# lost pla casting



## aonemarine (Jun 30, 2013)

Well I decided to try my hand at the lost pla casting. PLA is a plastic that is used for printing on 3d printers. Imagine designing something in your cad program, printing it, then investment casting it into a metal part 
This run didnt come out that well but I did learn a few new tricks, and I know the next run will come out 100 times better.
[ame]http://www.youtube.com/watch?v=GgZvtrNI7iM[/ame]


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## Putt-Rite (Jul 1, 2013)

Now that looks interesting.


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## Lakc (Jul 1, 2013)

Did you bake out the PLA like lost wax or displace it like lost foam?


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## aonemarine (Jul 1, 2013)

Lakc said:


> Did you bake out the PLA like lost wax or displace it like lost foam?


 
It was baked out in the kiln all day up to 730C, I needed to burn it out for a few more hours there was still some stuff in the molds that left inclusions in the castings.  This was a good learning experience.


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## aonemarine (Jul 1, 2013)

heres a pic of the iron part, the surface finish isnt that great but im certain that if the right investment is used it will come out much much better...


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## LSEW (Jul 1, 2013)

aone, very interesting. 

Thinking about it, why not print a mold of the part and pour in wax, then make your investment mold from the wax?

Also, what kind of plaster did you use? I have been interested in investment casting with bronze for a while now, but haven't jumped in yet.

Just did a bronze/petrobond pour today.

maury
www.lonestarengineworks.com


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## aonemarine (Jul 1, 2013)

Maury, thats in the works as well. The one part is a mold (printed in abs) for wax injection. I need to get a few things worked out but I feel there is real potential here. The investment was Americast from Ranson and Randolph. I plan on ordering some Kerr Platinite for the next iron cast. Here is a couple pics of the printed wax molds and the casting. Not 100% yet but the next pour will be better.


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## aonemarine (Jul 1, 2013)

On a side note, abs printed core boxes could save alot of time for sand cast items


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## jwcnc1911 (Jul 1, 2013)

aonemarine,

man you have almost convinced me to take up casting.  if i could squeeze 30 more seconds in a day i would make time to do it.  It looks like your retaining wall really helps with your work.  would you recommend having a stone table or something to replace the retaining wall.  sort of a casting work bench?

excluding the 3d printing and mould making, from the moment you decided to make the pour, how long did it take?  i mean the actual pour.  from getting your already made moulds together, putting on your gear, so on so on.  is one pour basically a day project or can you knock it out in a few hours?


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## Herbiev (Jul 1, 2013)

Great effort. As they say " practice makes perfect" and it looks like you're well on the way


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## aonemarine (Jul 1, 2013)

JW,  the total length of the casting session was 45 minutes. That's from first lighting, melting aluminum, then switching crucibles and melting iron.  The investment process was maybe an hours worth of work. That involved spreuing up the parts, mixing the investment, vaccuming the investment, and pouring the investment.  Once the investment is poured you let it sit from a few hours th a couple days, then start the burn out.
My kiln is fitted with a digital temp controller so its a matter of program it and let it go.
 Now if I'm sand casting, depending on the part to be molded, I can ram up a mold in 15 minutes or less and poured in less than an hour.
 I got dreeves hooked on casting, it only took him one casting session to get the bug and start building himself a furnace. And melting aluminum can be done in a metal cylinder in a good campfire. You can make your own green sand from some cheap fine sand and ground up kitty litter.
 So what's stopping you??


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## jwcnc1911 (Jul 1, 2013)

aonemarine said:


> So what's stopping you??



Fear of the unkown man!  Just kidding... I still lack knowledge to get started and I think good wife might kill me if I take on one more project that requires time.

I see you wearing PPE and you have all of these nice tongs you're lifting crucibles with and I'm sure many other goodies I'm not aware of.

Programmed temp control... did you do this with a purchased unit or did you do something like an arduino setup?

I've been studying... I figure I'll make the plunge in the Fall and into Winter.


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## moya034 (Jul 1, 2013)

The only way to really learn casting is to start making mistakes and figuring out how to correct them.


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## Lakc (Jul 1, 2013)

moya034 said:


> The only way to really learn casting is to start making mistakes and figuring out how to correct them.



