CoreXY I have been looking for CoreXy machine designs for a while now. I allready chosen D-bot as my choice of printer, but then I noticed that chinese mgn9 linear rails are dirty cheap nowadays. Frame and linear components for D-bot costs rougly 150€ and it is mainly 2040 - size framing On the other hand it costs about 120€ to make similar with linear bearings from china. Mechanical part is not a problem(I make it for a living) BUT! Is mgn9 rails enough for 300x300x300 3d printer and are there any reasons that I should choose wheels over rails??? https://reprap.org/forum/read.php?397,811801,811801#msg-811801 Tue, 08 Sep 2026 09:01:18 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?397,811801,820399#msg-820399 Re: CoreXY https://reprap.org/forum/read.php?397,811801,820399#msg-820399 jackantubis CoreXY Machines Fri, 27 Apr 2018 15:44:58 -0400 https://reprap.org/forum/read.php?397,811801,820397#msg-820397 Re: CoreXY https://reprap.org/forum/read.php?397,811801,820397#msg-820397
Theres going to be a little twist in design. I really need to put pictures here someday.

Yes, the electronics will be under there shielded with aluminium plate and litlle fans to ensure cooling.]]> kapperi CoreXY Machines Fri, 27 Apr 2018 15:39:03 -0400 https://reprap.org/forum/read.php?397,811801,820393#msg-820393 Re: CoreXY https://reprap.org/forum/read.php?397,811801,820393#msg-820393
Compare the cost of that frame plus all that hardware to the price of the same frame made from larger cross-section t-slot (which will be inherently more rigid). I think you'll find the larger t-slot cheaper, and you won't suffer the tedium of mounting all those ultimately useless corner braces.]]> the_digital_dentist CoreXY Machines Fri, 27 Apr 2018 14:59:10 -0400 https://reprap.org/forum/read.php?397,811801,820382#msg-820382 Re: CoreXY https://reprap.org/forum/read.php?397,811801,820382#msg-820382
I found this picture on the web close to your design with space bottom]]> jackantubis CoreXY Machines Fri, 27 Apr 2018 13:23:12 -0400 https://reprap.org/forum/read.php?397,811801,815532#msg-815532 Re: CoreXY https://reprap.org/forum/read.php?397,811801,815532#msg-815532
Any thoughts in this point?]]> kapperi CoreXY Machines Thu, 22 Mar 2018 08:54:15 -0400 https://reprap.org/forum/read.php?397,811801,814510#msg-814510 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814510#msg-814510
Should be rigid enough? Frame members costs about 65e now. Rails what I have to buy are about 140e.

Total budget must be under 500e, so theres maybe room for duet too.]]> kapperi CoreXY Machines Thu, 15 Mar 2018 13:02:38 -0400 https://reprap.org/forum/read.php?397,811801,814406#msg-814406 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814406#msg-814406
What do you think, should I make corner profiles so long that those works as a legs too? Is there any difference with vibrations etc.?

[Offtopic]

Today I was in the seminar where was 3 leading professors in Finland who studies 3d-printing. One professor studies using 3d-printer to create lenses. They can actually print lenses that is suitable for camera use also. Roughness was under 5nm and vertical repeatibilyty was something like 3um. Second professor is studying metalprintings and third one was one of the laserfysician in the 3DSystems. There was huge amount of knowhow in the same room!

Couple companies showed their business, other was doing mainly 3d-printing of plastic from powder and another one was printing metals. Powder printed plastic were not amy impressing thing, parts was very rough and moving mechanism are very difficult to print.

Wicked!!!

[/Offtopic]]]> kapperi CoreXY Machines Wed, 14 Mar 2018 16:42:40 -0400 https://reprap.org/forum/read.php?397,811801,814393#msg-814393 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814393#msg-814393
Quote
kapperi
That is rhe most expensive profile what I have seen...

