Plexiglass Barrier for a flat PDMS and smooth edge

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Alexandre
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Plexiglass Barrier for a flat PDMS and smooth edge

Post#41 » Wed May 28, 2014 11:18 pm

Hi Sotar 1921

I did not forget !
I will try to do it tonight if not i will do it this week end for sure !

Alexandre

Alexandre
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Plexiglass Barrier for a flat PDMS and smooth edge

Post#42 » Fri May 30, 2014 12:24 am

Hi

I remake the exact same bridge i did on my first vat, there is the picture of the tool i use.
The Plexiglas thickness is 2.5 mm but it doesn't matter if if less ! but to thin will bend to much while working.
The height is 5.5 mm

The glue i use is 2 component epoxy. because it as a high viscosity, it is easy to seal the corner !

And while working i just discover that we can simply print a bridge in the 100 xy um configuration.
this will be my next experience !
Less work and easier to share.

Tonight i will pour the PDMS and make more picture !

Alexandre

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tim.yoshi
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Plexiglass Barrier for a flat PDMS and smooth edge

Post#43 » Mon Jun 02, 2014 9:28 am

Ok, but why not to place bridge (barrier) vertically, with straight square window? Just like in the new mike's VAT design? Some king of hybrid design VAT :)
Just like this (modified Alexanders drawing) :

Whoops. Drawing in the next post :)
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tim.yoshi
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Plexiglass Barrier for a flat PDMS and smooth edge

Post#44 » Mon Jun 02, 2014 9:30 am

Here it is.
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brumbaer
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Plexiglass Barrier for a flat PDMS and smooth edge

Post#45 » Tue Jun 03, 2014 6:21 pm

Most likely, because this is the modification of an existing Vat, which has the slope of he waterfall.
The barrier has to be mounted somewhere and the waterfall is a natural choice, because it is the part, whose function is to be replaced, and because it offers a large flat surface to glue the barrier to.
If the waterfall would be a step instead of a slope, it would mostlikely be a vertical barrier resting against the step.

Alexandre
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Plexiglass Barrier for a flat PDMS and smooth edge

Post#46 » Wed Jun 04, 2014 12:25 am

Hi

Brumbaer you have the perfect answer !

Tim yoshi yes some user will prefer to have a cliff instead of a waterfall.
I was thinking about making a barrier printed instead of making one by hand for my next experience.
The printed one can start with waterfalls and finish a the top with a cliff. The barrier will have a angle, the bottom part will be glue on the waterfall.
If we don't use a strong glue it will be easy to replace the bridge if there a accident.
Some user was talking about making a barrier softer like silicone, the barrier can be printed with the makerjuice SUBFLEX. Its like hard rubber.
I will buy a new vat soon and remake some new experiment.
Everything here is to make user using the 48h pdms curing easier.
I will post soon those new pictures I promise about the pdms flowing over the barrier !

Thank
Alexandre

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tim.yoshi
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Plexiglass Barrier for a flat PDMS and smooth edge

Post#47 » Wed Jun 04, 2014 12:37 am

Ok, I see that it's for modification of existing VAT.

I was asking if there will be real benefit in making new vat with barrier installed vertical? Looks like we need to try it before there will be an answer.

One could leave it to cure for some 10-15 hours and then accelerate curing by placing it in the oven WITHOUT leveling. It should be already leveled and pretty hard.
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mikej
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Plexiglass Barrier for a flat PDMS and smooth edge

Post#48 » Wed Jun 04, 2014 7:43 pm

Quote from tim.yoshi on June 4, 2014, 06:37
One could leave it to cure for some 10-15 hours and then accelerate curing by placing it in the oven WITHOUT leveling. It should be already leveled and pretty hard.


Great idea!
Measure Twice, Cut Once.

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tim.yoshi
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Plexiglass Barrier for a flat PDMS and smooth edge

Post#49 » Wed Jun 04, 2014 11:30 pm

Quote from mikej on June 5, 2014, 01:43


Great idea!


Thanks :) I do always see that when cured in oven it becomes hard enough to hold it's form even after some hour. All other time is just to finish cure. I'd said that 1-2 hours is more than enough for already semi-cured semi-hard PDMS.
As per natural cure under room temperature - never tried it. But AFAIK 24 hours *should* be enough for normal full curing. Based on this I suppose that even 5-10 hours of natural cure *could* be enough to grab it for the 1-hour finish cure in the oven. Thus most likely use case for this hybrid scenario is:
1) In the evening mix PDMS, pour it in the VAT
2) Leave overnight LEVELED
3) Finish cure in the morning throwing it in oven for the time of breakfast
4) ???
5) PROFIT! :)

I'm gone try it when I'll order some new vat's from acrylic shop. After some nights of thinking about it, it looks to me like very good method with huge benefits.
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akgold
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Plexiglass Barrier for a flat PDMS and smooth edge

Post#50 » Thu Jun 05, 2014 7:30 am

Sounds good to me
I know that my problems last month all happened after it was in the oven or on the heater.
when it sat on the table level all dimples and bubles were gone. but it seems that after I put it in the heat
it "developed" bubbles and dimples that didn't seem to be there before.
I'm so far behind I think I'm First !!

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tim.yoshi
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Plexiglass Barrier for a flat PDMS and smooth edge

Post#51 » Tue Jun 24, 2014 8:54 am

So anyone have any updates on this method? I want to try it but stuck with not having spare VAT right now. Will make some in coming days/weeks. But it's interesting if someone already had extensive testing?
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Robert Howle
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Plexiglass Barrier for a flat PDMS and smooth edge

Post#52 » Tue Jun 24, 2014 9:03 am

I mix and pour, let sit till flow is complete and all bubles gone, (usually about 1 hr.) and put in preheated oven for 10 min at 250 F. Then raise to 275 F for 45 min. Done. Whole process takes me about 2 hrs.

All steps done with vat level. Sitting waiting for complete "flow" and no bubbles, and in oven.

I don't do the 1/2 vat thing anymore. I went back to full coverage and waterfall method, using new anodized KatVat. I really love it.

I am sure Mike's new vats will be as good. Don't have one yet, but will when the new kit comes
Dance like nobody's watching!

m0delista
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Re: Plexiglass Barrier for a flat PDMS and smooth edge

Post#53 » Thu Jul 06, 2017 10:46 am

If you make a strait botton mabe you can turn the tray and use the 2 sides when burn the pdsm ! or not ?

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