Author Topic: Anycubic Photon  (Read 38125 times)

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robert3985

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Re: Anycubic Photon
« Reply #825 on: February 21, 2019, 02:29:26 AM »
+1
To cast you would not only need to develop the supports but also include grown CAD for shrinkage (the struggle is real), gating, sprues, and feeders in the CAD model to ensure the metal can get to all of the negative spaces when the resin burns out and the metal replaces it:



It may be difficult to find a caster willing to cast parts for you, even if you have the printed master, and shipping it? Nope.

If you want to cast yourself, it can be done but you need a crucible/pot to melt the metal, an oven to heat the mold and a way to dip the print into ceramic to coat it or pour a ceramic mold around the print and a way to safely four the metal into the mold.  Maybe @robert3985 could correct and expand my thoughts.

Well, since I was developing and casting lost-wax investment cast brass HO scale detail parts for a couple of years about 30 years ago (damn!  Has it been that long???) I'll tell ya that to occasionally investment cast parts out of brass is a complicated and precise undertaking and not easily accomplished with "just" this, or "just" that.

When you look at an illustration of investment casting, it looks really simple, and it can be on crude parts, but for small, detailed parts like most of what model railroaders want, it isn't so simple.  Casting brass is a bit more difficult than casting gold or silver too since the temperatures are higher and brass will de-alloy if you get it too hot, so you have to have a way to control its melting temperature.

First off, just investing your wax tree, although it sounds simple, is a many-step process with definite steps that cannot be fudged, including how to mix your investment, how long you have to actually invest the tree, which includes how to get the bubbles off of it and make sure that it invades every minute dimple and detail before hardening up.  In my process...you needed a rubber canister cap to mount your wax tree into, then a stainless cylinder called a "canister" which fits in a groove near the outside edge of the rubber canister cap after you've built your wax tree.  Then, you have to calculate the amount of metal you'll be using, usually by filling up the canister with water and weighing the water, then converting the weight of the water to the weight of the metal you'll need...then adding a bit to compensate for splash.  Then, you mix up your investment as per specific instructions, and pour it a certain way into the canister.  Then you set it on a special vibrating table to dislodge most of the bubbles hanging on the tree...then transfer the filled canister to a vacuum bell-jar and suck a hard vacuum for a set time....and watch the investment bubble away...then the vibrating table again...then set the filled canister aside.

Then, you fire up the burn-out oven, let it get to a certain temperature, put the filled crucible in it after the investment has set after removing the rubber cap...and you carefully increase the temperature for very specific amounts of time so that the investment doesn't crack and fall apart, that the water in the investment turns to steam instead of just evaporating so that it melts and removes the wax masters and the tree sprues...then in those areas where the wax can't flow out...especially in complex parts like model railroading parts, the remainder of the wax must be totally burned out...vaporized.  Your burn-out oven will stink like crazy at this point, so you need a fan hood over it to get the vaporized wax gas out of your work area...then you raise the temp on your burn-out oven so that it's the same as molten brass.  Depending on the size of your wax master, this can take a while.

When your burned-out canister has risen to it's required temperature...remember, just because the burn-out oven is at the temp of molten brass...it takes a while for your canister filled with hardened investment to get completely to the right temp through and through...Then you get your metal....I buy my brass in dogfood-sized pellets and put it in a ceramic crucible...add some flux to it...and melt it in a temperature controlled metal-melt furnace.  Mine is fueled by natural gas.

You've already wound up your spin-caster in its protective metal-lined housing (mine is about 3' in diameter)...and you open up your burn-out oven, and with a mask on, a protective apron with protective sleeves and gloves...you take your tongs and carefully lift the burned-out canister out of the oven and quickly place it in the spin caster.

Then, you take your molten brass, which is in the ceramic crucible in your metal-melt furnace and place it correctly and quickly in the spin caster so that the nozzle on the crucible is mated to the enlarged opening cast into the investment inside the canister.

Then, you release the spin caster and step back as molten brass always splashes out...and let it spin for a time.

Next, after the spin-caster is done spinning, you let your still-hot canister rest for a bit to ensure the metal inside it is now hard, and you lift it out of the spin caster, and drop it into a large metal bucket of very cold water....and watch the investment crack and explode out of the metal canister.

I let the brass tree sit in the water for a while, then I take it out, blow it off with compressed air, and start removing the big pieces of investment still stuck to it.

