Eustathios Spider V2.5 build project is a go!

Hi everyone! I’ve been lurking here for some time researching the Eustathios when I learned about it through my search for a printer to build. I knew I wanted to tackle a ground up build but also understood that I couldn’t do it alone. Voron was my initial pick since it appeared up to date and their documentation was really nice. But after looking into the Eustathios more and making some inquiries, I decided to run with Eustathios. I’m not saying one is better than the other but what caught my attention was the simple design and what appeared to be a very supportive group. I’m glad I did because Eric was extremely helpful going above and beyond. So shout out to Eric for getting me rolling!

Once Eric published the BOM for V2.5, I hit the ground running and ordered everything I needed. With 90% of the materials in my possession I began my build. I took some inspiration from Walter’s Eustathios and went with silver extrusion rather than black. This is the first time I ever handled aluminum extrusions so I was quite intrigued with what you could do with it.

I opted for the Misumi T slot nuts which have dimples on them so I didn’t want to tightened them up to much and risk putting a depression on the extrusions.

I got as far as loosely constructing the frame. Next steps are to square it up and tighten the bolts. I’m open to tips or suggestions on the best way to square it up if anyone has any!


For squaring up, ideally upside down on a granite surface is best. Short of that a good solid countertop that you’ve checked with a straight edge to make sure it doesn’t have a crown or a bow. Then make sure all of the extrusions are meeting flush at the outside edges. Then check each mating corner with a good quality square. Nice thing about using misumi extrusions is their cuts are really premium. So when you go to assemble it there tends to be a lot less likelihood of things being pulled out of square. My opinion is tighten the extrusion ends (via the through holes), then move to the corner 90deg brackets.

Before tightening everything up, check corner to corner along the top. Realistically that’s the part of the frame really needs to be dialed in. If the bottom was off slightly you could always shim the feet. But if the top is out of square you’ll end up fighting the rods not being parallel and planar with each other. And if the rods don’t ride parallel with each other you’ll find there can be racking and binding in the gantry.

Speaking of the gantry once you go to install that there’s a few tricks I can go over with you. Alignment of the gantry is probably the single hardest part for most new builders. I’ve had mine apart so many times that it’s second nature, but there are nuances to getting everything just right.

One of the tricks is aligning the two self-align bushings on each of the side carriages, and the central carriage. Normally when I do them I install the rod through the part and then press the self aligning bearings into the part at once. It helps with making sure that the two sides are in line with each other. Also if things feel sticky chuck the rod into a hand power drill and spin it slow while applying a gentle pressure to the printed part with the bushings installed. This will help the self aligning bearings find the equilibrium of where they want to settle in.

There’s a bunch of other things that I’ve made numerous posts about over the years in Google+ and various forums. I should have taken the time to write them all down for documentation… I would have probably saved time by now. But it’s fun to chat about them with new builders who are engaged in an active part of the community. So maybe that’s why I don’t put all my secrets down on paper, it forces people to come and ask the question so I get to feel like I’m a little part of their journey :slight_smile:

Congratulations on starting the build, and as always feel free to ask any questions, no matter how silly they might seem. Chances are I or someone else in the community here has run into it before.


Thanks for the suggestions Eric! Hopefully I can get it squared over the next few days.

The gantry does look challenging and I took a sneak peak at one of your videos just to see what I’m dealing with. But I’ll deal with that when the time comes. One thing at a time.

I’ll make use of the search feature as much as possible but I totally appreciate your responses and support. Documentation is no fun so I don’t blame you one bit for not getting it all on paper. I look at this as a learning opportunity so I don’t mind not having it all on paper.

More updates to come down the road!


One thing on the gantry that a lot of people tend to miss is the shim washer behind the side pulleys up against the side rod bearings. Without those the flange of the side pulley can tend to rub on that bearing creating resistance.

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How are things going on the build?

Hey guys!

So far so good. I ended up disassembling and reassembling the frame since I wasn’t confident on how square it was using the existing the tools I had. I ordered some machinist squares and rebuilt the frame. I feel a lot better about it now.

