First Build Hiwin slide CoreXY. Need help selecting electrical parts.

Hi everyone! My name is Patrick and I have some questions, most of which will be asked in the next post.....

I need to make some of the decisions NOW though so I can size my printer and order the parts that will take a long time.

Things I need as soon as possible so I can get exact measurements and calculate frame and other part sizes:

1. Find Z axis stepper motor and order. Must be REALLY short but can be NEMA 23 to make up lost torque. Suggestions?
2. Must pick hot end and order. E3D-V6 or Prometheus V2 or ????? Suggestions?
3. Must find best cheap supplier for Hiwin MGN7C or similar rail & slides, and order. Suggestions?
4. Find and buy a good and cheap ball & screw with over 225mm travel. Suggestions?

Already ordered / Already have:

1. 215x215mm Hotbed
2. 2020 extruded aluminum frame.
3. Drive Belt and 16 tooth pulley wheels.

Decided items:

1. First trial build will use a 215mmX215mm hotbed because that is the most common and least expensive heated bed. Later version will have larger beds.
2. Basic frame is Misumi 2020 aluminum extrusion that I already have.
3. X and Y axis are going to be HIWIN or similar flat linear rails. Something like MGN7C size.
4. Z axis stepper motor needs to be SHORT to fit design. maybe NEMA 23 to compensate torque.
5. Z axis will be ball and screw actuated.

I am going to reserve this post for future use to list chosen parts and link to pictures of build.

Go ahead and read the next post for the question details!!...

Thank you and good to be here!!!

Edited 2 time(s). Last edit at 04/19/2015 01:04PM by patrickrio.

Hi, I live in New York, so keep that in mind when suggesting parts and suppliers....

So, I have decided to build a cross between THIS:

[www.youtube.com]

And Rectangled's build HERE:

[forums.reprap.org]

I really like the way that these use HIWIN flat linear slides in the X or Y axis. I have found a decent price on slides HERE:

[www.aliexpress.com] too long and big for chosen small printer

[www.aliexpress.com]

[www.aliexpress.com]

If you know where I can get even better pricing on HIWIN slides better than $18 per 300mm rail and slide combo, please let me know. Other flat slides besides Hiwin style will be considered.

Steppers I am looking at are:

[www.cisinks.com]
[www.ebay.com]
[www.ebay.com]

Any suggestions on where I can get better pricing on appropriate stepper motors?? are these motors good?

I found belt and pulleys at a good price HERE:

[www.banggood.com] Ordered!

Is this decent drive belt????

I found a good price on optical endstop switches here:

[www.ebay.com]

Are these the end switches that I want? what are the tradeoffs with mechanical and hall effect endstop switches? I guess all should be 3.3V.

I plan on building a threaded drive Z axis like THIS:

[forums.reprap.org]

I have found a threaded drive with stepper here:

[www.banggood.com] Doesn't work, need shorter stepper if possible

I would prefer to buy the threaded drive screw and nut for much less if high quality can be found elsewhere. Suggestions??

The size of my build will be determined by the size of the heated bed... I want a build area that is a cube the size of the bed. My current bed choices are:

215mmX215mmX215mm with this bed: [www.banggood.com] Ordered!

305mmX305mmX305mm with this: [www.ebay.com] Later build may be best to make 120v

400mmX400mmX400mm with this: [www.ebay.com] Later build may be best to make 120v

Any suggestions for quality square shaped heated beds at good prices would be appreciated. What size do you think I should build???

For Hot Ends, I think the E3D-V6 or Prometheus V2 are on my short list. Any better suggestions? Here are the links:

[www.dta-labs.com]

[e3d-online.com]

I am really not sure what is best for the cold end, so suggestions would be appreciated. Here is a list of options I have found:

[seemecnc.com]

[www.ultibots.com]

[www.ultibots.com]
[www.ultibots.com]

[www.thingiverse.com]
[www.thingiverse.com]
[www.thingiverse.com]
[www.thingiverse.com]
[www.thingiverse.com]
[www.thingiverse.com]

For controllers, I want to have a 32-bit controller. I would like to select the one with the ability to micro-step most effortlessly so processor overhead would be desirable. Here are some I have looked at:

