[Vilyoo]

Hello everyone,
I've been reading this forum for a month and decided to build my own milling machine. The machines you built inspired me a lot. Unfortunately I don't have any experience with cnc machines, but my hobby is electronics (repairing amplifiers, power supplies and inverters). I even applied at Techinical Univercity (Mechatronics) in my country, so if they accept me I will start on January(wish me luck). I want the machine to be small and rigid with good precision of 0.01mm or close enough. I want to cut aluminum and steel. I don't care how much it will weight, but i want to fit on a table like 1000-1200x800mm. Maybe I will make enclosure. I made a mistake buying the lineal rails, ball screws and nuts before making any 3d model, so I must design my project for them. Before I buy anything else, I want to consider my design with you. I've been learning Fusion 360 for about 2 weeks(no previous exp with other softwares) and I made a model which I want you to see. The base of the machine is now 800x500x150mm and the column is a structural steel tube 300x200mm with 10mm wall thickness(is this a good choice or should I weld plates 15-25mm as a rectangular?) with 25mm welded plate on the bottom. The whole base will be welded together, but the column will be bolted down to the base after stress relief and machining. The table on the drawing is 300x570mm with the working zone of 180x450mm (the green area).
In the future i may add 4th axis if everything is ok.

The parts I have:
2x 420mm 35mm HGR rail
2x 1300mm 35mm HGR rail which ill cut by 2x 530mm and 2x 770mm
12x 35mm HGH Tanks
1x 360mm x 20mm Ball Screw with Double Ball Nut
1x 450mm x 20mm Ball Screw with Double Ball Nut
1x 650mm x 20mm Ball Screw with Double Ball Nut
3xBK15
3xBF15
3xNut Holders

With those parts the working dimensions are X=450mm, Y=180mm, Z=260mm
All the plates in the drawings are 20-25mm C45 Steel. I'm also thinking to fill the column and the base, with concrete or epoxy. Z axis with epoxy. I will add counter weights for Z axis when I complete the drawings. Now the project is around 600kg and will reach 1000kg or more with the filling.

For the motors I chose Ac Servo DMM 750w nema 34 version for XYZ (haven't bought them). Is there anything better and cheaper than that? Do I need Z motor with a brake since it will be counterweighted?

Spindle?
I have no idea but I read in the forum that most of you guys use BT30? And the Spindle Motor I want something big like 2.6-3.8kw? What is your opinion about that?

CNC controller?
Can you recommend something for a beginner?
DDCS V3.1 is this good? Or should I use mach3-4. What CNC controller?
I want to work with fusion 360.

Before going any further i want share my work and see your opinions.
Any help, advice or feedback is appreciated.

[dazp1976]

First off.
What mains power supply do you have available?.
single phase 120v or 220v
Or
3phase 220v+
?.

[Vilyoo]

First off.
What mains power supply do you have available?.
single phase 120v or 220v
Or
3phase 220v+
?.

Single phase 220v. I have also 3 phase, but it is not in the same room that the machine will be, I prefer to use single phase 220v. The power consumption of the machine is not a problem. I can connect it direct to the circuit breaker.

[dazp1976]

Single phase 220v. I have also 3 phase, but it is not in the same room that the machine will be, I prefer to use single phase 220v. The power consumption of the machine is not a problem. I can connect it direct to the circuit breaker.

Technically it is a slight problem. You'll be restricted to the size of spindle motor you can fit.
For instance, if you use a servo you'll probarbly be limited to 2.2kw or less.
A 2.6kw and above servo motor/drive can peak above 50A.
You'll want to look into it a little further before commiting to anything.

An example:
https://www.aliexpress.com/item/4000...59247987%22%7D

That's why some people are dissappointed with the Tormach 1100MX.
That is built with single phase users in mind.


I have a 1.8kw for a PM25 type machine.

[Vilyoo]

Technically it is a slight problem. You'll be restricted to the size of spindle motor you can fit.
For instance, if you use a servo you'll probarbly be limited to 2.2kw or less.
A 2.6kw and above servo motor/drive can peak above 50A.
You'll want to look into it a little further before commiting to anything.

An example:
https://www.aliexpress.com/item/4000...59247987%22%7D

That's why some people are dissappointed with the Tormach 1100MX.
That is built with single phase users in mind.


I have a 1.8kw for a PM25 type machine.

I think 50A peak is not a problem for my installation. The circuit breaker is 63A and the cable to it is 6mm2 copper. But if there are any problems I'll plug it to 3 phase. I think the drivers for the motors work both for single and 3 phase?

[dazp1976]

I think 50A peak is not a problem for my installation. The circuit breaker is 63A and the cable to it is 6mm2 copper. But if there are any problems I'll plug it to 3 phase. I think the drivers for the motors work both for single and 3 phase?

Many do work on both but it's highly likely they will supply you a 3 phase only if you go for 2.6kw & above. A wiring regulation thing.

