Author Topic: CNC mill spindle up grade  (Read 1322 times)

Online fumopuc

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CNC mill spindle up grade
« on: September 25, 2021, 06:34:51 AM »
Hi everybody,
end of 2019 I have done the first step and replaced my original Proxxon FF500 spindle motor by a high revving mill motor, how is its common in wood working from Mafell.
Here the link to this older posting. I have been very happy with the possible high revs up to 24.000, specially for milling aluminium and brass.
I have been not so happy with the noise and the power and torque.

After checking the market, I have found the Teknomotor 1,1 KW HF spindle, which could be the step in the right direction. So, a quick sketch was made in the CAD to see the overall integration also in relationship to the movement of the table. A bracket had to be designed to adapt the new spindle to the mill also.
From the electrical and electronical side, an electrical cabinet was necessary to run it with 3 phases 220 Volts. Also here was the CAD check very helpful to select the right cabinet size. Space for a line filter, a switching power supply 24 Volt and a relay, the frequency converter and a brake resistor have to be found. I was a bit of a long-time project, but now the Hardware is installed and the cabinet has found its final place close to the mill now. Space is rare in my little shop under the roof.
Here the first test run with a minor adaption of the EdingCNC software to control the spindle correctly by a 0-10 Volt signal, originally given by the G-Code now in future. What means at the other side, the right speed has to be defined now always proper in the CAM, so the programmer has to work there carefully now.
Next to do, the assembly of the bracket with spindle at the mill and to find the best way for the moving orange cable.   


PS : I am heavily struggling with the text editor today. Nearly impossible to post anything.
« Last Edit: September 25, 2021, 08:45:37 AM by fumopuc »
Kind Regards
Achim

Offline Vixen

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Re: CNC mill spindle up grade
« Reply #1 on: September 25, 2021, 11:21:43 AM »
Hello Achim,

Fitting the Teknomotor to the mill looks like the easy bit, compared to making the electronics installation. I am impressed with the way you have made such a neat installation in the cabinet.

We have a saying "It looks like a bought one" and your installation looks very professional.

Please can you explain how you did the G-code to 0 to 10 volt signal conversion. Did you use an interface card, or was it achieved within the EdingCNC software?

Keep us posted with progress. Waiting for the first chips to be made.

Regards

Mike

It is the journey that matters, not the destination

Oh! sod the journey, lets hit the bar and pool instead.

Online fumopuc

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Re: CNC mill spindle up grade
« Reply #2 on: September 25, 2021, 06:54:08 PM »
Hi Mike,
the EdingCNC software can recognize the speed information in the G-Code.
This will be translated inside the EdingCNC into the 0-10 Volt signal, what is activated now.
Concerning the electrical cabinet, I have had some professional help.
A the very beginning, I have recognized that all this small bits and pieces for a proper assembly and the wiring are not available in my shop.
Everything is available online in the net and easy to order, but i.e. for the need of 0,3 meter cap tail, you have to order minimum 1 meter plus the freight charges.
All these added was together much more, than let the assembly job done in a shop, where everything is available of the shelf.
Kind Regards
Achim

Online fumopuc

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Re: CNC mill spindle up grade
« Reply #3 on: October 08, 2021, 06:53:19 AM »
Hi everybody, successes with my spindle up grade.
Everything seems to fit mechanically nicely.
I have swapped the Mafell against the Teknomotor with bracket.
I won a bit of z height, nearly 15 to 20 mm, by this design.
Followed by a tramming procedure.
The software (EdingCNC) had to be fed with the information about the new position of the lower end of the ER20 collet.
Also position of tool length sensor and collet had to new adjusted in the software.
The 3D printer was very helpful to fit the wire and to store new equipment for the mill now.
The test piece for first milling operation is in the CAD now and the CAM will start its work now.
   
 

 
Kind Regards
Achim

Offline Kim

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Re: CNC mill spindle up grade
« Reply #4 on: October 08, 2021, 05:36:24 PM »
A very tidy upgrade there, Achim!
You're 3D printer did you proud!  I'm going to have to get me one of those someday :)

Can't wait to see what parts you make with your new CNC spindle  :ThumbsUp:
Kim

Online fumopuc

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Re: CNC mill spindle up grade
« Reply #5 on: October 09, 2021, 07:27:48 AM »
A very tidy upgrade there, Achim!
You're 3D printer did you proud!  I'm going to have to get me one of those someday :)

Can't wait to see what parts you make with your new CNC spindle  :ThumbsUp:
Kim


Hi Kim, thanks for watching.
After I have learned to do my things in a CAD Program, there was no reason anymore  for not using a 3D printer.
Before I was a bit discouraged, because the printing of some Chinese dragons from a set up CD was not what I have had in my mind.
In the meantime I am very happy with it, an a lot of, for me useful, items are made.
Not for the shop only, also in the  garden or anywhere else in the house.
 
 
« Last Edit: October 09, 2021, 08:04:26 AM by fumopuc »
Kind Regards
Achim

Offline Kim

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Re: CNC mill spindle up grade
« Reply #6 on: October 09, 2021, 04:40:16 PM »
Wow! Such a tidy shop, with 3D printed holders for everything. A place for everything and everything has its place.
I'll have to say, my shop isn't quite as tidy.  I'm more of "A pile for everything and everything has its pile" type of shop! :Jester:
Thanks for the inspiration!
Kim