AZSMZ [www.ebay.com]

RADDS V1.2 [youprintin3d.de]

Duet [www.replikeo.com]

Which of these is the fastest at executing stepping? are there other, faster stepping choices? I realize that the Duet already comes with A4982 drivers, which max out at 1/16 micro-step. I would actually like to have DRV8825(1/32 steps), TMC2100(very quiet) or RAPS128 (1/128 steps!)drivers even...so I could microstep further for quietness... Here are the links for drivers:

DRV8825 [www.banggood.com]

RAPS128 [youprintin3d.de]

TMC2100 [www.watterott.com]

What suggestions do you have for drivers and how they mix with control board choices to give maximum steps per second? where can I get the RAPS128 and TMC2100 cheapest?

Welllll - that was a lot of questions.... I know there are some more missing parts, but the choices above will dictate the other choices like power supply etc.... so I need to firm up the above first!!!! Thanks for your suggestions!!

Patrick

Edited 7 time(s). Last edit at 04/19/2015 05:17PM by patrickrio.

My thoughts:

1. Heated bed. At the upper end of the size range you list, mains power is the most practical. For example, the 24V 15A heater you link to is underpowered for a 400x400mm bed if you want to print ABS (I think you need at least 600W), and even finding an affordable 24V 15A power supply to power that one may be difficult. Switching a mains powered heated bed using an SSR is very easy. OTOH if you use mains power, you need to take care over protective grounding, protect all the mains connections form prying fingers, and make very sure that the cables you use to feed power to the heated bed can stand a lot of flexing and have strain relief at each end.

At the lower end of that range of bed sizes, 12V or 24V power is practical.

2. Stepper motors. The first link you gave doesn't work for me. The second one gives no data on the motor, nor can I find any data for the part number shown in the photo. The third one looks good.

3. Endstop switches. Optical ones are OK, but microswitches are also entirely adequate. If you use optical or Hall endstops, make sure they are suitable for 3.3V electronics. Most should be.

4. Electronics. As you say, the Duet has the drivers built in so you are limited to 1/16 microstepping, OTOH is has an Ethernet port which supports an excellent web interface. The others do not, although I understand it is possible to connect a wifi adapter to the AZSMZ and use a serial host program such as Repetier to talk to it - not the same as having a proper web interface though. Duet supports a colour touch-screen control panel, the PanelDue (full disclosure: I manufacture this), the others support low-cost low-res mono graphics LCDs with rotary encoder. I'm biased towards the Duet because I maintain a firmware fork for it, so that is what I recommend. But if replaceable drivers are important to you, then the AZSMZ Mini looks a good choice to me. RADDS only runs Marlin AFAIK, and although there is at least one fork of Marlin specifically for the Arduino Due, it doesn't yet makes best use of 32-bit processing power or have the nice features that RepRapFirmware and Smoothieware have.

Edited 2 time(s). Last edit at 04/19/2015 01:49PM by dc42.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

You don't need a 32-bit controller to run a CoreXY mechanism, a standard Arduino Mega 2560 is plenty fast enough.

Also, beyond 1/16th microstepping the incremental torque becomes so small that you are not really getting the stepper to move in the precise microsteps i.e. there is no increase in precision anymore, although you get the benefit of less noise and vibrations. The state of the art in terms of silent-running stepper drivers is the TMC2100, which you can run in 1/16th microstepping mode with 1/256 interpolation on a standard RAMPS with a standard Arduino Mega 2560 with a standard version of Marlin. Check the existing videos on YouTube.

BTW a set of TMC2100 pololu-style drivers will cost you less than any 32-bit controller on the market.

Edited 1 time(s). Last edit at 04/19/2015 01:34PM by AndrewBCN.

Thanks Dc42....

My decision for controller is probably going to come down to raw processing power... which one can calculate the most steps per second, after overhead bite???? what other ones should I look at??

The truth is, it may not matter if I use a 1/16 step, depending on the steps per minute that a given processor is capable of achieving... The max steps per second that the processors can calculate with all other overhead items operating may limit me to fewer steps anyway.

