Adding 3D printer ability to my CNC / advice needed please

[dudz]

I know not alot about 3D printing hardware. I am going to be buying my controller from this site https://cnc2printer3d.wordpress.com/

Do I use thermistor or thermocouple type ??

I would appreciate some help on what hardware to get. I am currently putting a 4th axis on my CNC for the extruder. But I have no clue what extruder or other hardware to get.

My CNC has a cutting table size of X = 500 Y= 300 Z = 110mm
I am using M542 Motor Drivers

[Boyan Silyavski]

i was investigating the same thing last week.

It depends from the $$ you wish to spend. Single head or double head. Note that double does not mean that it will be double fast, the good thing is that you can use support and then dissolve it, while with the single head you have to print the support for overhang elements from the same plastic.

From all this investigation i went to this conclusion:

-Hotends:
E3D-v6 HotEnd (http://e3d-online.com/E3D-v6/Full-Kit) or Prometheus Hot End (http://www.dta-labs.com/collections/hot-ends/products/prometheus-hot-end-v1-1)

i personally think that the prometheus is the better choice here


-Extruders:


One of the Bulldog extruders (http://ooznest.co.uk/3D-Printer-Electronic-Parts/Extruders-Hotends) or one of the Goliat extruders (http://www.tytan3d.com/en/) coupled with:


-geared /planetary 5:1 or more/ nema 17 motor (http://www.ebay.es/itm/Kysan-5-18-1-Planetary-Geared-Stepper-Motor-3D-Printer-RepRap-Kossel-Nema17-/181435052637?pt=LH_DefaultDomain_0&hash=item2a3e5f325d) + the gear type like at the Goliat extruders web+ cheap micro stepper driver for 3 d printing

or

-nema 23 motor if you have the driver and make the extruder . take care what motor fits the exruders you buy



From the boards you suggest i will no doubt buy the thermocouple one cause i like to see exact temperatures on a display. Another thing is to search for PID temperature controller on ebay + thermocouple, you will need also cartridge heater. All here depends what voltage you want to drive all, what hot end and what fits there. The heater and the motor should not be driven from same supply.

So to resume: you need PID temp controller, thermocouple, heating element ~40-50w, PSU for the heating element, PSU for the stepper driver, stepper driver, geared stepper motor , Hot end, Extruder


Hope that will save you some time investigating. yes, there are cheaper around, but it needs to be reliable, or so the guys say. I dont want to spend my time cleaning nozzles

[dudz]

Thanks silvavski, that's alot of help.

I am confused about the heated bed platform. I saw these on ebay but they are the thermistor type : http://www.ebay.co.uk/itm/321336349749?var=510262370646&ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

I would like to buy a complete bed as I cant be bothered to build one.
Around 200mm x 200mm or larger. My CNC PSU is 24v , so I suppose I will stick with 24V to power everything. (even if I need additional PSU's)

Based on your info. I would probably go for the Thermocouple PID. The the prometheus hot end. The better of the extruders (whichever that one is ?)
I guess I can use another M542 Motor Driver for the 3D printing ? and use my PSU that is powering the other 3x M542's.

[Boyan Silyavski]

I am confused about the heated bed platform. I saw these on ebay but they are the thermistor type : http://www.ebay.co.uk/itm/321336349749?var=510262370646&ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649

It doesn't matter. If you buy the thermocouple controller (https://cnc2printer3d.wordpress.com/gecs2tc1/) it has input for 2 thermocouples , so just add /screw, stick or whatever/ the second thermocouple to the bed




The better of the extruders (whichever that one is ?)

The bulldog XL (http://ooznest.co.uk/3D-Printer-Electronic-Parts/Extruders-Hotends/BullDog-XL-Extruder) already comes with the reduction motor so it seems better choice.

The setup i am suggesting seems will cope with all materials possible and i have heard only good things for the separate parts. However to be sure just ask before purchase is the prometheus will fit the bulldog.


Also check what they have at the bulldog site , to save on shipping, seems they have almost everything. Seems their hexagon hot end is also a good choice. http://forums.robo3dprinter.com/index.php?threads/hexagon-hot-end.1888/


This (http://www.reprapdiscount.com/hotends/67-hexagon-hotend-set.html) is the original seller web but in USA .


Some dimensiones (http://forums.reprap.org/read.php?14,448951) and details (http://forums.reprap.org/read.php?94,263985). there is a good thing that it can be mirror mounted .


