Tronxy X3 Bed Upgrade

by Megreth, published

Tronxy X3 Bed Upgrade by Megreth Jun 20, 2017


Liked By

View All

Give a Shout Out

If you print this Thing and display it in public proudly give attribution by printing and displaying this tag.

Print Thing Tag


Thing Statistics

5266Views 940Downloads Found in 3D Printer Parts


!!!UPDATED!!! July 8th

So the Tronxy X3 has a horrible Y axis .. I knew that from the beginning when I bought it. But I planed on doing Kencam's Bed Upgrade as soon as I could. I printed up my legs upgrade and corner supports and even did an extruder sink cooler. Then I thought I was ready to do the bed upgrade, and then my printer melted down. After a Ramps 1.4 upgrade and a part cooling upgrade of my own design I created this, my own bed upgrade.

Note again that it is totally inspired by Kencam's bed upgrade!

NOTE & WARNING!! This upgrade involves tearing down a rather critical part of your machine to implement it. MAKE SURE YOU HAVE ALL THE PARTS YOU NEED BEFORE YOU START TEARING DOWN YOUR PRINTER. Nothing would suck more to discover that one of the parts you printed was messed up or missing and have to put your printer back together to print a part just to have to tear it down again!!

After installing this I have found:

  • My prints to be much better in precision!!
  • I hardly have to level my print bed anymore
  • Its quieter!
  • It's design style is similar to my leg and upper extrusion designs.

Here is a breakdown on each part:

The Bed Support

Obviously the biggest part.. It directly holds the print bed and slides on the liner Shafts using attached bearings. The shaft and the bearing this is designed for are two pieces of 8mm x 400mm Linear Hardened Shaft Sound Rods with four LM8UU Bearings. I bought them on eBay for about 17$ here is the listing. it might not be there when you read this so look them up. Also the belt attaches to the bottom using something I came up with, a set of teeth! Basically you press the belt into the teeth on each side and then zip tie both ends together (see photos). It works quite well and they haven't budged for me after the install. Just remember its going to be a tight fit, use a flat screwdriver to push them in. Also you might have to clean out the teeth depending on how good your print is...

PART UPDATED!! It seems that some were having trouble slicing this part so I made some changes to it that should fix it. (I just simplified the model) Also, I am getting reports that where the bed support attaches to the bed the measurements are off. It seems that there are different versions of beds where the four holes are in different positions. Great... So I have updated the Bed Support Model with measurements for that model. The latest one is 77mm by 42mm that is from center to center in the Y and X axis. Make sure to measure this before you print this rather large part... it would suck to print this then have it be off. Though if that does happen you could simply fix the bed with a drill so it does match the Bed Support. With the stock setup, the position of these holes is rather critical, which is primarily the reason why the Y axis on this machine sucked so bad. Off by just half a millimeter and the bed will wobble, with this upgrade, the positions of those holes is no longer critical.

NOTE: If the mounting holes for your bed are not 77mm c2c on the Y Axis and 42mm c2c on the X axis. Then get me those dimensions and I will whip up a new bed support for those dimentions.

The Belt Tensioner

My own design! And it works and looks rather well! I didn't like the tensioner that Kencam suggested, it felt a bit kludgy to me... and truthfully a bit ugly. My version requires only a single screw to adjust and it works on a concept of pulling rather than twisting that the other did. It consists of a bracket that attaches to the aluminum extrusion and an arm that holds the bearing that the belt is on and hold a nut that is adjusted by a screw that goes through the bracket. I included photos that should make it pretty obvious how it goes together. If it isn't contact me and I will provide more details.

The Y - Stepper Holder

It simply turns the stepper 90 degrees and holds it close to the aluminum extrusion... Its pretty obvious what it is doing.

The Shaft Supports

Again pretty obvious how those work except for the end stop sensor holder. It is designed to hold the stock switch and uses the Bed Support itself as the stop. Not that its a bit further back so you will have to adjust your offsets.

Print Settings


Tronxy X3










Here are the basic settings I used when printing the parts:

  • Layer height: .2mm
  • First: .28mm
  • Perimeters: 3
  • Top / Bottom: 3
  • Infill: 15% Rect

Using these speeds:

  • Perimeters: 60mm
  • Ext Per: 35mm
  • Infill: 60mm
  • S Infill: 80%
  • Travel: 130mm
  • First Layer 25mm

Except for the Y - Belt Tensioner Arm, I would beef that one up a bit, Like a 30 - 40 % infill (or even higher if you wish). Also the Y - Belt Tensioner Bracket you could up it a bit also.

