Ron's Prints and Casting

rkundlarkundla Member, Moderator, Backers, Ultimate Backer
I figure this year I will just post to a thread of my own work and update when I do something new.

Here are some photos of recent prints:

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Here is my last casting:


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Notice the ring I printed for @jayk up at the top - I was curious how to sprue it to get a good print. It wasn't one of my better castings, some damage due to incomplete resin cure. I was trying some new cleaning techniques and I don't think they worked as well as I hoped they would.

Some finished rings from this sprue:


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Ron

Comments

  • kbvprokbvpro Member, Backers
    Very nice. May I ask what kind of resins you use and casting material. What kind of investments was used and your burn out
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    @kbvpro here is the short form answer:

    Resin: 3DFacture Castable Green
    Metal: United PMR Sterlium+ silver casting grain (50% scrap)
    Investment: R&R Plasticast at 36 or 38:100 ratio

    Burnout:
    Paragon SC3 kiln with modification to pump in additional outside air into kiln
    Ramp 1200°F/hr to 300°F
    Insert flask button up and hold for 1 hour
    Ramp 1200°F/hr to 700°F
    Hold for 2 hours
    Ramp 1200°F/hr to 1350°F
    Hold for 3 hours
    Ramp 1200°F/hr to casting temp
    Hold for 1 hour
    Cast


    Ron
  • kbvprokbvpro Member, Backers
    Thank you for the information. I'm from Houston Texas and I'm a jewelry designer for more than 15yrs. I was on of the Backer for the Draken. I just now starting on my own and need your guys help to get my machine going.
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    I'll try to help as best as I can. Glad to have you on board!
    Ron
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    Decided to try the B9 Emerald resin with my Vivitek projector Draken and the flex vat:

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    This resin is a little sticky, so depending on the profile, it will snap the FEP film. It would probably benefit from less tension on the film, so I may have to tweak the flex vat a little bit.

    Now to do some casting and see how it works!

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    Ron
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    For the emerald, I am using the same settings I use with the 3Dfacture green castable resin. I do have to take the UV/IR filter out of the Vivitek to get the faster cure times. Now I need to get a IR filter to put back in to prevent my projector from melting down. :o
    Ron
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    Casting results using the same burn out for the 3Dfacture green castable resin:

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    Rings are cut off the sprues and in the pickle. Next up a heat hardening treatment, the pickle once more and then the magnetic tumbler before I am ready to finish them. ;-)
    Ron
  • Joseph_OsbornJoseph_Osborn Member, Backers
    Good work, Ron. Refresh my memory: with the flexvat, are you using tilt, or just letting the print pull itself off the FEP?
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    @Joseph_Osborn

    I am still using tilt.

    I am trying to find the right balance in operation. Which peel provides the least amount of resistance? Is the tilt from the side, with a kind of rolling action, better than the pull? I'd think any force applied perpendicular to the surface is harder on the print than if you tilt from the side. Sliding peel may be a better method, like the old B9C and the Autodesk printers (the vat moves sideways linearly (B9C) or rotary (Autodesk).

    For the Emerald, it sticks more than the 3Dfacture resin, so I modified the flex vat to not put as much tension on the film, which will roll off 'easier'. I ran a test print and need to get check it to see if it worked. It may be that I just need to get my supports more embedded into the model instead. ;-)
    Ron
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    Just an update on the flex vat - the reduced tension didn't make a difference there isn't enough bending action to effect a rolling style peel. I made some adjustments to the lift height and rates and with the original slow peel settings, it seems to be working better.

    The more I play with it, the more the peel process in SLA/DLP printers is black magic. ;-)

    Here is a ring model I just print in two parts and reassembled. The band and the head were printed separately and then I used liquid resin and a 405nm laser to bond them together.

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    I invested it last night and it went into the kiln this morning, so I should have some results by the end of the day.

    Ron
  • bryanbryan Member, Backers
    Why did you do it in 2 pieces?

    Did you coat both contact surfaces in liquid resin and laser-cure the perimeter?
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    The texture on the band goes all the way around and I wasn't sure how well the print would come out sideways with the two parts together, so in CAD I was able to cut the head away from the shank and then separate it. I just printed another copy of it so I will take a photo.

    All I did was place a drop of resin on the inside of the band and smear it over the surface. The head left two impressions on both sides from the boolean difference so the head dropped into place and then I used the laser around the perimeter like you mentioned. After it was secure, I put it in water and cured it for 4 hours under the 3Dfacture large lamp to make sure it was cured well.

    I am in the 1350°F phase right now and have 2 hours left. Cool down to 900°F for an hour and then casting time!
    Ron
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    Here is the last print I did on the Draken with the two-part ring.

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    Ron
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    Cast of the band/head combo:

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    Ron
  • GaryGary Member, Backers
    I was wondering how you were going to feed that textured band - what a cool solution!  I gave up on the MJ castable - awaiting delivery of the draken green - backordered. Vacuum caster arrived last week. mini kiln arrives today. 