What i have not decided is bowen or direct setup/ extruder at the back of the machine or on the Z/

[dudz]

On the heated bed from the link above it contains a heating element that produces 144W.
Would I have to put the thermocouple into the underneath of the bed ?


Once I understand everything, I am planning to mount it all on the Z plate. I have enough room I think, If I slide my spindle out of the clamp to mount it all. Ofcourse I am not even sure how all the printing hardware mounts together yet

[dudz]

Cost of all parts to put 3D printing ability on my cnc, around 530 euros plus connectors / time / waiting for parts and shipping costs

Cost of a He3D RepRap Prusa i3 - 3D Printer Kit With LCD around 370 euros (http://www.ebay.co.uk/itm/321617643405) http://thumbs2.ebaystatic.com/pict/3216176434054040_4.jpg (http://www.ebay.co.uk/itm/321617643405)

Is it worth the extra cost ??

[Boyan Silyavski]

How did you calculate that 530 euros? Double head setup? 1 head setup is around 250 shipped to you. Look below. I suggest powering the bed and the hot end 220V via cheap ceramic elements the right size ~5 euro at ebay and using separate cheap PID control, look 2nd snip below. Thats much cheaper than dedicated board which needs 12VDc or 24VDC. The only thing thats left from my calc is the driver.

But you are absolutely right, 2 head setup will be that money. The suggested setup we were speaking above is Top notch, full metal heads and reliable extruders. I believe, yes its worth it if you will use it.

My line of thought is this. If you prototype or produce something with strange shape from plastic, it would pay on the second job. Imagine making something bulky from solid plastic, wow, it will be very expensive. Imagine then making it where necessary and only surface machine it later. Thats where the 3d printing will shine, though most of the guys are unaware of that cause they don't have CNC routers.


But if you want to play around and make a couple of parts, just prepare 2 head setup but buy one head, so if you need later just buy the second head.

http://www.mycncuk.com/attachment.php?attachmentid=14286&stc=1 http://www.mycncuk.com/attachment.php?attachmentid=14287&stc=1

[dudz]

No single.
Well that's certainly cheaper than what i looked at thanks.:joyous:
The driver I am looking at is around 29 pounds, and I have to get a 4 axis Bob as mine is a 3 axis (has to be USB controlled 200khz as I have no printer port = 65 pounds)
To get a double head setup.....buy two extruders and 2x nozzles ??

I guess the bed on ebay is "slightly better" as it comes complete, but then there is an added post charge. Does nobody make larger heated beds ? I'd like one the same size as my cutting bed 500x300

Apart from all the parts above and a custom made Z plate adapter for all of it, is there any other hardware needed (apart from cable/connectors) ?

[dudz]

I wonder if these are any good

Extruder double ; http://sunhokeytech.en.alibaba.com/product/1961767180-222203505/Galvanic_couple_dual_extruder_3d_printer.html




(http://sunhokeytech.en.alibaba.com/product/1961767180-222203505/Galvanic_couple_dual_extruder_3d_printer.html)http ://ly3dtech.en.alibaba.com/product/1914798959-220596218/Reprap_3D_Printser_used_Heatbed_MK2a_300mm.html (http://ly3dtech.en.alibaba.com/product/1914798959-220596218/Reprap_3D_Printer_used_Heatbed_MK2a_300mm.html)

[Boyan Silyavski]

yeah, the bed you can get from aliexpress . Here are (http://www.aliexpress.com/store/group/Siliocne-Rubber-heater/709519_211292727.html) the guys that actually make them , so they can make one for your exact machine but first check cause they have many sizes

I would rather start with only 1 good extruder and hot end than 2 bad ones. And build piece by piece the system if i dont have the cash to buy it right now.
I know its hard but you have to take the bullet :joker: if you want to sleep well in the future.

The better the system the better will look the final product and more precise.

[dudz]

Are the better beds the ones heated by the silicone type or the ones with copper strips ? ........

Ah Ha.... The silicone ones give better "all over" heat Transfer

I can't see how the silicone ones would mount to the top glass build plate

Now I know..... Silicone pad goes on metal plate, covered by Glass build plate

[dudz]

Ok, Im in the oozest shopping cart. What filament size should I be starting with do you think ?
If I am using the bulldog extruder, I think it is 12V, so 12V PSU.

[Boyan Silyavski]

depends what size you will get cheaper. i would start with the thinner one b ut as i think it over 3mm will be better choice. cause later if you need some modification or whatever it can spit faster material. 12v PSU ATx from old pc is best then

[JohnHaine]

I started off making a 3dp, have part made the extruder. I realised that I just don't have the space, decided that making it to fit the mill is a much better idea.