After all of the big investment pieces are off...then I put the brass tree into my big ultrasonic cleaner with investment remover, and let it buzz for half an hour or so.

Then, it's nice and bright...all the investment is gone and I start snipping off the parts

Costs are not cheap.  I bought my stuff at a large jewelry supply and tool company in Salt Lake City, with a very willing staff and all sorts of casting tools and machinery in a showroom for me to see and get explanations about.  I also had to run a gas line to my garage, built a fire-proof space for the ovens and spin-caster, as well as a couple of extra sturdy workbenches and shelves to accommodate my casting equipment and supplies.  I would inject and tree up five large canisters of parts in my workshop in my basement, with some canisters holding nearly 1,000 parts if the parts were really small, such as eyebolts or firecracker antennas.  I made five vulcanized rubber molds of each part or small kit, so that while I was waiting for the hot wax to harden, I could be injecting additional parts, and removing the cool waxes each time I'd inject another rubber mold, five molds away from removing the waxes.  That make sense??  I'd say all the equipment 30 years ago cost me in the neighborhood of three grand.  Don't know how much they'd be today...and I didn't get the most expensive versions of everything either.

Anyway, I reserved an entire Saturday each week to do my actual casting, and it took the whole day...like 12 to 15 hours sometimes.

I got to the point of hating it...because it became WORK, so I sold my HO scale masters and molds to some guy in Wyoming, got a divorce and I've never set the whole shebang up again.  I do use my wax injector pot and rubber vulcanizer quite often, but I use the local rock shop to do my casting, because it's a lot more pleasant to just deliver the wax masters, and have them do the grunt casting work. 

At 25 bucks a canister, it's hardly worth it for me to do it myself unless I was going to start marketing my parts, which I am not planning on doing.

When I get my Photon, one of its main purposes will be to print castable masters for lost-wax casting of small parts that need to be metal, such as switch stands, grade-crossing cross-bucks...things that if they're made of resin or plastic are gonna break very easily and are located close to the tracks where rails must periodically get cleaned.  For other details, such as stuff for my U.P. engine modifications, the resin prints will be just fine as-is in most instances unless I want to turn 'em into brass, which I believe will happen rarely.

The guys at the rockshop use a simpler way of casting their small canisters, and the volumes are much less than what I was doing, their canister being about 1/4 the size of mine.  For my little parts, their service is perfect and the price is right since I supply the metal and sometimes, the investment.

Hope that maybe give everybody more of an idea what's involved in seriously doing investment casting of small parts.

Cheerio!
Bob Gilmore

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Re: Anycubic Photon
« Reply #826 on: February 21, 2019, 06:27:19 AM »
0
@robert3985 , exactly why I tagged you to expound on my overly simplistic understanding and explanation.  It's quite an undertaking.

But the idea of printing the investment, and taking it to a local caster is fairly reasonable.

Cymen

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Re: Anycubic Photon
« Reply #827 on: February 28, 2019, 03:00:10 PM »
+1
@Mark W I've read through this thread and I'm amazed that you were able to print the N scale children so well! I'm using a Photon with the translucent green resin and I'm having a hard time with limbs staying attached on adults. I'm using ChiTuBox with medium supports. I tried rotating them and having them straight down from the build plate and rotate does seem to help but it's tricky...

Can you explain a bit more about how you orientate something like the child and how your supports might look? I did read through how you do supports and I think that part is where I need to spend more time. I have been experimenting but it's slow going so any tips you have are greatly appreciated.

Mark W

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Re: Anycubic Photon
« Reply #828 on: February 28, 2019, 10:11:56 PM »
+2
@Mark W I've read through this thread and I'm amazed that you were able to print the N scale children so well! I'm using a Photon with the translucent green resin and I'm having a hard time with limbs staying attached on adults. I'm using ChiTuBox with medium supports. I tried rotating them and having them straight down from the build plate and rotate does seem to help but it's tricky...

Can you explain a bit more about how you orientate something like the child and how your supports might look? I did read through how you do supports and I think that part is where I need to spend more time. I have been experimenting but it's slow going so any tips you have are greatly appreciated.

Hi Cymen,

I'm not really doing anything special, that I'm aware of; just adding a few supports and printing them vertical. 
I do inspect each body scan and add a support to any appendage or clothing that overhangs or is otherwise unsupported. 

I aim to have at least one heavy support under the heal and another medium support under the ball of each foot (and a few more on those with bases, just for good measure).  When a support needs to go up to a hand or arm, Netfabb allows me to curve those supports so that they're far enough away from the actual part that they don't blend together.