I already know that any Arduino based boards that have to run Arduino sketches are going to be slower than their clock speed would suggest because the Arduino IDE takes a lot of overhead and is not really speed optimized anyway. Maybe this doesn't matter though.

Your display for the Duet is AWESOME... However I will likely always have this connected to a computer when printing so it is not really necessary for me I think.... but the Duet is probably still on my short list.

I also suspect that the 32 bit processors will become the standard shortly, so the software should improve.

Steppers and Endswitches are still being decided, and I have some time on those still... at least a few more days!!!

I decided to go with the 215x215 heated bed because they are cheap, good and no extra work. The small printer will prove the concept for a larger printer later!!!

Thanks again for all your suggestions.

Thanks Andrew BCN.

So you are saying that the 8 bit processors will not run out of OOMPH at the higher micro-stepping rates and higher print speeds??? It was my understanding that calculating CoreXY coordinates is more complicated than strait Cartesianal but easier than Delta. I have read that they sometimes even have trouble keeping up with 1/16 micro-stepping in certain situations. I really would like to use high micro-stepping to reduce noise!!!.

Indeed microstepping does reduce noise and vibrations but beyond 1/16 microstepping (and in some cases even lower) you will not get the stepper to rotate precisely 1 microstep per step pulse, because the incremental torque is very low.

This is well explained here: [www.micromo.com]

Regarding low noise and vibrations you should check out the TMC2100 videos I mentioned earlier.

I am not aware of AVR Marlin losing steps in CoreXY setups under normal circumstances.

I agree with Andrew that an 8-bit Arduino should be adequate for driving a CoreXY printer. CoreXY is only slightly more difficult to compute than Cartesian. The overhead of the Arduino core can be avoided by driving the ports directly, and I expect Marlin does this for the most time critical code. However, Arduino/RAMPS had other disadvantages compared to modern 32-bit boards, so I would not choose it for any printer unless I couldn't afford anything better. Marlin on CoreXY appears to have a known issue that limits the maximum speed (described in a couple of threads somewhere in these forums), and AFAIK that hasn't been fixed yet.

Boards that accept plug-in drivers (e.g. the AZSMZ Mini) don't give you software control of stepper motor currents. If you read these forums much, you will realise that lot of people have problems getting the stepper motor currents right on the plug-in boards. Software control makes it so much easier.

There are already at least two excellent 32-bit firmwares (RepRapFirmware and Smoothieware). I expect 32-bit controllers to become the standard soon as well, then we will likely see Marlin improved to make good use of them.

The 215x215 bed is a good choice to start with - you can always upgrade it later.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I watched the videos for the TMC 2100. Huge difference in sound level!! So do these work in any Pololu socket on any controller or does it only work on some of them? It is difficult to find info on them as it seems these are supported primarily in Germany??

Where is the best place to get them for US residents? Here is the only place I could find them for sale:

[www.watterott.com]

The shipping will probably kill me from Germany...

So, are there any advantages to using DRV8825 or RAPS128 over these? Are there any disadvantages to the TMC2100 besides difficulty in finding them in the US???

Dc42, thanks for the advice. I have read about the issues with Marlin also... That makes me a bit wary of Marlin of course, but I assume that this problem will eventually be solved.

As far as the choice between 8 bit and 32 bit, for this machine, having it connectable to a web server would be a big future advantage, and not easy to do with 8 bit. I guess I could connect it to a pc and VMWare to the PC..... Also, I assume that the winning 32 bit choices will all eventually have nice screens like the one you built for the Duet. THIS machine is being designed with the goal of shedding XY axis moving weight, so some of the other 32 bit advantages won't apply to to my CoreXY iteration. I am not likely to do multiple print heads, for example, because that will increase moving weight on XY axis. I like that there is overhead to spare for future use. What other advantages are there for my implementation currently??

I figure that AZSMZ will eventually add an ethernet port, or get their wifi setup working so it just doesn't need ethernet. Or I could get a Smoothieboard or Sunbeam which both already have ethernet....

So do you consider Smoothieware and Marlin the main "in the running" software choices for 32bit along with RepRapFirmware? any other software/hardware I should learn about in the 32bit space?

