Tuesday, September 1, 2020

Design tips

When using homemade 3D printer there are some restriction during the printing process, if your model got overhangs parts, there are few options:

1. We will print it with surport material, you will need to remove the unwanted surport material by cut or file it off.

2. Or you can break your model into parts, stick them together after printed.




Design for No-Support: 45 Degree Rule

The homemade 3D printer don’t have support plastics like the expensive 3D printing machines from Dimension, and while Skeinforge does have a “support gridding” option, at the moment you’re much better off altering your model so you don’t need it. Today we’ll discuss making shapes more print-friendly with a minimum of impact to the shape of the final object. The basic design rule is: no overhangs greater than 45 degrees. If you always obey this, odds are you will never have a problem with dangling plastic noodles.



This, however, is a rule that can be bent, and occasionally even broken, if you think ahead and in terms of 3D printing technology. One key: overhang is size dependent. A 2mm circular hole will print just fine with no tear dropping, but a 2 centimeter hole will start to get droopy loops:



Droop is also a function of how long the overhang goes on for. If an edge of a layer is resting almost on thin air, but the noodle marking this perimeter only dodges briefly out over the abyss, it’ll likely hold firm, whereas a long trek can cause the whole thing to sag in the finished print. You can even get away with short horizontal jogs out into nothingness if they’re brief, especially if they have someplace to go. Note the test part with a square(!) horizontal cavity here:



The truth is that both holes will probably be usable, although you’ll have to file off a bunch of ugly hanging plastic on the cavity to the left. Horizontal overhangs shorter than a centimeter will often hold up just fine!

PLA for makerbot MK7

I was thinking to try using PLA as I found that most people online said that it's better than ABS.
here is some setting I found online from some experience user. You can click here to view if you like.


Use 60C for the bed. This is from MBI, too, as is the 210C extruder temp

Monday, May 7, 2012

Owl statue

Owl statue printed, model are downloaded from Thingiverse.com.
Photo taken before any touch up.



Wednesday, April 4, 2012

Better support setting

When doing overhang printing, support material is very important. I found out a setting which is very good support setting for my TOM, so I just record it down for my own reference.





Interface infill density (ratio): 0.4 (0.3-0.7)’
Interface Layer Thickness over Layer Thickness: 1.2 ( also 0.7)
Support Cross Hatch: No.
Support Flow Rate over Operating Flow Rate (ratio): 0.7 (0.4-0.7)
Support Gap over Perimeter Extrusion Width (ratio): 0.005
Support Material Choice: Everywhere Support Minimum Angle (degrees): 35.0



you can go to the site to see the original post.

http://www.makerbot.com/blog/2011/06/27/makerbot-microtip-using-the-support-features-in-skeinforges-raft-tool/


Thursday, January 26, 2012

ABS glue

As my makerbot print area is kind of small so most of my model need to split into a few parts to fit the print size of the machine, therefore I'll need some glue to stick those parts together.

I found some tutorial teaching people how to make their own ABS cement. And it looks very easy to make one.

I find that kind of hard to buy Acetone in Singapore, I found that many people asking around where to buy Acetone in Singapore. I can't fine the Acetone like what you see in the image below, but you can buy a 80ml one in pharmacy like Guardian, please note that not all Guardian sell Acetone, you got to try your luck and ask around.

I tried to ask at some paint shop, some of them don't sell Acetone, some got but not sure whether it's the pure Acetone. Maybe you can try and share the result.



you can visit the site below for details:
http://www.protoparadigm.com/2011/12/abs-glue-weld-cast-texture-and-more/




Below are what I copied from the blog for my own records.



Looking for an easy way to permanently fuse printed parts? Want to smooth, texture or paint printed walls? Need a way to cast ABS at room temperature? All this and more awaits you with this handy concoction.
Here’s a handy concoction to have on hand when working with ABS regardless of whether or not you use a 3d printer. We’re calling it ABS Glue (thingiverse ‘thing‘), and it’s pretty awesome. So far we’ve used it to…
  • Fuse printed beams and assemblies
  • Fix broken parts
  • Smooth & Texture ABS surfaces
  • Cold Cast ABS in printed PLA Molds
  • and More! (spoiler: Glow-in-the-Dark ABS Rocks)

MAKE IT!

Warning! : This mixture is a basic ABS Cement and as such all the same precautions should be taken as when using store-bought ABS Cement, especially providing adequate ventilation during use. At no time should anything be dumped down the sink. Acetone and skin aren’t friends, try not to let them spend much time together. If this mixture gets on your hands, there is the possibility of absorption through your skin from the defatting caused by the Acetone. This isn’t finger paint.
From which you make ABS Glue
Gather Materials:
  • Nail Enamel/Polish Container (or other solvent resistant container, preferably with a brush set in the cap)
  • Acetone
  • ABS Filament of choice
  • Something with which to clip above filament
  • Rags are handy for messes
Assemble:
1. Empty and Clean Nail Polish Container
Acetone is the active ingredient in nail polish so a good rinse at full concentration should do an effective job of cleaning it out. Once clean, fill container approximately half full and seal the cap. (Acetone is highly volatile and will quickly evaporate away if the cap is left off for too long)
2. Fill container approximately half full with Acetone and seal.
Acetone is highly volatile and will quickly evaporate away if the cap is left off very long
3. Snip filament into pieces
4. Drop into Acetone until container is about 3/4 full
5. Swirl and wait
If your impatient like me you’ll go back and check it EVERY 5 MINUTES to see if it’s done…it won’t be. Light concentrations can be ready to use in under an hour, heavy mixtures can take as long as day to be fully suspended.
6. The mixture should be ready when it is relatively free from lumps and of the desired consistency. Add more Acetone or filament to get needed thickness (if you filled it only 3/4 full there should still be room).
“Say, how thick do I want this stuff anyways?”
Basic welding needs less filament, casting and painting does well with more, smoothing and texturing is anywhere in-between depending on the degree to which you wish to modify the surface. If your bottle is left open too long the Acetone will quickly evaporate leaving a pudding-skin like texture; simply add more Acetone and mix.
I keep a bottle of each filament that I commonly use so I am able to match it to the job. Natural is always a handy one to have around as it contains no added pigments.
Black - Natural - Neon Green - Glow

Wait; Glow? Yes, this process works with Glow in the Dark ABS (Don’t have any? We have half pound coils in both 3mm and 1.75mm).