Thats true about everything. With casting, you have to keep your mistakes in the sand, and not make harmful ones, or ones injurious to life or limb.


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## aonemarine (Jul 1, 2013)

PPE is important, casting in flip flops bad. 

 Gloves and face sheld are a must and thats all I used until I started casting bronze then  iron, thats when the danger level went up 100 fold.
I have been casting for about 5 years now, and so far have avoided getting burnt, but there is all ways that one time.
  At the end of the video there is a screen shot of molten iron flying over my shoulder, I didnt see it while I was casting but Moya did and told me at the end of the casting session. It was interesting to see it on video, I never saw it when it happened....


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## jwcnc1911 (Jul 1, 2013)

aonemarine,

In the video, the first glowing hot item you set on the ground... is that a heated mould?  The moulds are heated to glowing hot as well?


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## aonemarine (Jul 1, 2013)

jwcnc1911 said:


> aonemarine,
> 
> In the video, the first glowing hot item you set on the ground... is that a heated mould? The moulds are heated to glowing hot as well?


 

 They were that hot, but honestly they should have only been about 200C.
Being as hot as they were caused some shrinkage issues in the castings where the sprue cooled faster than the part (in the center of the mold) and robbed metal from the casting. I also needed to extend the burn out time as there was still some residue inside the mold that caused inclusions in the castings and I also noticed some steam tracking on the cast parts (also an indicator of too short a burn out time)  It was a learning experience for sure. Now I have a much better idea of what to do so the next castings will be well improved.
  If I can perfect this process....man the sky is the limit!!


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## jwcnc1911 (Jul 2, 2013)

The sky is the limit if you have a HUGE 3d printer!  Did you DIY your 3d printer?  I've been considering that too (I like your style all the way around it seems!).


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## aonemarine (Jul 2, 2013)

No, the printed parts are from a friends 3d printer, he has actually started a small printing business (printedsolid.com) and has some interesting things he has printed on his web site. I am really surprised at the quality of prints you can get now from what they were a couple of years ago.
  I may diy my own printer and have been sitting parts off to the side, but to be honest the cost of the printers has come down so much it might be better off just to buy one.


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## jwcnc1911 (Jul 2, 2013)

aonemarine said:


> but to be honest the cost of the printers has come down so much it might be better off just to buy one.



I agree, I've been watching these for about 5 years now.  We got one at work and I saw it printing "prototypes" but they were coarse, "boxy" and very rough.  It seems the resolution of the extrusion is much better nowadays.

You can get a Cubify for about $1k if you call them and talk them down.



aonemarine said:


> No, the printed parts are from a friends 3d printer, he has actually started a small printing business (printedsolid.com) and has some interesting things he has printed on his web site.



A bit of a horror or goth fellow?


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## aonemarine (Jul 2, 2013)

http://www.robo3dprinter.com/

this semms like a nice printer if you dont mind the wait, but there is a bit of the learning curve when it comes to printing items. I keep thinking the way I do when it comes to machining parts, wich is totally wrong for printing. For the cost of printed parts, ill just have printedsolid print mine for me for now...


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## jwcnc1911 (Jul 2, 2013)

Wow!  That Robo is really affordable.  I may have to buy that instead of a new laptop and just keep using this one as a desktop for a while.

I'm considering sending him a turner's cube or something to get a quote and to see the quality.  All of my 3d printing experience is with big bad-a industrial machines.  I've never seen anything that was done on a DIY or home market machine.  The pictures you put up look nice enough to get me really interested in it.  Do you know the resolution of his machine?    That Robo has a layer height of 0.1mm or about 0.004in and can't find the filament diameter.  Obviously it's like a dotmatrix printer... the higher the resolution the better the part.  However, after all the pictures I've looked at a little gentle filing and sanding could result in a superb part.  The little squirrel at the bottom of this page doesn't look so sharp: http://www.robo3dprinter.com/pages/robo-3d-gallery

Here he is:






Make sure your friend hits www.grabcad.com for more free solids than he can shake a stick at.  Plenty to print out if he needs ideas. I even have solids of some engines on there under the same username.