[StrawberryBoi]

Technically it is a slight problem. You'll be restricted to the size of spindle motor you can fit.
For instance, if you use a servo you'll probarbly be limited to 2.2kw or less.
A 2.6kw and above servo motor/drive can peak above 50A.
You'll want to look into it a little further before commiting to anything.

An example:
https://www.aliexpress.com/item/4000...59247987%22%7D

That's why some people are dissappointed with the Tormach 1100MX.
That is built with single phase users in mind.


I have a 1.8kw for a PM25 type machine.

If a 2.2kW drive is peaking over 10kW then something is wrong in that spec! Can you confirm the 50A peak is on the INPUT side? You can drive 50A on the motor three phase, the inverter is a DC-AC device with a rectifier AC-DC and DC link capacitor bank. If it's limited to 2.2kW it shouldn't pass ~10Aac on the input side regardless of the current on the output. Power is power is power, even with a power factor of 0.7 and an efficiency of 80% you'd only be drawing 2.75kW average and 3.93kW peak (1.18kW ripple). That's still under 20Aac.

[dazp1976]

If a 2.2kW drive is peaking over 10kW then something is wrong in that spec! Can you confirm the 50A peak is on the INPUT side? You can drive 50A on the motor three phase, the inverter is a DC-AC device with a rectifier AC-DC and DC link capacitor bank. If it's limited to 2.2kW it shouldn't pass ~10Aac on the input side regardless of the current on the output. Power is power is power, even with a power factor of 0.7 and an efficiency of 80% you'd only be drawing 2.75kW average and 3.93kW peak (1.18kW ripple). That's still under 20Aac.

Well. There's a reason why once you get up to 2.2kw in servo motor, single phase drives start to vanish in favour of 3 phase.
You'll be constantly tripping the breaker on startup bursts for a start.
My lowly little 1.8kw servo alone requires a 30A breaker.

[awerby]

"For the motors I chose Ac Servo DMM 750w nema 34 version for XYZ (haven't bought them). Is there anything better and cheaper than that? Do I need Z motor with a brake since it will be counterweighted?"

If you're using AC servos, make sure to get compatible drivers at the same time. They are all different - even some made by the same company can be different from others they also make.

A brake on the Z axis servo motor is one way to avoid having a heavy spindle drop to the table when power is turned off. But if you've got counterweights or gas struts to hold it up, it's probably not going to be necessary.

[pippin88]

Servos sold for CNC use are all marketed based on their continuous output.

[Vilyoo]

can you recommend servos 750w-1000w for xyz, DMM are a bit expensive for me.
Maybe something like this?
https://www.ebay.com/itm/32424632673...gAAOSwdUJcHGPp

[mactec54]

can you recommend servos 750w-1000w for xyz, DMM are a bit expensive for me.
Maybe something like this?
https://www.ebay.com/itm/32424632673...gAAOSwdUJcHGPp

You get what you pay for the eBay servo your link is to there encoder PPR is too low for CNC machines

[mactec54]

Hello everyone,
I've been reading this forum for a month and decided to build my own milling machine. The machines you built inspired me a lot. Unfortunately I don't have any experience with cnc machines, but my hobby is electronics (repairing amplifiers, power supplies and inverters). I even applied at Techinical Univercity (Mechatronics) in my country, so if they accept me I will start on January(wish me luck). I want the machine to be small and rigid with good precision of 0.01mm or close enough. I want to cut aluminum and steel. I don't care how much it will weight, but i want to fit on a table like 1000-1200x800mm. Maybe I will make enclosure. I made a mistake buying the lineal rails, ball screws and nuts before making any 3d model, so I must design my project for them. Before I buy anything else, I want to consider my design with you. I've been learning Fusion 360 for about 2 weeks(no previous exp with other softwares) and I made a model which I want you to see. The base of the machine is now 800x500x150mm and the column is a structural steel tube 300x200mm with 10mm wall thickness(is this a good choice or should I weld plates 15-25mm as a rectangular?) with 25mm welded plate on the bottom. The whole base will be welded together, but the column will be bolted down to the base after stress relief and machining. The table on the drawing is 300x570mm with the working zone of 180x450mm (the green area).
In the future i may add 4th axis if everything is ok.

The parts I have:
2x 420mm 35mm HGR rail
2x 1300mm 35mm HGR rail which ill cut by 2x 530mm and 2x 770mm
12x 35mm HGH Tanks
1x 360mm x 20mm Ball Screw with Double Ball Nut
1x 450mm x 20mm Ball Screw with Double Ball Nut
1x 650mm x 20mm Ball Screw with Double Ball Nut
3xBK15
3xBF15
3xNut Holders

With those parts the working dimensions are X=450mm, Y=180mm, Z=260mm
All the plates in the drawings are 20-25mm C45 Steel. I'm also thinking to fill the column and the base, with concrete or epoxy. Z axis with epoxy. I will add counter weights for Z axis when I complete the drawings. Now the project is around 600kg and will reach 1000kg or more with the filling.

