NuVat by Evert - Testing Results

B9Creator - Ideas and Discussions
User avatar
tim.yoshi
B9 Master
B9 Master
Posts: 822
Contact:

NuVat by Evert - Testing Results

Post#21 » Fri Nov 21, 2014 4:49 am

Dunno about mylar but teflon for sure must scatter light. At least a little. But all that should finally affect quality. So surface must be clean and truly clear... as glass.. Maybe ordinary glass?
Image

User avatar
Metalcaster
B9 Wizard
B9 Wizard
Posts: 1293
Contact:

NuVat by Evert - Testing Results

Post#22 » Fri Nov 21, 2014 5:26 am

I use teflon film instead of pdms on a different machine and it works in that application. Glass should work also.
maybe at a slight angle to direct the resin away from the projector

User avatar
lobby
B9 Maker
B9 Maker
Posts: 263

NuVat by Evert - Testing Results

Post#23 » Fri Nov 21, 2014 6:01 am

Seems to me that if the problem with these larger prints is the resin releasing from the NuVat layer and pulling the glass off the vat, then perhaps the solution is better adhesion between the glass and the vat.

Others have already stated this.....

lswatson
B9 Wizard
B9 Wizard
Posts: 1157

NuVat by Evert - Testing Results

Post#24 » Sat Nov 22, 2014 2:22 am

Very sorry to see your projector killing incident, Mike. Looks like sealant failure was part of the problem.
With MS Black, I've noticed that sometimes, if I do not give the vat a bit of a push on the first few layers, or it will bind. After that, its been smooth sailing since June.
I think all my jewelry parts fall into the "small" category, although I printed one just under 100mm and then the 200 test which I posted.
Could be that the NuVat material works best within a certain size range of model. If that's the case, it should help you broaden your market to people that print those kinds of parts. I'm not really married to the idea that one material will solve all problems.
Please let me know when you will be offering a vat with removable glass and the NuVat material. I would order two to start. My current vats are showing wear (hair line cracks, with no alcohol wash) and will need to be replaced soon. I don't anticipate using PDMS again.

User avatar
mikej
B9 Moderator
B9 Moderator
Posts: 4189
Contact:

NuVat by Evert - Testing Results

Post#25 » Sat Nov 22, 2014 2:28 am

Yes, whatever sealant Evert used on the vat he sent gave way when it tried to release.
I don't anticipate selling NuVats, I'll let Evert do that if he wishes.
Measure Twice, Cut Once.

lswatson
B9 Wizard
B9 Wizard
Posts: 1157

NuVat by Evert - Testing Results

Post#26 » Sat Nov 22, 2014 2:36 am

I just ordered one of your alum. vats. Very excited to start working with it.

User avatar
Metalcaster
B9 Wizard
B9 Wizard
Posts: 1293
Contact:

NuVat by Evert - Testing Results

Post#27 » Sat Nov 22, 2014 5:02 am

If Switching to the new glass from evert, I have 2 suggestions ( which I will be trying soon) 1 is to use Black RTV Silicone Instant Gasket ( Napa auto parts). It has an 800 oF temperature resistance and bonds to the aluminum and glass. I cure it in 1 hour in my electric oven at 200 degrees.
I am using this sealant now on my trays as the clear silicone was leaking and I had to redo 2 of them.

The second Idea is to cut a thin silicone rubber gasket and create a screw down metal rim that will hold the gasket tightly with no sealant.
This would allow you to remove the glass easily and replace the glass when needed. You would probably have to set the Z axis to raise high enough to clear the thin metal / silicone retainer. I like this idea better just in case the glass has to be re-coated .

User avatar
Metalcaster
B9 Wizard
B9 Wizard
Posts: 1293
Contact:

NuVat by Evert - Testing Results

Post#28 » Sat Nov 22, 2014 5:04 am

Also, If the new glass from evert is coated from end to end with this special release coating, that may explain why the sealant gave way in mikes experiment. You may have to sand down the glue area of the glass to get better adhesion... just another thought !

lswatson
B9 Wizard
B9 Wizard
Posts: 1157

NuVat by Evert - Testing Results

Post#29 » Sat Nov 22, 2014 6:16 am

The second Idea is to cut a thin silicone rubber gasket and create a screw down metal rim that will hold the gasket tightly with no sealant.
This would allow you to remove the glass easily and replace the glass when needed. You would probably have to set the Z axis to raise high enough to clear the thin metal / silicone retainer. I like this idea better just in case the glass has to be re-coated

Evert and I talked about this when he developed the Undead Vat a year or so ago. Maybe this will spur development.
L

User avatar
akgold
B9 Wizard
B9 Wizard
Posts: 2085

NuVat by Evert - Testing Results

Post#30 » Fri Nov 28, 2014 11:37 am

I just got back from a short 10 day vacation, sorry to hear about the projector Mike,
as for a way to prevent the glass from releasing I would guess that putting a metal bar or set maybe three metal stops on the deep side of the vat would prevent the glass from moving in the xy position on the release cycle. most likely there is no need to hold it down in the z as we shouldn't see any upward pull of the glass from the cured resin.
So one way to do this that comes to mind would be to use some basic self tapping metal screws with gaskets. drill the appropriate holes and use a hex head like shown here. I would grind off the rounded bottom or find some that are just the bolt head then remove the excess under the vat of course. you could use the glass as a template for the the straight edge needed and then just mark the 3 or 4 holes along the line and drill. use a silicone seal or some locktite on the threads and the squared edge of the bolt could hold the glass in place prior to epoxying or silconing in the glass.
Image
I'm so far behind I think I'm First !!

