3D printers and Alphadrome Members

[Andyman]

Wow, that's a lot of waiting to find out if something was screwed up. You have the virtue of patience, John.

[robothut]

Yes it takes time to get things right, but I move on to the next part as the last one is printing so I do not do much waiting around. Here is a pile of the parts that either were not right or in most cases I had a better idea after seeing the printed part and made a change. 

[Andyman]

Is that pile biodegradable since you are using plant based plastic?

[robothut]

Yes. PLA in the USA is made from corn, in the rest of the world sugar cane is used most often. You can dump it in the ground and one day it will be dirt again. I do not know how long that would take but you can bet where ever we are we will not smell to good.

[robothut]

Here is a picture of a RAFT and the start of some support fill. The Raft is a layer of plastic that is put down so the support material will stick to the bed. In this case I am printing two Legs and I print them top up. Yes I could print them Top Down "on the build plate" and not need any raft or bottom supports, but if I print them Top Side up I get a cleaner top area where the servo will mount. The raft will just brake off as well as the support parts from the bottom of the leg part when its done. It does add some time and wasted plastic but some times its the best way to go. The other parts I position so that Raft material will not be needed and No supports most of the time. The arms have some supports and the Foot "large gear" has only 2 or 3 supports, the Battery Door has two small supports on the hinge lip and that's about it. The little round dimples are the start of the support "tree's" they will go up and contact the bottom of the Foot part. 3D printers love to to print UP and will print up to a 45 degree angle with out a problem but a over hang of more than that can cause print problems if you do not have some sort of support or postion the part so that the angle is not more that 45 degree's.

[robothut]

Here is the printed legs and a picture of the raft and support material removed. Print time is 4 hours, 53 minuets with current settings.

[robothut]

Just a word on the build pate in 3d printing. There is nothing more talked about on the web in the 3d printing "how to" topic than getting the first layer of extruded plastic to stick to the build pate "bed". If you have never worked with the extruded plastic you might think, well it's melted plastic it must be sticky and want to bond to the Build Plate. But thats not the case. The plastic does not want to bond to anything unless the other thing has a lower melting point , or is hotter that the plastic or has a Matt type mechanical finnish so the plastic can grip on to it. So you will see all sorts of crazy thing being done by the hobby print world, like using painters tape on the build plate as it gives a matt type mechanical surface and does work, or hair spray, or Glue stick, or well you get the idea. Basicly if that plastic coming out of the hot end can not grab hold or bond to something then it just gets draged along as the extruder moves and ends up a big pile of plastic on the hot end tip. The Flash Forge Dreamer comes with a lexan pad that sticks to the build plate, it has a egg shell "matt" type finnish and the hot plastic sticks to it very well. But some day that pad will need to be replaced so I decided to try out what the experts say to use. They say just cut a scrap piece of clear plexiglass to the build plate size. Then ruff it up with some sand paper and clamp it down. Thats it no messing around with glue sticks or hair spray or painter tape. My God it works great! Realy amazing. So if any of you get into 3d printing then give it a try. I want to try a glass plate that has been sand blasted for a egg shell finnish and see how that works also, but have not yet.

 

[robothut]

Here are pictures of the arm's for the Alpha-Rama robot with and with out support material. With the good build plate grip I found that no support was required and saved 30 minuets of each print build time.

Also on another note. Flash Forge builds a stripped down version of the Dreamer for DREMEL to sell, you can buy it Home Depot for example. It does not have the heated build plate and only 1 extruder and is sold for PLA printing  mostly. There should be a boat load of these "Dremel" ones for sale as defective or Used for dirt cheep as normal consumers will not be the right people to own a 3d printer. So you might pick one up locally for a good deal and just fix it up a bit. You can buy heated beds on line and you do not have to use the small reals of PLA plastic for $30 bucks a pop for your local Dremel dealer, you can buy the larger reels of PLA for $20bucks free shipping on line and just add a external reel holder like I did.

[Ranger]

John, your a genius!