For the motors I chose Ac Servo DMM 750w nema 34 version for XYZ (haven't bought them). Is there anything better and cheaper than that? Do I need Z motor with a brake since it will be counterweighted?

Spindle?
I have no idea but I read in the forum that most of you guys use BT30? And the Spindle Motor I want something big like 2.6-3.8kw? What is your opinion about that?

CNC controller?
Can you recommend something for a beginner?
DDCS V3.1 is this good? Or should I use mach3-4. What CNC controller?
I want to work with fusion 360.

Before going any further i want share my work and see your opinions.
Any help, advice or feedback is appreciated.

With the Dmm Servos get the new 20Bit encoder

What grade is the Ballscrews

[Vilyoo]

I dont know what grade are the ballscrews it is not written in the site i bought them......
I bought them from here, im very dissapointed from this supplier but in my country is the only one. They always make mistakes with the order and their product's quality is poor.

https://exallto.com/sachmeno-vintovi...t-sfu1605.html
https://exallto.com/sachmeno-vintovi...-sfu-2005.html

actually my ball nut is different from those in the site

you mean to wait for DYN5 release?

[mactec54]

I dont know what grade are the ballscrews it is not written in the site i bought them......
I bought them from here, im very dissapointed from this supplier but in my country is the only one. They always make mistakes with the order and their product's quality is poor.

https://exallto.com/sachmeno-vintovi...t-sfu1605.html
https://exallto.com/sachmeno-vintovi...-sfu-2005.html

actually my ball nut is different from those in the site

you mean to wait for DYN5 release?

They are Rolled Ballscrews so will never be that great no matter who you buy them from, the double nut will help a little but they won't be as smooth running as a Ground Ballscrew

I thought they had released the Dyna 5, Yes I would wait 16Bit is ok but 20Bit is much better, always go for the highest Encoder PPR you can get for any axis movements if for a spindle then it does not matter what the PPR is

[joeavaerage]

Hi,
I bought and use three 750W Delta B2 series (160,000 count per rev) servos and drives for my new build mill, one of them braked.
They are Taiwanese but made in China are good quality and well supported and have the all-important set-up and tuning software with which to program the drive.

https://www.fasttobuy.com/flange-80m...er_p28084.html

$438USD plus shipping from China for the 750W B2 servo, drive and cables is fair value. They are very similar in terms of quality and support and cost to DMM.

I paid $80USD each for shipping to New Zealand via DHL and I tracked them from Schenzen to my workplace in Christchurch New Zealand in two days 14 hours....I got what I paid for.

There are cheaper Chinese brands and while the quality seems reasonable the documentation is crap, support questionable and most importantly no set-up
and tuning software, you have to program the drive by pushing buttons like a microwave, very tedious and error prone. Avoid like the plague.

If this is your first experience with servos I would avoid the cheapest Chinese stuff and get at least Delta's or DMM's. Once you got a few servo installs under your
belt THEN perhaps the el-cheapo Chinese made brands make sense.

Craig

[Vilyoo]

A little upgrade on the drawins. Added counter weight steel box with 20mm walls, which i will fill with Lead, it will fit around 80k of lead. The working table will be with m16 holes since i dont have T slot table.

[mactec54]

A little upgrade on the drawins. Added counter weight steel box with 20mm walls, which i will fill with Lead, it will fit around 80k of lead. The working table will be with m16 holes since i dont have T slot table.

You could mill the T-Slots once you have it built if you have enough table travel, threaded holes can be a pain if you don't plug the unused holes

Using a counter weight can take the load off the Z axis drive motor and Ballscrew

[Vilyoo]

Thanks everyone for your comments. So I will buy dmm or delta motors with high PPR. About the ballscrews I will see how my ballscrews will operate and if I'm not satisfied with the result i will change them to ground ballscrews.

My Z axis will be around 150kg, is 750w servo with a brake enough for it, cuz I see it is cheaper to buy a motor with a brake instead of making counterweight.

Any words about the design? How do you find it. Should I change anything there.

[joeavaerage]

Hi,
my Z axis motor at the current time has to pick up about 50kg, and will eventually be required to pick up about 100kg when I get around to an ATC
spindle and 3kW servo motor to drive it. I elected to get one servo wit a brake rather than bother with a counterweight.

As it turns out I use 32mm diameter ground ballscrews and the large diameter screws by far and away dominate the inertia equation...NOT the axis mass at all.
I know its counter intuitive but the axis mass is only about 5%-10% of the total inertia with the ballscrews themselves contributing 80% and the servo armature another 10%.
This might surprise and that's why it makes sense to do the calculations BEFORE you commit to buy. My ballscrews are 5mm pitch and even without a brake do not slump
when de-powered. They might when I build a new spindle, but as the brake cost about $100USD premium over a plain servo I got it...so I'm ready for it no matter what happens.

Craig