[dudz]

I'm curious to know "after putting everything together" how much setting up and calibrating should I expect to do, to get the system running properly ?

[Neale]

I'm curious to know "after putting everything together" how much setting up and calibrating should I expect to do, to get the system running properly ?

If you think that there is a bit of black magic about getting speeds, feeds and depths of cut right with a router or mill, then you ain't seen nothing yet... There is probably as much art as science in the current 3D printing technology. Admittedly, you will probably have better chance of success in using a commercial hot-end on the extruder (mine is all home-made) but there is a whole set of parameters to tweak, from hot-end temperature to layer height, from printing speed to nozzle calibration. Have you seen how many parameters there are in something like Slic3r, which is a popular slicing package? (That is, the 3D equivalent of CAM and toolpath generation). It's a lot of fun, but I'm not sure that fused-filament 3D printing is quite as straightforward as the current hype suggests. I built my printer about 2 years ago and even though I've printed a fair bit of useful stuff on it, I'm still learning.

[dudz]

Ok, I have bit the bullet ! Made an order with ooznest.

Just got to buy a good heat bed (470mm X 300mm) and Heat controller.

I thought there might be a lot of messing about with parameters. Always is with open source projects :frown:

[dudz]

Parts bought.

Bulldog XL extruder
Hexagon all metal hot end
Spare nozzle
1KG of 3mm filiment
Inc Shipping

Total 250 EUROS

Plus ;

Gecs2tc1 (https://cnc2printer3d.wordpress.com/gecs2tc1/) PID Controller = 75 EUROS

Thermocouple = 3 EUROS

SSR (solid state relay) = 3 EUROS

A Axis motor driver = 27 EUROS

900W 230V silicone heat mat
420mm X 270mm and Aluminium
plate. = 92 EUROS


TOTAL = 450 EUROS

[Boyan Silyavski]

Yeah, quality is not cheap and it all piles up. At least you saved yourself from thousand of eventual problems and are ready now to face hundreds new ones :hysterical:


But seriously, i believe its good investment. Make for somebody or yourself 2-3 big prototypes and that's paid off. I went to a local guy and he showed me some prototypes, that plastic is damn strong, much more than i expected.

Man, right now i need at least 3-4 prototypes made. I will be adding this too when i have ready my big machine.

What do you have in mind to use it for? Sure you have some plan.

[dudz]

What do you have in mind to use it for? Sure you have some plan.

I use my CNC for small motorcycle parts. The 3D printer add on, is just because I would like to learn it, and to let my children learn something new.
I have always thought of 3D printers as Useless , apart from making parts for other 3D printers. But the wife though it was a good idea, so I thought I'd have a go. So far all I have seen is toys and 3D printer parts made. I am sure I will come up with something one day .
If this gear will extrude Nylon or Delrin ( Acetal ) plastics, then I can think of a few good uses straight away.:thumsup:

Thanks for steering me towards the better quality stuff. I hate the "half a job" route.

[FatFreddie]

If this gear will extrude Nylon or Delrin ( Acetal ) plastics, then I can think of a few good uses straight away.:thumsup:


Taulman do various nylon formulations - I've used Bridge which prints on glass with a dilute PVA coating ok. I'm quite impressed with the strength of this material.

You can also get an acrylic (t-glase) from them - have a look on http://taulman3d.com/

PLA is still a useful material even though it's not the toughest available - I've made a laptop stand from it and various bits for the kitchen - custom hooks for ikea cooking implement racks, plate racks for a cupboard, kitchen roll dispenser etc. Oh, and parts for the next 3d printer :-)

[Trispectiv]

I use my CNC for small motorcycle parts. The 3D printer add on, is just because I would like to learn it, and to let my children learn something new.
I have always thought of 3D printers as Useless , apart from making parts for other 3D printers. But the wife though it was a good idea, so I thought I'd have a go. So far all I have seen is toys and 3D printer parts made. I am sure I will come up with something one day .
It pretty much depends on your view on plastic objects. Plastic will never match metal in terms of toughness. On top of that, printed parts are printed in layers and small sections where the contact area between two successive layers is small, are prone to delamination. Also, you will have to live with the vertical ridges representing each layer. Overall, you should be able to use printed objects for very many application, or at least give it a try before machining the real part.