Online fumopuc

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Re: CNC mill spindle up grade
« Reply #7 on: October 10, 2021, 01:34:22 PM »
Hi everybody, now it was time to get some swarf all over it.
I have made a test part in Fusion360, which should give the possibility to check as much as possible of the known 2D CAM strategies.
Than I had to define a basic spindle speed for new coming feed rates.
The below graph from Teknomotor shows, that at 18.000 revs the torque starts to drop down a bit.
So my decision, when ever possible, 18.000 revs is the speed to start with and adjust the feed rate in accordance to this.
The material of the test piece is a 7075 aluminium, the tool for nearly all is 5 mm, 3 flute, HSS Co8 cutter from an industrial German source.
First test was a face milling.
18.000 revs and a feed rate of 2.000 mm/min. Mist cooling as always. For me the fastest ever used feed rate.
ae 2,5mm and ap 0,5 mm.
Chips are flying around my ears and after some seconds it was over already.
The result in my eyes perfect.
Next one, a kind of trimming around the whole part.
So one time around the part, ae 0,5 mm and ap 2,5 mm, same speed/feed as above.
Kind Regards
Achim

Offline Jasonb

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Re: CNC mill spindle up grade
« Reply #8 on: October 10, 2021, 02:18:47 PM »
That sounds quite fast for and HSS tool of that diameter, I will be interesting to see if tool life suffers. You say it is a commercial grade cutter so do the makers give any suggested cutting data? If I had the top speed of your spindle I would be at 8-12 thousand rpm with Carbide and 5-6 for HSS

looks a nice spindle and should be better and quieter than the more router based one you had before.
« Last Edit: October 10, 2021, 02:24:48 PM by Jasonb »

Offline steamer

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Re: CNC mill spindle up grade
« Reply #9 on: October 10, 2021, 02:42:05 PM »
Nice neat and orderly storage is soooooooo  nice to have.   I'm glad you put the effort in to build that, I know how convenient it is to have everything at arms reach!    :ThumbsUp:  :ThumbsUp:
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Damned ijjit!

Online fumopuc

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Re: CNC mill spindle up grade
« Reply #10 on: October 11, 2021, 06:23:49 AM »
Nice neat and orderly storage is soooooooo  nice to have.   I'm glad you put the effort in to build that, I know how convenient it is to have everything at arms reach!    :ThumbsUp: :ThumbsUp:


Hi Dave, thanks.
My shop is really very small, more a kind of a box under the roof. So if I start to search anything, I have lost already.
I like it to have a fixed place for (nearly) everything.
Kind Regards
Achim

Online fumopuc

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Re: CNC mill spindle up grade
« Reply #11 on: October 11, 2021, 07:16:15 AM »
That sounds quite fast for and HSS tool of that diameter, I will be interesting to see if tool life suffers. You say it is a commercial grade cutter so do the makers give any suggested cutting data? If I had the top speed of your spindle I would be at 8-12 thousand rpm with Carbide and 5-6 for HSS

looks a nice spindle and should be better and quieter than the more router based one you had before.


The spindle is fantastic, very, very quiet and with enough power for my model engineering jobs.
I am really happy that I have done it, it was a kind of long term decision.
The speed of the Mafell before was O.K., also it was good to start the high speed milling learning curve with it, but the noise and vibrations was always an issue I didnīt like very much.


How long the cutter will last here ?
No idea, it is a used one, already more than 6 month in use, o.k. not every day.
Here the product information from the supplier.
He recommends

Feed fz for slot milling in steel < 750 N/mm2                                                                 0.008 mm


 For me this is not very helpfull, because it is a kind of upper limit, worst case, for this cutter.
I donīt do any slot milling here in steel.


I prefer a little tool, calculator since some years to see how the cutting data could be.
I can choose here first  the material.
Next step the cutter diameter and the number of flutes all in the first line.
The second line in the box below, shows the optimal calculation result for the input of material, cutter diameter and flutes.
In this case n=31.832 rpm, far away of what my spindle is able to do.
So now the first line in the box can be adjusted.
In my case I adjust the max rpm to 18.000, an a new calculation has to be made.
Result shown by the next picture.
This calculator is sure not made for big industrial machines, because as you can see in the last line, it recommends a max depth, ap, of 1 mm if used in slot milling.
And of course the given selection of material is not complete, but for me it gives me a first idea about were I am. 
There is another information available which was very useful for me to nearly understand the relationship in cutting data calculation.
Thatīs the way how I try to find my way through these jungle.
Kind Regards
Achim

Offline Jasonb

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Re: CNC mill spindle up grade
« Reply #12 on: October 11, 2021, 07:43:35 AM »
I'm off out now but will get back to you later,

Online fumopuc

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Re: CNC mill spindle up grade
« Reply #13 on: October 11, 2021, 08:41:01 AM »
Hi everybody,
next test to do with the new spindle, an open pocket.
2D adaptive cleaning.
Same speed and feed, ap, I have been more courageous as usual, 2,5 mm and ae 2 mm.
The result looks a bit ugly and starts to get "greasy" ( no idea if it is the term for this light floating material) , but for roughing out may be still o.k.
There is still 0,2 mm over stock for a cleaning operation.
« Last Edit: October 11, 2021, 08:46:19 AM by fumopuc »
Kind Regards
Achim

Offline Vixen

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Re: CNC mill spindle up grade
« Reply #14 on: October 11, 2021, 12:27:48 PM »
Hello Achem,

I am following your adventures into high speed milling with great interest. I am also exploring adaptive machining etc. I am currently limited to a 5,000 RPM spindle.

I agree with you, the adaptive clearing marks are a bit ugly to look at but they are more visually noticeable than measurable. I find a additional 0.002" (0.05 mm) deep finishing pass with 45% stepover improves the appearance

The Sorotec cutting data calculator (schnittdatenrechner) appears to be a very usefull addition. I have searched the Sorotec online shop but cannot find any reference their cutting data calculator. Please can you help me find it.

Cheers

Mike
It is the journey that matters, not the destination

Oh! sod the journey, lets hit the bar and pool instead.