CNC servo control

Hi Peter, you are perfectly true with a very clear and detailed explanation.

Making a hybrid CNC & 3D Printer is an idea I have already though, but always discarded as the cost to make a similar tool the consts vs benefits analysis is loosing. Not only we should consider that there are some components not fully compatible in one case than the other. This means that every time moving from a 3D print job to a CNC milled part the result is at least:

1. Replace the milling tool with the extruder (need calibration and other delicate operations)
2. clean the area from milling for 3D printing
3. remove the metallic CNC base and replace the bed
4. Managing a lot of connections some excluding the other

There are other intuitive aspects that are complementary and very different that needs to have a a bigger machine (at least) and more space and a relatively complex electronic architecture and a powering system to make the final result just an academic challenge and not a really useful cheap tool.

Enrico

All very good points

To add to this

You can't build either cheaper that one or the other or even the same price. The cost will be more than the more expensive but should not be double. With proper planning you can build it as a hybrid but you need to select the right software to drive it. Also you need to build it to the strength needed for the CNC Router and therefor need to know the load of the cutter, so are you going to just use a dremel style cutter or something much bigger like a Bosch Colt woodworking router. or are you just planning on doing wood / plastic and perhaps a little PCB milling ?

As Enrico pointed out, there are considerations needed when considering a hybrid, calibration being the most critical, the heated bed should be removable and or protected when CNC Routing, the head will need to be switched between the extruder and the cutter, this is where alignment dowels may come in handy to help accurate assembly and therefor easier calibration, the router is not so critical but the printer is, it need a flat bed or software to compensate for an uneven one.

You need a controller that is a superset of one or the other (So the 3D printer style but more power for when doing CNC Work)

I have one of the ST Micro 3D printer reference boards coming so I will see how well it can meet the needs, it runs Marlin and supports 3 extruders, 6 stepper motors etc but only upto 3 Amp per winding (Enough for small CNC router and pretty much any 3D printer or laser cutter), as it has 6 stepper drivers it will handle a 4th axis in CNC mode too. STEVAL-3DP001V1 STMICROELECTRONICS, REF DESIGN BRD, 3D PRINTER DRIVER, Newark element14 Canada

The price of the only board you mention is about 9 times the single controllers price

Enrico

yes but look at its specifications

32Bit vs 8 bit

6 steppers vs4 or 5

3 hot ends at 8Ams each (Not total)

3 heat zones at 20A each, not total and support for 24V heaters here

WIFI Enabled

now find one with similar specifications at 9 times less ??

Pretty much everything is built in

peter

Peter agree and if I would try building an hybrid this is the right one IMHO. The point is about the pricing in general. I am almost sure that the total price maybe heigher than the two tools separate

Enrico

peter I saw your videos on this gigantic building many times and I really love them. Well done, clear and you have done a very good job. Every time I see them I have a question. Why in a so well done structure good and precise the shaft is just something like a Dremel o Proxxon or similar? Is not the case to include a motor controlled spindle? I have a 30x30 cm mill machine but the better part is the water cooled spindle 800-300 rpm. Or I am wrong respect the kind of material that should be worked ?

Enrico

Thank you and Yes, swapping the servos for steppers is what i'm currently doing.

The small pcb's are just interface boards with no ic's

Well I do have way better than a dremel, I have a Bosch Colt 1HP 30,000 RPM woodworking router, still not as good as a purpose designed spindle with a proper ERxx collet etc but to keep things simple...

I have no budget to buy a nice spindle, all except the Colt was donated by my sponsors to make the videos, No Payment aside from the gift of the parts and I dont get paid to create any of my content so I rely heavily on generous sponsors but none so far have sent me a spindle or even carry one as a product surprisingly... maybe soon , I do have a 3.5W laser that will be added from Banggood and I am looking forward to integrating that /

and I get very little from Google Adsense, barely enough to pay for the internet access.

I hope that clarifies your question

Hello Peter,

all is clear. Me too I am veeeery sensible to this kind of problems (i.e. $$$) but I thought it was some different reason. My mill machine - at the moment in standby due the new lab reset - has a spindle like what I have described but I got it as partial development support from a customer years ago. And I was astonished discovering that it was about 400$ to replace one

For some reason I was thinking there was a more technical reason.

Enrico