[Boyan Silyavski]

It pretty much depends on your view on plastic objects. Plastic will never match metal in terms of toughness. On top of that, printed parts are printed in layers and small sections where the contact area between two successive layers is small, are prone to delamination. Also, you will have to live with the vertical ridges representing each layer. Overall, you should be able to use printed objects for very many application, or at least give it a try before machining the real part.

I cant agree with you . With a good extruder and hot end, like in this case, there is no delamination and the parts are super tough. Even where overhang meets with other part of the model.

Thats the good thing of the CNC retrofit, combining additive and removal in one machine. You can build the part and later machine its surface. That's a big big saving. 20 kg block of plastic versus 1kg of material, for example. Which is cheaper?

And i have held some parts from a good print and honestly i was impressed by their strength. And i am not that easily impressed. I like breaking stuff and i couldn't :joker:

At the end all is art. Its not automatic. But once you have it, all stuff that goes out from a machine is strong and beautiful.

[Trispectiv]

The problem is that delamination is not tested with your hand. Among others things, I am designing and assembling 3D printers and there are numerous cases when the part had to be redesigned and made beefier in order to sustain the mechanical stress. In some cases the thinner part showed unacceptable wear during testing; in other cases it happened after the machine worked for a while and the stress broke through the part. As a side note, in particular elastic filaments such as NinjaFlex and nylon are very hard to delaminate as the object is also elastic, but that's a different story.
However, I am not the debating type, if you consider that 2 layers that have a too small contact area cannot be delaminated, that's ok.

[Boyan Silyavski]

It seems you may know then better than me. My impressions were as you said, just trying the material with my hands. I have never done extensive tests. One thing is clear though, that of course the part should be beefy, compared to normal one. I have more experience with stereo lithographed parts and most of all PolyJet-ed.

As i said its an art. At least when you have all good set up, you can start to reliably test and play until you have it figured. Having unreliable setup will further complicate or even make perfection impossible.

[Trispectiv]

Yes, that is also true, printed object are amazingly tough. First impression usually is that you can tear it apart with your hands, but a well printed part won't go down easily. However, in very many assemblies plastic parts will join against metal parts. If you don't factor the forces pushing against that plastic part and you size it as a metal part for example, you stand a good chance to get it delaminated. A good strategy is to design and print the part so that the force pushing against it goes the other way around, squeezing the layers together, instead of working against them. It obviously is not always possible, sometimes because of the shape of the part, sometimes because there are multiple vectors pushing against that part and you can only satisfy one or a couple of them.

Anyway, on topic, before adding 3D printer capabilities to a CNC, one should also check that the machine can sustain decent travel speeds, main reason being oozing during non-printing very slow moves.

[dudz]

MY X and Y cnc Axis will travel at over 2000mm/min. My Z = 1800mm/min without stalling. Hope this is enough
Anyhow, If this is a success I plan to build a separate / much lighter machine for the 3D printer hardware I have. I am using my existing CNC now, to keep costs down.

[Trispectiv]

Being belt driven, 3D printers usually move faster. But than again, don't worry yet, it pretty much goes down to what size your printed object has. A very large object will mean longer distances during travel moves, while smaller objects require short distance moves. Also, nowadays slicers can use various toolpath strategies such that using already printed areas from the current layer (when possible) for traveling moves, hence minimizing the ooze - the already printed area from the current layer being at the same height as the nozzle and acting as a plug.

[dudz]

I have managed to change the motor settings to X = 7000mm/min . Y= 3500mm/min and Z = 1800mm/min

[Trispectiv]

Y axis has a different screw lead, or is it because of the weight that it has lower maximum feed?

[dudz]

Y axis has a different screw lead, or is it because of the weight that it has lower maximum feed?

Yes. The Y axis is quite heavy, plus it has the weight of the WC spindle on it.

[Trispectiv]

I see. So did you mount the extruder?

[dudz]

I have made a mount. But those speeds are for when the spindle is mounted. When I mount the extruder, I will take the spindle off the Z plate.

[Trispectiv]

True, you will be able to reach slightly faster feedrates after taking the spindle off. Well, drop a couple of photos after you have run your first couple of test prints.

[dudz]

will do. Still waiting for other parts to arrive

[vargai]

................

