PreForm - New Print Report off a bit

[LEADNAV]

While I like seeing how much my parts will cost within PreForm, as far as material costs… it is a bit off.

It has been proven that Nylon 12 GF must be printed at a 70% refresh rate to produce durable parts that are not brittle and just to keep the print job from failing repeatably.

So when needing to run 70% refresh, you are going to be throwing ALOT of Sifted powder in the trash to empty the Sift as your Refresh rates are “upside down” at that point.

At one point a Formlabs rep tried to tell me to “save all that powder”… but storing excess powder that you can never use… did not make sense.

Anyway, here is the issue with the new Report in this example.

With 70% refresh and the cost added…

So as you can see it looks great up front… with this 3 component part estimated at only $31.50 and the three components costing each $25.47, $3.77 and $2.26 up at the top… but that obviously is not the correct projected cost per part.

At 70% refresh you are only going to be “saving” 30% of that “excess powder cost” down there on the bottom right of this report. Even at 50%…I’d rather see each part quoted with the refresh rate in mind…

In this scenario the “Part Cost” would be well over $100 and no where near the “$31.50” estimate given.

So not sure at a glance what this report feature would provide you with…other than “wishful thinking”?

Note… making this part for over a $100 would never financially make sense over other manufacturing means…as this powder is WAY OVER PRICED to make production parts possible…but even if this part was a “prototype” or for “aerospace”, this new cost estimate is not very useful as is, at providing a quick estimate at a glance.

In this scenario, you are better off just subtracting the “unsintered powder” in your chamber by the 30% that you could actually salvage (not even all that 30% would get used in the next job with the additional refresh), adding up the total used cost of powder in that chamber and dividing that by the number of parts in that chamber…

In fact, with Nylon 12 GF, to be on the safe side, with print failures, layer shifts on larger parts and everything else with vacuuming out the trays, doser, etc before the next print…at 70% refresh and all that factored in you are better off just taking 100% of that powder used in the chamber and dividing it by the number of parts within it for you actual “cost per part” Haha sad but true…so in this example we would just go ahead and say that this assembly would cost the $152.07 you have down there in the Total Print Cost + post labor

[eaglechen]

Question for you sir, if 12GF can theoretically achieve that 30-50% refresh rate with reasonable part performance, how much would this part cost (well, this pertains to your business, so I don’t expect you to answer on public forum if you do not want to)?

I ask this to allude to the main point, as to how does one actually manually measure part cost? So if a given typical packing density, like a 30% refresh rate should in theory lead to sintered power+30% of unpacked volume in cost expended per print?

I’m guess it would then be absolutely cost ineffective for printing like one thing with low packing density unless you are “prototyping rocket duct to sell to aerospace…”

edit: fortunately if I buy this thing I would print regular Nylon 12

[br4n_d0n]

@eaglechen

if I buy this thing I would print regular Nylon 12

I would advise against this as users seem to have nothing but issues with Formlabs current SLS technology and it’s even more expensive than the Form 4 stuff you’ve been having issues with.

[LEADNAV]

You absolutely cannot print Nylon 12 GF anywhere near the 30-40% refresh rate range. So let’s just ignore that as being even a possibility.

“If” you printed at 50% , you will still have a very high failure rate and not worth it… I try even down at 60% and it just ain’t worth the failures. This report they generate would only work below 50%…as you would need to take that Cost per part they tell you of $31.50 and still have to take that “Excess powder cost” down there at the bottom right, subtract the actual refresh rate from that and add it to the cost per part. (again I’m not sure why they chose to generate this report system like this)

So if that powder usage in this report was right, you would still be up there for this one part.

But… it is already a HUGE gamble running parts of this size even at a 70% refresh. At a 70% refresh I eliminated nearly all of the issues and print failures I had for over a year, trying to print Nylon 12 GF at a 50% refresh.

That being said, I still only run parts on this system, if I can get around “100+” units of that part…per chamber.

I would never do a part of this size or anything where I could not at least get 100 units into one chamber.

I say this number because for these parts you can get that many in…you are most likely doing rows of 7-10 parts and these rows are only an inch high in the Z axis. That way… when you get a random layer shift or a blemish in “a part”…you are only down 7-10 parts in that row or a single part from a blemish out of that entire chamber.

If you try to print a larger part like this, where you can only get 5-10 units in a chamber, depending on how they are stacked… you could very well be throwing the entire chamber of parts in the trash with nothing to show for it. A blemish may kill one part but if they are tall parts and a layer shift happens…well that wipes out the entire chamber of parts…

So generally when looking at an SLS system you have to basically divide how many parts you can fit in each chamber…by at least $1,000-$1,500 in material, post processing labor and any overhead you have at scale as a business. The problem is the MAJOR amount of this cost is this cost of SLS powder alone and its 70% refresh needed to run.

Has very niche use cases but if you can get 100+ units in a chamber…then maybe the gamble is worth the job to run that part!

[eaglechen]

Wait, so at 70% refresh you are still gambling for the prints finishing without defects? Build chamber and general reliability issues are still not sorted? I guess even printing nylon 12 is no guarantee of things consistently working…

I guess my dreams of service bureauing just with just nylon 12 for many geometries or reasonably big things occasionally is just not realistic. I probably need to look elsewhere then.

I think the inkling I have heard from industry is that the if you pay the blood money for a big MJF or SLS machine upfront the material cost is cheaper, especially if bought at volume (I think I also generally hear those machines will finish prints reliably and the claimed refresh rates are not snakeoil):

HP 3D HR PA12 300L/130Kg

eos-materials-price-list_06-19-14.pdf

50-85/kg of powder beats Formlabs by quite a bit. I have done many spreadsheets that allude to Formlabs running costs not being lower than those 250K printer companies and I’m starting to believe that. That could be fine, but if I have to gamble with nylon 12 with a 5 figure machine then its not exactly a wise proposition…

[LEADNAV]

I mean to be fair… I hear everyone running Nylon 12 alone is doing fine and can easily hit at least a 50% refresh rate for production parts. I needed the additional heat resistance and finish quality from the Nylon 12 GF. Still this powder is crazy as far as costs go and by itself is definitely killing this system as a great production possibility.

I have yet to really meet a true company running these at scale for production parts… a few of us…in very niche use cases seem to be making it work but I have only met three others like myself.

Supposedly there are bigger companies running “tons” of powder at scale… but I have yet to hear who that is and if they are doing something other than aerospace or government contracts. I also hear they get powder discounts at scale, which this would be awesome if Formlabs actually promoted this publicly as even a possibility and if so at what cost. That way, we could see at least a path forward of possibility…

But yes, I know several folks actually running production level parts and they are absolutely running HP MJF systems. In fact one company I know is running three of those.

When the cost of powder comes down greatly…this system will be absolutely awesome. However, I think that will take another outside company to get this one out of the high dollar “printer ink” business model.