Also, if you think that's awesome... check it:

http://www.shapeways.com/materials/steel

http://www.popsci.com/diy/article/2009-08/3-d-printing-now-stainless-steel


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## aonemarine (Jul 2, 2013)

Im familiar with all those websites.  Im pretty sure he prints at 1 micron resolution for the fine detal stuff. There is a finishing operation useing acetone vapor polishing that makes the abs printed parts smooth and glossy but it does not work for the pla printed parts.
  Here is one of his prints in pla at the 1 micron layer height, I think it is any ways...
Care to guess at the bots name??


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## aonemarine (Jul 2, 2013)

Oh, JW you have to check out thingiverse.com for free stl files of things you can print....


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## dreeves (Jul 2, 2013)

Dave got me into casting and I must say it does not take to long to get started.  Dave let me borrow a small tin can furnace and a pattern and I did a brass and aluminum cast in about 2 hours. Most of the time was the little furnace getting up to temp to melt the brass. With the new and larger one should be much quicker.  If you are interested jump in. I got lucky meeting Dave with his willingness to help and guide.  Thanks Dave 

Dave


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## jwcnc1911 (Jul 2, 2013)

0.001mm resolution?  Maybe 0.001in?  One micron resolution is... wicked.  What's the diameter of the filament deposition?


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## aonemarine (Jul 2, 2013)

Sorry, its 100 Micron or .0037".   Something like that LOL.   The filiment varies in his machines one runs a 3 mm dia and the other is 1.75.  I think the nozzle diameters are the same at .4 mm
    I have probably botched everything I just said so you should contact him to verify. He's the printer and loves printing things up, me I like burning up his prints with molten metal LOL


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## cfellows (Aug 13, 2013)

Although the price of 3D printers has been falling, the quality of prints on the lower cost machines are still in question.  I've been collecting parts to build my own to ensure I wind up with a good quality machine and will still keep the cost to something under $600.  The secret to good quality prints is positioning repeatability which usually means zero backlash.  It also requires long lasting parts to keep backlash at a minimum.

I'm planning to build a delta style printer, like one of these:

https://www.youtube.com/watch?v=3EfxZTI-3B0

It requires fewer parts, the build platform is glass and is fixed position.  With magnetic ball joints on the arm ends, backlash can be reduced to nearly zero.  There are quite a few variations on this design and there are many parts files on thingiverse.com that can be downloaded and printed.

Chuck


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## aonemarine (Aug 13, 2013)

Chuck, I hope you post a build when you do. Im collecting parts to build one myself and hope to start on it in the next couple of weeks. Ive checked out my friends Robo3d and it is build to a minimum of what a 3d printer can be. it has some z axis wobble issues, the bed cant be adjusted for height, but the thing still does a nice job on printing. I keep thinking these things need to be very accurate and ridgid, but truth be told, they dont seem greatly effected by thier short comings.....


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## cfellows (Aug 13, 2013)

I've been working on a MakerBot Replicator at the TechShop.  They are remarkably simple in their construction.  Most of the structural parts are made from laser cut plywood and the plastic parts are 3D printed.  I have access to both a 3D printer and a high quality laser cutter so printers like the MakerBot and the UltiMaker keep drawing my attention.  I could build one for just the cost of materials, there is no charge for using the machines.

The print quality is also based on layer thickness and extruder temperature.  I've  only used ABS so far and it is kind of finicky about platform temperature as well.  I'm going to switch to PLA because it's more rigid and pretty darned strong.  However, it will snap when stressed whereas ABS will bend or compress a bit before breaking.

I'm pretty excited about this project.  It's very gratifying to draw up an object in Alibre or even Sketchup, write it out to an STL file on an SD memory card, transfer the file to the 3D printer and sit back and watch it get built.

Chuck


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## RonGinger (Aug 13, 2013)

I just got a 3d printer to work. I bought the kit for the Printrbot Simple. As the name says it is a very simple machine. I think the design is rather elegant. It is only $299 for everythinng, electronics, power supply, motors, etc.

I assembeled it with my 15 yr old, nerd, grandson. He did the major work, with me checking over it and guiding him a bit. It took most of an afternoon. 

The amazing thing is the first part we tried came out very good. We used PLA, and just blue masking tape on the bed. It took quite a force to get it off the bed.