Just to make sure you realize you are going to need 3 of the Shaft Supports without the sensor! everything else one part!

Print Times

  • Bed Support 4.5 hours.
  • Shaft support with sensor: 40 minutes.
  • Shaft support: 30 minutes each so 1.5 hours total.
  • Y - Stepper holder: 1.5 hours
  • Y - Pully Arm: 30 minutes
  • Y - Pully Bracket: 45 minutes

Total: 9 Hours 25 Minutes.


  • 10 of the screws plus cams that screw into the aluminum extrusion. There should be some leftovers when you bought the printer and when you upgraded to my legs and extrusion covers.. You did do this right.... :-) (naaa you don't need to)

  • 1 of the long screws plus nut that came with the printer. It's the ones that were supplied with the printer to bolt together the controller case.

  • 4 - #10 - 24 screws plus some lock nuts. Used this to hold the bearings to the bed support.

  • Two pieces of 8mm x 400mm Linear Hardened Shaft Sound Rods with four LM8UU Bearings. I bought them on eBay for about 17$ here is the listing.

Other than the 4 bolts to hold the bearings all the other hardware you should have left over from the printer... I had extra parts when I built it so... you should have some.

Good luck!

More from 3D Printer Parts

view more

All Apps

Auto-magically prepare your 3D models for 3D printing. A cloud based 3D models Preparing and Healing solution for 3D Printing, MakePrintable provides features for model repairing, wall thickness...

App Info Launch App

Kiri:Moto is an integrated cloud-based slicer and tool-path generator for 3D Printing, CAM / CNC and Laser cutting. *** 3D printing mode provides model slicing and GCode output using built-in...

App Info Launch App
KiriMoto Thing App

With 3D Slash, you can edit 3d models like a stonecutter. A unique interface: as fun as a building game! The perfect tool for non-designers and children to create in 3D.

App Info Launch App

Quickly Scale, Mirror or Cut your 3D Models

App Info Launch App

So, I built it all and my y-axis now runs the other way (it thinks that the y end-stop is at the front of the frame). Is there any way of reversing which way the y-axis runs, other then rebuilding the firmware?

Y axis bumps into the tensioner just a tad! Can you please let me know what i need to adjust in my firmware settings?

That is interesting... I never had that issue. Your Y axis bed size is initialized by the Y axis end stop at the back. If you are using the default bed size then there should be no issue...

Ah fixed. I had the nut facing up and screw head was down. Flipped it and works great.


Just did the upgrade. Works great! Just had a few issues trying to get the rail holders to hold tight with the t-nutS. Had to really tighten so it would stay put. Also had to swap wires on my y stepper because my motor was reversed.

But very solid and great job!!! Love the tensioner! Simple and works great.

I am glad you liked it!

just what i need to convert my 802 frame to square tube. thanks.

Obviously this design makes for an excellently stable and rigid building bed and smooth linear movement. However I`d like to know if one can redesign the front Y-Belt tensioner to be more "forward" towards the user thus providing more space for the bed to move forward. My train of thought is that because the Y-stepper pulley is above the frame and to the rear there-of why not a similar arrangement for the front Y-tension setup?

Further will one be able to use the IGUUS LM8UU "bearings" here?

Well if you look at the bed support piece it makes space for the Y-Tension.. so the Y access movement loss is quite limited I would say only 7 millimeters is lost.

As to the IGUUS LM8UU Bearing, as long as the outer diameter is the same they should be ok. Just don't tighten the clamps down too much as they might deform.

Thank you for your work and insight as well as the explanation and 7mm really is negligible. It is just that on the photos it looks quite radical :p

Thank you also for the advice about the bearings.

Hi sir.. firt off.. thanks for the design. It works good and looks good. However, the Y stop switch sits too far back for me. It has changed my 0 by a lot. Maybe the X3 and X3a have different Y stop switch positioning? I will have to add an ajuster there

You should be able to adjust that by adjusting your software offset. I could have sworn I mentioned that in the description... but yeah it does change the y back stop position. Oh and thanks for making it! I am glad you like it, please mark it as made and post some pics! I would love to see it!

yeah I could that.. but I printed a part that I glued on the printed bed as a spacer . Works perfect ! thanks

Sweet! If you want send me the file and i can include it with thia and give you the credit if you wish.

Just finished printing all the bits, looking forward to assembly. Looks like the bolts for securing the bearings might be 5mm? Not sure what #10 translates to.
It looks good though, excellent work!

Glad you liked it!! Yea, 5mm should do just fine. Marked that you made it and I want to see pics!!

