Mini - MendelMAX - #30DoC days 11,12 & 13

I'm getting a little behind Blogging my 30 days of creativity ( #30DoC ) updates, but it has still been going on.

Believe it or not, I do work full time, so getting any time for RepRap is actually extremely tricky, and the daily updates have been getting later and later, so I'm going to blog a few days at a time until the end of the month if I can actually manage to stick it out that long!

One thing this has taught me is that I really enjoy writing up my ideas, developments and adventures with RepRap, but I prefer to do it after a good long session of work rather than every day...

That said, I do think it's pushing me to get around to starting all the many things I have had on my RepRap list for so long. I may not get them finished or even working, but a start is better than nothing, so I'll continue to blog ideas as I think of them and hopefully take a few of them all the way to complete solutions or working prototypes. I also think it may help as I have had so many comments, suggestions and people contacting me with similar ideas, that it's convinced me that a few smaller updates are better than one big one  when the project's finished - let me know what you think?

Mini - MendelMAX -


Recently I have had a need for a smaller machine, that's rock solid, and prints mainly smaller parts with a finer nozzle and 1.75mm filament, so I decided to build up the parts into a mini sized MendelMax (as I had initially planned many months ago, when I built up my first MAX)

Mini MendelMAX - small but great. - progress so far after 3 evenings building up.

It's not all wired up and without electronics or power at the moment.

I printed this set of parts last month, but didn't get around to deciding on a build for them, it's based on the MendelMAX V1.5 and some excellent derivatives I'll talk about below.

The lower vertex sections are the integrated design by Jib there is even a triple height version now!

The Awesome printed Y axis is by tommyc - LM8UU Y carriage for MendelMAX, and I love this design.

I disassembled my earlier frame made of green PLA-V1 MendelMAX parts and replaced them with shiny new Gold and black parts. All the black parts including the Y carriage and Quick-Fit X are made with RepRapsource ABS, all the other parts are printed with Faberdashery PLA.

I'm planning for this to print in both PLA and ABS, so I have made my own smaller heated bed with resistors and PCB Material.

I will be using the little quick-fit  'Huxley sized' extruder on this machine.

The new MendelMAX Y mentioner is really handy, as you can make your belt a little tighter just with a quick turn of the screw on the front.

The lower Motor mounts work very well, and just make the machine even easier to assemble.

For the Z Axis I decided to stick with theM6 threaded rods, they work so much better than M8, this machine will not be doing very high printing, but it will be doing very low layer heights, so M6 being 1mm pitch is a good choice.

The only thing I'm changing is by using an M6 studding connector instead of two M6 nuts, I think this should give me a little more stability, and a little more friction to deal with.

The only other mechanical change I made was to add some little PTFE end-caps to the threaded rod ends, this helps stop them wobbling around and reduces noise.

I also wanted a small printer robust enough to carry around to events and meetings, this should do the trick, it's going to be bomb-proof.

I'll let you know how the rest of the build goes, and also how well it prints.

Thanks for looking.

Rich.

123 Counting Fun for Kids - #30DoC Days 9&10

Day's 9 and 10 of my 30 days of creativity ( #30DoC ) involved my Kids, they are always such a massive source of ideas and creative opportunity. We have been doing numbers and basic maths recently with them, using the normal flash cards and coins. They are still not visualising numbers all that well so I decided to try and design a basic set of counters that could form games and number play before bedtime.

The visual numbers board is similar to the ones used in UK schools, but as it's 3D printed I can evolve it over time.

A simple Sketchup design gave me a board of 100 squares, a strip of 10 and a single counter.

The main board is 150mm x 150mm so fits on a Prusa Heated bed, I also used this model to test out the 'Brim' idea to stop warping, see below- 

The 'Brim' as proposed by Idolcrasher here  uses the normal outline that's used to prime the extruder, but given 0mm distance from the part and with more outlines makes a 'Brim' on the border of the thing being printed. the only down-side is that it does not hug the outline of the printed object especially if you print more than one thing at a time.

This was a very large single print, but I was impressed with how level and smooth the first two layers went down, this was quite a mesmerising print to watch, build up, I almost watched the entire thing for over an hour.