50 dollars per meter, that cannot be true...
Which profile are you looking at? HFS5-4040 is $15.40 per meter, and prices include cut to length at no additional cost with near flawless accuracy.]]> 691175002 CoreXY Machines Wed, 14 Mar 2018 14:40:31 -0400 https://reprap.org/forum/read.php?397,811801,814356#msg-814356 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814356#msg-814356
50 dollars per meter, that cannot be true...]]> kapperi CoreXY Machines Wed, 14 Mar 2018 11:40:03 -0400 https://reprap.org/forum/read.php?397,811801,814287#msg-814287 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814287#msg-814287

Quote
Vigilant

I suggest that you use 4040 that is consist of 2 2020 if you want it more rigid. A lot of hardwares sold are based on 2020 mounting.
MIsumi 40X40

Neat profile, but I think that that consist 4 2020 afterall.

That would be great profile, Atleast that could be bolted with 4 bolts to thru other profile. Could make super heavyduty corners too, no need to put extra corners with that.]]> kapperi CoreXY Machines Wed, 14 Mar 2018 01:54:19 -0400 https://reprap.org/forum/read.php?397,811801,814277#msg-814277 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814277#msg-814277 I made the same mistake.

I use robotdigg Stainless steel linear rails for my delta and it's ok.
It's cheaper than hiwin equivalents but more expensive than the typical chinese rails.
To me that is better value for money.]]> Vigilant CoreXY Machines Tue, 13 Mar 2018 23:18:12 -0400 https://reprap.org/forum/read.php?397,811801,814243#msg-814243 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814243#msg-814243
Maybe thats useless with ballscrews and these big rails...]]> kapperi CoreXY Machines Tue, 13 Mar 2018 13:46:11 -0400 https://reprap.org/forum/read.php?397,811801,814240#msg-814240 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814240#msg-814240 the_digital_dentist CoreXY Machines Tue, 13 Mar 2018 13:40:54 -0400 https://reprap.org/forum/read.php?397,811801,814236#msg-814236 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814236#msg-814236
This time nut would be constained to bed gantry only from top and arm is replaced by 2020 profile from nut to nut.

By the way I managed to salvage two more egr20 bearings and 2 370mm rails, shamefully too short.

Now I have 5 bearings and 2 too short rails.]]> kapperi CoreXY Machines Tue, 13 Mar 2018 12:44:56 -0400 https://reprap.org/forum/read.php?397,811801,814220#msg-814220 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814220#msg-814220
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kapperi
Quote
the_digital_dentist
Others have tried using screws without guides and the result is never pretty.

Whats the problem? Only the lift is using ballscrews as a guides and the bed is constrained properly with bearings.

I don't understand what this means. Ball screws are not guides. The bed is attached to the "lift", so if the lift shifts laterally, the bed does too.]]> the_digital_dentist CoreXY Machines Tue, 13 Mar 2018 11:01:09 -0400 https://reprap.org/forum/read.php?397,811801,814156#msg-814156 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814156#msg-814156
Quote
the_digital_dentist
Others have tried using screws without guides and the result is never pretty.

Whats the problem? Only the lift is using ballscrews as a guides and the bed is constrained properly with bearings.

Quote
Vigilant
I suggest that you use 4040 that is consist of 2 2020 if you want it more rigid. A lot of hardwares sold are based on 2020 mounting.
MIsumi 40X40

Yes I think that i have to use 4040 because Egr20 bearing is 34mm 42mm wide.

It doesnt help to use 4040 because bearing is still wider, but I allready have 4040 profile, and man that it´s going to be ridig, even DD likes it. (:P)]]> kapperi CoreXY Machines Tue, 13 Mar 2018 01:26:59 -0400 https://reprap.org/forum/read.php?397,811801,814148#msg-814148 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814148#msg-814148
Quote
kapperi
Quote
the_digital_dentist
I wouldn't let my dog (if I had one) use 2020 to build a 3D printer. Go with the larger stuff.

Ball screws will probably allow the bed to drop when power to the Z motor is cut, if everything is aligned well.

I definitely would not mix bearing blocks and rails from different manufacturers. Linear guides are systems, not parts.

So do you think I go with the 3030 or is 2040, you build your megamaxsuperhyperturbo with 4040? So I think with much less Z, I could go with 3030.

Ball screws will allow the bed drop, but could I use geared Nema to stop that?

Edit: God tha PLA is so easy to print. If only it could come in better strength..