I had earlier built a SeeMeCNC H1-1. That thing is a hackers nightmare. Its made of threaded rod and plastic connectors. Its big and bulky and rather shakey. I had it running when my grandson arrived, and we tried several prints and never got a recognizable part. I cant decide whether to just tear it apart and put the hardware in my bolt and nut stock, or offer it for sale.

I agree that the current state of these printers makes them nothing but a toy. My hope would be to make a master part for investment casting, but these things look like they are made of the old lincon logs sets. The surfaces are completely ribbed.

An amusing toy, Ill probably drag it along to some of the model engineering shows just to demo.


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## aonemarine (Aug 13, 2013)

Ron,  have to disagree......the prints I have been seeing are far better than you describe. Sounds like you have been looking at print jobs with a 300 Micron layer height and a .5 mm nozzle. Most printers will do 100 now and some as low as 50 Micron thru a .25 mm nozzle.  No lincon logs there.


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## cfellows (Aug 14, 2013)

One of the things that excites me about the 3D printer is the relatively short process of going from design to finished part.  The other advantages are that they are relatively small and quiet, and don't require anything but hand tools to assemble a finished piece.  I expect the day will eventually come when I have to give up my shop, but I don't think I will ever lose my desire to make things.  The 3D printer seems like a perfect means of satisfying my creative needs in the confines of a small condo or apartment.  Not giving up the shop anytime soon, just trying to think ahead a little bit.

Chuck


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## aonemarine (Aug 14, 2013)

Totally agree with you Chuck, and to just add a bit more, the speed for making a rapid prototype and having a working model in your hands is wonderful on these things. Im getting really hooked on 3d printing. combine the plastic print with investment casting....well im sure you can see where im going with this.....


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## cfellows (Aug 14, 2013)

So, what are the steps, once you finished 3D printing the prototype?

Chuck


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## aonemarine (Aug 14, 2013)

Print part, sprue up with wax, mix and pour investment, burn out, melt metal, and pour.
I have another thread on here "lost pla casting 2" that shows the entire process in the video in good detail.
 Also my printer has a new filament that's some sort of a pla blend that prints ultra smooth the he claims will be a real game changed for investmentcasting.  Can't wait to see!


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## cfellows (Aug 15, 2013)

Thanks for the link to the video.  When you burn out the plastic pattern, do you turn the mold upside down so the melted plastic runs out?

Chuck


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## aonemarine (Aug 15, 2013)

cfellows said:


> Thanks for the link to the video. When you burn out the plastic pattern, do you turn the mold upside down so the melted plastic runs out?
> 
> Chuck


 
 Yes it is turned upside down. I used to do this to reclaim the wax, but with the pla I think its just force of habit because it does not seem to run out.


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## vnkiwi (Aug 15, 2013)

PLA burns out, (vapourizes) and leaves no residue


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## RonGinger (Aug 15, 2013)

Yes, the printer I have is about the lowest end of the market- a Printrbot Simple for $299. I think it does have a .45 head.

What printer was used to do the two elephants shown above?  I know there are commercial printers with much better resolution.


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## aonemarine (Aug 15, 2013)

RonGinger said:


> Yes, the printer I have is about the lowest end of the market- a Printrbot Simple for $299. I think it does have a .45 head.
> 
> What printer was used to do the two elephants shown above?  I know there are commercial printers with much better resolution.



I'm not 100% certain, he has several different printers it may have been on the ultimaker or the replicator2  both machines give very good prints.  Those commercial printers come with a commercial price tag too...lol
    If you want really high detail those Sla printers that use the resin are really nice. There is a couple home versions of them also. The  Forum1 and the B9creator are interesting to say the least.


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## aonemarine (Aug 15, 2013)

[ame]http://www.youtube.com/watch?v=NFnfLsrSuAM[/ame]

Heres the other video, more to come..


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## aonemarine (Aug 26, 2013)

Ok been doing some researching on 3d printing and ran across this great article  http://davedurant.wordpress.com/2011/10/12/ultimaker-faq-but-what-about-the-quality-of-prints/

It is possible to print at a resolution of 20 microns, im sure this takes alot of tinkering but the results are spectacular!! The sprial bevel gear really catches my eye on what is posssible. Friday I will be ordering myself a printer (and a bottle of asprin for the learning curve)
 3d printers arent for every one, and do require alot of effort to achieve the quality of prints in the above link. but what the hay If they can do it so can I..