It's printing at 80mm/sec so it's really nice to see no gaps in the filament.

I switched to Neon Pink, during the last final layer before doing the numbers.

Very Pink! 

I was very pleased with the end result, and so were the kids. No warping at all thanks to the Brim?

The files are up on Thingiverse here, if you fancy printing a set or improving it.

Thanks for looking,

Cheers,

Rich.

Key Skins - #30DoC Day 7

The creative inspiration for Day 7 came out of necessity today, I had yet another Key given to me, and it was starting to get to the point of madness with all my key-rings and fobs. I decided to make it easy to recognise my keys at a glance and hopefully be able to remove some of my key-ring-trinkets.

Part of my 30 days of creativity ( #30DoC ) month -

I'm calling them Key Skins, and before you say, I know you can buy things a bit like this, but I wanted to make them *custom* and different coloured, also I wanted them to fit my keys and not take up too much extra space.

The first job was to simply scan my keys, import the image into Sketchup and trace around the outline of the key, much easier then measuring anything.

Then just extrude the outline and put a top on it. I made the internal dimension 2.6mm as most keys seem to be under 2.5mm thick.

Within 15 minutes I had the basic Key-Skin for the two most common shaped keys I have.

Quick Print, and they fit well.

Add some extra identification (H = House, G = Garage etc.)

The possibilities are endless! I'm sure you can think of more uses for Key Skins - Files are up on Thingiverse

Print them in Bright fluorescent colours if you always loose your keys!


Thanks for reading, more tomorrow.

Cheers,

Rich.

Half a Ball of Stars - Support structures #30DoC day 6

For Day 6 of  30 days of creativity ( #30DoC ) I'm having a rest from designing things, but I wanted to give my printer a challenging print while I worked.


A few weeks ago I did a quick test print of the Ball of Stars Created by @Dizingof
I used basic support structure and low-grade PLA just to test it out.

I have been meaning to print another one, much bigger and with full support structure. Today I set it off to print while I worked. It would have been a 17+ hour print, but 9 hours into it, at about half way it shifted on the Y axis, probably due to the head catching on the massive structure with the rather high acceleration settings I use on MendelMax.

Some of the support removed.

You can see that about 40% into the build the Y axis shifted, so when I came home I stopped the print.

Before removing support - This is what it looked like after 9 hours of printing (the half a ball of stars is inside there somewhere!)

This was my first test print a few weeks back, I didn't clean all the support structure off, and it had some unsupported areas, this was sliced with Skeinforge V46 using external support structure at >60 degrees overhang giving me some sections that sagged when they printed in free space.

For the new print today, I made it 150mm wide and enabled support everywhere, as you can see from the above Visual Gcode (Repetier Host) it was a real monster! Skeinforge had to slice for almost 2 hours to output the Gcode for it.

In hindsight a little too ambitious and I should have slowed down the travel moves and enabled Z Lift (Hop) I think it would have printed OK if I had done that.

Doing the same model in Slic3r with support enabled only gives a support column in the centre of the model, so I could not use Slic3r for this print unfortunately, a real shame as it slices in just 8 mins.

It is fun watching these things print.

And it used a fair bit of PLA.

Removal of the support structure is quite easy, but takes a little time.

It needs a little more support removed, but I'm quite happy with how it came out, and it would have looked really good as a complete model and not for the Y Axis Shift.

My proposed new settings for a future print attempt -

I have sliced it again and this time enabled Z lift (Hop) and used Exterior Only support with a 45 Degree minimum support angle, this should give me some support on almost everything, but not cover the entire model.
These are my support settings shown above, if anyone can give any advice to improve these, do get in touch or leave a comment, I hardly ever use support, so could do with any pointers you have.

It still looks like a lot of material, but compare the Gcode image below with the failed print above -

Fingers crossed, it should print well next time, and have a lot less support material to remove.

I'll give it another try soon and give an update.

Thanks for reading,

Cheers,

Rich.

