Spring 3D Prints 2018

I haven’t done a “Prints Of The Month” post in a while, but that doesn’t mean I haven’t had a pile of stuff popping off the printer.  Here is a smattering of prints I completed in the last 2 months or so.


I needed extra retainer cases for some orthodontics equipment I have (bummer).  I could buy them, but where is the fun in that?  Fusion 360 has a half decent thread database, so I dug into it and made a screw together case.  I started with the default settings and couldn’t get the top to screw down all the way.  It turns out I was using a Class 3 thread.  Class 1 is the loosest, while Class 3 is high precision.

I eventually oiled the threads and worked the Class 3 one back and forth a number of times and it closes now.  The Class 1 set I printed worked itself into fully closing a lot faster.  If you are worried about your prints coming together, pay attention to the thread class.


Continuing with the gaudy yellow color, I added a magnifying light to my shop.  They sell screw on bases you can plug the light post into, but they charge 20 bucks each.  I can print as many as I want for less than a dollar a piece.


A co-worker builds guitars with a CNC mill, but occasionally needs chisels to help clean up segments.  I took his flunky grade D chisels and put a nice shine on them.  3D prints and a magnet means nobody gets stabbed by accident when transporting them back to the owner.

20180512_114215


I printed a small cable guide for my car a year ago.  It lasted a while, but fell off recently.  The tape failed to hold the printed part.  Time for an upgrade.  I increased the width by 50% and made it three times taller.  Before attaching the tape I scuffed up the back to help it grip well.  The PETG didn’t melt or deform in the summer heat, so I am sticking with that material.


Not my own invention, but rather a Thingiverse submission by user iamjonlawrence.  They are a set of printable radius gauges.  They have inside radius, outside radius, and a set of circles.  The hole of the circle has the radius marked on the gauge, the outside has twice the radius.  The metric versions have that fact labeled better.  They pack a lot of function in a few small prints.  They are available every 1/16″ up to 1″.  I might have to make a set that goes over 1″.

An example of how to use them is on the right.  A pair of calipers wouldn’t really tell you the proper radius, but this gauge has it pegged.


Last but not least, we have a beloved octopus stained glass in our kitchen window named Eddy.  He guards over the cooking and cleaning activities and always lends a limb.  He is too heavy to hang on a suction cup for more than a few weeks, so we always just sit him on the window edge.  He has fallen before, and that will not do.  I printed this basic profile to clip into the window frame and provide a little spot for Eddy to stay firmly in place.

Dovetail Transfer Jig

I have quite a few dovetails to cut in the upcoming months.  One part of the process I always felt very weak was in the transfer of markings from one piece to another.  Whether you do tails first or pints first, at some point you need to clamp the to parts together and do a transfer.

I have seen a few different variations on this idea, this is just my take.  Essentially the two boards need to be held at right angles, and up against a fence that references two sides of the boards as co-planar.  I don’t normally keep around extra big plywood because I don’t have the room to store it.  I found out lowe’s has 1/4 sheets of “lauan grade” plywood.  Not as good or as pretty as birch, but it looks stable enough for jigs, and was much cheaper.

I started by using pocket holes to join the base. together.  I relieved the edges up against the fence with a plane to make sure no dust would keep the aligned boards from interfacing with the fence.  A 90 degree cut of plywood made a fence/reference surface for the boards.  I made sure the base was good and square before nailing in the fence.  The fence only protrudes enough to act as a reliable alignment surface.

This might have been good enough, but I wanted additional assurance that it was square, and a little help lifting it up off the table.  These blocks do both as well as stiffen the jig.

DSC_1224


To demonstrate the use of this jig I have a (admittedly poorly cut) dovetail that needs transferring.  The jig sits on the bench top, or could be clamped down.  Adjust the two boards to be jointed until they are lined up.  When set, transfer the edges of the cut dovetail to the pin board as shown.  Because the jig hangs out over the edge, a really tall board could be dovetailed without issue.

This simple easy jig should be helpful in the months to come.  Hopefully I reference it soon with high praises.