What are your opinions concerning A4982 vs A4988 vs DRV8825 vs RAPS128 vs TMC2100 drivers. what are the advantages and disadvantages of each as it applies to my single extruder CoreXY build?

Of course, AndrewBCN has some good points for 8bit... simple, mature and cheap!!! in the short term I may just punt and set up RAMPS while I am getting the kinks out of the mechanicals...I can always dump the cheap stuff and go 32bit later.

I have about 2 weeks to decide on Control Boards, Software and Drivers. The reality is that I am going to be doing hard work to reduce moving weight in the XY axis, and also trying very hard to reduce the frame size to the minimum required to hold the 215x215x215 build area.... THIS is where my short term work is really going to be....

My current critical path items are mechanical and electro/mechanical in nature:

1. Find Z axis stepper motor external linear actuator and order. Motor must be REALLY short but can be NEMA 23 to make up lost torque due to shortness. I would love to find a decent motor close to 1 inch/ 25mm tall. Screw must have 225mm or more travel. Suggestions?
2. Must pick hot end and order. E3D-V6 or Prometheus V2 or ????? Suggestions?
3. Must find best cheap supplier for Hiwin MGN7C or similar rail & slides, and order. Suggestions?
4. Find 3 other good and cheap steppers.. probably NEMA 17.

Anyway, I am really glad to have input from you and AndrewBCN!!

Thanks,

Patrick

Edited 1 time(s). Last edit at 04/19/2015 07:16PM by patrickrio.

Personally, I wouldn't consider Marlin for 32-bit boards yet - IMO it's so naff having to recompile and reupload the the firmware to make any small configuration change, or build a new thermistor table if the thermistor you want to use isn't catered for already. There's a lot more you can do in the firmware when you know you have more processing power available. I expect 32-bit Marlin will eventually break away from the limitations of its 8-bit ancestor, but it hasn't done that yet.

There are solutions for interfacing 8-bit electronics to the web, involving adding a Rasperry Pi or similar box to run the web server. But as I said before, Arduino/RAMPS has too many weaknesses for me to want to use it even if I didn't need the processing power (i.e. fragile voltage regulator, slow USB-over-serial connection, no on-board SD card so you are forced to add an LCD, no software control of stepper motor current, limited to 12V or slightly more).

A4982 drivers are easier to cool than A4988, that's why the better boards and stepsticks use them. I haven't used the other drivers you mention yet. Higher microstepping should make the machine quieter at low speeds, but will make no difference at high speed because then the microsteps happen too fast to be noticed by the motor anyway.

Why does the Z stepper have to be so short? I'm not sure you will find anything as short as 1 inch. My Ormerod uses 34mm high motors that work nicely with the Duet.

I've used the E3D hot end and been very happy with it. I have no experience of the Prometheus.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Patrick,

You seem to be extremely worried by the maximum step rate that each controller board + firmware combination is able to achieve. The truth is that maximum achievable step rates hardly matter for RepRap 3D printers for the very simple reason that when printing any object with acceptable quality, we are going to be well below the maximum achievable step rate of even the slowest controller board + firmware combo.

Maximum achievable step rates only matter if you take part in the pissing contest of 8-bit vs 32-bit controller boards, and without any doubt the fastest ARM solution out there will always win, but that doesn't change the reality of things.

Take a look at this page in the wiki and the discussion tab too: [reprap.org]

One more thing: there are no NEMA 23 or NEMA 17 steppers close to 1 inch tall, or if you find something that size, it's likely to cost more than your entire printer. Also, for RepRap 3D printers, imho NEMA 23 steppers have no advantage over the smaller, lighter, less expensive and just as fast NEMA 17's; they just have more maximum torque, but we rarely if ever run our steppers at maximum current/maximum torque anyway.

Finally, imho using standard components (e.g. 40mm or 48mm NEMA 17 steppers) requires in some cases more thinking and design work, but it's a sign of good engineering. A RepRap design that requires a part machined from unobtainium with micron level tolerances is a total failure before the first prototype is even built.

