TOS Enterprise question????

[DarthJRW]

hey guys

im making a 3 foot vaccumformed model of the TOS enterprise.

now ive got all the parts covered EXCEPT the saucer.

could someone give some tips on how to make the saucer,like what material to make the mold out of ???

thanks

DarthJRW

 

[jakob2121]

seems like MDF would be the way to go.

 

[DarthJRW]

ya but with all the little dips and curves how would go about shaping it ??

 

[jonnytrooper]

Hey, if you need any help, I can stop by sometime this week. Did you ever cast them in resin, or did you decide to vacuform the little greeblies?

 

[DarthJRW]

hey jonny

the little greebles will be cast resin but i still cant find a way to get the saucer done

Originally posted by jonnytrooper@Jul 23 2005, 08:08 PM
Hey, if you need any help, I can stop by sometime this week.  Did you ever cast them in resin, or did you decide to vacuform the little greeblies?

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[phase pistol]

Well you'd have to turn a disc of wood on a lathe I guess?

The saucer is symmetrical except for the teardrop shaped B/C deck on top...

- k

 

[jonnytrooper]

Reporting for duty sir, when should I come over. Hows tomorow?

 

[DarthJRW]

pm sent

Originally posted by jonnytrooper@Jul 23 2005, 08:15 PM
Reporting for duty sir, when should I come over.  Hows tomorow?

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[jonnytrooper]

I'll talk to you tonight or tomorow then. Just sitting down to watch lotr, talk to you later

-JT

 

[DarthJRW]

any other suggestions????

 

[jakob2121]

MDF would be easy, though you'd have to hand-shape it with a plane. Heck, you could make "steps" of various diameters and bondo the slope between 'em.

 

[star-art]

Well, without trying to reinvent the wheel, there are basically three approaches that have been done in the past:

1. Turn a very large disc out of Renshape or other wood substitute. Requires very expensive special equipment, limited by the size of dish needed.

2. Make radial ribs, fill in with foam, then sand to shape. Difficult to get a perfectly even surface this way, but you can work in any size.

3. Build a custom rig and turn the shape from hydrocal. This is what Custom Replicas did with their big 5.5-foot model. It works. And hydrocal should make a good master for vacu-forming -- just watch out for shrinkage. You might try to avoid making the plaster too thick so it won't crack or shrink. Place it on a strong backer board as well that won't flex under pressure and allow it to crack.

 

[DarthJRW]

how would i go about making the rig????

Originally posted by star-art@Jul 24 2005, 01:41 PM
Well, without trying to reinvent the wheel, there are basically three approaches that have been done in the past:

1. Turn a very large disc out of Renshape or other wood substitute. Requires very expensive special equipment, limited by the size of dish needed.

2. Make radial ribs, fill in with foam, then sand to shape. Difficult to get a perfectly even surface this way, but you can work in any size.

3. Build a custom rig and turn the shape from hydrocal. This is what Custom Replicas did with their big 5.5-foot model. It works. And hydrocal should make a good master for vacu-forming -- just watch out for shrinkage. You might try to avoid making the plaster too thick so it won't crack or shrink. Place it on a strong backer board as well that won't flex under pressure and allow it to crack.

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[star-art]

Unfortunately I see the photo is no longer on their website. You start with a flat surface such as a table, in the center is a rod or tube. Over this mounts a scribing template which is a piece of rigid sheet metal in the shape of 1/2 of the hull profile. You would build up the center area with scraps or whatever to make the final plaster surface an even thickness.

Apply the plaster when it is the consistency of whipped cream, then rotate the scribing tool in a circle to shape the plaster. This is tricky and requires some practice. Shape the plaster as much as possible before it is fully hardened. Keep building up layers until you are done, keeping in mind that additional layers will cure more quickly because the underlying layers will absorb the water from the new material as soon as you apply it.

Be sure to use only high quality hydrocal plaster.

If your finished model is 1/350 then the saucer won't be that big, so the very best approach is probably turning a master from Renshape if you can get access to a lathe that can turn bowls and dishes that large.

Hope that helps.

 

[DarthJRW]

whats renshape?

 

[CaptCBoard]

Originally posted by DarthJRW@Jul 25 2005, 01:33 AM
whats renshape?

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Renshape is one of a family of mastering materials intended to replace wood and aluminum, made of a filled urethane it comes in various thicknesses and densities. Model Plank, from BJB is a similar product but not as expensive as RenShape. That being said...

I really hate to say this, but if you don't know about the plaster technique and you don't know what RenShape is, you probably don't have enough expertise to pull the job off without a whopping huge amount of experimentation. My recommendation is to find someone who already knows how these parts should be made and have them do the mastering. And second to that suggestion is, in the case of this particular part, you should definitely NOT be trying to vacuform over a postive master, but pulling the plastic into a negative. Getting the pull out of the negative will not only be much easier (basically it'll just jump out) but if you put any detail on the 'positive', it will come out much crisper since the finished surface of the plastic will have been against the finished surface of the mold. Pulling plastic over the positive itself means the contacting surface is on the inside and any detail will be 'mushed' due to the thickness of the plastic (even if its really thin...). Even if there isn't any detail being formed other than the general shape, its still better from a production standpoint to pull the plastic into a negative mold-- the parts will be very easy to remove and the mold will hold up much longer as there are no shrinkage stresses building up on it. If you are only making a few (less than 5 or 6) of these parts, it probably won't matter. But if this is going to be a kit where you make more than that, this is a consideration you need to be aware of.

Scott
CaptCBoard@AOL.com

 

[cobywan]

Smooth on sells resins that are specifically created for making vacuumfoming molds.

 

[DarthJRW]

Originally posted by CaptCBoard+Jul 24 2005, 11:39 PM--><div class='quotetop'>QUOTE(CaptCBoard @ Jul 24 2005, 11:39 PM)</div>

i finally figured it out 

i have the blueprint for the 3 footer and i used basswood for the basic disk shape then im carving the details such as curves domes ect, out of carving foam and its working great ....

i will post pics shortly






<!--QuoteBegin-DarthJRW

@Jul 25 2005, 01:33 AM
whats renshape?

[snapback]1041309[/snapback]​

Renshape is one of a family of mastering materials intended to replace wood and aluminum, made of a filled urethane it comes in various thicknesses and densities. Model Plank, from BJB is a similar product but not as expensive as RenShape. That being said...

I really hate to say this, but if you don't know about the plaster technique and you don't know what RenShape is, you probably don't have enough expertise to pull the job off without a whopping huge amount of experimentation. My recommendation is to find someone who already knows how these parts should be made and have them do the mastering. And second to that suggestion is, in the case of this particular part, you should definitely NOT be trying to vacuform over a postive master, but pulling the plastic into a negative. Getting the pull out of the negative will not only be much easier (basically it'll just jump out) but if you put any detail on the 'positive', it will come out much crisper since the finished surface of the plastic will have been against the finished surface of the mold. Pulling plastic over the positive itself means the contacting surface is on the inside and any detail will be 'mushed' due to the thickness of the plastic (even if its really thin...). Even if there isn't any detail being formed other than the general shape, its still better from a production standpoint to pull the plastic into a negative mold-- the parts will be very easy to remove and the mold will hold up much longer as there are no shrinkage stresses building up on it. If you are only making a few (less than 5 or 6) of these parts, it probably won't matter. But if this is going to be a kit where you make more than that, this is a consideration you need to be aware of.

Scott
CaptCBoard@AOL.com

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