Simplified multi-colour filament experiment - #30DoC day 3

I woke up today and had an idea for a simple way to join lots of tiny sections of plastic printing filament together, so I thought I would give it a try for Day 3 of  30 days of creativity ( #30DoC ).

Ever since my first filament joiner I have been thinking about easier ways to simplify the process. It's quite hard to join sections smaller than about 50mm manually and I always wanted a simple way to change with lots of colours every layer of an object, that would indeed look totally great!
Filament joiner here on Thingiverse if you fancy making one.

So my idea was to use PTFE tube (6mm outer and 3mm inner) to hold tiny cut sections of 3mm printing filament and pop the coiled tube in an oven to fuse the sections together, all sounds perfectly dandy and totally awesome? it should work? right?

Cutting sections of PLA and inserting into the tube was no problems at all.
I had a 1.2M coil of PTFE tube and lots of tiny sections of filament.

It coiled easily and fitted in the oven, heated up and the filament started to melt.

It has a little oozing at each end and I could see the sections were not fusing together as I had hoped.

Exactly the opposite was happening, they were moving apart from each other.

The PLA was getting nice and soft, unfortunately so was the PTFE tube. I removed it and tried to push a 2.5mm metal rod up the tube, this didn't work and I concluded the tube was just too long.

I cut the tube in half and popped it back in the oven, this time it worked a little and I had a section of joined filament out the other end. Then the PTFE tube cooled down and trapped my rod inside the tube stuck to the filament!

I had a few more attempts, but each time the sections that came out were not fused well enough together or the PTFE tube swelled and got jammed up.

I'm pretty sure that PTFE tube elongates as it heats up, and as my PLA sections were not constrained in the tube they also moved along the tube or generally decided to not want to fuse together and actually shrink in length while getting a little fatter in diameter.

So could blocking one end of the tube with a M3.5 bolt and then compressing the filament the other end as it heats up give a single filament? well worth a try at some point?

Or maybe the tube needs to be quickly cooled down so the contraction helps form the filament?

Or possibly the filament needs to be squashed down the tube while still hot and then allowed to cool. (I'm thinking that it will never come out again then)...

Or just maybe the hot tube and contents needs to be passed through a number of aligned sets of bearings squashing it and it's contents to allow fusion and also reducing the filament inside a little to give it a fighting chance to get the damn filament out of the tube again!

Thinking about it now as I type this, it's the same problem we get when the thermal insulator of a hot-end is above 60 degrees C, the PLA jambs up and refused to slide so it could just need to be mechanically stretched after fusing inside the tube while it's still all hot, the bearing die idea may actually work...

So it failed... but I still wanted to post the idea as someone out there may well be able to make it work.

It could have been great! If I get more time I'll try again, Ideas anyone?

Don't forget to take a look at all the other wonderful work for 30 days of creation, * be inspired *
#30DoC the story so far - Day 1 -    Day 2 -   Day 3 -

This is really going to bug me now...I was dreaming of printing a rainbow Giraffe for you all :(

You gotta fail a bit or you're not trying hard enough!

More tomorrow.

Cheers,

Rich

Herringbone Gear set for Huxley Extruders #30DoC Day 2

Day 2 of 30 days of creativity month brings an update for my eMaker Huxley printer, it's only ever had normal gears, and I have been using Herringbone gears on all my other extruder's.

The Huxley extruder uses a Nema14 motor and smaller gear spacing than a normal Wade/Greg Extruder.
It's also using an M6 hobbed bolt.

I have used the same great SCAD script from Triffid Hunter to make a drop-in replacement for Huxley sized extruder's.

I didn't have a lot of time to optimise the hole spacing perfectly, so it is a little tricky to fit, but well worth the effort. Take your time and get the motor aligned first, fix the motor tightly, then tighten the hobbed bolt onto the large gear, fit washers and bearing and slide both the large motor into the body and at the same time the smaller gear onto the motor shaft, tighten up the smaller gear to the motor shaft.

They print very well with a 0.5mm or smaller nozzle, use one outline and >30% infill.

All the files are up on Thingiverse here

Enjoy perfect printing with Huxley.

More tomorrow.

Rich.