A good question to ask yourself in these early design stages is whether your CoreXY printer can be made to print better quality objects in less time while making less noise and costing less to build than a good old Prusa i3.
You'll be surprised by how hard this question is to answer.

Edited 2 time(s). Last edit at 04/19/2015 08:04PM by AndrewBCN.

Hi Dc42,

The Z axis motor needs to be short because it is going under the Z table, and the shorter it is, the larger the reinforcements to the Z table can be. I am trying to shorten the Z distance of the frame as part of my design goals. Admittedly, shortening the Z axis is not as important as keeping the XY axis' short, but shorter Z will still be better.

AndrewBCN is suggesting that cost will be prohibitive for a super short stepper... So I guess that I should qualify here. I would LOVE to have a motor that is 1 inch tall, but am only willing to spend an extra $30 to get the shortest motor possible. Also, Shortness is not worth losing functionality over... It still needs to be able to do an excellent job of turning the screw!!!!

Where did you get the 34mm high motors? are they available with external linear screws????

Hi AndrewBCN,

You are totally right about design.... and my post did not outline that I am not willing to make really bad design choices in order to get a shorter motor. If bad design results, I will just raise the Z axis more. HOWEVER, all other things being equal, I am willing to spend a little more money to get a shorter motor and shorter Z axis.

GOOD design on this piece means that I need to find a motor that has the screw and the motor shaft as the same part... no need to go short if I have to add extra complexity with set screws and also more height before the threads start....

I am trying to shrink frame size which makes for a sturdier frame for a given build area.

I am trying to reduce moving weight... I am going to be pretty aggressive at doing this.

I am also trying to remove screws and parts where possible.

I am trying to center forces exerted by the belts and screws and align with slides and bearings.

Lastly, I am trying to reduce moment arms of moving parts that are not supported. Center of gravity for extremeties is being considered... like the extremities of the hot end for example.

I will probably build several mock up iterations with some 1"x1" wood pieces as stand ins for the frame in order to make sure my assumptions actually fit.....

As for maximum step rate, you are right that it usually does not matter. I also obviously overestimated the importance of step rate overhead. However, I am trying to give myself some extra overhead in this area though, as I am hoping that my other design choices will allow for faster low resolution printing for mechanically useful parts than is usually possible. I may be experimenting with faster step rates than are usually advisable and want the machine to be able to handle that.

For this machine I will over design it, see if I can get low resolution speed improvements, and then figure out what I can take out of the design to make it cheaper.... For example, I may lengthen the Z axis again and put back a cheaper motor....

The truth is, I am much better at thinking through mechanical issues than software and electronic issues. I am glad you are here to set me strait, and call me on my bullshit thinking!!!

Best,

Patrick

I have a first find for the z axis stepper. 1.5 inch high motor at $50 FOB Las Vegas.

Any reason this won't work???

[www.pololu.com]

this is the one I need to beat.

I think these are the other 3 steppers:

[www.ebay.com]

$37 for 3 78 oz in holding $12.32 each

Quote
patrickrio
I have a first find for the z axis stepper. 1.5 inch high motor at $50 FOB Las Vegas.

Any reason this won't work???

[www.pololu.com]

this is the one I need to beat.

That one certainly looks good and is from a reputed very good supplier of 3D printer parts.

Quote
patrickrio
I think these are the other 3 steppers:

[www.ebay.com]

$37 for 3 78 oz in holding $12.32 each

Indeed these look good to me too. They'll probably work fine for your project.

Quote
patrickrio
I have a first find for the z axis stepper. 1.5 inch high motor at $50 FOB Las Vegas.

Any reason this won't work???

[www.pololu.com]

this is the one I need to beat.

Have a look at Robotdigg they are HK Based but have a very wide selection of stuff needed and they are very good and Quality is also good.

I get all my Belts pulleys etc from them.

Doug

Thanks Doug.

I checked them out. did not find any motor that was short..... I will email them.

Control Board Research... The options:

Cheap Ramps 1.4 complete with 2004 LCD $16:

[www.ebay.com]

comes with stepper drivers, Mega2560, cables and LCD all for $16. I am going to get a set as a backup. so cheap it may go up in smoke..hahahah. this was too good to be true... when you get ready to order it pops up with an options screen and what appears to be $16 becomes $70...... not happening.