Hurricane Season Start

Hurricane season hasn’t started yet, but we already have our first named storm of the year.  Happy hurricane season everyone!  As of writing this it is still subtropical (I guess for specific weather nerd reasons it isn’t called a tropical depression), but expected to become a tropical storm.  As a wise guide once stated, it is never too early to start thinking about getting yourself ready for the storm.

I went around and found a few minor issues that could be a big problem if a storm were to hit.  These are easy to do now when I have free time, but would be stressful to complete when a storm is coming.

First up on the list, my screened in porch is getting old and one of the vertical supports broke loose.  It doesn’t hold the roof up, there are 4×4 posts for that, but buffeting winds would do a lot more damage with this part flapping around.  A few right angle brackets and metal screws secured it in place.


Second, I have a set of areca palms that have gotten too close to the house.  I probably shouldn’t have planted them that close in the first place, and might cut them out completely when they start pushing out the fence.  For now, I like them, but need them to be away from the house.  Again, under normal storms they aren’t a problem, but heavy winds could whip those fronds around enough to do real damage to the corner of the roof.


Last but not least my poor fence had another post shear off.  Not sure why they all happen on just this one side, but they do.  The left picture shows a distinct bend.  As it turns out the most bent post is actually rock solid, just not straight.  The one closer to the camera has broken off at the ground.  I left the broken post in place and sank another one next to it.  Everything is much more solid.  Thats it for now.  Time to enjoy a margarita and hope we have quiet season.

Printer Upgrade Part 2

Last we left our printer saga, everything was quite broken, and I was waiting on parts.  The 625z bearings came in and I put the extruder motor back together.  When I could easily turn it by hand, I knew my extruder problems were solved.  Sure enough, I can extrude PETG at high speeds and no jams.  The hot end was not to blame.  I did develop a new problem though.

20180430_202617

That is the status of my end stops.  The printer thinks the inductive sensor is touching the bed even though it is nowhere close.  I had an occasional issue with the inductive sensor reading poorly.  That has become constant now, all my messing with the cables finished off my probe.  I can’t start a print without that probe.  I massaged the cable and found a spot that flipped the 1 to a 0.  Time to troubleshoot.

Ok, so the cable is pretty well shot.  I opened the jacket where the issues was, but couldn’t figure out the exact problem.  They used very thin wire, it could be a break within the jacket.  I just cut most of the cable and redid the wiring.  That got me back up and running.  I printed everything I needed for the upgrade plus spares in both PETG and PLA.


I double checked all the instructions to make sure I wasn’t missing anything and started with the tear down.  On the plus side I am really good at disassembling the whole hot end/extruder!  It looks so naked.

DSC_1210

I only ran into one small snag.  The part that holds the x-belt wasn’t accepting the belt on the right hand side.  I printed 3 different versions, and they all had the same issue.  I took that part off and worked around the groove with a hobby knife.  It eventually relented and let the belt seat fully.

After that, the extruder assembly was pretty straight forward.

The bed assembly was a breeze.  I like most of the changes they made to the cable management, and think this will be more robust.  How the rats nest gets handled in the controller box could be a little better though.  Maybe just a bigger box.

I went through the calibration wizard, did some nozzle height testing, then printed a smart looking benchy.  Dimensionally it is great, but course settings mean it isn’t cosmetically the best.

I am thrilled to be over the failures, and proud of myself for solving all the issues.  Given that is almost exactly the 1 year anniversary of getting this printer, I decided to share a few stats.

Printer Stats:

  • 380 successful prints (more than a few failures, especially these last 2 weeks)
  • 44.7 days spent printing (12% of its life)
  • 6.3km of filament

 

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.

DSC_1206

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.

DSC_1208

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.

DSC_1207

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.

DSC_1209

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.

20180411_124051

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

20180411_124203

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.

20180411_134954


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.

20180415_080844

20180416_112702

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.

Screen Shot 2018-04-05 at 7.03.43 PM.png

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.

Screen Shot 2018-04-05 at 7.09.30 PM.png

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.

DSC_1200

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

DSC_1202

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.

DSC_1203

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.

DSC_1204

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.

DSC_1192

DSC_1193