Thanks Jim for the further info.
I'll add it to my list of queries,
and thoughts to be taken into consideration...
Peter
3D Printing - whether to buy, what to buy and how to use it?
Thanks Jim for the further info.
I'll add it to my list of queries,
and thoughts to be taken into consideration...
Peter
ICH60
Western Thunderer
Elegoo have deals on at the moment ELEGOO Deals though the Mars is now sold out.
Dog Star
Western Thunderer
Previously... when wanting to convert a 3D CAD dwg to (real world) lost wax castings I have provided Slater's Plastikard with a 3DP from Shapeways ( done in FUD). Slaters has converted the 3DP into a mould for a brass master and then used the master to produce repeat copies of my original print.
Now that my Son is doing 3DP in-house we have come to the point where we are ready to send one of our 3DP for mould making and casting. At this t ime we use an Anycubic Photon Mono X with Sariya Tech Fast Navy Grey resin.
Anyone have experience of the route that we intend to take for production of the brass castings?
Anyone have of Sariya Tech FNG as a suitable resin patterns to be used for mould making?
thank you, Graham
Now that my Son is doing 3DP in-house we have come to the point where we are ready to send one of our 3DP for mould making and casting. At this t ime we use an Anycubic Photon Mono X with Sariya Tech Fast Navy Grey resin.
Anyone have experience of the route that we intend to take for production of the brass castings?
Anyone have of Sariya Tech FNG as a suitable resin patterns to be used for mould making?
thank you, Graham
Big Train James
Western Thunderer
Hi Graham,
I have recently been part of an endeavor to produce brass parts via lost wax casting, using 3d printed parts for the mold patterns.
I'm using Siraya Tech FNG for the patterns, printed on an Elegoo Mars 3 Ultra. The parts in question were driver center castings for a PRR locomotive, so some areas of detail but more critically nearly 100% non-planar surfaces in an infinite number of orientations. I ultimately printed them at 10 micron slicing thickness, in order to achieve a surface quality that was acceptable without requiring post processing. The patterns were then sent to the caster for use in making RTV molds. The molds were in turn used to shoot waxes for burnout.
I don't think there were any issues at all with using the FNG prints as patterns to create the molds. One caveat to note is that the driver centers are fairly robust, so no thin sections or fine details to worry about. Finer parts might present more issues in the mold creation process, although I'm not sure how as long as they don't fail before the mold material sets. Anyway, no issues to report with the FNG in my particular application.
Another caveat to consider would be if you want to create vulcanized molds. The additional heat required in that process would likely exceed the the capabilities of the FNG. However, Siraya Tech does make Sculpt, which has a heat tolerance that is suitable for use in vulcanized mold making. According to the marketing, Sculpt should be able to render prints with an equivalent level of surface quality and precision as FNG allows. So that may be a viable alternative if you want to pursue vulcanized molds.
After the molds are made, the rest of the process is the same as with any other pattern. You will need to account for shrinkage in the mold and the brass. You will need to consider whether the wax shots can be safely de-molded. You will need to properly sprue the parts for material flow, and consider the size and mass of parts and their effect on casting temperatures. The shrink factor should be discussed with your caster, they should be able to give you a figure based on all relevant criteria.
I'll have to have a look around and see if I have photos of the prints. If so I will post them. No photos of the resulting brass parts, but I can say that the end user was very satisfied with them. He's as particular as I am, so they must have been good.
Now we are moving toward using a castable resin for 3d printed parts that will burned out directly, with no molds made. This is the same process outlined in John Baker's thread. The castable resins are quite a bit more expensive than standard ABS-like types. However, their use is economical compared to the cost of producing molds, if a short run is all that is required, and we fit that description. More on that when it happens, which will likely happen mid-summer.
Jim
I have recently been part of an endeavor to produce brass parts via lost wax casting, using 3d printed parts for the mold patterns.