I suggest that you use 4040 that is consist of 2 2020 if you want it more rigid. A lot of hardwares sold are based on 2020 mounting.
MIsumi 40X40]]> Vigilant CoreXY Machines Mon, 12 Mar 2018 21:29:12 -0400 https://reprap.org/forum/read.php?397,811801,814139#msg-814139 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814139#msg-814139 the_digital_dentist CoreXY Machines Mon, 12 Mar 2018 19:23:40 -0400 https://reprap.org/forum/read.php?397,811801,814068#msg-814068 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814068#msg-814068
I have thinked that I could put ballscrews to lift one 2020 profile what lifts the bed thru somekind of teflonplates. This way there cant be any wobble too. If ballscrews are constrained from bottom and top, it would not need any linear bearings.

Only the bed would be running on two smoothrods.

I really have to get my designs on here to show what I mean.

Xy mechanism is now rigid enough with egr20 rails and bearings. These are the real Hiwin products so I expect that these are good. Rails are ordered too, cost was about 100e for 3x400mm rails.]]> kapperi CoreXY Machines Mon, 12 Mar 2018 10:49:05 -0400 https://reprap.org/forum/read.php?397,811801,814061#msg-814061 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814061#msg-814061
The only real problem with belts is preventing bed-drop when Z motor power is cut. Some people try to fix that with counterweights or bungee cords with varying degrees of success, and it's always ugly. I used an elegant and relatively expensive ($140 all-in) 30:1 worm gear reducer on the motor with a keyed output shaft. I have designed a much less expensive 40:1 worm gear drive and am waiting for parts to arrive from China to test it. My new design will be smaller, and use "standard" parts (no keyed shaft!), and will cost about $40 for similar performance, assuming reasonable gear quality (we'll see...). The gearbox/motor mount will be printed, and will use a NEMA-17 size motor to deliver 100 full steps/mm resolution. I am expecting it to lift 5 kg without breaking a sweat.]]> the_digital_dentist CoreXY Machines Mon, 12 Mar 2018 09:55:15 -0400 https://reprap.org/forum/read.php?397,811801,814010#msg-814010 Re: CoreXY https://reprap.org/forum/read.php?397,811801,814010#msg-814010
Is there any way to change topic name?]]> kapperi CoreXY Machines Mon, 12 Mar 2018 04:58:24 -0400 https://reprap.org/forum/read.php?397,811801,813280#msg-813280 Re: CoreXY https://reprap.org/forum/read.php?397,811801,813280#msg-813280 kapperi CoreXY Machines Wed, 07 Mar 2018 06:11:45 -0500 https://reprap.org/forum/read.php?397,811801,813031#msg-813031 Re: CoreXY https://reprap.org/forum/read.php?397,811801,813031#msg-813031
If I waterjet plate what is same size than my width*length and hole in the middle what is 30mm smaller from sides. It's going to be base for the rails. I can mill it with same settings so it should be pretty accurate. I could then put holes in the corners to put 2020 profiles to make top cage. Does it make any sense?

This way the corexy mechanism is in own plate at the top of the printer and accuratly milled in the place. I too have flat surface at the work but sadly its pretty small.]]> kapperi CoreXY Machines Mon, 05 Mar 2018 13:13:33 -0500 https://reprap.org/forum/read.php?397,811801,812993#msg-812993 Re: CoreXY https://reprap.org/forum/read.php?397,811801,812993#msg-812993
I don't think you can mill exact width slots into the aluminum frame members to mount the linear guides unless you can be sure that the frame pieces are going to be exactly parallel. I milled a slot that was wider then the guide rail, assembled the Z axis frame, put the linear guides loosely into position, then used a metal block as a spacer between the rail and the flattest surface I had available- a pool table- and set the guide positions and tightened their mounting screws. It worked pretty well. We have since acquired a granite slab at the makerspace that I would use to do that if I had to do it again.

I am re-examining UMMD's X axis and extruder carriage designs and may make some changes in the near future.]]> the_digital_dentist CoreXY Machines Mon, 05 Mar 2018 06:49:40 -0500 https://reprap.org/forum/read.php?397,811801,812975#msg-812975 Re: CoreXY https://reprap.org/forum/read.php?397,811801,812975#msg-812975
As a designer, I didn´t realise that you could make threads to aluminium too... And to thinking about it, I can put thru holes to aluminium and t-slot nuts underneath...
I was thinking about to mill exact places to aluminium plate to hold the rails in correct position, and thru thruholes attach the plate and rails att the same time. This way it should be easy to have everything in correct places.

