Belt Tensioner X Axis Anet A6

The original belt tensioner by vernierroger is a very clever idea/design. However, I had some trouble fitting the internal components into my A6 X carriage. Also, I was confused as to what hardware (nuts and bolts) I was supposed to use to make it all work. So, I re-worked it using vernierroger parts as the starting point. I made a little more space for everything and changed the design so you could use spare nuts and bolts that came with the A6 printer to assemble it (instead of having to go to the hardware store and buy something).

In detail:

• The"edited frame" remains the same.
• I modified thetendeur/stretcher slightly (I call it"pulley block") to accommodate the nuts and bolts I wanted to use. For the pulley axle, I used a spare M3x30 flat head bolt (cut to approximately 15 mm of thread) and M3 nut. For the tension bolt, I used another M3x30 flat head bolt with a nut jammed up against the head. I pushed the tension bolt down into the slot on the pulley holder. (It's a tight fit, but it needs to be so it does not rotate.) I made the pulley block slightly less tall as well, so it does not bind against the top and bottom plates. Once printed, I filed the sides of the pulley holder just a bit, so it slides smoothly.
• I modified the"knob", so you can put a hidden M3 nut inside of it. Start the print and figure out then it's going to be about 80 percent complete. That's when you'll put the nut inside. When it starts making the hex-shaped space for the nut, get ready. Wait until the space for the nut is about 2mm deep (about the thickness of a nut) and then pause the print. As the print head moves away, put an M3 nut into the cavity and then restart the print. The print head will come back and print the remainder of the knob around the nut.

I made a video but unfortunately, it's not very good quality. Hopefully, it will still help to demonstrate this explanation. https://youtu.be/07crnQ8DOuU

Since the nozzle oozes some filament while you pause, you may get a small defect in your print. To minimize this, I give the filament a little shove into the print head when it's on its way back. It also helps to slow down the feed rate on the printer when you do this process, so you don't miss the opportunity to place the nut. To do that on an A6, turn the controller knob CCW while it's displaying the main information screen.

• I created a new part called"Middle Plate". It's a replacement for the acrylic plate that holds the original idle pulley. I made it thinner, so there is more space for the pulley block to be installed in the carriage.

In addition to the printed parts you will need:

2x M3x30 flat head bolts (Anet A6 spare) 2x M3 nut (Anet A6 spare) (You will gain 3x nuts and 1x bolt from the parts you take out.)

Print Settings

Printer:

Anet A6

Rafts:

Yes

Supports:

No

Resolution:

0.15 mm layers

Infill:

35% ish

Post-Printing

Assembly Instructions:

1. Take a few photos of the printer and the area where the tensioning assembly will go, so you have something to refer to if you're unsure how to put it back together.

2. Disconnect and remove the X belt from the printer.

3. Remove the two horizontal rods that the printhead assembly slides on.

4. The printhead assembly will be "free" now. Sit it down on the build plate.

5. You'll need to disable the right side pulley "box" that the rods and belt (you just removed, above) were attached to. I was able to do it in place (while still connected to the right-side Z rods), but you may find it easier to remove the right-side Z rods, so that box assembly comes free of the printer.

6. Take the "box" apart, removing the inner wall.

7. From the inner wall (you just removed), take the pulley off, and install it into the new printed part called "Pulley Block". A few important points here.

• You need to make sure the pulley spins freely in the pulley block (so the belt will move smoothly). You might need to scrape a bit of plastic off the inside of the pulley block to accomplish this. Also, scrape-out any loose filament from bridging at the far inside end of the print. A small flat head screwdriver works well for this.
• It can be hard to get the belt looped around the pulley once the pulley is installed deep into the pulley block. Try having the belt already looped around the pulley, as you push the pulley into the pulley block.
• If you haven't cleaned up filament stringing, etc from the pulley block yet, now is the time to do it. You want the pulley block smooth on the sides so it moves freely and will not hang-up on anything.
• The bolt/screw you use for pulley axle needs to be just long enough, and not much longer. Otherwise, it may hang up on the Z rod in the assembly as the pulley block moves. You'll have to cut it to length. I put some blue Loctite on the nut, so it would not loosen over time. This may not be completely necessary, but I did it out of caution.

1. If you have not already done so, install the tensioning bolt/nut into the end of the pulley block (see thing photo). It's a tight fit on purpose.

2. Start to re-assemble the box. Replace the inner wall (that the pulley was attached to) with the printed part called "Middle Plate". It's the same shape as the part you removed, just a little thinner. DO NOT install the side walls yet. Just assemble the middle wall with the top and bottom walls. Don't tighten it tightly, just get it together.

3. Install the printed part "Edited Frame" to the right side of the box assembly. This is the same shape and replaces the original part you removed. (Tip: Make sure the X rods fit into the holes in the "Edited Frame. On my printer, they fit, but it was tight. Check now, or you may have to deal with it at a later step. Don't install. Just verify the fit.)

4. Put the pulley block into place inside the box assembly. Feed the tensioning bolt through the hole in the "Edited Frame" wall you just installed. Thread the printed tensioning "Knob" on loosely, just to keep it in place.

5. Install the left side wall into the box assembly. You'll need to feed the belt through the cut-out as you do so.

6. Start tightening up the screws holding it all together. Once done, test out the pulley block and knob, making sure you can change the tension and that the block moves smoothly.

7. Reverse steps 2-4, re-installing the box assembly onto the printer. You'll need to get the X rods horizontal enough that you can go back through the bed leveling process. (i.e. Be careful doing your first Auto Home, so you don't crash the print head into the build plate.

Category: 3D Printer Parts