#30DoC Badge & simple guide to manifold 3D design

I'm starting the 30 days of creativity month with a two colour #30DoC printed 3D badge designed in Sketchup and printed on a RepRap 3D printer.

If you are new to 3D printing, take a look at my Blog and on the RepRap Wiki pages.
If you want to explore the sorts of things you can print with a 3D printer, take a look at Thingiverse

Here is how it was designed and printed -

Open up Sketchup and import a picture you wish to trace or use for inspiration (File-import - Jpg)

Go to 'View' menu bar face-style and select X-ray, this will allow you to see the picture below any 3D objects you place over the image, you can trace around things or align parts to the image.

You can now draw circles and add text, push-pull the various sections to make the model.

With this badge it's going to be printed face down so the text and the X are pushed into the face, allowing for the second colour layer to be seen from the front.

We need to draw and add a simple safety pin clip holder on the back - we will insert the clip while printing!

Export 3D model, slice it and print it out, starting with yellow plastic.

After about 7 layers or while it's still doing the last of the text outlines, switch over to Black plastic.

Let it print the rest of the back and get ready to pause printing when it has done some of the clip.

After is has printed half of the clip when it has a channel, pause the printer while it's doing an infill and insert a  safety pin into the channel and tape it in place. Resume printing

The pin will be trapped and after it's cooled down you can wear your badge with pride, and it's bound to bring creative inspiration for the rest of the month.

The 3D file is up on Thingiverse here, along with the Sketchup model, go print one out!


A very simple guide to making models that are manifold (valid) for 3D printing -  
While I was making the badge in Sketchup I had some of the usual errors you get when joining sections of modelled parts together (the text onto the badge face), so as a guide and tutorial here are a few notes about how to make a simple 'manifold' object for 3D printing.

Background - 
Objects for 3D printing are usually .STL files, the information in a STL file describes the 'mesh' of the model using points and faces, basically made up of lots of triangles joined together describe the surface and contours of the model.

Typical model 'mesh'

Unlike a photo with a set maximum resolution, you can print a 3D model at any size you like, the triangles just get bigger, so you don't gain or loose detail and with most current fused filament 3D printers, if you enlarge a good model you will see more features being printed that were not possible with a smaller size due to the nature of the filament printing process.

This means that the model has a 'Quality' depending on number of triangles describing the surface, I will go further into model quality in another post shortly, but a basic example is shown below -

Top model uses many triangles and can be considered high resolution, middle is half the quality of the top and the bottom is a quarter of the quality / resolution.

Back to valid meshes - 
If the mesh is valid and said to be 'manifold' is will have a surface without any defects, these can be holes in the faces, triangles that intersect each other, faces that share the same plane and other odd things like triangles or objects inside other complete meshes that basically make the object invalid.

If a 3D mesh has a problem, it's usually called a 'non-manifold' model, these can be repaired using programs like Netfabb but when designing 3D objects to be printed it's best to try and find and fix problems in the source rather than attempt to repair them later.

Many 3D modelling programs will allow you to join (union) objects together, (the basic free Sketchup does not let you do that automatically) programs like Autocad123D should make a valid mesh out of the two objects, and all you may need to do is remove the part of the object that was not part of the union. But it's always good to be aware of potential issues with 3D.

Example with two cubes - 
Step 1

We start with two cubes both are components to make it easier to move them together and so they won;t interact unless you want them too.

Step 2

The two cubes have been pushed together, this has made a non-manifold mesh, the cube faces are intersecting each other, so this would not print as you woudl expect from the above image.

Step 3

If you delete the front face you can see the problem.

Step 4

To fix the problem we are going to draw lines around the cube on the surface of where they meet, the red section inside the box is now the problem, but as we have just isolated it, by drawing the lines around the meeting point we can now remove it.

Step 5

After deleting the red cube, you still have a face inside from the dark grey cube, you need to delete that next.

Step 6

 Now you have a hollow mesh of the two cubes, this is almost a valid object, you just need to replace the front face by drawing a line down one side and it's done.

All finished

You can get the sketchup file on the thingiverse page Here


Thanks for looking, and see you for more #30DoC tomorrow.

Rich.