Now it turn to think about x-axis gantry, If I put rails on top of the extrusion, should the MGN12 be enough withous extrusion to hold the mass of hotend. How much does MGN12 rail hang if the span is max 400mm, if somebody know this allready... Offcourse rail is going to be vertically.
Whats the best way to attach rail to bearing vertically, Is DD:s structure great? I was thinking about I-beam piece? No I wont put another bearing to another end...

PS. Is there a way to edit the title of this topic?]]> kapperi CoreXY Machines Mon, 05 Mar 2018 03:36:07 -0500 https://reprap.org/forum/read.php?397,811801,812974#msg-812974 Re: CoreXY https://reprap.org/forum/read.php?397,811801,812974#msg-812974 I modified my Prusa i3 with a Volcano 0.8mm nozzle. That's probably the best use case for slow_by_design printers.]]> o_lampe CoreXY Machines Mon, 05 Mar 2018 03:33:24 -0500 https://reprap.org/forum/read.php?397,811801,812941#msg-812941 Re: CoreXY https://reprap.org/forum/read.php?397,811801,812941#msg-812941 Plate needs to be thick enough to accept the countersink, and have enough, yet not too much, screw length into the slot for a T-nut.
Considering most likely tap the plate for the rail bolts, it'll be at least 1x diameter of the screw diameter thick for a decent thread engagement. Anything more than 2x is a waste.]]> prot0typ1cal CoreXY Machines Sun, 04 Mar 2018 19:14:47 -0500 https://reprap.org/forum/read.php?397,811801,812915#msg-812915 Re: CoreXY https://reprap.org/forum/read.php?397,811801,812915#msg-812915
With small pieces and countless hole perimeters this slows my printer down, and offcourse theres this enclosing thing what is easier and better looking with corexy things...

I'm driving now with sav mk1 and in vase mode it clearly shows that it have to slow down. So controller must do great difference with this. I have mks sbase waiting to get to work and I think that its going to faster this.

/Offtopic

But man that vase mode looks wonderful even with 0.3mm layerheight.

Another thing that is with pla that my layerbond is great, parts are way stronger than with petg.]]> kapperi CoreXY Machines Sun, 04 Mar 2018 12:43:40 -0500 https://reprap.org/forum/read.php?397,811801,812910#msg-812910 Re: CoreXY https://reprap.org/forum/read.php?397,811801,812910#msg-812910
When you move the bed in Z there are all sorts of potential problems that are a function of the Z axis mechanism. Cantilevered beds tend to bounce and that will cause print quality problems. It doesn't matter if you're lifting a bed or an X axis, if you use bad screws and/or multiple motors, you're going to have problems.

CoreXY can print fast, but it depends on how you build it and the controller you're using. It doesn't matter what architecture you use, print quality is always a trade for speed. It's a lot easier and cheaper to build a bad printer in any architecture, so you see a lot of bad builds in every architecture. The thing that ultimately limits print speed/acceleration is the fact that you're extruding molten plastic from a nozzle. Once it leaves the nozzle, it goes where it wants until it cools off.

The mechanisms to move the nozzle/bed around are relatively easy. Controlling extrusion is the biggest problem in 3D printing.]]> the_digital_dentist CoreXY Machines Sun, 04 Mar 2018 12:12:06 -0500 https://reprap.org/forum/read.php?397,811801,812907#msg-812907 Re: CoreXY https://reprap.org/forum/read.php?397,811801,812907#msg-812907
I was thinking about using waterjetted aluminium plate under the rails but I cant think of way to attach the plate without bringing it out of the extrusions...

I want to do another level above the extrusion to get proper enclosement.

Today I was printing my I3 XLSteel over 70mm/s and it was foing great quality. I was printing PLA. Please tell me that theres some advantages with corexy, can it do faster speeds? Any other advantage?]]> kapperi CoreXY Machines Sun, 04 Mar 2018 11:46:42 -0500