Thor, or should that be Zeus?

[Chaz]

Just a quick question - Why so much mass in this design? Looking at the likes of production mills like Tormach etc, there is nowhere near as much mass in them and they are proven designs.

I like the ideas but over designing is surely as bad as under designing something ??

The idea is to allow for absorption of vibration etc. The hollows in the base structures improve strength and keep the weight bit more palatable. I need to check what the final weight estimate will be, I have had some issues with the files in Fusion, so redrawing some of the machine.

The idea here too is that this machine could be running a lot quicker (velocity and acceleration) than a Tormach. Considering the cost of a Tormach (ignore shipment / import duties, just the raw buy price), Thor should be a better machine.

The Tormach 1100 specs are below:-

Feed Rate:

110 IPM (X,Y) 90 IPM (Z)

110 IPM is 2800 mm/min. I am aiming for upwards of 10 000mm/min at least. The rails, ballscrews and motors that I am using cost more than the entire Tormach machine if I paid full new price (which I did not). This is before adding the controller, electronics, structure costs, spindle etc.

[Davek0974]

The idea is to allow for absorption of vibration etc. The hollows in the base structures improve strength and keep the weight bit more palatable. I need to check what the final weight estimate will be, I have had some issues with the files in Fusion, so redrawing some of the machine.

The idea here too is that this machine could be running a lot quicker (velocity and acceleration) than a Tormach. Considering the cost of a Tormach (ignore shipment / import duties, just the raw buy price), Thor should be a better machine.

The Tormach 1100 specs are below:-

Feed Rate:

110 IPM (X,Y) 90 IPM (Z)

110 IPM is 2800 mm/min. I am aiming for upwards of 10 000mm/min at least. The rails, ballscrews and motors that I am using cost more than the entire Tormach machine if I paid full new price (which I did not). This is before adding the controller, electronics, structure costs, spindle etc.

Interesting, thanks.

I was only using Torch as an example really but those feed specs are interesting, any idea of the spindle HP rating? It's obviously designed for normal mill usage - bigger tooling, more cut depth, more radial cut depth so I guess 2800mm/min would be in that area.

I guess you will be running fairly high power motors to gain decent acceleration in small distances or it may never reach your high feeds??

Following your build with interest.

[Chaz]

Interesting, thanks.

I was only using Torch as an example really but those feed specs are interesting, any idea of the spindle HP rating? It's obviously designed for normal mill usage - bigger tooling, more cut depth, more radial cut depth so I guess 2800mm/min would be in that area.

I guess you will be running fairly high power motors to gain decent acceleration in small distances or it may never reach your high feeds??

Following your build with interest.

The motors spec were in the first post. 1.5 KW servo for Y, 750W for X and Z.

Spindle power will likely be around 4 KW / 5 HP.

One of the goals of this machine is to be able to run this all from single phase, 32A supply.

The higher feeds allow for more creative milling techniques like Adaptive clearing. Having good speed and acceleration opens the machine up for more uses and will hopefully reduce the typical times currently experienced with my Denford.

[JAZZCNC]

110 IPM is 2800 mm/min. I am aiming for upwards of 10 000mm/min at least. The rails, ballscrews and motors that I am using cost more than the entire Tormach machine if I paid full new price (which I did not). This is before adding the controller, electronics, structure costs, spindle etc.

Well you better get ready for dissappointment if you think 4Kw spindle is going to let you cut at 10mtr/min with any DOC.! There's Reason why Industrial Strength VMC's have 15-20Hp spindles.

[Chaz]

Well you better get ready for dissappointment if you think 4Kw spindle is going to let you cut at 10mtr/min with any DOC.! There's Reason why Industrial Strength VMC's have 15-20Hp spindles.

The plan is not to cut at 10m/min. It will be nice to do some tracordial milling and not be limited by speed of 'non cutting' movements. Id rather have too much speed than to little, even if its not used all the time.

[Boyan Silyavski]

Well you better get ready for dissappointment if you think 4Kw spindle is going to let you cut at 10mtr/min with any DOC.! There's Reason why Industrial Strength VMC's have 15-20Hp spindles.

This is more for the ability to cut at lower spindle speeds the metals and have there enough power, and i agree with that, but i wonder then if the small mill head rated 10 000rpm, BT30 spindle coupled with servo motor would not do the job better here? I can not remember if there was 10 000rpm variant, cause typically it was 6000rpm. Or just have to be ordered with other bearings.

That could change the design so should be clear before hand. But will give ability to tool change, and hard tap. Cause at the end of the day, why so fast machine if then you will loose time changing tools.

I read a study that said most time in production was spend changing tools, and we are talking a bout machines with tool changers. So obviously not only a tool changer, but a fast one is better.

But i like to say, if the purpose is not clear, the result could be mediocre

[Davek0974]

My thoughts too, I do spend more time changing tools on my manual mill than cutting, also setting up etc. I just am not sure of the design here, especially with only 4Hp on the spindle, still limited to light cuts at average speeds, there is a reason large mills weighing tons have 20-30-40Hp spindle motors and only move at reasonable speeds.

[Chaz]

My thoughts too, I do spend more time changing tools on my manual mill than cutting, also setting up etc. I just am not sure of the design here, especially with only 4Hp on the spindle, still limited to light cuts at average speeds, there is a reason large mills weighing tons have 20-30-40Hp spindle motors and only move at reasonable speeds.

Understood. Perhaps 'all' Ill get is a very sturdy accurate 'average' machine. I cant fit a 20 HP spindle. The point here was to prove a few points.

1. How much better will something be with higher end kit?
2. The kit I have bought wasnt cheap, but it was not new, so I did not pay full price.
3. I want to see the 'max' of what can be done using single phase power.
4. I like playing around, this is my fun that detracts from a fairly tough day job :-)

Thanks

[Davek0974]

Understood. Perhaps 'all' Ill get is a very sturdy accurate 'average' machine. I cant fit a 20 HP spindle. The point here was to prove a few points.

1. How much better will something be with higher end kit?
2. The kit I have bought wasnt cheap, but it was not new, so I did not pay full price.
3. I want to see the 'max' of what can be done using single phase power.
4. I like playing around, this is my fun that detracts from a fairly tough day job :-)

Thanks

That is the important bit i think, you will end up with a machine that has capabilities beyond the average frame-build unit, but most likely not something that can rip through metal like chocolate;)

I have a feeling resonance and vibration will not be an issue:)

[JAZZCNC]

The machine will only be has good as the weakest link.! . . . No point fitting high end parts and then throw cheap under powered chinese spindle on it IMO.

Datron Spindles are 60K rpm and not your average Spindle, very expensive I'll guess.? If you notice they also mostly only use smaller diameter tooling and the machines are much more agile.

IMO with all those oversized heavy weight components and Frame design your building Sledge hammer to crack an EGG if all your doing is cutting aluminium with small tooling. Even then it probably won't give better results than lesser built machine with quality spindle on it. (ie Datron)

If you want to HOG aluminium out then you'll want larger tooling and this will require HP from the spindle. Fast tool changing is easy enough.? It just costs lots of money.!