Without photos, the only other thing I could suggest is to bump your exposure time by a second or two.  At this size, undercurring is more likely to fail than overcurring, so caution on the side of overcure. 


(Here's another comment opportunity for @David K. Smith. :D )

https://i.imgur.com/10gIfIP.jpg



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timwatson

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Re: Anycubic Photon
« Reply #829 on: February 28, 2019, 10:18:26 PM »
0
Thank for posting this Mark. I can attest that a few extra seconds for people is a better way to go and at least medium supports. My next batch will be with mixed medium/heavy supports as I’ve cut the bases off mine.

Good luck and let us know how you get along.
Tim Watson

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Modeling a version of the Jay Street Connecting RR. in Brooklyn.

Lemosteam

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Re: Anycubic Photon
« Reply #830 on: March 01, 2019, 07:10:43 AM »
0
Hi Cymen,

I'm not really doing anything special, that I'm aware of; just adding a few supports and printing them vertical. 
I do inspect each body scan and add a support to any appendage or clothing that overhangs or is otherwise unsupported. 

I aim to have at least one heavy support under the heal and another medium support under the ball of each foot (and a few more on those with bases, just for good measure).  When a support needs to go up to a hand or arm, Netfabb allows me to curve those supports so that they're far enough away from the actual part that they don't blend together.

Without photos, the only other thing I could suggest is to bump your exposure time by a second or two.  At this size, undercurring is more likely to fail than overcurring, so caution on the side of overcure. 


(Here's another comment opportunity for @David K. Smith. :D )

https://i.imgur.com/10gIfIP.jpg

This image reveals much to me, but not regarding the hard hat man's appendage.

Thanks for posting.

DKS

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Re: Anycubic Photon
« Reply #831 on: March 01, 2019, 07:52:03 AM »
0
They need some bug repellent.

(There you go, @Mark W!)
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Thunderhawk

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Re: Anycubic Photon
« Reply #832 on: March 01, 2019, 01:43:31 PM »
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Replaced the FEP and it pops pretty noticeably now. And the build plate seems to move up a fair bit before the pop. This is on the base layers so there is a LOT of surface on the FEP.

Normal I assume?

Mark W

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Re: Anycubic Photon
« Reply #833 on: March 01, 2019, 06:26:05 PM »
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Replaced the FEP and it pops pretty noticeably now. And the build plate seems to move up a fair bit before the pop. This is on the base layers so there is a LOT of surface on the FEP.

Normal I assume?

Yep, more than normal.  To be expected.

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Thunderhawk

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Re: Anycubic Photon
« Reply #834 on: March 01, 2019, 07:40:33 PM »
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Yep, more than normal.  To be expected.

Very pleased with it so far except for having to replace the FEP already. Somehow managed to get a couple rough spots. Perhaps there was something small on the counter that I set it on, but it had a couple pretty sharp little dings in it. And then I made it worse by trying to scrape them off, before realizing it was the FEP itself, with my fingernail which left ridges in the film.

On the plus side, they shipped two spare FEP's with my printer so I still have a spare.

btw-The cap of a Gatorade bottle is just under 13mm for replacing the FEP.

Thunderhawk

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Re: Anycubic Photon
« Reply #835 on: March 04, 2019, 07:31:48 PM »
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Ordering two more of these as I have to wait too long for test prints. Happy so far though.

Will likely get a Phrozen Tranform as well when they come out unless another big resin machine shows up before then.

bnsfdash8

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Re: Anycubic Photon
« Reply #836 on: March 05, 2019, 08:55:42 PM »
+4
Norfolk and Western Leslie 5 chime horn.

It took me 3 tries to get it supported correctly, but I'm very happy with the results.

Reese
Modeling Norfolk Southern one loco at a time.

Chris333

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Re: Anycubic Photon
« Reply #837 on: March 06, 2019, 11:31:44 PM »
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Maybe someday prints will only take a few minutes :

Chris333

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Re: Anycubic Photon
« Reply #838 on: March 07, 2019, 05:52:04 AM »
0
Anyone happen to know of a file for HO scale wooden barrels?

I found one online and they wanted $1.30 for it. When I tired to buy it my ad blocker blocked something over 100,000 times! So luckily I didn't give them my credit card.

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Re: Anycubic Photon
« Reply #839 on: March 07, 2019, 06:29:36 AM »
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@Chris333 Got a pic?