User avatar
tim.yoshi
B9 Master
B9 Master
Posts: 822
Contact:

NuVat by Evert - Testing Results

Post#31 » Fri Nov 28, 2014 11:26 pm

Cool idea. But are you sure that vat will not get bent?
Image

User avatar
Metalcaster
B9 Wizard
B9 Wizard
Posts: 1293
Contact:

NuVat by Evert - Testing Results

Post#32 » Sat Nov 29, 2014 4:06 am

In addition to my suggestions above on using a thin silicone rubber seal on the bottom of the glass and creating hold down strips of metal on the sides. I would suggest an L shape aluminum angle . You put the retaining screws in the Long side of the L so that you do not have to drill holes in the glass( which could also be done ) the screws would go out the side of the casing. You might also need screws in the bottom of the L perhaps to apply pressure on the glass.
Finally, to strengthen the bottom of the aluminum tray,you can epoxy some metal strips around the opening in the tray... underneath. there is an area about 1/8" (3 mm approx) that the enforcement can be added to keep the aluminum tray perfectly flat where the seal is.

After thinking a little further, I will first do the experiment on my old acrylic trays where the main area is damaged. Remove that area and put the Evert glass in place with a removable system.

User avatar
Metalcaster
B9 Wizard
B9 Wizard
Posts: 1293
Contact:

NuVat by Evert - Testing Results

Post#33 » Sat Nov 29, 2014 4:09 am

Also,
I have built similar system on a different machine. The rubber seal system does work.

User avatar
akgold
B9 Wizard
B9 Wizard
Posts: 2085

NuVat by Evert - Testing Results

Post#34 » Sat Nov 29, 2014 7:25 am

I would wonder if the orings would make the vat un level siting in the vat.
It is important that the vat glass is actual slightly tilted more to the deep side rather than the print side. also getting it level in the Y as well make it easier to calibrate the table if it is either dead flat or slightly tilted.
a small angle shaped metal piece is a good idea. I was just think about something that is very simple and not having all the parts to get gooed up with resin and all the floater gremlins hiding in the all the little gaps just waiting to get washed out on the next print to mess it up.
if the force from suction is causing the glass to slide off of the vat then the only place you need a stop is on the open end of the glass.
there should not be any suction pulling the glass upwards. That is a whole different set of problem.
I like the idea on the other thread of using a flat glass on the entire bottom so you can switch it. I suggusted it could be done if the new glass had a V cut in it or if it is PDMS a V cut in the very middle and there would be 0 overlift.
I'm so far behind I think I'm First !!

User avatar
Metalcaster
B9 Wizard
B9 Wizard
Posts: 1293
Contact:

NuVat by Evert - Testing Results

Post#35 » Sat Nov 29, 2014 1:05 pm

I mentioned the flat glass on the other thread as I think it is the best way to have a totally flat tray... I use heat cured silicone sheet as a gasket material... not an o ring. that way the glass stays flat on the silicone. I use a similar system on a different machine.

User avatar
Metalcaster
B9 Wizard
B9 Wizard
Posts: 1293
Contact:

Re: NuVat by Evert - Testing Results

Post#36 » Sat Dec 13, 2014 10:31 am

I modified one of my old Acrylic vats by machining the acrylic window out, giving me a nice smooth surface to glue the NUVERT Glass. I used 800 oF Black silicone engine gasket sealer. this works fine.

On my second NUVERT glass, I installed it in one of Mike's Aluminum Vats. The glass that I purchased was smaller then the original glass. After glueing it in , I noticed how much smaller the glass actually was. It only had a little over an 3/16th " holding all the way around.

I think that is why the glass may have popped off on Mike's Machine... not enough surface glued to hold in place on larger items.
Need to find out if the glass he received was small.....

I emailed Evert to let him know that if he supplies the glass all coated, he must find out what tray it goes on . If you supply your own glass to him, then you may not have a problem.

I will not run large parts on that tray as I do not consider the holding power to be safe currently and I can't afford to loose a projector. Small parts are running fine with no apparent problems. I have run medium sized parts with no problem with B9Rred

Return to “General Discussion”

Who is online

Users browsing this forum: No registered users and 1 guest

cron
Close Menu Shop Forum