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## cfellows (Aug 26, 2013)

The Ultimaker is a highly regarded printer.  I just bought this Tantillus printer locally for $100, missing the electronics & hot end.  


















It is smaller than the Ultimaker, but uses pretty much the same X-Y axis construction and movement.  The plastic case was created in 9 sections by a 3D printer, and while it looks a little hokey, it's actually quite rigid and well made.  I'm in the process of restoring it, replacing the axis rods with hardened 8mm shafting, replacing the plastic gears with timing pulleys and belts, adding a new Sanguinololu board, and a hot end of my own making.  Should make a decent machine for printing out parts for my Delta 3D printer.

Chuck


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## aonemarine (Aug 26, 2013)

Chuck, I found that video on the "Berry bot"  delta with magnetic couplings, very impressive. I can see why you like the design.
  Seems as though you have been doing alot of research on the printers?
Interesting printer you have there, dont like the gear drives but the timing belt replacement will fix those issues righ up.


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## cfellows (Aug 26, 2013)

aonemarine said:


> Chuck, I found that video on the "Berry bot"  delta with magnetic couplings, very impressive. I can see why you like the design.
> Seems as though you have been doing alot of research on the printers?
> Interesting printer you have there, dont like the gear drives but the timing belt replacement will fix those issues righ up.



Yeah, I like the BerryBot a lot.  The Delta that I'm considering is the Cerberus Pup, a little smaller than the BerryBot.  All the printer files to build it are on the web along with a complete bill of materials and a fair amount of discussion.  The only bad part is that some of the parts take close to 4 hours to print, the maximum amount of time I can schedule on the TechShop's 3D printer.  And, I can only schedule 3 sessions a week, so it could take several weeks to get all the parts printed.


The plastic gears on the Tantillus seem to work well with no backlash, but they are quite noisy in operation.  Also, they are not perfectly round, so you have to match up the two gears so the fat side on one meshes with the skinny side on the other.  Still, the fact that you can make and put together something like this with little more than hand tools is quite impressive!

Chuck


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## wackyvorlon (Sep 1, 2013)

I know one trick jewellers will use is to make a mould from rubber that can be reused for injecting wax. Basically you make the model, pack around with this rubber. Then vulcanize the rubber in a heated press, and carefully cut the new mould in half.


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## aonemarine (Sep 1, 2013)

Well I bit the bullit and ordered a rostock max. I think im in for a huge learning curve!!!


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## cfellows (Sep 2, 2013)

aonemarine said:


> Well I bit the bullit and ordered a rostock max. I think im in for a huge learning curve!!!



Not to mention a whole new level of fun!!!  Modeling something in 3D CAD then watching it come to life in a 3D printer, without ever touching a tool, is a real kick in the pants.

And, yes, there is a huge amount to learn.  If you haven't already found it, I suggestion you have a look at:

http://reprap.org/wiki/Main_Page

It's not intuitive from the main page, but there is a huge amount of information available on that site, particular in the forums.

Chuck


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## wackyvorlon (Sep 4, 2013)

And dig around thingiverse.com. They have a huge array of models you can download for free.


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## blighty (Sep 4, 2013)

been wanting to give this ago ever since i saw them make flutes on "How It's Made" 

I've got 8 bin bag's full of Ali swarf and about 30lb of scrap........ need to make a melty down thing....... so i can add that to the list of other things that i need making.


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## wackyvorlon (Sep 5, 2013)

Look into cupola furnaces. Very easy to build for casting iron.


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## aonemarine (Sep 7, 2013)

Well I got my rostock max on thursday at 5:00, just finished the assembly and wireing and have been making it move around a bit. Man this thing is neat!!  I need to run thru the calibrations and get more familiar with it, then its time to print something!!  Ill keep you posted..

Oh and cupola furnaces arent much good for aluminum castings....


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## Chriske (Sep 8, 2013)

Hi,

We just finished assembling this one :
http://reprap.org/wiki/File:Assembled-prusa-mendel.jpg

First prints came out very neat.