I'm using Siraya Tech FNG for the patterns, printed on an Elegoo Mars 3 Ultra. The parts in question were driver center castings for a PRR locomotive, so some areas of detail but more critically nearly 100% non-planar surfaces in an infinite number of orientations. I ultimately printed them at 10 micron slicing thickness, in order to achieve a surface quality that was acceptable without requiring post processing. The patterns were then sent to the caster for use in making RTV molds. The molds were in turn used to shoot waxes for burnout.
I don't think there were any issues at all with using the FNG prints as patterns to create the molds. One caveat to note is that the driver centers are fairly robust, so no thin sections or fine details to worry about. Finer parts might present more issues in the mold creation process, although I'm not sure how as long as they don't fail before the mold material sets. Anyway, no issues to report with the FNG in my particular application.
Another caveat to consider would be if you want to create vulcanized molds. The additional heat required in that process would likely exceed the the capabilities of the FNG. However, Siraya Tech does make Sculpt, which has a heat tolerance that is suitable for use in vulcanized mold making. According to the marketing, Sculpt should be able to render prints with an equivalent level of surface quality and precision as FNG allows. So that may be a viable alternative if you want to pursue vulcanized molds.
After the molds are made, the rest of the process is the same as with any other pattern. You will need to account for shrinkage in the mold and the brass. You will need to consider whether the wax shots can be safely de-molded. You will need to properly sprue the parts for material flow, and consider the size and mass of parts and their effect on casting temperatures. The shrink factor should be discussed with your caster, they should be able to give you a figure based on all relevant criteria.
I'll have to have a look around and see if I have photos of the prints. If so I will post them. No photos of the resulting brass parts, but I can say that the end user was very satisfied with them. He's as particular as I am, so they must have been good.
Now we are moving toward using a castable resin for 3d printed parts that will burned out directly, with no molds made. This is the same process outlined in John Baker's thread. The castable resins are quite a bit more expensive than standard ABS-like types. However, their use is economical compared to the cost of producing molds, if a short run is all that is required, and we fit that description. More on that when it happens, which will likely happen mid-summer.
Jim
76043
Western Thunderer
Quick question about shapeways.
I'd like to purchase just some 4mm RCH buffer bodies, can't see any anywhere else except Shapeways. I have lots of buffer heads in stock.
www.shapeways.com
I assume the best quality is the most expensive and is the price quoted the total price plus shipping? There's no other handling fees?
I've no experience of Shapeways.
Cheers
Tony
I'd like to purchase just some 4mm RCH buffer bodies, can't see any anywhere else except Shapeways. I have lots of buffer heads in stock.
RCH Fitted Buffer * 40 by MikeTrice on Shapeways
Check out RCH Fitted Buffer * 40 by MikeTrice on Shapeways and discover more 3D printed products in Trains.
I assume the best quality is the most expensive and is the price quoted the total price plus shipping? There's no other handling fees?
I've no experience of Shapeways.
Cheers
Tony
Mike Trice
Western Thunderer
Sadly shipping is added at checkout and tends to put people off buying: https://support.shapeways.com/hc/en-us/articles/360006412813-Shipping-time-costs
simond
Western Thunderer
Modelu have a Patreon project - some details here
www.patreon.com
and my foray...
Patreon
Patreon is empowering a new generation of creators. Support and engage with artists and creators as they live out their passions!
www.patreon.com
and my foray...
SimonD’s workbench
Highly unlikely, but hypothetically possible, they started production in 1930 and I’m sure I can whistle up an appropriate local registration plate. In any case, it’ll need to be at the back of the layout as it’s a bit small… and the wrong model. Wikipedia has some photos. As a military...
www.westernthunder.co.uk
Dog Star
Western Thunderer
My Son Peter has been expanding the range of what he prints... we started with parts that can be described as detailed lumps and we have moved on towards underframe details such as buffer guides. Other rolling stock details are in our sights and before we go there I am inclined to ask for the wisdom of the WT-clan.
