Prusa or CoreXY for Diamond hotend?

Hi,
I'm in the process of rebuilding my Prusa i3 to run a Diamond hotend.
Following the "swinging extruder" design of my Delta, I want to keep the Bowden tubes as short as possible. The steppers would be mounted above the hotend on a horizontal 2020 extrusion and a third z-stepper would lift the assembly in sync with the hotend.

The rebuild is huge and the acrylic Prusa frame might not be worth it, so I thought to build a 2020-Prusa.
But I also consider " going all the way" and building/modding a CoreXY printer.

Can you recommend a CoreXY kit that has all the special parts and is adaptable to fit my extruder assembly?

I'm not going to recommend you actually purchase the Smartfriendz Smartrapcore ALU kit (primarily due to the state the kit arrived in my case with mismatched designs/parts and other people have had similar issues), but all of it's design is up on Onshape and could be easily copied and modified to fit your diamond hotend setup.

The design itself is very stable, and with a few modifications upgrading to 32-bit electronics and modifications to the rear pulleys, it works very well. It does have a belt driven Z-axis, but I've not had any issues out of mine and modifying the cantilever bed to be 180mm wide has stabalized my printbeds. I've been very happy with the 200x200 design that I've built 3 more based on the kit, and get very good results with the E3D V6 hotends and 0.15mm layer heights on a 0.4 nozzle. The ones I've modified to be a Titan E3D direct drive have been more accurate than the Wade Geared Bowden extruder I have on one of them.

Edited 1 time(s). Last edit at 02/04/2017 12:29PM by PDBeal.

Thanks PDBeal,
it seems the printed version has no real advantage against a Prusa? Same rods/linear bearings, but even longer belts for more ringing?!

The Alu version looks better, but I'm spoiled from my Deltas linear rails. Have you tried to convert your printers to rails instead of rollers?

All of mine are the ALU version, especially considering I can buy the ALU from Misumi for about $25-30 for the entire machine pre-cut and all I have to do is tap the center hole and drill a few holes.. With the Bowden setup on them, I don't see any ringing while printing at 60 mm/s. On the Titan extruder ones that are direct drive, have some ringing at 60 mm/s, but nothing at 50-45 mm/s.

DJDemonD did convert his to use linear rails, but for what I've seen on mine with the Duet controllers I don't see any ringing for what I do with the machines.

Edited 2 time(s). Last edit at 02/05/2017 11:40AM by PDBeal.

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o_lampe
I also consider " going all the way" and building/modding a CoreXY printer.

you seen the hypercube on the thingiverse, its a nice design and well documented I cannablised an mendel i2 +£60 am happy with it been a great introduction, to corexy. The x axis supposed to be10 mm tubing but I just used 8 mm bar there few option in the remix section. the orginal a little short on Z at 160mm but its easy enough to extend to get 200mm. and the creator provided some well documented build log.
vid of the extended in action forgive the quality! lowers head in shame

Edited 1 time(s). Last edit at 02/05/2017 01:15PM by jinx.

I am also considering putting a diamond head on a hypercube. With all the extruders just on the top back tslot.

The main issue is that this printer is largely built in place. It not meant to have the E3D mount removed form the x carriage. You have to disassemble it. (blower fan and fan ducts cover mounting screw heads.)
I will be looking at updating mine to use hex head bolts, held in place in the plastic. As you can get to the Nuts easily. This would solve it.

Other than that I think it would be a good option for a diamond head

The hypercube seems to have a better cube design than the smartrapcore and also the z-cantilever looks better.

I've also seen the G&C corexy and the D-Bot. The latter seems to be the easiest to convert to linear rails.

About the D-Bot: Would it be possible to rotate the gantry 90°, so the beam for the hotend would be shorter/lighter?

One thing I really didn't like about the D-Bot was it's use of plastic corners. If your going 2020, you really should have metal on metal for a corner.

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PDBeal
One thing I really didn't like about the D-Bot was it's use of plastic corners. If your going 2020, you really should have metal on metal for a corner.

Oh, I've thought they were only an add on and he was using the center hole connection method. That's what i'd do...
But at some closeups you can see a gap between the extrusions. Seems he is going the cheap way of hacksawing the extrusions without milling the ends afterwards.

I know the "tap the centre hole of extrusion and drill a clearance hole through the neighbouring piece" is a popular assembly technique, but I have reservations about it. I don't particularly trust aluminum with threads, it's very soft and easy to strip with modest torque compared to even mild steel. And then fixing two members with a single screw under-constrains the joint, leaving the possibility of rotation. There's the temptation of cranking on the screw to try and prevent that rotation and then stripping the thread. Or under-torquing it and have it work loose. Having spent the money on extrusion it seems wise to me to match it with decent corner brackets and steel T-nuts. The brackets engage with the slots to prevent rotation, and the steel nuts allow decent tightening torque.