I started to work on the bed and z-axis next and part way through building the bed frame I ran into an issue with not having the right bolt on hand for the bed leveling corner blocks. Which reminds me that I think a couple corrections may be needed on the BOM, assembly PDF, and model. Unless I have the incorrect bed leveling corner blocks. The assembly PDF shows button socket cap style bolts which unfortunately does not fit since the head of the bolt is too large. I reviewed a photo of Walter’s printer and it appears that he used socket cap style heads which fit. So I put in an order with Trimcraft for the 5mmx14mm SCS and 5mmx25mm SCS. Also, a warning if you order from Banggood. The integrated thread screw motors I ordered from them shipped in a padded envelope with no box or additional padding! I hope they didn’t get bent on their way here. Fingers crossed.

I moved on to the gantry in the meantime and been reviewing all related posts and your video about it. I currently have the rod end bearing holders installed as well as the bushings on the side carriage and center carriage. They slide on the rods pretty well under there own weight. I started to assemble the cross rods into the side carriages but its a bit tight and hard to adjust so I may need to just work the rod into it a bit more to loosen them up. I’ll upload some pictures once I have the gantry up. I understand there some tweaking involved to get them lined up correctly so I’ll be sure to follow your guide on that!

I also got my bed plate from Midwest Steel and it came in really good shape. No issues with scratches and packaged pretty well.

Other than that I am still waiting on my order from Biqu for the controller and screen. It’s been a month so I need to reach out to them to see where my package is.

How much larger do you think the hole would need to be to allow the standard bolt for the leveling block? I printed those bearing blocks off of Walters original STL. Then in the latest SolidWorks model when I redrew everything I might have made it larger. If you need them reprinted I could do that as well. Though I’m out of your exact color.

I measured the BSC head and the diameter came out to be 9.3mm. The leveling block recessed hole is about 8.48mm. I suspected that the blocks I have may have been different from the model. It’s all good though and I’m fine with using the printed ones I have. Thank you for the offer Eric!

I do have question about the side carriages and the cross rods. Are the cross rods supposed to be easily pushed into the side carriages? I started to assemble the gantry and because of how tight the rods fit into the side carriages it is really difficult to adjust.

It is a tight fit by design. But if it’s too difficult to fit in, it could be chased with a 8mm drill bit.

I did chase them with a 5/16 bit I think which is 7.9375mm. I didn’t want them to be too loose, but if that 0.0625mm press fit is causing issues and you don’t have an 8mm bit, you could just take the 5/16" and give it a little bit of a wiggle to open it up.

Okay I’ll give that a try if I can’t get it adjusted perfectly. I haven’t been able to get the sweet spot once I connected the cross rods to the side carriages. The side carriages moved great on their own though.

I made some progress over the long weekend on my build. I got the bolts I needed to install the corner leveling blocks and have the frame installed onto the printer. Gantry is also installed with belts following Eric’s video for alignment. I can move all around with a finger. It’s not as smooth as when the parts were on their own but I imagine the break in will get it smoothed out. I’m still waiting on my controller so hopefully it arrives soon so I can run the break in and test my hotend. In the meantime, I need to get the bed plate drilled and countersunk for the mounting bolts and thermistor as well as a new thermistor to mount to the bed.


It’s looking really great, I am excited to see you when you get to put the first moves on it. The break-in G code from the Eustathios 2 repository should help things smooth out a bit. It’s a lot of stacked up tolerances that have to kind of equalize themselves out.

You probably noticed that it was pretty stiff without the belts on, but as soon as you install the belts and get everything squared up the gantry moves better. That’s because any amount of racking tends to side load the bushings causing them to stick a little bit. Luckily the bronze bushings do kind of wear in a little bit which will make the motion much smoother.

Thanks Eric. That was exactly my experience prior to putting the belts on. I tried hard to get things aligned as much as possible so that it was smooth off the bat but I couldn’t quite get it as smooth as when things where not all connected. Anyway, I still feel pretty about it and hoping the controller gets here soon.

Is the following post still relevant excluding the controller and PI? I’m mostly concerned about the power related wiring and using the correct size wires. Thanks for your help and the discussion on how to wire up an Eustathios

Yup. You would be good with those sizes for sure.

Hey all. Not much progress since I’m still waiting on my controller and screen. I’ve been going back and forth with Biqu on my order from them for the past two weeks trying to locate my order. According to tracking records, its been in Compton, CA since July 24th. Anyway Biqu sent me this the a few days ago:

Thank you for your understanding. The logistics provider said will reply within 1 week to 1 month. If the item is lost or cannot be delivered to your address, I will arrange for you to resend it as soon as possible

I know that COVID will impact deliveries but I’ve gotten everything else from China within a matter of a couple of weeks so I’m at a loss on what’s going on with my order from Biqu. Anyway, that is not really what I wanted to focus on for this post. I figure I take the time to start mapping out my wire runs since my electronics placement will differ from the design since I won’t have a bottom panel. It’s clear that the wires I received with my parts for the X stepper, Y stepper, Extruder stepper, hotend, and heated bed will be not be long enough and will either need to be extended and or a new harness made to length.