One board ramps solution, MKS Mini $36:

[www.ebay.com]

Duet $88 after shipping:

[www.replikeo.com]

Radds v1.2 with 4x DRV8825 $85 with shipping:

[max3dshop.org]

[www.ebay.com]

AZSMZ Smothieboard clone with 4x DRV8825 $72 total:

[www.ebay.com]

[www.ebay.com]

All the other 32 bit options were sold out or were too expensive... or both. If anyone knows of good prices for something else that is good, please let me know so I can consider it.

Cool Stuff coming soon:

Smoothieboard V2 Pro:

[plus.google.com]

Replicape B (interesting because I have a beaglebone black already...):

[www.thing-printer.com]

FastBot BBP. Beaglebone power for the same price as Replicape, and you don't need a beaglebone black...now trying to overcome the Kickstarter Curse....:

[www.fastbot3d.com]

Edited 1 time(s). Last edit at 04/22/2015 01:21PM by patrickrio.

So, Do these control boards allow you to use 0.9 percent steppers too?

What about these motors:

[www.ebay.com]

[www.ebay.com]

[www.ebay.com]

[www.ebay.com]

[www.ebay.com]

Some of them are the same motor just from different suppliers.... Do these work?????

#1: rated current is a little on the high side for the usual drivers, so not an ideal choice IMO but will probably work OK.

#2, #3, #5: all the same; 1.7A rated current which is a good match for the usual drivers; looks good to me.

#4: rated current is even higher than #1.

You can use 0.9 degree steppers with any of the boards, but the board will have to generate twice as many steps as for 1.8 degree steppers. If you combine this with DRV8825 drivers set at 1/32 microstepping, then that's 4x the usual step rate, and 8-bit boards may struggle to generate the steps fast enough at moderate or high speeds.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Turns out, right now that the DRV8825 drivers are the cheapest of all drivers... So I think that as long as you are not buying a kit, or buying a board with drivers built in, there is no reason not to buy the DRV8825. If the board can't handle 1/32, you can always do 1/16 or 1/8 right????

Power supply. Will this work?

[www.amazon.com]

Quote
patrickrio
Power supply. Will this work?

[www.amazon.com]

This one PSU Would be better and give you more headroom.

Doug

Quote
patrickrio
Power supply. Will this work?

[www.amazon.com]

Yes, that's a standard Chinese LED PSU similar to the one I use, but 24V instead of 12V and 360W instead of 300W.

Sorry, I got this thread confused with another one. Unless you will be using a 24V heated bed AND your electronics can take 24V, you would be better off with a 12V power supply, such as the one Doug linked to. The one I use on my Ormerod is a 12V 25A PSU, fanless but otherwise similar, sourced from eBay.

Edited 2 time(s). Last edit at 04/22/2015 12:24PM by dc42.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hmm. I think these are essentially the exact same transformer with the save power level. One is 24V 15A and the other is half the volts and double the amps at 12V 30A. I figured that going 24V would let me use smaller wire for my wiring.

What are the advantages and disadvantages of going 12V vs 24V?????

Some electronics (e.g. Arduino/RAMPS) will only take 12V. For electronics that can take 24V, you are right, 24V will allow the use of thinner wires to the heated bed and hot end heater. But you will need 24V versions of those heaters.

Most people use 12V for small printers (e.g. heated bed about 200 x 200mm) and 24V for larger ones. Really large printers need AC mains for the heated bed, and the electronics and hot ends are usually powered from 12V - but there is no reason not to use 24V if the electronics supports it. Other advantages and disadvantages:

- 12V PSUs are more readily available than 24V PSUs and typically cost less
- 24V gives you more voltage headroom for the stepper motors, which helps to achieve higher speeds

Edited 1 time(s). Last edit at 04/22/2015 12:30PM by dc42.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

my heated bed says it can use either 12v 0r 24v depending in how it is wired. 12V takes 10A max and 24V takes 5A max. which electronics can't take 24V???? Just the Ramps, right???