    Off hand, do you know what the specific gravity of the draken castable resin is? Same as wax, or a little heavier?
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    @Gary

    I decided to try it this way and it worked out well. I was able to feed it from both sides and removing it wasn't too painful. Some saw magic, then a coarse grit sanding drum took off much of the extra before going in with finer abrasives.

    For any resin I've been casting with, I use a SG of 1.1, which is heaver than wax. I treat all of the sprues as resin so I may use a little more metal than I need, but it is a small percentage overall and the button isn't too big.
    Ron
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    Here is a photo of the finished big stone textured band:

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    I did a mixed casting. The one on the left was a 14K white gold wax casting from a Stratasys from Shapeways and the one on the right is a Draken printed sterling silver band.

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    The blobs on the gold were part of a support and I cracked the wax (it is really fragile) so I fixed it with some wax melted on the crack. I went with the wax because I wasn't sure if my 14K white gold casting process was all messed up. This came out pretty good, so I will have to try it with the resin again.
    Ron
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    If you want to see a comparison of how much better the Draken can print against a $10K+ printer like the Stratasys wax printer, here is a model I sent to Shapeways because I was having some issues getting a clean cast.

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    The surface finish is nowhere as nice as the silver ring in the previous posting. I just need to keep working to tweak the casting process with the thinner resin prints to get the best results. :-)

    Ron
  • GaryGary Member, Backers
    Was that your spruing of theirs? (I mean did you have them do the cast of just the wax?)

    imageIve never been fond of the results I got from shapeways - one of the reasons I bought the traken!

    I got my very first cast with my new rig today. I'm actually quite pleased with it considering that I was casting MJ SR Yellow (still waiting for my Draken green), and using 100% old metal.  A 3 1/2 inch perforated flask came with the rig, so I used the extended burnout (11ish hours total). Pic is just out of the pickle with a little brass brushing...


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  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    I sprue and cast my own work @Gary. I hate not having control over the quality of the process.

    Burnout of Makerjuice SR? Wow - if you can get it hot enough, you can burn out just about anything! :-D Any problems with pitting or inclusions? From the look at your photo, it looks pretty decent. I wonder if the black is some sort of residue from the burnout the pickle wasn't able to remove.

    I assume you are casting sterling? What alloy do you use for your work?
    Ron
  • GaryGary Member, Backers
    Believe it or not, I'm currently casting classic sterling I bought from Hagstoz early in the century. I used to do a lot of wire work, and a lot of those pieces are being recycled for metal and stones. 

    The surface quality is not great - but until I get the right resin in my hands, it will due.  Up until recently I did only fabrication - no casting. So this is all new (except the metal :)).  Here's a pair from the tree semi-finished. 

    The tiny kiln I bought will go up to 2100F, but I'm not sure plasticast could handle it. I'm topping out at 1350 for 4 hours currently.  I could go higher. what do you think? I have a flask burning out overnight with some rings - pattern shank with a 8x12 cup sprued like your patterned shank. I print the whole tree, sprue, feeders, and all. I'm all thumbs attaching wax to wax, always wind up dripping all over details :(. Wasting plastic is better than wasting time IMHO.
     (can't seem t get the pic - so here's a link)

    garysnyderjewelry.com/data/uploads/20170303_013848.jpg
  • rkundlarkundla Member, Moderator, Backers, Ultimate Backer
    edited March 3
    @Gary

    All of these easy investments are only good to 1350-1400 max before they start to breakdown and reduce the surface finish of the cast model, so your kiln is good temperature-wise. The biggest factor is whether or not you have a good flow of air through the kiln to provide the oxygen necessary to completely decompose the resin. Air injection via an aquarium pump or holes drilled though the bottom of the kiln are needed to help ensure a quality output. If you have a gas kiln, airflow isn't an issue typically.

    Using resin as your tree structure can be a little dicey if you don't have adequate oxygen since the resin doesn't melt like wax, it will liquefy, but moves back and forth between liquid and solid until it turns into a tarry sludge. If the gates don't melt away allowing air into the cavity, you need to keep holding that 1350 temp a lot longer (as you mentioned above with the 11 hour cycle) to make sure you get all the resin and minimize the ash residue.

    I'm still a little rough with the wax, but I bought one of those Foredom wax pens with the attachments and it has been easier for me to do my work versus one of those electric wire wax pens I had before. Tools can help make that task a little easier. ;-)
    Ron
  • GaryGary Member, Backers
    Good to know Ron. My kiln has no airflow at all. No vent. It is only big enough to hold a single flask. The electronics are at the bottom, so drilling there is not an option. Until I get the green resin I'm in experiment mode. Maybe I'll kick the top temp up to 1375 and hold for 6 hours next time. I screwed up today's cast with a series of errors. Missed the end of the program while distracted by other issues and the flask was down to 600F. Then I forgot to flip the vacuum on. Tomorrow is another day :)
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