I am trying to decide which is better to put my money and effort into. The cables are all different sizes and if extending the wires, I would have to get all the different gauges to match what came and splice them. And since they all have different connectors to the boards I may have to replace those too.
I make new harnesses and consolidate cables to 2 or 3 different gauges . From reviewing other posts about wiring and determine the amount of amps that will be running through the cables, I am thinking 14 awg for PSU to board, SSR, and heatbed, 18 awg for hotend heater cartridge, and 24 awg for everything else (steppers, fans, etc…) should work.

So a few questions:

What have others done and their experience with their choices? What worked and what didn’t? Anything you would have done differently?

For anyone running the BTT SKR 1.4 board are all the connectors JST-XH type connectors?

For terminating the Molex Micro Fit connectors, what crimpers have worked well for you? I’ve seen a lot of positive things about the Molex 63811-1000 and the Engineering PA-09.

I’m making of list of things I’ll need to order so your input is greatly appreciated!

This post slipped by me.

Sorry, I should have just put amazon links in the BOM vs BTT directly. Sorry they have treated you so poorly.

For crimpers, I own many. But these ended up being my favorite. You have to crimp the wire, then the insulation separately with these. But I get way better crimps, and I can afford the extra time.

For cables I make all my wiring from scratch. I get good quality belden or carol multiconductor wires and make each to length. Either that or I get good quality silicone wire and makeup individual harnesses and put nylon braided sleeve over the top.

But I have the benefit of working at a place where I can get end cuts from some of our work automation projects so it basically doesn’t cost me anything. When I first started I did a lot of premade wire lengthening. That’ll work fine too, but I don’t necessarily like having all those splices everywhere. I’m kind of a wiring fanatic at this point.

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@Eclsnowman Those look conceptually similar to the PA-09 to me, but cheaper, available with quick shipping (vs. the two month slow boat from Japan for my PA-09s), and two extra sizes of crimps as well.

I have an IWISS ratchet crimper which crimps both wire and insulation, and at first didn’t like the PA-09, but now I pretty much only use the PA-09 and wouldn’t want to go back to the ratchet crimper. If I had known about that AWG28-20 I would have bought it instead. :slight_smile:

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Hey Eric it’s not your fault what Biqu is doing so no worries. It was much cheaper going directly to them vs Amazon so I took a chance that it would arrive when they estimated it would. I just wanted to share my experience in case anyone else was considering ordering through them.

Anyway, thank you for the response. I like a clean wire layout and install so I think I’ll be making my own harnesses and keep the splices you a minimum. I’ll also check out the crimper you linked to.


That’s the same experience I had with the ratchet crimpers… of which I own two. It’s faster in theory, but I found the time it takes to shorten wires if I have to cut off a 'miss crimp" is not worth the speed the ratchet crimpers provide. Plus since I’m only crimping one of the two tabs at a time I can get far more precise crimps especially if the crimper isn’t an exact fit for the wire end im using. Plus I found I can fit slightly oversized wires into a terminal end if needed because I have a lot more finesse with it. Overall that crimper I linked has become a favorite tool in my maker toolbox.


FYI, I just did an upgrade of my Eustathios V1.65 to the latest Marlin 2.0.7 and switched from my 4x LV8729 drivers to 5x TMC2209 drivers per my current Eustathios BOM. So I took that config, adjusted it for the Eustathios 2.5 and uploaded the marlin firmware.bin, the marlin VSCode folder, and the BBT TFT35 custom setup I use to the Github for the Eustathios V2.5. It should give you a good starting point for your firmware once your board arrives. I have a few things that differ since I have an older printer design, so please take time to double check my work getting it configured for the V2.5. But I hope you can find it helpful. If you find any required changes please let me know.

One thing to note is with my latest upgrade I implimented dual independent Z via 2x drivers so that the bed can auto-tram with a G34. This is implemented in the firmware I just uploaded. So if you plan to use it make sure to use independent drivers for each Z motor.