MK1 Steel router build log 1500x800x200

[driftspin]

I would re think this for me I would use 1610 for X & Y and 1605 for Z

With nema 23 3.1nM

Have a look a Joe's build http://www.mycncuk.com/threads/4513-...ight=joeharris

Hi Clive,

I was playing around with the stepper calculator from this forum...

1605 on Z 1:1 ? or also reducted?


Picking the 2010 over a 1610 on x axis ,1700mm between bearings, is about critical rpm vs speed... looks like i need 2010 to reach up to or over 5 m/min.

What is your opinion on these?

Since i am a beginner i am not sure what the max speed is i would need for cutting and rappids

Some other materials might need faster speeds i am not sure...


2.2kw spindle makes cutting at lower rpm easier combined with a quality vfd.

I am trying to pick the right quality parts to make a versatile machine.

Any help is welcome.

Please share your concerns.

No linear parts or elektronics are bought yet.





Verstuurd vanaf mijn SM-A320FL met Tapatalk

[Clive S]

Picking the 2010 over a 1610 on x axis ,1700mm between bearings, is about critical rpm vs speed... looks like i need 2010 to reach up to or over 5 m/min.

Yes I agree. Have you decided on one motor or two?

Don't buy any electrics until you have it all drawn up in CAD AM882 or EM806 work well for the drives at 68V

[driftspin]

Yes I agree. Have you decided on one motor or two?

Don't buy any electrics until you have it all drawn up in CAD AM882 or EM806 work well for the drives at 68V

Dear Clive S,

My design dictates at least 2 idler pullys per ballscrew if i want to go single x axis nema 34 stepper... and have the whole bed space.

Or... i have to limit bed space and cross the bed...There is room in the design to do this though.
And 1 side is up against a wall anyways.

When going single stepper,
i think i would buy a wide stepper pully,
and shift the ballscrews a belt width and use 2 belts, 1 for every ballscrew.

For now a 2 stepper x setup looks more convenient from a mechanical point of view.
2 short belts.
lots of bed space

My Electronic pov is opposit.

For inertia it seems, in my mind, better too.
2 powerful 3+Nm steppers on high voltage digital drivers. Instead of a single bigger 8/12nm nema34. this is just a gut feeling , not based on any sound research.

Not sure what makes a 3, 3,1 or 4 Nm nema 23 stepper best choice.
Just high amps low inductance right?



Any thoughts?

Verstuurd vanaf mijn SM-A320FL met Tapatalk

[Clive S]

For now a 2 stepper x setup looks more convenient from a mechanical point of view.
2 short belts.
lots of bed space

That's what I use you can run them 1.5:1 or 2:1 I used 3.1Nm but with 1610 screws motors from https://www.cnc4you.co.uk/Stepper-Mo...YGH301B-Nema23
with am882 drives from China

I do have a nema 23 4Nm on my mill but don't see a difference in them

[driftspin]

Ok some progress.

In the summer months the build did not get a lot of attention.

I did manage to get some of the steelwork done.


Did any of you run wiring through the box section?



Verstuurd vanaf mijn SM-A320FL met Tapatalk

[Nickhofen]

Aren't you going to put brace at the bed, at the long axis?

[driftspin]

Aren't you going to put brace at the bed, at the long axis?

Frame bracing.

Well no...well not yet.

Span is 2x1650mm span 120x80x4 mm box section....

plenty stiff one would think...

In Theory,

At 400 pounds of moving gantry weight 0.0027 inches vertical deflection would occure ... but the bed would move also. so. well.

At a more realistic 100 pounds 0.00068 inches

This would only be a problem if the workpiece was stiffer than the box section right?


In my design there is no absolute movement between router bit and workpiece when vertical X axis flex would occure. So no accuracy problems there.


By now total weight is 190 kg with no gantry...

I do believe "ringing" might become a problem... the assembly has a +/- 1khz resonance frequency.

I might fill her up with something like sand or epoxy mix concrete or something need to look in to that.


For shaking appart there is something to be said though.

Bracing at the bottom should solve x axis flex.. some of it anyway. It felt plenty stiff  those diagonals are out of the way great.



Y/X direction flex / bracing... yes.. well.. erh there is going to be cabinets installed ..

And maybe a few bits like: compressor airbrush type , vacuum cleaner, dust removal cyclone, cooling for spindle,
electronics cabinet.






X-direction flex bracing
I cannot yet fill the under the bed space with diagonals... yet.

There will be bolt on triangles when stuff like that is sorted.


Y-direction flexbracing

There is a 3mm thick plate 1000mm x 200mm with curved edges between the legs.. bolted with 4xm10 threaded rod to the legs.. plenty long m10 rod +/- 100 mm for building up tension.



Diagonal cross frame flex.

At this time i have prepared 4 m12 screws at the bottom of the legs to level the frame
And help with aligning icw anker bolts to the concrete floor.


When it is level and all legs (set screws) are in contact with the floor.
It feels incredibly stiff.


When now a set screw is set out of alignment by a 1/4 turn (M12) the table is wobbly ... proof of stiffness...

Any thoughts?

I have no good idea what the shaking forces are like in real life.

Verstuurd vanaf mijn SM-A320FL met Tapatalk

[Davek0974]

I have no good idea what the shaking forces are like in real life.

These depend on the mass of the moving item and your acceleration/deceleration curves.

Don't forget - acceleration/deceleration is king of the hill, its more important than travelling velocity, far more, as it will directly affect the path following ability of the software controller - with these figures too low you will see bad corner rounding etc where the trajectory planner cannot perform the moves in time, the only solution then, if you cant increase accel/decel is to lower the speed, this then gives you issues with cutter burning etc - its a vicious circle but all determined by your acceleration/deceleration curves.

My plasma machine only has a very light gantry - no motor, no cut forces, and it can shake quite badly at times, that has a steel frame too.

Always build as stiff as possible :)

[Boyan Silyavski]

Yes, as stiff as possible. Thats the way. If you use trochoidal HSM toolpaths /you will / all will shake very seriously if not stiff and heavy

[driftspin]

Hi guys,



A little progress update.

First layer of paint two tone black and white.


What do you guys think?


grtz Bert.



Verstuurd vanaf mijn SM-A320FL met Tapatalk