Jump to content

Su-27UB - New kit from Zvezda - 1/72 scale


Recommended Posts

  • 6 months later...

I'm very much looking forward to this kit. I like the looks two seat Su-27 better than the single seaters, and I'm glad to see a better treatment than the mediocre Trumpeter kits.

 

Cheers!
 

Hoops

Link to post
Share on other sites
  • 3 weeks later...
  • 2 weeks later...

Note the unique method of moulding the clear windscreen and canopy - invented by the Zvezda designer.

 

It enables the canopy to be moulded with the correct horseshoe/Omega cross section - but without a slide mould that results in a seam down the canopy.

 

A breakthrough in moulding technique.

 

Ken

Link to post
Share on other sites
5 minutes ago, Flankerman said:

but without a slide mould that results in a seam down the canopy.

Axial slide mould where the inner mould arrives and goes at the front of the outer mould ?

Link to post
Share on other sites

Yep it is a solution to the old "Omega" problem!  :worthy:  :yahoo:

Hope they did not use this time the "soft" clear plastic resulting in so many rejects.

 

eAY4V54.jpg

 

 

But also see that the canopy frame is separate.  :hmmm:  Which is also a solution but also could be a problem with the glued surface which will be visible. Using white glue could be an alternative to make it invisible. But will have to see it when the plastic is available.

 

 

VKmqTJy.jpg

 

 

Best regards

Gabor

  • Like 1
  • Thanks 1
Link to post
Share on other sites
On 31/10/2018 at 23:19, Flankerman said:

Note the unique method of moulding the clear windscreen and canopy - invented by the Zvezda designer.

 

It enables the canopy to be moulded with the correct horseshoe/Omega cross section - but without a slide mould that results in a seam down the canopy.

 

A breakthrough in moulding technique.

 

Ken

Sorry, I don't think that is unique, Hasegawa moulded the Omega croess section windscreen of their 1/48 F/A-18C this way too(in 1992), it's similar to moulding a nose cone or spinner vertically, I think the part will still need to be placed/oriented in a way that it can clear the mould, this is not always possible, an obvious example is the F-16's main canopy, it's tear drop shaped, which means that no matter how you orientate the main canopy in the mould, the largest cross section will always be in the middle potion of the cavity , so the same problem as the Omega cross section will always exist, it would stuck in the mould without the slide mould to open up the cavity.

 

In fact because canopies usually curves down at the front and at the rear end, in most case it's not possible to mould an Omega cross sectioned vertically at all: when oriented vertically, the largest cross section would not be at the end of the cavity, but in the middle, so basically it would be impossible to remove it from the cavity without breaking the part, if the mould itself could still close and wouldn't then be locked together.

 

That is also the case with Su-27UB's canopy, but I see that Zvevda cleverly divided the main canopy into 2 parts, right at the middle frame, where the cross section is at it's largest. This way they can orientate both sections, so that the largest cross sections are at the end of the cavities, which makes it possible for these parts to clear the mould.

 

This type of technique obviously can not be applied to canopies without middle frame. For those who would care, it requires some more careful alignment of the two sections. At this zoom level, a very slight step/misalignment is visible here at the middle frame:  

181018061851977202.jpg

 

 

By the way, what was the problem with the soft clear plastic?
 

Edited by delide
  • Like 1
Link to post
Share on other sites
6 hours ago, delide said:

At this zoom level, a very slight step/misalignment is visible here at the middle frame:  

I think that is simply due to a small mistake in actual model building by the company

 

6 hours ago, delide said:

By the way, what was the problem with the soft clear plastic?
 

I think the uniqueness is in that this technology has not been applied before to the Flanker “Omega” canopy (dont remember seeing it).

The worst scenario was when manufacturers made the correct outer “Omega” cross section while on the inside they simply had a flat surface which basically resulted in an optical lens distorting completely the view.

 

Of course you will never be able to reproduce in all its glory the original canopy for a plastic kit, be it any scale. Here the 72nd has an added disadvantage of minimal demanded plastic thickness for molding, which in this scale is unfortunately very noticeable.

 

Well it is always possible to do a good vac form canopy but as far as I see modellers and manufacturers are starting to forget how it worked.

 

I did not have a problem with the “soft” plastic, did polish it and after a “Klear” treatment it looked perfect. But I have seen photos of canopies from different parts of the world which were a complete reject as far as its surface looked. Zvezda did provide some replacements but I don’t know where this stands today.

 

Best regards

Gabor

Link to post
Share on other sites
1 hour ago, Onetogo said:

That clear plastic was nat possible to polish.

 Thanks! But I was referring to Gabor's post earlier, where he said "soft" clear plastic causing many rejects. I had Zvezda's Yak-3, it's canopy hat a defect, so I was wondering if it's that's problem he talked about. I contacted Zvezda but got no reply, then I bought an other one, and it has exactly the same problem☹️  

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...