Printer Upgrade Part 1

While out on our euro-trip the MK2.5 upgrade for my beloved Prusa printer came in.  I had finally plowed through enough chores to get started on the upgrade when I realized you need to print everything first.  I ordered this 6 months ago and could have easily lined up all the replacement parts by now.  Oh well, shame on me for not reading ahead.  They did include a 1/2kg spool of PETG to print everything with, so lets get that started.


Now I know my bed is shot, thats why I wanted this upgrade.  It gives you a double sided spring steel printing bed.  Still, I couldn’t get the first layer of Prusa supplied PETG to stick to save my life.  This was my best attempt, and this was pretty bad.

I switched to some Push Plastic brand PETG that I had around and it initially looked golden.  Soon though I ran into issues.  There were z-layer striations in many of the prints like the nozzle was partially jamming.  I thought some of the odd and difficult to print features were to blame and broke up the prints into smaller batches.  These batches had problems too.  I spent 2 days printing with different settings, cleaning out the nozzle, replacing the nozzle, taking everything apart, switching to PLA, and doing about 10 other things.  All I did was get more frustrated and produce a pile of garbage.


I was incapable of producing small parts without error and big parts would completely jam before finishing.  These were the most horrible frustrating times I have ever had with a printer.  Even worse than my monoprice, and that is saying a lot!

I thought the hot end section was damaged, and on one of the tear downs to look for issues, I decided to give the extruder a rotate.  I had checked its pin out with a multimeter, and inspected the wires for frays, but a single rotation by hand gave me the clue I needed.  It was nearly impossible to turn.


Here is what the inside of a Prusa MK2 extruder motor looks like in case you ever wondered.  The bearing on the left is fine, the one on the right is frozen solid.  They are a smaller size than the 608 bearings I have around, and that most people use for projects.  I ordered some to repair this unit, and contacted Prusa about getting a whole new extruder.  If it isn’t too expensive I will eventually swap my repair job for a new unit.

The bearings will be in shortly, but I am dead in the water till then.  Once repaired I will, hopefully, be able to finish printing all the upgrade parts, then I can have a whole new extruder setup and print surface.  Until then, this is what my poor printer looks like.  Never a good site.  Nice use of my printed organizer tray.  It keeps screws and bits separated and organized when you take something apart.


Euro Trip!

The wonderful wife and I went on a little trip to England and France.  I have a number of complaints about France, but this isn’t a travel blog, its a craft blog!  One of the woodworking highlights was a visit to the Victoria and Albert museum.  They had a furniture exhibit that showed an exploded cabinet with all the traditional joinery.


They also had many different examples of marquetry and other types of highly decorative woodworking.  Stunning!


The whole building was a work of art even without any contents.  It is a piece of history too.  On the way out we walked past one of the sides and I slowly noticed something was wrong.  Instead of immaculate, the building wall was a little dreary.  It had a lot of chips and damage.  In fact that damaged looked kind of specific.  Like it was hit by something ballistic.  The realization came over me that this could be left over from the war.  At that point, we came upon this portion of the wall.


Further on in London we went to Kensington Palace.  It is where some of the royalty live, and has something about queen Victoria and princess Diana’s clothes or whatever.  On the plus side I got to be royalty for a few minutes!  Having had my fill of royal baby clothes I left my fearless partner to take her time and sped ahead to the cafe.

I was most of the way through when I had to go down a large stair case that caught my attention.  It was a 30×30 foot area that was at least 20 feet tall that was completely paneled with quarter sawn oak.  By the time I got to the bottom I became really interested in its construction and stopped to inspect up close.  After a minute the attendant asked me if I was ok.

I proceeded to give the guy a small talk on how frame and panel construction is done.  The picture above is how my wife found me!  The guy had worked there for years and never had anyone stop at the bottom of the stairs like that.  I explained to him how the large panels will grow and shrink with the seasons, but the relatively thin frames will keep the doors and structure stable.  Once I said that he noticed a sliver of color difference at the edges of the panels from seasonal movement.  He had been there for years, but was seeing all kinds of new details with a little knowledge.

