Saturday, August 29, 2015

A new hot end

I decided to replace the hot end on my Folger printer with an E3D. The model I went for is the E3D lite6. The full E3D v6 allows you to go to hotter temperatures, and as I rarely print anything other than PLA, this isn't much of an issue. Besides, you can iteratively transform a lite into a v6 by replacing some of the parts. I bought mine from filastruder, and they delivered promptly, with the trademark pack of Gummi bears.

The E3D lite6 comes as a kit. Assembling it is fairly straightforward, and there's only a couple of things I found tricky. One was keeping the thermistor insulation in place as I tightened the mounting screw for it. A bad of glue might have helped. The second was getting the PTFE insert in solidly, as it tended to slip back a little as I pushed the collet on. The instructions recommend holding pulling the collet up with a fingernail as you push the PTFE in. A third hand would have helped to hold it all steady while I did this. As the instruction say, the screws for the fan are tight - very tight, in fact, and they didn't got all the way in. The fan is a little noisier than the original one, with a slight hum which could get annoying. I was a little nervous about the step of heating the nozzle to 245C then tightening it up with a wrench. It turned out to be easy and I didn't end up with the third degree burns I was expecting.

There are several good mounts for E3D on the Folger extruder, such as this one. I didn't have all the parts I needed for it, and decided to go for something simpler, by simply replacing the aluminium block which holds the hot end in the original extruder with a printed block that can hold the E3D. Although this sounds simple, I ended up going through many failed versions before I got something that worked.
Thingiverse link for the final version: http://www.thingiverse.com/thing:990300.

Part of the problem was that I initially mismeasured dimensions or misread them from the plans, so I had the mounting holes 1mm further apart than they should be, and the position of the E3D relative to the mounting holes also off by about 1mm in both the X and Y directions. What I also hadn't allowed for is that the front on the motors is not flat: there is a disc of diameter 22mm and thickness 2mm around the motor shaft. The E3D is only 9mm in front of the flat face of the motor, and the top of the E3D is 16mm in diameter. Put all this together, and you either need to make sure the E3D it below the disc on the motor or in front of it. Below doesn't work, as the mounting holes would then cut through the 16mm rim of the E3D, so you have to move it forward. And then the center of the E3D doesn't line up with where the filament comes out of the bottom of the extruder. This is probably all incomprehensible. Here's a screenshot from Blender which maybe clarifies some of the geometry:
The extruder positioning can be solved by moving it forward a tiny amount, which you can do by inserting a washer on each screw between it and the motor. The block is printed in two pieces which clip onto the motor. I mounted it with 30mm M3 screws. They are slightly too long, and the nearest other size I had was 20mm which is definitely too short, so I padded it out with more washers. Here are some pictures of the finished product:





In doing this, I got rid of a fan shroud and a light that I had attached to earlier. The fan is for cooling the object as it prints, and I might add this back if I need it. The light was useful in the early days when I wanted to look closely at what the printer was doing, but I've not made much use of it recently, so I left it off for now. Less weight on the X carriage is probably a good thing. I also changed the way the motor attached to the X carriage, so it is mounted using the bottom two screw holes in the back of the motor rather than the top two. This reclaims all of the extra Z space taken up by the E3D.

Is it an improvement? It's really too early to tell. All I've printed so far are a few test objects. The nozzle oozes slightly, though less than my old one. I've printed down to 0.05mm layers. On a thin wall cube, I don't see the slightly wavy patterns that I used to, though they didn't always show up before.

(Footnote: there is a second version of the mounting block at http://www.thingiverse.com/thing:1030184.)

21 comments:

msaeger said...

I ordered a lite6 and will probably be stealing your mount so thanks for posting it. Yours is much simpler than the others where you are mostly making a new extruder.

I also ordered a e3d hobgoblin gear not sure if it will fit or be an improvement but I was compelled to buy it.

Have you found a assembly video for the lite6?I have watched a couple for the v6 which should be pretty similar but they don't show inserting the liner and that sounds like it can be a problem if you don't do it right.

Moosteron said...

I used the instructions here: http://wiki.e3d-online.com/wiki/E3D-Lite6_Assembly. No video, but the instructions are quite clear.

The only suggestion I would make is to tighten the nozzle a bit. The instructions are slightly vague on this point and make it sound like you should not tighten it very much. I found this led to a bit of leakage on the top of the heatbreak, which was fixed when I tightened it more.