Siraya Tech FNG has some flexibility and that is ok if we are printing solids such as buffer guides. What is the long term behaviour of this resin if we print parts that could benefit from a degree of flexibility, such as bearing springs? Does FNG suffer from stress failure induced by cyclic loading?
regards, Graham
Siraya Tech FNG has some flexibility and that is ok if we are printing solids such as buffer guides. What is the long term behaviour of this resin if we print parts that could benefit from a degree of flexibility, such as bearing springs? Does FNG suffer from stress failure induced by cyclic loading?
regards, Graham
michael080
Western Thunderer
simond
Western Thunderer
Graham,
I do not think I’d use the inherent flexibility of the material to make visually accurate, working springs. The details that you’d want to include will inevitably cause stress raisers which I’d expect to lead to cracking & failure sooner or later. Near-enough all materials will fatigue, eventually - that’s an exaggeration, but not a huge one.
Also, whilst FNG is flexible, it exhibits brittle failure in some circumstances - to an extent that surprised me. I’m guessing this implies a crystalline nature, if so, the stress raisers will be all the more critical in a fatigue loading situation.
That said, it’s not like it’s expensive or difficult to try, Peter could print a few chassis with working springs and you could see a) if they work acceptably, and b) how long they last. Would be good data!
some drawings here…. https://www.westernthunder.co.uk/resources/rch-wagon-drawings.4/
Sorry, one last thought. Springs have shackles, or sliding shoes, in order to allow the ends to move outwards as the arc flattens. Whilst sliding shoes are feasible in 7mm, I suspect shackles are going to require some watchmaking skills!
atb
Simon
I do not think I’d use the inherent flexibility of the material to make visually accurate, working springs. The details that you’d want to include will inevitably cause stress raisers which I’d expect to lead to cracking & failure sooner or later. Near-enough all materials will fatigue, eventually - that’s an exaggeration, but not a huge one.
Also, whilst FNG is flexible, it exhibits brittle failure in some circumstances - to an extent that surprised me. I’m guessing this implies a crystalline nature, if so, the stress raisers will be all the more critical in a fatigue loading situation.
That said, it’s not like it’s expensive or difficult to try, Peter could print a few chassis with working springs and you could see a) if they work acceptably, and b) how long they last. Would be good data!
some drawings here…. https://www.westernthunder.co.uk/resources/rch-wagon-drawings.4/
Sorry, one last thought. Springs have shackles, or sliding shoes, in order to allow the ends to move outwards as the arc flattens. Whilst sliding shoes are feasible in 7mm, I suspect shackles are going to require some watchmaking skills!
atb
Simon
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simond
Western Thunderer
As those of you who follow my workbench will be aware, I am in the final stages of the CAD for a GW match truck, all curved iron plates and rivets.
SimonD’s workbench and a couple of preceding posts
there are a further 14 rivets to add to this (unless I spot any more that are missing) and I am intending to print over the weekend. I would be very grateful for any thoughts as to the best way to support it on the build plate.
pretty much as it sits on the wagon.
My thought to support it is to angle it backwards so the resin can easily drip off both the top, and from the inside.
Something like this (these being during the actual printing, so build plate above)
I might kick one end up a few degrees as well.
thoughts, comments and suggestions are most welcome!
thx
Simon
SimonD’s workbench and a couple of preceding posts
there are a further 14 rivets to add to this (unless I spot any more that are missing) and I am intending to print over the weekend. I would be very grateful for any thoughts as to the best way to support it on the build plate.
pretty much as it sits on the wagon.
My thought to support it is to angle it backwards so the resin can easily drip off both the top, and from the inside.
Something like this (these being during the actual printing, so build plate above)
I might kick one end up a few degrees as well.
thoughts, comments and suggestions are most welcome!
thx
Simon
simond
Western Thunderer
Thanks Andy,
The challenge with this particular part is that it has traps. I have angled it so that, as far as I can tell, the resin can run out, and that it won’t trap air when the plate goes down into the resin. Actually, it will a bit, but hopefully not so it’ll cause an issue.
