Saturday, May 16, 2015

Reprap 3D Printing Toolkit

I wanted to take a few minutes to compile a list of a few useful tools for RepRap 3D printing. I do this because I have been fortunate enough to learn a lot about the tools of the trade from people at school and various other sources, but others may not be that fortunate. I know that there are many other lists of this sort out there, but I will trust the magic of Google to take you to those posts if they are more relevant than mine.

Tools


Hairspray
A friend at school that is very experienced with 3D printing recommended Garnier Fructis Style Natural Hairspray. Strength of 4 or 5 works well. I haven't had too many issues with ABS not sticking when using this. Purple Elmer's Glue stick is also a popular bed treatment, but I have not tried that yet.

Giftcard
This is my trusty iTunes giftcard that I use to pry parts off of the build plate and scrape the plate clean. Any credit card will work, or you could spring for an epoxy spreader.

Screwdrivers
I use a small philips screwdriver to adjust my bed level and change filament. It is one of the few real tools I need unless I am doing serious modifications or repair.

Mini Needle Nose Pliers
I use these to clean off the nozzle just before a part prints. I basically use them to grab anything near something hot.

Acetone
This is a must for printing with ABS. ABS dissolves with acetone. I brush it on to polish parts (too lazy for vapor polishing) and use it to clean the nozzle and seperate fingers glued together. Note that some nail polish remover contains acetone, but I use a bottle from the paint department.

Super Glue (CA)
Plastic glues very well. Printing primarily in ABS, I find that cracks happen. Usually they can be repaired with at drop of CA. While I know from my RC airplane days that there are different thicknesses and even glue with an external hardener, those are more expensive. I use the cheapest stuff walmart sells and it works fine.

Kapton Tape
High temperature electrical tape. This stuff is pretty pricey, but you will likely need some for something. The small roll in the picture came with my Replikeo printer kit. 

Calipers
An all around must have for any aspiring engineer (in my opinion). I use it to calibrate extruder steps, measure parts when drawing them in CAD, verify printed part dimensions, and basically every other linear measurement less than 6 inches. These are fairly cheap ones from Harbor Freight. They work, but I doubt you will regret buying a decent pair from somewhere else.

Test Prints


Overhang Tests

Overhang Test print

Websites

  • RepRap Wiki - The official wiki of the RepRap Project
  • Thingiverse - Run by Makerbot. An archive of CAD models for 3D printing. If you want to make something, search here first to see if someone has already made it.
  • Youmagine - A thingiverse competitor that has sprung up. Some people don't use thingiverse for a variety of reasons. This is another good resource.
  • RichRap Blog - This is a blog that I have personally found useful. He has covered many useful topics over the years.
  • Projects From Tech - A nice blog of generally useful information
  • Google - If at first you don't succeed, Google the problem and find out why.

There are always more tools and test prints out there, but this post is long enough. If you know of any other must have items feel free to comment. I will be interested to see them.

-Matthew

Saturday, March 14, 2015

Replikeo Prusa i3 Rework Build - Part 4: Initial Prints and Modifications

This is Part 4 of my Replikeo Prusa i3 build account. This post will cover the initial modifications I made to the printer, how they effected print quality, issues I had with those modifications, and work for the future. It will also feature pictures of first prints and tests because I think those are obligatory when writing about a RepRap 3D printer. If you are interested in my other posts on this topic:

Printer Modifications

Board Mount
In my mind, the single most important upgrade I made to my printer was to mount it to a plywood board. This allows me move the printer easier without getting it out of alignment or level. It gave me a place to mount the PSU and several of the other upgrades I will discuss.


The board is 3/4" oak plywood, but any sort of plywood would likely work (just make sure it is flat). The board is 20.25" x 22.5" . I mounted it with 1/2" pipe mounting clamps from Home Depot as shown in the picture. I used 8 of them, and it is rock solid. The corners never get loose, and I don't worry about it shifting when I put it in my car or rotate it on my work table. On the bottom I used some no skid rubber feet also from Home Depot. It keeps the vibration down and makes it feel very steady.



Filament Spool Holder
This was actually the first modification I made to the printer. I quickly got tired of having to manually unwind printer filament. It is a combination of parts almost identical to THIS blog post.


This spool holder actually did work pretty well. It would probably work better if you used real 608 bearings. I eventually abandoned the OSFA spool holder and just hung it on the rod. That actually works better for me. Another note, the spool mount limits the z-height on the printer as the stepper hits the mount. It needs to be a little thinner. At some point I will get around to fixing it. It is also worth noting that without the z-axis support (next mod), this spool holder causes the z axis to bend over slightly. This causes the nozzle to raise off the build plate. This means when you put a heavier spool on the holder the nozzle gets pulled off the plate more. Not ideal. Overall I would recommend this setup, but if you have something better, go for it.

