Printing A Lathe - Files and Information

I received a request for the Mini Lathe plate files.  I've copied them to my Google Drive and have posted the info and links below.  In fact, I think I should list once again where I got the designs from in the first place.

The Mini Lathe I'm printing is on Thingiverse.  The title of the design is Mini printable lathe V2 + Chuck - OpenSCAD version by Daid, and the link to the Thingiverse page is here:  http://www.thingiverse.com/thing:12472

The 3-Jaw Chuck I'm printing is from Sublime, and it is hosted on GitHub here:  https://github.com/Intrinsically-Sublime/Longworth-chuck

I downloaded the assemble.scad.stl file from the lathe page on Thingiverse and the Three_jaw_chuck.stl file from GitHub, and imported the solid bodies into SketchUp (deleting the chuck that came with the lathe_assembly_.stl and replacing it with the 3-jaw chuck from GitHub), and this is how the full assembly looks in SketchUp:

Lathe Assembly from Daid with 3-Jaw Chuck From Sublime

I then divided the parts up into plates that fit into a 18cm x 13cm build area (for several not so great reasons this was my maximum build area at the time).  It took three plates to cover the parts for the 3-Jaw chuck, and five plates for the lathe itself.  I did include extra copies of several of the gears and smaller parts where there was open space (if the printer is going to run overnight or during work, might as well have it make replacement parts).

The five lathe .stl plate files look like this:

Lathe Print Plate 1 of 5

Lathe Print Plate 2 of 5

Lathe Print Plate 3 of 5

Lathe Print Plate 4 of 5

Lathe Print Plate 5 of 5

 
The SketchUp and .stl files can be downloaded here:  https://docs.google.com/folder/d/0BzlyGd7meNzeWmcyUVpOVENyUTA/edit

Two of the parts for the 3-jaw chuck did not print properly.  After looking at the .stl files in netfabb, it appears that there were some issues with some of the surfaces.  I am going back to reconstruct/fix those in SketchUp now.  Once I have those corrected, I will try to upload the plates I constructed to print the chuck as well.

After printing those last couple of parts it's on to assembly :)

D

Printing A Lathe - Only 2 . . . 1 . . . 0 Plates To Go!

At the time of the post last night I had completed 3 of the 5 mini lathe print plates, and the printer was working on a fourth.  This morning I was greeted with a print bed full of good parts:

Plate 3 of 5 for Mini Lathe Print

And a closeup:

Plate 3 of 5 for Mini Lathe Print, Detail

What's more, these parts popped off of the glass relatively easily.  To prep the glass for the previous plate (where the parts had adhered almost too well) I had applied the diluted PVA mixture to the glass and used a fan to dry it, and the glass had set overnight before I printed.  

For the parts shown above (and a few prints since then), I applied the diluted PVA mixture to the glass while it was sitting on the heated build plate and warming up to the target 85 C or so that I've been using.  Basically as soon as the coating dried I started printing.

For a few prints now that strategy has resulted in parts that stuck well during printing but that also popped off pretty easily.  I may have ironed out the last wrinkle in my method for using diluted PVA to get PLA to adhere.

So that left only plate 4 of 5 to print.  I took about 15 minutes this morning to get it started before I headed to work, confident that using diluted PVA on the heated glass was going to perform once more, and it did!  Here are the prints from the last plate:

Plate 4 of 5 for Mini Lathe Print

You can see in the picture that there are some issues with the holes in the large part in the lower right corner. It looked like the printer had tried to bridge across the holes and failed.  Going back and looking at the G-code viewer in Pronterface, that is in fact what happened.  

For some reason, Slic3r put a single layer over the top of the holes on that surface of the one large part, and I did not catch that until after I saw the completed print.  Not a big issue in this case, but another reminder to review the sliced models and compare them to the .stl's or the geometry of the model you are printing from.

Failed Bridge on Top Layer of Large Part

Except for two pieces that I need to reprint for the 3-jaw chuck, I now have everything printed out for the mini lathe.  Next step is to assemble the various vitamins (nuts, threaded rod, smooth rod, bearings, screws, etc.) and get down to assembly.  Still lots of work to do, but I decided to take a break from the lathe for tonight's overnight print and make something that I could put on my desk at work and show off (hopefully :) ).  Right now the printer is working on this spiral cup from MakeALot over on Thingiverse:  http://www.thingiverse.com/thing:6917

Spiral Cup from MakeALot via Thingiverse.com

So far so good on the first few layers, interested to see what greets me in the morning . . . 

D

Printing A Lathe - Only 3 Plates To Go

So, I did finally have success with the blue PLA.  I ended up using PVA glue (Elmer's Glue-All) diluted 1:8 in water on a piece of glass over a heated bed (see the previous post).  When I got up this morning plate 2 of 5 had completed printing, and seeing finished parts out of the blue PLA was very satisfying.

Plate 2 of 5 in the Mini Lathe Build

Completed Print of Plate 2 of 5

The parts were difficult to remove from the glass covered in PVA glue.  I ended up using a metal wedge I had with a razor edge (an old piece of lab equipment, I think for slicing thin layers of tissue) and was able to pry them off without a huge amount of effort.  It was not ideal though, and I think I would have had more success heating the bed and glass back up to 85 C or so before trying to pry the parts loose.  I will try that with the next print.

Here is a pic from a better camera (the image above was from my Galaxy Note) showing the blue parts from last night's print.  The blue PLA does look very cool (blue is my favorite color, so that helps).  The gold is also nice, but after a couple of months I was starting to get tired of it.  I have a spool of green still in the box that I haven't even opened yet.

Plate 2 of 5 of Mini Lathe Print in Blue PLA

Plate 4 of 5 is now printing (saving 3 of 5 for last I guess), and it also appears to be adhering well.  Here are a couple of shots of the first layer perimeters going down.

Plate 4 of 5 of Mini Lathe Print, Bottom Layer

Plate 4 of 5 of Mini Lathe Print, Bottom Layer Image 2

As you can see, I'm really squishing the first layer of plastic onto the glass plate.  The small flange that this forms around the bottom of the part does not seem like a big issue for these parts, so I'll take that small imperfection in order to be sure that nothing is going to come loose during the print.

I'm going to let the plate 4 print run overnight, and I have another piece of glass waiting to place on the printer tomorrow morning to start plate 3 of 5--the last plate to print--before I head to work.  It is so satisfying to be back where I can start a print and let it run without worrying about parts coming loose again. Really makes all the difference in the world in terms of output, since I can only spend a couple of hours at a time actually monitoring the printer.

One other note about using the PVA mixture--it did leave a milky white film and some white material on the bottom of the parts.  I first tried a little rubbing alcohol to see if I could wipe it off, then decided to try a small torch for some heat.  That worked like a charm, and I plan to record and post a video showing the torch making the white film disappear the next time I use this method.

Overall, the PVA seems to be an acceptable solution for getting the parts to stick well going forward.  Removal of the parts from the glass after printing is the only thing I'm not happy about for now, but I will try to re-warm the plate and see what happens.

As I type the current print has finished several layers and all seems well.  Time for some sleep while my MendelMax works on through the night . . .

D

I'm Back . . . I Think

Just a quick post to say that I'm seeing good results with a 1:8 PVA:Water mixture on top of heated glass with the infamous (if only in my own mind) blue PLA.  I'm confident enough in what I've seen on the first three layers to let the print go for the next four hours while I sleep, and hopefully I will wake up to the first complete parts I've seen come off the printer in somewhere around a month!

More tomorrow night . . .

D