Thor, or should that be Zeus?

[Boyan Silyavski]

If i were you, i would evaluate what exactly i will be doing, as first jobs and jobs that i make money from. Then decide what spindle to put there, according to the jobs i will be doing.


If you are going to do engraving, aluminum and so on, then 24krpm will definitely be much better. Especially if you are going to use bits 6mm or smaller than that. Thats why i opted for 3kw spindle on my machine and i am very happy. But if you are going to do mild steel mainly, then you need the BT30 or other.

All in one is not a very good option. In fact your machine best will be fit with 3kw 24k RPM and BT30 or similar., both at the same time. I know, $$$, other wise i would have fitted High speed tool change spindle BT30 on mine.

Follow the $$ priorities and you will not do wrong / the making $$, not spending $$ /

[Chaz]

If i were you, i would evaluate what exactly i will be doing, as first jobs and jobs that i make money from. Then decide what spindle to put there, according to the jobs i will be doing.


If you are going to do engraving, aluminum and so on, then 24krpm will definitely be much better. Especially if you are going to use bits 6mm or smaller than that. Thats why i opted for 3kw spindle on my machine and i am very happy. But if you are going to do mild steel mainly, then you need the BT30 or other.

All in one is not a very good option. In fact your machine best will be fit with 3kw 24k RPM and BT30 or similar., both at the same time. I know, $$$, other wise i would have fitted High speed tool change spindle BT30 on mine.

Follow the $$ priorities and you will not do wrong / the making $$, not spending $$ /

In this, I was not specifically referring to making money from the machine to be it's purpose, was referring to my own day job but agreed, I need to decide what the machine will be used for.

So are you saying doing both may be a good option or not? Sorry, not sure if the 'not' in your sentence is correct or not.

Ideally it would be good to have something versatile. If I can engineer a solution when you can almost do a 'multi head' setup. Heck, even look at some form of grinding attachment, potentially with a very high geared 2nd Z setup that can hang off the side or front of this Z Axis.

[Boyan Silyavski]

In my opinion both will be best. Then you dont need the spindle to be 3kw. It could be smaller. And cheaper. As the 3kw is almost 500 euros with the inverter.

[JAZZCNC]

Having machine built to this level of strength then fitting router spindle restricted to small tool sizes is little like using sledge hammer to crack nut don't you think.?

Don't stray from the path Chaz.? . . . .If want router/Engraver then build router/Engraver.! . . . If want machine to Hog out aluminium/steel with meaning full DOC and tool sizes like what you intended with this build then you need spindle with some muscle.! . . . . Never the twian shall meet and if they do they never get along very well IME.!

For me machine built to this level of strength requires minimum of BT30 and proper motor with plenty of torque/speed.! . . Down side is Not cheap but that's the nature of the game. If want to play like the Big boys do and with big boys toys get the cheque book out.! . . . . Any other way is false economy and will always be lacking.!

[Boyan Silyavski]

Mchine build like this requires 15kw Spindle, toolchanger and so on.

[Davek0974]

I've just re-read the first 8 pages of this excellent project and the subject of spindle power was discussed in depth, i would tend to agree that using a small spindle will be limiting its use, I would be looking at a decent BT or INT taper spindle with tool change ability and a large motor maybe 7-8Kw and possibly a two speed pulley to give maximum speed range or the choice of steel vs alloy machining etc. ;)

[Chaz]

I've just re-read the first 8 pages of this excellent project and the subject of spindle power was discussed in depth, i would tend to agree that using a small spindle will be limiting its use, I would be looking at a decent BT or INT taper spindle with tool change ability and a large motor maybe 7-8Kw and possibly a two speed pulley to give maximum speed range or the choice of steel vs alloy machining etc. ;)

Thanks. Our posts just about crossed over.

Any suggestions on what type of pricing for something in that range (7-8KW)? Secondhand may be an option. I may be able to get my single phase power increased (in terms of available current) but not by much, so not sure if I can drive it with the power I have available to me at present.

[Chaz]

In my opinion both will be best. Then you dont need the spindle to be 3kw. It could be smaller. And cheaper. As the 3kw is almost 500 euros with the inverter.

Thing is (and Dean has commented since), going lightweight on this machine is a waste. I already have a 4KW VFD that I bought some months ago (did not get the spindle at the time) as I wanted something to run a 3 phase vacuum pump and then later potentially use it on my machine.

Another option is to look at the spindles like they use on Datron machines - up to 60K RPM, 5 KW typically. Not cheap, probably £3-5K Id guess.

15KW, I cant power that (and I know Thor wont be stressed) - even the weight of that will be interesting to move around.

Anyways, Jazz, I did send you an email a few days ago about AC Servo setup in case you had time to look at it please?

Thanks

[JAZZCNC]

Anyways, Jazz, I did send you an email a few days ago about AC Servo setup in case you had time to look at it please?

Sorry Chaz you'd been dumped into Spam box and I've been really busy so not checked lately. When get chance later in week I'll reply.

[JAZZCNC]

One other thing not mentioned or consdiered is weight.?

The combined weight of Spindle cartridge, motor and all that concrete will most likely require some form of counter balance. Servo alone unless large KW won't be enough I think.

My big mill has got Int40 (Same as taper BT40 with slightly different holder) spindle with 5.5Kw Inverter Motor which spins at 7500rpm and the motor alone is too heavy for one man to safely handle. The pulley alone (which uses 2 x multi V belts not HTD.!!) must weigh same as 2.2Kw spindle.

Recently I removed the head unit from column and reckon it must weigh 500kg. There is 10" sqr 3ft long Solid steel block runs down the centre of column that counter balances it. The whole thing can be lifted up/down turning the ballscrew by hand.!!