Chris


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## aonemarine (Sep 29, 2013)

I have had the Rostock up and running for a few weeks now and have to say "I love it" It does some very nice prints at .1mm
  The only thing I have not liked is the way slic3r works. I have switched to cura for the slicing and am much happier with the prints from it. Im reworking some of my cad models to make them more printer friendly and will post the results soon.


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## cfellows (Sep 30, 2013)

aonemarine said:


> I have had the Rostock up and running for a few weeks now and have to say "I love it" It does some very nice prints at .1mm
> The only thing I have not liked is the way slic3r works. I have switched to cura for the slicing and am much happier with the prints from it. Im reworking some of my cad models to make them more printer friendly and will post the results soon.



I'll show you mine if you'll show me yours!  

Here's a video of the Tantillus I bought locally in nonworking condition.  I just got it all put back together and working.  This is my first print...

https://www.youtube.com/watch?v=6a1nUHacB1k

I've also been working on my Kossel Mini Delta printer but am waiting on parts from, you guessed it, China.  

Chuck


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## Ken I (Oct 14, 2013)

Gimme more - keep it coming - I've just bought a 3D printer and this is exacly the sort of thing I want to do with it.

Any more foundrymen out there want to chip in their 10c worth ?

Regards,
              Ken


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## xlchainsaw (Jan 26, 2014)

well done going iron  aonemarine


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## RonGinger (Jan 26, 2014)

Chuck that Tantillus printer looks like a very neat design. Can ypu post a few more photos of it? I am confused by the drive at the top corner- The rod is beinging driven by the stepper motor, but it seems to be the linear bearing supporting the upper carriage. I found the Tantillus web site but its not much help on the base mechanics.

How is the outer case made- it looks like nice rounded corners, but I would expect sharp square corners if its laser cut.

These photos got me thinking- I wonder if you could take one of the plastic milk crates and make it the case for such a printer?


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## aonemarine (Jan 26, 2014)

Ron, somewhere on the net there is one made from a milk crate. I remember seeing it, but cant find it now....


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## cfellows (Jan 26, 2014)

RonGinger said:


> Chuck that Tantillus printer looks like a very neat design. Can ypu post a few more photos of it? I am confused by the drive at the top corner- The rod is beinging driven by the stepper motor, but it seems to be the linear bearing supporting the upper carriage. I found the Tantillus web site but its not much help on the base mechanics.
> 
> How is the outer case made- it looks like nice rounded corners, but I would expect sharp square corners if its laser cut.
> 
> These photos got me thinking- I wonder if you could take one of the plastic milk crates and make it the case for such a printer?



Hey Ron,

The original Tantillus had a plastic case that was printed on (another) 3D printer, in sections, that were then interlocked together. Each section is small enough that it could be printed on a another tantillus which has a 100mm x 100mm x 100mm build envelope. The outside dimensions of the case are 8" wide x 8" long x 12" high. 

There are a number of variants of the Tantillus which use laser cut acrylic panels or plywood panels. There are also some variants made from extruded aluminum beams and printed plastic joints and bearing carriers.

Here is a thread with a number of pictures of my Tantillus from when I was restoring and modifying it:

http://forums.reprap.org/read.php?279,241379

And here are a few threads in the same forum for some variants of the Tantillus, including one I started but haven't finished. On some of these topics, you have to click on the picture to open it and view it

http://forums.reprap.org/read.php?279,253753

http://forums.reprap.org/read.php?279,190661

http://forums.reprap.org/read.php?279,299107

The outside rods that support linear bearings also turn to provide motion to the opposing axis. The rods on each side are connected with fishing line wrapped about 10 times to act as a belt. Seems crude but works amazingly well and is a whole lot cheaper than timing belts and pulleys. The rods around the outside are 5/16" drill rod and the linear bearings they support are solid, either bronze bushes, printed plastic bushings or, in my case, turned UHMW. The two crossed rods in the middle are hardened 8mm rods, since they support 8mm linear ball bearings in the print head. These do not rotate.

Happy to answer any other questions. By they way, if you have access to a 3D printer, there are lots of free printer files for the parts to the Tantillus as well as other 3D printers.

Chuck


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