Damn, didn't realise it needed to be up on legs to work. Mine doesn't have legs and won't fit in my enclosure if I add them. This has been an expensive learning exercise!
Can you add to the first line of your description that it is only suitable for printers that are elevated, might stop others making the same mistake as me.

Could have sworn i had something the listing pointing to the legs i created.... If i didnt sorrg about that... some of my other items are legs i have an assortment of heights. I cant do more than that right now... I am in Idaho for the eclipse.

No problem, I still plan to use your design, I think it's fantastic (assuming these bearings behave themselves!) so I've ordered a low profile stepper motor to replace the stock stepper. Enjoy the Eclipse (it comes and goes a lot faster than you might expect, so be ready) and don't risk your eyes!

Oh we are totally set up were going to be with tbe weaber collage science department... lots of eye protection. Have modifyed 10 goggles with solar filters. Have cameras set up.. been planing tbis for years... literally

First time I've used LM8UU bearings for something, do they usually need lubricating? They seem really loud and not moving very smoothly.

Yea mine had the same issue. Get some WD40 and spray it on them. I tbink what happens is they come with something on the to protect them.. the WD40 should break that up. But no i have never had to keep any lubricant on them.

Cool, thanks very much :)

Is the bed support supposed to be one solid peace because when I slice to be printed it has
Two lines through it making it in to three pieces I am using simplify3-D can you tell me what I'm doing wrong

Ok, I think I fixed it... I looked at the model and there was a bit of complexity where there didn't need to be. Also, make sure the measurements for the mounting holes match the bed you have, I updated the main description to explain why. Hope this works out I would love to see someone send me pics of a completed build!

Thanks for all your work and getting back with me .

It works thanks awesome work what software do you design with ?
I 'm new to 3d printing and just want learn all can thanks for the Help.

I use Tinkercad, there are much more powerful pieces of software out there but I have used this for almost 90% of everything I do. Also its free and getting more and more powerful as they upgrade it, google it.

Comments deleted.

Awesome design !!! Just curious what do you print
The parts in abs pla

I just realized it looked like I responded with only 3 letters!?! PLA... there was much more there I wrote, not sure what happend to the rest. But thanks for the compliment! I really enjoyed designing it!

buenos dias compañero, primero de todo felicitarte por el trabajo me a gustado mucho el diseño al ponerme a imprimir las partes me e dado cuenta que va con las guias LM8UU y yo tengo las guias SCS8U lo que no se exactamente como lo tendria que modificar para poderselo poner sin que fallase tu diseño ya que no paro de tener problemas en las piezas altas con la cama y cada 3 o 4 impresiones se me afloja y se tambalea, muchas gracias por adelantado, un saludo

I had to use google translate to go from Spanish to English, here is the result of that

"Good morning mate, first of all congratulate you for the work I really liked the design to get me to print the parts I noticed that it goes with the LM8UU guides and I have the SCS8U guides which I do not know exactly how I would have to modify it You can put it without failure your design since I do not stop having problems in the high pieces with the bed and every 3 or 4 impressions I loosen and wobbles, thank you very much in advance, greetings"

Thank you for the compliment! I had the same problem with the bed moving around. I tried to solve the wobble by moving the wheels into the TSlot, but I could never get it tight enough. After implementing this modification my prints are much better and I rarely have to level my bed anymore and there is no longer a need for an automated bed leveler. As to modifying this design for the SCS8UU bearings... After looking at the specks for the bearings it looks like there are LM8UU in there own mount. Modifying the design for these bearing would be relatively easy. The only issues I see are that I don't have any of those bearings in my possession so I could not verify the design and I would have to make the bed support at least 2cm wider to accommodate them, that is a big part with a huge printed surface area. I had trouble popping the bed support I printed off a glass surface... If you could purchase the the LM8UU bearing it would save you a great deal of headaches. I found a listing in Spain on eBay for only 1 Euro each if you can this would be a much easier option for you.

I love it! It's definitely prettier than mine. I have more Y travel though. :-)

Yea you do but .. not buy much. :-) .. I was just looking for stability so I widened the shaft placement. I was so tired of the Y access giving me trouble especially on tall objects.

You did an excellent job

Thank you, sir! Now I am working on a new part cooling system... It's so freaking far over the top, I am trying to finalize the design now. It's so radically different that what is out there now for well... any other printer I am trying to get my prints perfect before I unleash it. But I pretty much have no problem with overhangs anymore, it can almost deal with a pure 90-degree angle.

I can't wait to see it. Let me know if you need a guinea pig.