[dudz]

How thick can I go with the aluminium bed ? (using a silicone heater of 900W 230V). The full size of the Aluminium is 470mm by 300mm. I have a 3mm piece but the span seems to large for 3mm. Can I go 5 or 6mm ? It will only be supported in the corners

[Trispectiv]

There are few (or none) printers that use a 470mm long bed supported at the corners only. The reason is the aspect you mentioned yourself, you have a 470mm long sheet of aluminium supported at the ends only. There will definitely be some deflection at the middle of that length. If your deflection is 0.1mm and you are printing 0.1mm layers, you have a deflection of one full layer thickness at that spot. It can be suppressed by using a raft or setting a thicker first layer in your slicer, but you will soon find these methods inconvenient.

I would assume a 5mm aluminium thickness would be required, but it also depends on the aluminium alloy in terms of stiffness. You will probably have an extra sheet of glass/mirror/borosilicate on top of it, which will be your actual printing surface. The extra glass layer will tend to remove the deflection. However, even so, if in theory the glass manages to keep its straightness while the aluminium is slightly bent at the middle, the missing contact surface will mean less heat conductivity.

All printing surfaces over 300mm I have built were not supported by the 4 corners method. 3 parallel beams were laid under the bed - one on each side and one at the middle. No springs were used and during calibration the beams were shimmed under after checking the surface with a dial indicator.

Silicone heaters are effective but more dangerous then the usual 12V/24V stuff. I would add a thermal fuse or two under that bed.

[dudz]

Thanks. Very helpful. I did think about supporting it more or less the way you suggested, but I am paranoid about supporting underneath the silicone heater (I dont know how much stress the silicone heaters will stand). Because It is a CNC machine, the bed will be put on and taken off when I need to mill, so I need to make it as easy as poss

[Trispectiv]

Silicone heaters should sustain the stress we are talking about here, but since yours goes directly into the wall plug, I would avoid giving any bright advice about the setup - if something goes wrong, it can cause major damage.

If you don't wish to use the 3 beams method, you could then use 2 beams on the long 470mm side. This way you would have to worry about the bending on the small 300mm side only. With no central beam, the silicone heater will not be mechanically stressed. Beams will also replace the springs, which in my opinion are not a good choice for anything larger then 200x200. You could use spring washers or shims under the beams instead, to perfectly level the beam ends (which represent the 4 corners). Common 10x20 or 20x20 Profile 5 extrusions from Misumi/item/Rexroth are perfect candidates for the beams. Or you can just craft your own if you having a good fly cutter or rectifier machine.

A method for switching between setups is kinda hard to suggest since I am not familiar with your machine. You will probably have some bolting spots near the center of your current router table.

[dudz]

The heater is controlled via PID temp controller using a Thermocouple. Your supporting suggestions sound good. I will plan around this idea.

[Trispectiv]

It doesn't matter which method you use for temperature control and temperature reading. A thermal fuse should still be used with a wall plugged heater. You never know when your thermocouple slips of the heater and starts indicating room air temperature instead of heater temperature. This fools your PID controller that it still has not reached the target temperature and supplies current continuously to the heater. 120-150 degrees thermal fuses are cheap, you can even scrap them from certain household appliances (some baby bottle sterilizers have 130-140 degrees thermal fuses, for example).

[dudz]

Ok I hear you. I am bolting the thermocouple to the bed, but I get what you are saying. Good idea
What tolerance are we talking about regarding the flatness of the plate ?

0.005mm ??

[Trispectiv]

It pretty much depends on the layer height you are printing at.

If you are printing 0.1mm layers and your surface has a 0.1mm deflection in the middle, you are one full layer off. Meaning that a) if your surface is 0.1mm lower, there will be almost no first layer adhesion in that spot, or b) if your surface is 0.1mm higher, there will be no room to extrude the plastic as the surface will act like a plug against the tip of the hotend, creating backpreasure or even jamming the extruder.

If you are printing 0.3mm layers and your surface has a 0.1mm deflection, you still have some error margin, the first layer will still be printed but if you flip the piece over and look at that first layer, you will notice the imperfections.

Once you lay your first layer, if it sticks, after the first couple of layers (depending on how bad the deflection was) the print settles and layers will be fine.

Simple methods to get around this:
-Z probing, a probe tests the surface in various spots and automatically compensates for the found variations by adding/subtracting Z height according to the surface deviation.
-raft, a discardable raft is printed first and then the actual object
-thicker first layer, the thicker the layer the easier it will swallow any slops in the surface
-probably many other

I would expect the surface to be within +/-0.005mm compared to the center.

[Boyan Silyavski]

Dont forget to share the results :triumphant:. It will be very interesting to see how it worked. After all it was not a small investment. Mini review with some pictures will be nice.