Best hydraulic couplings according to redditors

Below is a copy paste of a comment I made the other day on the cause of this problem.


the shaft of the z motor is 3mm and the threaded rod is 4mm the coupler they use is 4mm on both sides so the z motor shaft is pushed to the side inside the coupler so the center axis of the motor is off .5mm from the center axis of the threaded rod. Imagine putting a drill bit in a drill off-center of the chuck, the bit would wobble around in a circle. The is what the threaded rod does and pushes on the gantry every revolution. You should have horizontal stripes in the sides of your prints that coincide with the threads of the threaded rod. Since this is my first printer, I thought those were layer lines. upon closer inspection I realized the layers are much thinner and they were shifting back and fourth. I replace the coupler with one of these and it fixed the issue. https://www.amazon.com/gp/product/B018VE5YAW What you need to look for in a coupler is that it is 3mm on one side and 4mm on the other. Now that I have fixed that , I can now see the vertical lines in my prints that were masked by the horizontal lines. It is probably due to the smooth side of the y belt running on the plastic toothed pulleys.

3x4mm coupler https://www.amazon.com/dp/B018VE5YAW/ref=cm_sw_r_cp_apa_i_JdakDb3YWS9Z6


Note to self, get Amazon affiliate link.

2pcs 3x4mm CNC Motor Jaw Shaft Coupler 3mm To 4mm Flexible Coupling OD 19x25mm (3x4mm) https://www.amazon.com/dp/B018VE5YAW/ref=cm_sw_r_cp_api_i_53-RCbJ1NFFRV

Takes out z-wobble.

I haven't heard of a T3, who makes it? One of the best diffusers I've seen is the Xtava Black Orchid for $15. I got a cheap pipe coupler here to adapt it to a Devacurl dryer.

This is what I ended up using and seems to be working well:
2pcs 3x4mm CNC Motor Jaw Shaft Coupler 3mm To 4mm Flexible Coupling OD 19x25mm https://www.amazon.com/dp/B018VE5YAW/ref=cm_sw_r_cp_apa_m4N2AbMH6HZM7

Printed couplings are prone to slipping which means the Z axis doesn't rise(or lower) the correct amount. You're better off buying a real coupling for a few dollars.

Found these couplers on Amazon. Two for $4. Need to test but sofar it looks good.

https://www.amazon.com/gp/product/B018VE5YAW/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1

Edit: This is a better solution than the 3dprint couplers available on thingsverse that I've tried. The reason is that the printed couplers clamp on the stepper motor shaft transferring the entire load of the X axis assembly to the bottom stepper motor bearing. This new coupler, like the Malyan original, retains the two nylon washers and transfers the load to the top bearing surface which is fixed to the motor case and printer chassis.

The support page for the Mini has all the links to mods. To get nice prints, I had to:

1. Fix the z-banding with a printed coupler . This made the biggest difference. You can also order an adapter , but I don’t know the quality.
   
2. Get stable temps by adjusting your PIDs. I can just give you mine if you’re interested.
   
3. Cool the main board to stop the extruder motor from conking out. The part is also on Thingiverse .
   
   You may not have to do all these things, but my printer was a train wreck.
   
   I also put in an E3D v6 hot end for $15 off Amazon and designed a double fan to cool it. You may not need that, but the extra cooling certainly helps with small parts.
   
   I’ll upload some pics of print quality later. I have to head to work now.

You show nothing for scale, but I think it is a Hydraulic quick disconnect cap

http://www.amazonsupply.com/dixon-31-200dc-hydraulic-quick-connect-coupling/dp/B00835VYIQ

I had the same problem. This fixed mine.

2pcs 3x4mm CNC Motor Jaw Shaft Coupler 3mm To 4mm Flexible Coupling OD 19x25mm (3x4mm) https://www.amazon.com/dp/B018VE5YAW/ref=cm_sw_r_cp_api_i_x2IPDb932DYNE

I've tried everything to get rid of this ridge pattern, every 4.3mm or so. It happens along the X-axis (both sides) of a lithophane box, but not the Y-axis. I tried both .1325 and .175mm height. The litho is 115x115mm. The belts appear tight. I replaced the base coupling with this flexible coupling: https://www.amazon.com/dp/B018VE5YAW/ref=cm_sw_r_cp_apa_i_w5j2CbQ95ZEE4. I replaced the heat break and nozzle. The hot end temperature looks stable at 200C, and same for bed temperature at 65C. The extruder is stock, but I dont see how it would create a cyclical pattern on one axis only. The repetitive pattern suggests a mechanical problem. Also, it appears the grooves are facing one direction in that what is a groove on one side of the wall is a protrusion on the other.

I have a second MPSM, where the lithophane prints without ridges with the same Cura profile.

I have no idea what is happening. Help.

Thanks for the reply.

So, just to get this straight, I should get a trap, male trap adapter, and no-hub coupling (only including links as examples, i'll go to the hardware store to get the pieces). Then I saw off the wall side and attach the whole thing.

May be a dumb question, but I assume there is no water pressure on the wall side of the pipe? meaning I can saw it off without getting the room flooded?