Even on something the size of a mouthpiece, the thickness can change if the air in the room changes as a person walks by. No lie.
Same thing about the surface bubbles too.
Even on something the size of a mouthpiece, the thickness can change if the air in the room changes as a person walks by. No lie.
Same thing about the surface bubbles too.
I appreciate what your saying Dave but when selling a product if the results are positive and some are negative its best to re do the negative results.vaderdarth said:
"When building a new car the brakes often fail due to parts being faulty or miss aligned, thats ok the customer is aware of it???"
Although maybe true, its not a great ideal?
Im not banging on George here but if we except any product in any field thats inferior then its our own fault. With these pulls I had 2 sets and they where replaced for Free by George, He was great and looked after me quickly from my original email. It seemed to me that this was the deal as the pulls where similar from separate batches, i went with it.
If your PD's all went to customers with large holes in them and you used a similar post as above it wouldn't stop stuff being sent back. Quality control is important at every level especially when buying a product or service.
Thats why no one has an EFX Tie fighter yet!
Re the mottled surface (bubbles) I've never had a vac pull that has this problem it seems to be on the slave pulls quite a lot so am guessing its transfer'd from the bucks, this conclusion may be due to my lack of experience with vac puling and knowledge on the subject though, like you say it could be cos people where moving around the work shop
I did some work on the front hull late last night and after a light flat sanding over the surface it brought out all the trouble areas, there are a lot like I'd previously mentioned. I went with an apoxie sculpt to make the surface flat and slightly built up to line up with the tail section, hopefully it will be set by tonight and I can sand it smooth and crack on with scribing and cutting the front hull.
It seems to be more prominent around filled panel lines from the bucks as you can actually map them from from the bare pull in places. As the styrene is stretched over quite a high buck it is like you say a very tough thing to get them uniform in thickness, the down side of this is they are very thin towards the skirt. THis makes it impossible to sand out any imperfections as the shell would be way too thin, thats why I'm building it up and lining it with Foam it 8 as recommended by Mike Salzo. The trouble i have with the front is fitting the cockpit, I need to work this out still so cant be too generous with the foam as it may come back to haunt me in a few weeks when the cockpit bucks are made.
Last edited by Guy Cowen; Aug 9, 2012 at 5:23 AM.
Well, I do know the bucks were re-sanded by the vac guy as I got them smooth, but not "glass smooth" apparently. They seemed smooth to me when I sent them out, but I've never vacformed large pieces before, so it was out of my hands. Maybe they were sanded down too much? I hit them with a couple hundred thousand coats of primer to ensure there were no imperfections, but again - that could have been undone?
In sharp contrast to the Blade Runner blimp pulls, which were primed foam - the inside of the pulls are rough (almost like Kydex!) but the outsides are smooth as silk. VERY weird, but a different vacform shop.
I'll really scrutinize my pulls this weekend, and see if I have traces of panel lines or pitting. Really frustrated for you, Guy, but it sounds like you can overcome just about anything! THAT is model making tenacity.
Cheers Jason, I've had a problem with primer lifting of bucks when I've done it at home, on my first attempt at the gun mounts my own buck got ruined and the primer was all over the inside of the pull.moffeaton said:
yeah I agree guy, it's truly frustrating when quality control is missed. No doubt. Of all the methods of fabricating we have, vacuum forming is the least accurate way to reproduce something. Always will be. Way too many variables involved.
First wave of Clay on the front hull has improved stuff by about 90%, 10% more effort required to get a match in the hulls
Once its uniform in shape I'll clean up the edges with P38. Theres also a 2mm styrene plate to go between the 2 halves to represent the internal structure that doesn't exist on my build.
Cheers Dave, Got some more work done tonight. Re sanded the clay work and tidied it up a bit and also made the centre layer that goes between the 2 halves.
You can see below its not a pretty site on the inside. The lower section has just foam it 8 on the inside and the top section just has Apoxie sculpt for now, this is to hold the glue joins solid as it will take some stick with sanding. Aslo this now has a 7mm thick solid rib now. The hole armature and and weight of the model will be supported by this, its the key to it all fitting together.
If I went down the route of copying the ILM build I know it wouldn't work and would need at least 4 pulls of each section in a good uniform thickness.
My plan in my head is to have a 6mm (2 x 3mm) styrene strip going horizontally between the front and back skirt to make them one piece, this will thn bolt to the centre rib shown here with angle brackets. All the engine detail will then mount to the Skirt horizontal rib.....all in my head.
Like a gutted fish!
Slightly more accurate now
I respectfully bed to differ.vaderdarth said:
If you use an inset riser and drill vent holes you can get a consistent thickness throughout the pull.
The K'tinga is roughly 3 times the size of the Slave and the styrene is perfectly 1/8" of an inch in every area. Steve N can attest to this as he saw it in person.
http://www.therpf.com/f10/studio-sca...3/#post2276225
Another advantage of the inset riser is you don't have to do any special measurements to find the edge of the part, you simply cut it off where the riser ends, and it's perfectly straight.
I plan on using this technique on my own vac formed Slave hull.
An example of using the technique I described. The parts fit flawlessly together with no distortions or varied thickness.
I thought you had a really nice hull alreadyREL said:
REL said:
Thats true, although it is shape dependent. the flatter the part the more consistant the pull. the higher the part and more draft will cause irregular thickness. you can some times use a mold release to help the plastic even out over the plug. IE, baby powder or vaseline.
my half a peso.
REL said:
Where you standing still when you pulled em
Apparently my upper hull is fine but the skirt is too small. I'm in the process of remedying this.Guy Cowen said:
I thought you had a really nice hull already
This is the biggest flaw in the slave pulls, they're so high that the styrene does thin out as you get to the lowest part, quite considerably on mine. The first set I have measure from around 2.5mm at the crown to 0.5mm.
Another issue with the skirt is the curve is too great where it meets the hull, you loose a lot of the rear plate detail cos of this, if you can lesson the highest curve you cant go wrong.
That's what I plan on doing with mine. Fill one of the fiberglass castings with foam, then reshape the entire thing, flattening it out some. After looking at more of the reference my skirt had the same problem.
At that point if I do a vac pull it will be the correct shape and size. Then I will do a reverse vac mold to pull the upper and lower so all the detail will be present.
LOL, yeah, me too?
Glad you're still in the Slave 1 mix, REL!
LOL. You've got a tough row to hoe, as it were. But, it is coming along nicely, Guy. Thanks for the tag line!Guy Cowen said:
...Like my tag line says, part of my drive is so that you actually get to see a finished Slave, it may not be your own but its a indication that it wasn't a failed or wasted project. I know what this meant to you and seeing mine painted will be a gift from me, you cant have it though
Looks great Guy nice and sharp so far!
I never prime the bucks and form the
primer lifts from the heat......then your
stuck working on the buck between pulls.
I always prime it see if it looks good .....
then sand all the primer off. You can use
the heat resistant paint if you want but thats
not really primer.
Vacuum forming will never save you ......it will
show you all your problems just like primer. If you
have irregularities like high and low spots in your pulled part you can go
right back to the buck and find it.The first pull should be primed and then
you see how much work is left to do on the buck.
The thinner the plastic you use will show more of the irregularities ,
if there are any.
Have fun with it ............that's what it's all about!
If there's a list can I be on it too..?REL said:
Cheers
Phil
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