As you might see, I have a second version of the mount which I think gives a it more support than the first one. You might need to file out the holes for the M3 bolts a little.

msaeger said...

I got the lite6 today yay. I must be doing something wrong with either version of the mount the top of the cool block hits the bottom of the extruder so the screw holes on the mount and the motor don't line up.

msaeger said...

Looking at the pictures more my extruder looks slightly different than yours.

Moosteron said...

Mine was the opposite way round from the orientation in the Folger manual (nozzle on the left), and the hole position is asymmetrical between the back and front edges so you can't just turn it through 180 degrees. The second version of the block is a bit taller than the first one, and it has a small slot in it to allow for the disc on the front of the motor. It was a bit difficult fitting it on even so. If you are using that, you could try to the original version as it doesn't have the same issue and also has a lot more clearance between it and the bottom of the extruder. Also check how much the collet stick up - maybe that's what is interfering. Keep me posted!

msaeger said...

I printed out both versions and have the same issue with both. The mounting blocks fit it's just the top of the cool block hits. I am supposed to have the collet in there right? The e3d instructions show installing it in there. (it was already in there on mine)

msaeger said...

Here's pictures of what mine looks like.

https://goo.gl/photos/SJ2ZRxw7jUxgxLZm9

Moosteron said...

Of course, now I think about it the collet would be in the same position on either design as its set by where the screws on the motor are. Maybe we have different versions of the extruder mechanism? Is your collet pressed down into the top of the E3D? That's how I have mine (which might not strictly be correct). It is quite a close fit even so.

Moosteron said...

Looks like it doesn't need much of a change to get the clearance, which could be done by moving the screw holes up a little on the block. I'm not going to have any time to look at this for a few days, but I can send you the blender file if you like. IIRC I didn't put it on thingiverse as it needs some explanation.

msaeger said...
This comment has been removed by the author.
msaeger said...

I got the lite6 today yay. I must be doing something wrong with either version of the mount the top of the cool block hits the bottom of the extruder so the screw holes on the mount and the motor don't line up.

msaeger said...

Thanks I am going to try to import it the stl in sketch up and do it with that. Sketch up is about as advanced as I can handle :)

You did post the blender file on thingiverse by the way.

Thanks for your help I will post when I get it mounted.

msaeger said...

Here's what I came up with so far. It looks like everything is lined up so far hopefully I don't have some other issue now. It would really stink to have to reinstall the stock setup to print something after getting the new one all wired in there. By the way the hobb goblin gear I ordered will not work on this extruder without changing the idler or something. It's outside diameter is much smaller than the stock one.

https://goo.gl/photos/cdprRKwjgwvC1d2k9

Moosteron said...

Looks good - nice work.

msaeger said...

Here's another dumb question if you have a moment. I am configuring marlin. They say to set "#define TEMP_SENSOR_0 5"

In there now I have

#define TEMP_SENSOR_0 6
#define TEMP_SENSOR_1 0
#define TEMP_SENSOR_2 0
#define TEMP_SENSOR_BED 6

Am I supposed to add another line or change one of the lines in there now?

msaeger said...

I am thinking I should change #define TEMP_SENSOR_0 6 to #define TEMP_SENSOR_0 5 from looking on google but not 100% sure.

Moosteron said...

You can either replace the line that says
#define TEMP_SENSOR_0 6
with one that says
#define TEMP_SENSOR_0 5

Or you can add a line that says
#define TEMP_SENSOR_0 5
and comment out the original line by changing it to
// #define TEMP_SENSOR_0 6

I did the second, in case I wanted a reminder of how it was set originally.

msaeger said...

Thanks again for the confirmation. I am going to run auto tune now. That fan is way too loud! Toms review for the V6 said they replaced the 5 blade fan with a quieter 7 blade one well I got the 5 blade. I will be needing to print a new shroud so I can put my 40mm on back on there.

Moosteron said...

I did the same - the 30mm fan was annoying.

msaeger said...

Here's what I came up with so far. It looks like everything is lined up so far hopefully I don't have some other issue now. It would really stink to have to reinstall the stock setup to print something after getting the new one all wired in there. By the way the hobb goblin gear I ordered will not work on this extruder without changing the idler or something. It's outside diameter is much smaller than the stock one.

https://goo.gl/photos/cdprRKwjgwvC1d2k9

Moosteron said...

Looks nice. I added a comment to the Thingiverse pages warning people about using my blocks with the modified extruder.