I was lucky apparently, this wing was going to be closed off for renovation within the next week or two.  The staircase was from the 1600s and needed some help.  Lucky me!  A house full of royal artifacts, and I was apparently the only person to appreciate the fact that a million hours had been spent building this room.  It was a lot of oak.

Aside from England we had a decent river cruise on the Seine in France.  The boat we were on was pretty swanky.  They had a frame of gorgeous honeycomb at breakfast for your oatmeal.  That can’t have been cheap.  Makes me miss our bees.



Our tours took us through a number of old abbeys and churches.  Much of the stone work was marvelous, but once again, I have an eye for staircases.  This whole place had hundreds of pegged mortise and tenon joints.  Otherwise the only real woodwork of interest were some very old doors here and there.  I was too busy ogling to get any pictures.

I should start a tour company that just takes you places with really cool woodworking.  Wood Wonders of the World has a nice ring to it!


Printing With Supports, DC Fittings

I started off wanting to create more custom dust collection fittings.  This time for my router table.  I need something to go from the back of the fence to the dust hose, and take a tight 90 degree turn.  I quickly came up with a 3D design that smoothly transitioned between the two diameters.

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This isn’t a simple print.  Previously I used a PVC elbow to make the turn, but I wanted to work on my support skills. The shape starts large on the left, but gets smaller on the right.  That means very little is ever touching the print bed.  I knew this would require a lot of support material to work, but thought it would be a good challenge to fiddle with support settings so that bottom surface was as smooth as I could get it.

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The slicer software shows in green the support material.  I can only print one material at a time.  What it does is tries to make a very sparse little structure just below the main model surface.  The printed model will droop a little bit, but hit the support and not droop any further.  If you get it right, the bottom looks good, but is able to be broken away from the support.  That is the theory at least.  In practice, anything I have printed with support has looked horrible on the bottom.

I started with the default settings that were recommended for my printer.  Instead of printing the whole thing I only let it print the bottom bit just past the support.


It made it out alive, but looks rough.  The bottom layers are pretty loose and separated from each other.  Could I improve on this?


Not really as it turns out.  One trick is to reduce the print temperature.  If it is cooler it will solidify faster and not droop as much.  I also tried modifying that support surface to be more solid so it would offer smoother support.  On every one, the edge would peel up and get caught by the nozzle.  They all failed at roughly the same spot.  No big deal, go back to the settings I started with.


The left one was the original settings, and the right one had the support structure even closer than before.  All of them fail in the same way, that thin bit on the bottom right bends up and catches the nozzle.  Printing the support with no gap would make it hold well, but might make removal difficult.


Ok, the print didn’t fail, that thin bit was firmly stuck down, but the support structure is welded on there.  Time for a re-think.

I wanted elegant, but now I am going with simple.  Instead I printed a tube to connect to the hose, a tube to connect to the router, and a block with a swept section that connects the two.  5 minute epoxy is the universal force that binds us together.

This lets me print each segment in the ideal orientation and then put them together later thus maximizing the ability of the printer in each situation.  The final result works well.  So much for increasing my supported print skills.



Green Power Station

DSC_1186I have a poor solution to storing my yard tool batteries.  I never developed a clear place for them, so they ended up piled onto the cart that holds all my drill press junk.  That seems to be the story of my organizational life.  Either make a place for something, or expect it to be awkward and always in the way.

No more, I am going to clean this up a bit and make a specific place for these chargers.  Behind the drill press is a good location.  It is right next to the garage door and easily accessible when I am mowing.  I had a few ideas for mixed wood and printed brackets in my head and decided to use this as an opportunity to try something.

Angled braces are doable in wood, but can be a little tough to make symmetric.  This printed bracket ties the two pieces together well and should be able to support a massive amount of weight.  I don’t need it to in this case, but it was a good test.

They are green because I had some older green filament I wanted to use up.  Might as well go green on everything.  The wooden parts got a spritz of some well matching green I happened to have.

Once dry the brackets made installation pretty simple.  It holds the mounting plate at a consistent 45 degree angle and is pretty strong even with only one side installed.  I mounted the top charger so I could figure out impingement free placement for the lower charger.


The L piece the two chargers attach to has a notch in it so it will hang on a lip on the red toolbox below my drill press.  The drill press area is still a hot mess, but this ticks one problem off the list.