrO0rok

I could not get the rigidity I needed and making centre holes (on a different gear) proved almost impossible.

Well what do you expect if you built it out of spagetti.!! . . . . . I'm talking about properly built machine built with substantial materials and correctly done.
If done properly then it's not difficult to build a machine that will do everything you need and do it much better than any cheap chinese import mill can.!

The difference between th 2 bridgeports is the series. MK1 & Mk2 They look like this.

[Chaz]

Well what do you expect if you built it out of spagetti.!! . . . . . I'm talking about properly built machine built with substantial materials and correctly done.
If done properly then it's not difficult to build a machine that will do everything you need and do it much better than any cheap chinese import mill can.!

The difference between th 2 bridgeports is the series. MK1 & Mk2 They look like this.

Ye, understood and lesson learnt with schoolfees to match.

Can you link to something that you refer to as a suitable DIY type machine please? Appreciate your time with the feedback / comments.

[JAZZCNC]

Ye, understood and lesson learnt with schoolfees to match.

Can you link to something that you refer to as a suitable DIY type machine please? Appreciate your time with the feedback / comments.

There are several Fixed gantry machines on the Forum search for those.
To get the strength you require then fixed gantry is the way to go and built from steel if possible. Moving gantry machines can do it but they need to be very very strong.

[JAZZCNC]

Going to be honest now and you may not like it.!!

It appears to me that you don't have enough machining experience yet to justify laying out big money on machines when you don't even know what you require.
For instance the best mill or CNC machine won't make relocating your part any more accurate if you don't know how to do it.!

The fact the machine you built doesn't make the grade is purely down to poor weak design and choice of materials. The fact you can't relocate on centre is down to your low level of experience.
If you'd made fixture jigs to hold your work and indexed to a known fixed reference point then it's easy.

But your machine is so weak it will flex like jelly so this can't happen. Trying to re-locate centres without a fixture is hard at best of time on any machine and requires accurate devices to help. So no matter weak or Strong if you haven't got the abilty or the equipment then you will always struggle.

Your weak build is to blame for low part accurecy for sure but has nothing to do with reloctating and no amount of strength in the machine will helps this as it's down to you to come up with ways to fixture.

Properly built DIY machine which uses good components will easily do what you want.

[Chaz]

Going to be honest now and you may not like it.!!

It appears to me that you don't have enough machining experience yet to justify laying out big money on machines when you don't even know what you require.
For instance the best mill or CNC machine won't make relocating your part any more accurate if you don't know how to do it.!

The fact the machine you built doesn't make the grade is purely down to poor weak design and choice of materials. The fact you can't relocate on centre is down to your low level of experience.
If you'd made fixture jigs to hold your work and indexed to a known fixed reference point then it's easy.

But your machine is so weak it will flex like jelly so this can't happen. Trying to re-locate centres without a fixture is hard at best of time on any machine and requires accurate devices to help. So no matter weak or Strong if you haven't got the abilty or the equipment then you will always struggle.

Your weak build is to blame for low part accurecy for sure but has nothing to do with reloctating and no amount of strength in the machine will helps this as it's down to you to come up with ways to fixture.

Properly built DIY machine which uses good components will easily do what you want.

Ah, a bit harsh, but that OK.

I dont know what I need, hence the thread to ask for advice.

The relocation of the centre was badly explained. I dont think the machine had the rigidity to be accurate enough and the centre was the easiest place to spot this. But agreed, I have a lot to learn and yes, I dont know the techniques.

So I consider myself 'told off', no problems there. At least I tried based on what I could do on my own.

Are you able to link to something that you would consider suitable on the DIY side?

Out of interest, what would a machine like this cost in the UK?

https://www.youtube.com/watch?v=26RNc0OA_fU

Its a Tormach PCNC 1100

[JAZZCNC]

Ah, a bit harsh, but that OK.

I dont know what I need, hence the thread to ask for advice.

The relocation of the centre was badly explained. I dont think the machine had the rigidity to be accurate enough and the centre was the easiest place to spot this. But agreed, I have a lot to learn and yes, I dont know the techniques.

Erm well sorry but better being said than just thought and seeing you taking wrong route.!

When ever you have to flip parts and require more than 2 it's worth taking the time to make a fixture Jig. Provided the Jig is well made and indexed to a fixed known location you will always get back to absolute accurate position. If the machine is made from jelly then you'll still be back in absolutle position you started it's just the machine doesn't go there if it's wobblying about.!!

[Chaz]

Something like this?

http://www.cnczone.com/forums/diy-cn...82294-cnc.html

Found the vid of it milling alu, then found the thread.

[Boyan Silyavski]

Not trying to sell you or anyone anything here but may be would be of interest to you. If time is not an issue, cause i am a bit busy right now.

I am currently designing a couple of small CNCs cause i want to start small home production of quality machines. All will be made entirely of 20mm aluminum plate. All 200mm Z axis.

So i have semi finished 3 designs of small machines. I don't want to load you with information now, just the thing is that maybe i will start making first the 600x400x200 moving gantry prototype. As i have semi finished drawing of the fixed gantry machine if you are interested i could provide you the drawing, only condition will be to use what elements i tell you, so you act like a test pilot

The said machine will easily handle 3kw spindle or even much more.

400x400x200mm, the bearing design and rails spacing is already tested on my previous build 1, the yellow machine, so no risks here. Parts will be around 3000$$ so you only have to put all together.

Apart from being light years better from anything i know of for the same $$ it would be extremely strong and beautiful, remember, all parts 20mm aluminum including the tool table.

Even the moving gantry machine will easily do the same plus its even more versatile. The yellow machine using mere 0.8kw spindle handles with fully extended Z aluminum with perfect finish with 1.5mm depth of cut, 800mm/min 12000RPM

And remember i am talking about OTT machines capable of working 24/7, not toys.


About the Tormach, i dont believe it could hold 0.05mm precision from what i have read around.