[robothut]

Brian if you happen to read this maybe this thread should be in the Tips and Tricks section so it does not get lost before more you get in to 3d printing ?

Here is a tip for you if you want to repair or add more material to a 3d print you can use one of the cheep 
$18.00 or less" 3d printing pens off ebay. The cheep one I got for the grand kids to play with has a small screw that you adjust for different extruder temps so you can use it for PLA and ABS type plastics. here is a you tube I did on the subject.

https://www.youtube.com/watch?v=887U91UByIA&feature=youtu.be

Now here is a tip for a free program that lets you modify a STL 3d file.  Its called MeshMixer. down load the latest version as they keep improving it. I just used it to fix a problem with the arms for the Alpha-Roma robot. since I was using arms from a robot clock off ThingAverse "with permision to do so" they only had a small hole at the end of the arm that attaches to the body. I like to use round magnets to hold the arms on to the servos so I had been drilling out the small holes to large ones. But by using MeshMixer I was able to go in and change the Arm STL file so that there is now a large hole with a set depth for the magnet. The post above shows the small hole of the arms being 3d printed. here are images of the arms in red plastic that I drilled out and in Yellow plastic where you can see the improved meshMixer hole. OK the picture sucks but trust me the 3d printed hole is much better than the drilled out hole and will be the same part to part. Here is a link to MeshMixer.

http://www.meshmixer.com/

[Action Robot]

John,

I am happy to see you picking up 3d printing. I have been following the field since discovering it some years back, "before it was cool" ;). I was immediately thinking about making robots and robot parts. I am still waiting for the technology to hit the point where I can get a good machine without breaking the bank.

If anything, I think my efforts would best be spent in teaching myself the 3D software, and letting someone with better mechanical skills do the printing for me. Despite being clever with my hands, I am usually at a loss when a tool/appliance breaks down, and the system is set up so that repair is usually as expensive as replacement :(.

Keep your eye on the forum, as I will be sharing some info soon on an open source project that offers plans for machines to process, melt, and extrude plastic scrap. The machines are designed with readily available materials, and I'm sure they would be well within your skill set. I only just discovered the site, and haven't thoroughly researched it, but I did see them making filament for 3d printing from found plastic. Exciting stuff!

[robothut]

I decided to play with some ABS filiment. all the Alpha-Rama bots so far have been PLA plastic as well as the Hopping robots for Botstock and the Jaggernaut robots "legs and feet"  last year. So every thing I had heard about ABS is true, it does require a higher heat setting for the extruder and for the print bed "105C" if you do not want warped parts. The ABS does stink, both when printing and when done, they say its stop's stinking after a few days we will see.

ABS is less brittle "more flexable" and will take a higher temp to deform it so those are the plus's. Seem's to print fine but when you factor in the long time it takes to pre heat the print bed and extruder and the long time it takes for the part to cool enough for you to touch it with out getting burned and the stink its not worth using. ABS can be glued with solvent just like styrene plastic model kits so thats a plus for assembly and a minus for the rest of time when the part might come in contact with things it should not, like certain paints. PLA and PETG are both solivent resistent and FDA food safe materials. Now there are lots of other filiments out there like PETG. I want to try some PETG as it's supposed to be stronger than ABS, does not need the high print bed temp "does use a higher extruder temp" and does not stink so much. But the PETG does seem to cost about twice as much as PLA. So for now I think I will stay with PLA until there is a price shift.

Here is a picture of the ABS white robot.

[Ranger]

As usual, very interesting and the end result is a cracking good robot...great stuff John!

[Eagle]

John,,is it possible to print Clear ?   Jaimie [the giant robot builder] prints his own props..   https://www.youtube.com/watch?v=2qHsRTqDWIo&nohtml5=False

[robothut]

All the filiment they sell as clear prints out as a translucent white. Just look at the colors I did for Botstock 13 you will see the translucent white one that I call Frosty, that is what they sell as CLEAR 3d printing filiment. There are lots of manufactures so they might be one that prints more clear out there.