No I am not abandoning FEP, it is the release material the vat was designed for, as I said above the pdms insert is an option for the vat. The FEP based vat floor can be used with 3rd party printing resins that would quickly ruin a pdms based vat but using 3rd party resins will in some cases require print testing by the user because I cannot test every available resin. The pdms insert allows you the option of using formlabs resins with standard settings whereas using 3rd party resins or formlabs resins with FEP will require you to use the OpenPF version of Preform and custom material files.
I will print one or more of the above models but it may have to be this weekend. If you have stlâs of the entire assembly I may print the whole thing if I have time. I will post measurements and photos.
Iâve uploaded the stl files: http://ge.tt/9Sjt7lk2 (fixed, one of the planet holder files was wrong))
There are 7 of them. The planet gear, annulus and sun gear I posted earlier.
The assembly also contains input and output faces and two parts of the planet holder.
Youâd need to print 3 identical planet gears, the rest only once.
In order to fully assemble the gearbox youâd actually also need:
bearings:
5x type 692 (out dia: 6mm, in dia: 2mm, thickness: 3mm)
1x type 689 (out dia: 17mm, in dia: 9mm, thickness: 5mm)
Alternatively just print some spacers instead of them.
About 10cm of 2mm diameter rod and some tiny screws.
As the whole operation seems to be rather time consuming (if you do not actually want the gearbox), Iâd consider printing just the gears of the three different sizes and perhaps one of the input/output faces (which is a flat circular object) in order to check the roundness, dimensions and possible bends of surfaces that need to be flat.
Would you print the gears tilted with supports?
Thanks, Iâm looking forward to the results.
Btw. the dimensions and the flatness were spot on on the SLS printer, but the fine features are lacking detail (the involute shape of the teeth) and the surface is, of course, rather rough.
I printed the 3 gears in the original zip file, I will print 2 or 3 additional planet gears this weekend so i can drop all of the gears into the assembly to see how close the fit is, however, itâs hard to see how the gears could be off unless the printer itself is out of alignment. The flash you see around the gears on the build plate is from the build plate attachment exposure (10 passes), I sanded the flash off after removing the gears from the plate.
The annulus ring measures 89.69mm (tips of the mounting tabs), the netfabb measurement is 89.84. Printed using straight makejuice sf clear (not the form 1/2 mixture) mixed with red pigment, printed with 0.1mm layers.
I saw you mentioned the rtv silicone inhibited the cure of pdms. This might be due to the rtv silicone you used might be tin cured and not platinum cured as pdms is platinum cure. They need to be the same. tin cure will weep and this will contaminate plat cure silicones.
Thanks for the test print. The results are impressive.
Especially the annulus looks like it was injection molded.
Several teeth on the planet gear seem to have lower total depth than the others.
Is this the case throughout the whole width of the gear or is it just a rest of the build plate attachment layers?
Iâm just curious since the planet gear was in the middle of the build platform where the accuracy should be highest. Anyway I do not think it has anything to do with the vatâŠ
I assumed you would print the parts tilted with supports. Itâs good to see that the peeling worked well even with all three parts flat on the base. On the other hand printing them tilted would show whether forces applied on the parts during peeling cause any measurable warp. The in/out faces would have to be printed tilted, wouldnât they?
Youâll need just two more planets for this assembly, 3 planets are the maximum.
As I wrote earlier, the tolerances of this model are quite fine in order to reduce backlash, letâs see if the gears fit together.
I probably missed your explanation of why there couldnât be a F2 tray with FEP-over-thinner-pdms, with smaller clamps to resist the slide peel force. For smaller jobs, the wiper may not be that important. Having FEP would help reduce the wear from the greater exposure and heat with the new v3 opaquers?
I have always had a tendency to redesign things I have designed that I am not satisfied with and I had a problem with the limited starting volume of resin the original vat design held, Although the vat held a reasonable amount of resin I found that the vat needed to be topped off early in a build because of the limited starting resin volume. The issue concerned both the vat and the build plate. Because the build plate carriage arm drops so low when the build plate is all the way down the vat wall can only be so tall, this limits the amount of resin the vat can hold. By re-designing the vat so that the wall of the tilted side of the vat is taller I was able to increase the amount of resin the vat could hold. The original build plate with the box shape also displaced quite a bit of resin at the beginning of a print run this also added to the vats resin volume issue so I eliminated the build plates box shape and went with a shape that allows the resin to flow over the back of the build plate this displaces less resin. The vat will be available at flexvat.com August 1.
Looking at the design is there a chance it could leak around the gasket? Or is the whole tub with glass below one unit with the FEP and tensioner inside?
The vat will not leak when the gaskets (there are two one below the FEP one above) are âcrushedâ down by properly tightening the clamping bolts, the gaskets both grip the FEP film tightly and seal the vat. I have left resin in a test vat for several weeks without any leakage problems, also, I have used this vat sealing method on all of the vats I have designed and have not had any leaks reported back to me. There is no glass in the vat, the vat wall and FEP film are the âvatâ and the base plate retains the vented acrylic support plate against the underside of the FEP film. The vat, build plate, spare FEP (1 mounted 2 spare), 1 spare acrylic support plate (2 total) will be $165.00 USD, the cost is higher than the previous estimate because of the addition of waterjet cut aluminum plates to the design.
What is the total cost of the initial kit including the build platform?
Consumable costs there after?
I see the water jet cut plate on the bottom. Good idea. I didnât notice that before and thought you were using all cast urethane tank. I have done quite a bit of urethane casting and find structurally the parts donât have a memory and will distort over time. Nice to see it is backed up by a plate.
The complete kit is $165.00, this includes the vat, build plate assembly, FEP and gaskets (1 set mounted, 2 spare sets), 1 spare acrylic support plate (2 plates) . Replacement gaskets and FEP will be $12.00 per set (2 gaskets, 1 sheet of FEP). A replacement vented acrylic support plate will be $10.00.
Please note: The FEP vat must be used with the matching build plate assembly. The standard build plate is too large and will damage the FEP vat if used with it. The FEP vats build plate assembly can be used with the standard vat and because of itâs adjust-ability may work better than the standard build plate under certain circumstances.
The Form 1 vat is available at flexvat.com. The vat is available in 2 configurations FEP and PDMS, the vat can be switched between the configurations by changing between the FEP/Gaskets/Acrylic support and the PDMS insert.
I will be adding additional usage video and technical info (mostly about setting up and using PreForm OpenFL and material files for the FEP vat configuration) to the Flexvat.com technical info page later in the week.
We have received many request to sell FEP films but previously we only sold full rolls. Now I started a website that sells small pieces as well, in various thicknesses and worldwide delivery. FEP film Looking forward to hearing what you think.