FUSE AND WELD

We originally started using this to create beams longer than the build envelopes of our printers. Fusing separate pieces together is as simple as brushing some of the glue along the interface and gently pushing them together. Depending on the type of joint and the amount of glue used it can take a few minutes to fully set. Once set, the joint is often the strongest part of a print. This beam of Plastic T-Slot is made from 4 pieces and has a total length of over 400mm.

There it is, a clean good looking seem. Fusing multi-part prints and repairing broken pieces is now quick, easy and looks good. I love it.
Speaking of fusing. If you’re having trouble with prints sticking to the build platform, painting a bit of this on the bed before hand can go a long way towards keeping that part flat on the print surface, just be careful when you try to pry it off.

SHINE AND TEXTURE 

A use that definitely has potential and one we have had reasonable success with is using the brush to smooth, shine or texture a surface. A smooth glossy surface is difficult and would take a bit of experimenting with different concentrations and brush textures. Sanding before helps though is not necessary. On the beam below you can see how different amounts of ABS Glue produce a different effect. The top right side produced a very smooth surface using less than the face below it but more than the quick brushes done on the left, it all comes down to experimenting.

Placing wax paper or Polyimide Tape covered aluminum over the surface until it sets is another option to try. Want a bumpy surface or porous look, try pressing heavy grit sandpaper onto the surface. Scales; a mesh screen. Similar methods are used with Sugru. Here. However unlike Sugru, which cures, you have the opportunity to repeat the process as many times as you like.

COLD CAST ABS

The suspended ABS mixture can also be poured into casts to create, well, anything…To show this we printed the ProtoParadigm Logo set .5mm into a block of PLA.
The PLA isn’t affected by the Acetone and will evaporate away leaving the ABS Behind. Multiple applications will completely fill the mold with ABS. To create a smoother surface, I found it helps to pour a little straight Acetone or a light mixture of Acetone and filament on the top. I don’t think this would work where large amounts of ABS need to be deposited but for small things it works quite well.

MORE!

Paint Glow-in-the-Dark ABS on a mirror or glass and send a friendly message to your house-mates.
A Shining Example
Lower your life expectancy by bonding a glowing thermoplastic to your nail. (Please don’t though)
A Probably-Bad-Idea Idea

If you make some of this stuff and find it helpful or come up with other cool uses. Tell us about it. Or better yet, take a picture and send it to us at pics@protoparadigm.com.
Update: It has correctly been observed that MEK (also available at hardware stores) can be used instead of Acetone. MEK will provide a longer working time which may or may not be beneficial for your application. It is in general a more active solvent, better at dissolving ABS, but also a bit more nasty a chemical.

Safety switch red light on - Solution



You can refer back to Safety switch red light on

I've search through internet and found nobody have the same problem as mine, and I write to Makerbot support they can't gave any solution to this issue either.

But I manage to get this problem solved, guess what did I do? I just do a few tabs in the thermostat and this magical tabs just solve the problem.


Don't ask me how come it work in this wat like some ritual or black magic act. At least now I'm using it like normal and whenever the issue come again I just do a few tabs on the termostat.

Thursday, January 5, 2012

Safety switch red light on

The safety switch tripped only when the thermal core is over heat. My problem is the red light was on ever since I first turn on the TOM.


When the first time I encounter this issue, I found a solution here saying that tighten the thermostat connection will help and it solve the problem, but I when I turn the TOM on at the following day, the red light on again, and I couldn't solve it by tighten the thermostat connection.

I'm still looking for solution at the moment, and found out some other possibility cause of this issue.
I made a copy of the info for my own record:


EC output voltage fail (and safety cut-off) in the middle of print when ABP temp above 100/105 -- Power Supply (Cooler Master) Problem?


I have a problem with my prints failing due to the safety board tripping in the middle of a print.   The temp of the ABP is not really that hight as I have monitored it closely during prints.  The issue only occurs when I have the ABP temperature above 100/105 (e.g. 110, 115, 120).  The red light comes on, but the machine keeps trying to print (but no longer extruding due to temperature of the extruder being too low)
Measuring the input voltage from the extruder input into the safety volt is less than a volt after the failure (which leads me to think it is the power supply and not the safety cut-off relay).   Further, if I switch the system off, I am unable to switch it back on for about 10 minutes (indicating the power-supply is in 'safety' mode or whatever).   I  In the middle of a build the safety board trips and seems to kill power to the extruder. 
I think that the power-supply is tripping and  causing the safety shutoff to trip (because the temperature is no longer at the built-temperature...too low or due to input voltage dropping).  
Does this happen for anyone else?  Does the Cooler Master 460W just suck?  Or do I have more serious things going on? (EC board failure of some kind).  
Any ideas on how to diagnose this?   I will check the input voltage to the EC and post results.