I hope I've been of some help!
Most of these types of issues are definitively resolved via functional prototype. Doesn't have to be fancy, cardboard from the recycling bin usually works great.
Full Metal Hot End (Let The Filament Flow)
I like my Ender 3, but of course it has been somewhat necessarily modified (notably a new controller board & magnetic textured print bed which should have been standard equipment IMO). Previously the filament feed motor was moved from the chassis to the X axis, making it more of a direct feed than a Teflon Bowden tube type. While this was in many ways an improvement due to reduced retraction and stringing, the remaining short length of Teflon tubing still went all the way to the print nozzle, and over time the tube would degrade with heat, necessitating replacement. It's kinda tricky to know when the tube is at fault, so you end up replacing any time prints start looking bedraggled. One can purchase full metal hot ends, but I was unaware until shopping on-line that one could also just replace the feeder tube with an all metal version at a much lower cost. I got this on Amazon for $12 USD and some change (https://www.amazon.com/dp/B0971FNCM4):
I installed it and did a print. Afterward I noticed that there was a lot of leakage at the top of the aluminum heat block, and the nozzle was at a funny angle. Turns out the block threads on the nozzle side were stripped, which is something that just happens when you have to periodically replace the Teflon tube. Looking around on Amazon, I found this brass version for $9 USD, which comes with a new rubber boot (https://www.amazon.com/dp/B0CLD54CYF):
I very carefully moved the thermocouple and heater element over to the new block, using Creality thermal grease for both. I also put some grease on the metal feeder tube. Afterward I heated it up to operating temperature (240C) and re-tightened everything. The PID adjustment was built-in to the software, so that was pretty quick and painless.
So, one more mod, and hopefully I'll never have to mess with the stupid Teflon tube again. Since the filament has much more contact with the hot end it may be able to print better with larger nozzles and higher flow rates (it's all about the flow).
Tour 2
I just finished another build, this one was unfortunately gestating for years due to my laziness and life in general. I think it turned out pretty nice:
Did a write-up on it here: https://d-lev.com/support/D-Lev_Tour2_Kit_Build_2026-05-23.pdf
Love that Dura Tex finish!
Eric, really nice build. I want to do similar one.
Will original D-Lev kit contents fit into this box?
Could you please share more details about antennas construction?
It looks impressive, and better than plumbing (etherwave-like) solution.
Are the RF connectors the following ones?
* SO-239 female x2
* PL-259 male plug
* PL-259 adapter / elbow
"Will original D-Lev kit contents fit into this box?" - Buggins
Yes, the original kit is inside there.
"Could you please share more details about antennas construction? It looks impressive, and better than plumbing (etherwave-like) solution."
The PDF write-up linked above has some details, including the connectors (your list is correct). I didn't take any pictures of the process other than those in the write-up. Either 3/8" milky white poly tubing or 3/8" gray PEX tubing (the short sections with the knob on the end that connect to faucets) should work.
I'm thinking of removing the ground banana jack and substituting a TOSLINK keystone. Powering the DAC internally introduces hum problems in some setups, which an external DAC fixes.
New Coils & Mounts
I wanted to get at least the pitch side out of the AM broadcast band, which would require a much larger coil than the current 1mH. The bottom of the band is 530kHz, and an 8mH inductor would resonate around 400kHz. Past experiments revealed the following:
1. Wire smaller diameter than 32 AWG hurts Q.
2. Wire smaller diameter than 32 AWG is significantly more difficult to wind.
3. The aspect ratio of the coil should be somewhere between 1 and 2.
4. Positioning the "hot" end of the coil closer than approx. 2/3 the coil diameter to the plate antenna hurts Q by acting like a shorted turn.
5. The capacitive divider should probably consist of a string of capacitors down the center of the coil where the electric field is essentially zero.
6. The coil in general should be reasonably kept away from anything metal, or even wood as it tends to be slightly conductive.
7. 3D printed coil forms can help guide the winding process by making the Z-step slightly larger than the wire OD.
8. Concentric items printed with the same Z-step can produce significant locking friction when fitted together.
9. The pitch coil should probably be the larger of the two coils.
Toward this end I've printed a bunch of candidate configurations, and have finally arrived at something that I'm fairly happy with. Both pitch and volume coil forms will be 70mm in diameter. Coil mounts on both ends will provide ~2/3 * 70mm = 45mm clearance on both ends. The mounts will have mounting holes for the AFE on one end and for possible attachment to a plate antenna on the other. The AFE will mount on the "cold" end of the coil mount. The width of the mounts should allow them to be slipped into the controls & tuner hole.
Above: the full thing rendered in OpenSCAD. This is the volume coil, the pitch coil will be somewhat taller.
Above: Old 1mH pitch coil on the left, new 4mH volume coil on the right.
Above: the old pitch box (left) and the new volume coil assembly (right).
Above: a view of the tube which will hold the capacitive divider string (left), and the AFE cover (right).
I'm printing the mount ends with 0.333mm Z-step. The 25mm overlap with the coil forms is printed with this same step in order to encourage interlocking. The winding section of the coil form is printed with a Z-step slightly larger than the wire diameter, and this is a simple thing to do in the slicer software. The coils and mounts will likely be secured via a couple of nylon M3 screws drilled and tapped through the OD of the overlap region.
TODO: Build AFE and make sure that end mounting on the coil form is OK (the magnetic field might interfere). Also check new AFE filtering (still working on that too).
4. Positioning the "hot" end of the coil closer than approx. 2/3 the coil diameter to the plate antenna hurts Q by acting like a shorted turn.
I feel like we’ve discussed this before.
To avoid a shorted turn, the shield needs a break—or better yet, a structure that prevents eddy currents from forming. Fractal patterns look pretty good for this. You could start with a ‘comb’ design, similar to the one used on the EW Pro board.
5. The capacitive divider should probably consist of a string of capacitors down the center of the coil where the electric field is essentially zero.
We also seem to have touched on the chain of capacitors located inside the coil—a short segment of thin wire, rising coaxially from the ‘cold’ end toward the ‘hot’ end, could act as the capacitor.
"To avoid a shorted turn, the shield needs a break—or better yet, a structure that prevents eddy currents from forming. Fractal patterns look pretty good for this. You could start with a ‘comb’ design, similar to the one used on the EW Pro board." - ILYA
Could you provide examples of such patterns? I've tried plates made of spiral turns, plates with a big hole and slot, nothing seems to significantly reduce the "shorted turn" effect, and all reduce the capacitive interaction to some degree. Since eddy currents are circular, I imagine a conductor of any significant area would support them? So I'm guessing the conductors on the plate antenna would need to be really thin, like less than 1mm wide? Probably easier just to sufficiently distance the solid plate.
"We also seem to have touched on the chain of capacitors located inside the coil—a short segment of thin wire, rising coaxially from the ‘cold’ end toward the ‘hot’ end, could act as the capacitor."
True, but it can be a very controlled amount of distributed capacitance yielding a distributed voltage and distributed 90 degree phase by using the real deal components in series.
You must be logged in to post a reply. Please log in or register for a new account.