45 degrees is easy, because there is an increment in Chitubox, I’ve just kicked off the print, and the angle I had gone for was 21 degrees, not hugely different, let’s keep our fingers crossed!
the springs and a couple of other bits were kicked over at 10 degrees to try to not have a horizontal face as the meniscus seems to keep some resin on such surfaces. I might well try increasing that based on your “trade secret”
cheers
Simon
The challenge with this particular part is that it has traps. I have angled it so that, as far as I can tell, the resin can run out, and that it won’t trap air when the plate goes down into the resin. Actually, it will a bit, but hopefully not so it’ll cause an issue.
45 degrees is easy, because there is an increment in Chitubox, I’ve just kicked off the print, and the angle I had gone for was 21 degrees, not hugely different, let’s keep our fingers crossed!
the springs and a couple of other bits were kicked over at 10 degrees to try to not have a horizontal face as the meniscus seems to keep some resin on such surfaces. I might well try increasing that based on your “trade secret”
cheers
Simon
garethashenden
Western Thunderer
Aren't these what you want? Available with or without heads: B003Quick question about shapeways.
I'd like to purchase just some 4mm RCH buffer bodies, can't see any anywhere else except Shapeways. I have lots of buffer heads in stock.
RCH Fitted Buffer * 40 by MikeTrice on Shapeways
Check out RCH Fitted Buffer * 40 by MikeTrice on Shapeways and discover more 3D printed products in Trains.
I assume the best quality is the most expensive and is the price quoted the total price plus shipping? There's no other handling fees?
I've no experience of Shapeways.
Cheers
Tony
SimonT
Western Thunderer
I have found about 11degrees in one plane and 7 in the other to work well on both the Form and Saturn. If there is a void which can trap resin I place a drain hole to get rid of the trapped resin. Formlabs will not let a print start if there is a trap. I've also kicked Chitubox into the long grass and started using Lychee, a vast improvement to my mind.
mickoo
Western Thunderer
Interesting about angles, I've found anywhere between 32° - 36° works best or if twin axis then 32° and 14.4°.
All of which kind of confirms what I've been banging on about for ages, all machines are different and the one thing that does not transpose, even when using identical machines and resin, is angles and exposure, it's all bunkum.
You have to find whats best for you locally and use that. So beware when someone tells you their magic numbers, there's a high chance they won't work for you.
It's also dependent on layer thickness as well, what works for 50 microns rarely works for 30 or 20.
All of which kind of confirms what I've been banging on about for ages, all machines are different and the one thing that does not transpose, even when using identical machines and resin, is angles and exposure, it's all bunkum.
You have to find whats best for you locally and use that. So beware when someone tells you their magic numbers, there's a high chance they won't work for you.
It's also dependent on layer thickness as well, what works for 50 microns rarely works for 30 or 20.
SimonT
Western Thunderer
And to push home Mick's point about different machines, I have been printing at 50 microns on the Saturn and decided to print one of these files at 20 micron. I expected to get a problem to sort out but the file printed perfectly with no changes to the settings other than the layer thickness. No, I don't understand either.
simond
Western Thunderer
Well, as a first attempt, I’m quite pleased. It needs more prominent rivets, but the panels seem to be pretty much square and flat where they should be. A good start.
A little more thickness in the plate that supports the beam might be wise.
The T straps, otoh, we’re not so successful.
Nice& crisp, but probably a bit too thin. Still, I can check the fit, I hope.
Side doors, not bad, more definition on the rivets, but we’re in the ball park
End doors, what was I thinking…?
yes, you can see through them!
and the cross beam, a bit thin, rivets a bit faint, but we’re nearly there.
And I’ve done some more bits of the holster wagon. Back to the workbench thread.
Thanks to all who made suggestions, WT is a great resource.
Simon
A little more thickness in the plate that supports the beam might be wise.
The T straps, otoh, we’re not so successful.
Nice& crisp, but probably a bit too thin. Still, I can check the fit, I hope.
Side doors, not bad, more definition on the rivets, but we’re in the ball park
End doors, what was I thinking…?
yes, you can see through them!
and the cross beam, a bit thin, rivets a bit faint, but we’re nearly there.
And I’ve done some more bits of the holster wagon. Back to the workbench thread.
Thanks to all who made suggestions, WT is a great resource.
Simon