Z Axis Support
Downloadable HERE this modification supports the z axis so that it doesn't rock during the print. It bolts right on to the back of the z axis rod supports at top of the frame and screws into the plywood board. It requires 2 each of the printed parts and one 5/16" x 36" threaded rod cut in half. It works great. I highly recommend an upgrade like this.



PSU Mount
This is not so much about performance as it is convenience. I drew up a PSU mount in CAD for the PSU that comes with the Replikeo kit. A couple screws and some zipties and the PSU is firmly mounted to the plywood board. Now the printer is one unit that can be carried or put in a car without worry. Get the printed parts HERE.


Power Switch
I was going to wire up a fancy power switch on my printer, so I would not have to unplug it all the time. Then I realized I could just get a cheap surge protector and use that instead. I think I got a 2-pack for $6. Worth it in my mind.

X Axis Belt Tensioner
There are a couple of these drop in replacement x idlers that add tensioners. I liked THIS one the best. It went on with no problems. Now I can tweak the x axis tension however I want. This probably isn't a high priority upgrade, but it is something that I changed.


Z Axis Adjustable Endstop
THIS upgrade has been very helpful in tuning the printer. It allows me to change the endstop location with the turn of a screwdriver. It is a little flaky having the screw hit the limit switch arm. Someday I plan to put a larger pad on the end of the screw so that it hits more uniformly, but it works for now. I printed the tall version and snapped off the bits I didn't need with some wire cutters.



Print Cooling Fan
I use THIS cooling fan setup and it works great. I highly recommend that you shell out the extra $2 and get a centripetal fan. This fan setup blows more air than I need.It blows air right across the nozzle, so I had to wrap a little insulation around the extruder block to keep the temperature from fluctuating too much when the fan comes on. Possibly against common practice, I use it both on PLA and sometimes ABS depending on what I am printing and what other settings I am using. See the next mod as well.


Dual Fan Mount
THIS clips onto the Wade's extruder body that comes in the Replikeo kit where the fan would go and allows you to mount two fans. That means you can keep your current extruder cooling fan and also use a print cooling fan like above. If you are going to add a fan, it works great for me.



That is all of the modifications I have made to my Replikeo Prusa i3 printer thus far. To me, I would consider the first 5 "must have" improvements. They just improve the performance or convenience of the printer so much that they are definitely worth your consideration. If you have any other improvements you recommend, let us know in the comments. Now the obligatory first prints I promised.

First Prints

These are some of my first prints. The green is Hatchbox PLA. The white is the ABS that came with the kit. They are printed at various temperatures and layer heights using hairspray as the bed adhesive.
First ever prints. Learned the importance of bed prep right off the bat

Switched to the included ABS

Printed a few replacement parts

While I could post plenty more pictures I'd say this post is about long enough. If you want to see more, check out some of my other posts under the 3D printing tag to the right. If you have any questions or comments feel free to post below.

-Matthew



Tuesday, March 10, 2015

Fixing Autoscroll in GNU Octave for Windows

Introduction
A quick and dirty post documenting an Octave "fix" for a problem I was having. Running GNU Octave version 3.8.2-5 from MXE installer found HERE on a Windows 7 64 bit PC on 3/10/2015.

The Problem

The output of GNU Octave as installed above has a feature that while I am sure is useful to some, is quite irritating to me. Outputs that are too long to fit on the screen of the terminal are paginated. It will display the values that will fit on the screen and then wait for you to press "f" to see the next page worth's of data. See below. It displays "-- less -- (f)oward, (b)ack, (q)uit" at the end of each page.

While this may be great if you want to see every single value, if you are running long programs where the output is mostly for debugging purposes or similar, this can be irritating. I finally decided to figure out how to change this. Here it is.


A Solution

While I don't claim to understand exactly what is going on above, it is clear that the "pager" being used on my install is "less". I wanted to change it to "more".

1) Check what pager you are using - Type "PAGER()". My guess is it will probably be "less". 

2) View help file on PAGER() - Type "help PAGER". A couple useful websites: Documentation from a German university and Documentation on the Octave Wiki.

3) Change pager to "more" - Type "PAGER("more")

This should make the output look like the picture below. As you can see it scrolled through my entire output just fine. I will note that "PAGER()" now returns "more". Honestly, I don't really know what I changed under the hood, but it worked. Also note that it will reset when you reopen Octave.


That is all I have on this. If anyone has a more detailed explanation of how this works or other ways to fix this "problem" feel free to post in the comments.
-Matthew