Jump to content
This site uses cookies! Learn More

This site uses cookies!

You can find a list of those cookies here: mysite.com/cookies

By continuing to use this site, you agree to allow us to store cookies on your computer. :)

RidgeRunner

Building a MIG-21PF - using a Zvezda or RV as a base? (Renamed)

Recommended Posts

Hi all,

 

Renamed thread (16th Feb 2018)

 

Seeking a bit of advice.

I am embarking on a number of MIG-21 builds - two underway - and at some point will tackle the MIG-21bis. I have two in my stash, from RV and Zvezda. Which is regarded as the better of the two? To me the Zvezda looks the better one but I'm open to your thoughts. Thanks.

Martin

Edited by RidgeRunner
Change of emphasis

Share this post


Link to post
Share on other sites

I believe Zvezda is considered to have the more accurate shape between the two.

Share this post


Link to post
Share on other sites

Thanks a lot. I reckon so too but any guidance from the collective here would help me! :)

Share this post


Link to post
Share on other sites

Zvezda way better as You can see, but not without errors, especially the aft fuselage too narrow, but the RV fuselage, spin and canopy are absolute off. The blueprints not in 1/72 (1/73-1/74), Sorry.

Share this post


Link to post
Share on other sites

Zvezda way better as You can see, but not without errors, especially the aft fuselage too narrow, but the RV fuselage, spin and canopy are absolute off. The blueprints not in 1/72 (1/73-1/74), Sorry.

Thanks for the information ! Would this apply to the Bis only or also to other RV MiG-21 kits ? I'd like to build an MF and I'm considering if it's better to use the RV kit or the Zvezda bis with the quickboost spine. The two options would cost roughly the same here, although the RV kit would offer more detail

Share this post


Link to post
Share on other sites

Hi Giorgio!

Wait for Eduard 1/72 MiG-21 family (begins the releases in this year). As I know, the first release will be the mf, as was in 1/48 scale too (some release order).

The RV mf and smt series worse, then this new bis. The nose contour in the bis is a little better, than mf and smt series, but not good enough.

Your idea is not worth it, I think. Wait an Eduard mf and be a little patient ;) But I think, that the new Eduard bis's nose shape not will be different than mf, as it happened in 1/48 scale. This would be too expensive for Eduard for this "little difference"

Share this post


Link to post
Share on other sites

Thank Zkalos, I had forgotten about the new Eduard kit. I hope it will be here soon, I have planned a good number of MiG-21s !

Share this post


Link to post
Share on other sites

How about the PF in 1/72? I am currently planning to make an RV Mig-21PFM to a PF

Share this post


Link to post
Share on other sites

Eduard's MiG-21s won't be released this year, theyare starting the project this year. If we're lucky, their first Fishbed may be out next year, maybe even in 2017. Not to mention, we may only guess in which order they will be releasing particular versions.

Share this post


Link to post
Share on other sites

That's a shame. Meanwhile I'll get on and build my Zvezda 'bis and get building my 'PFM as an 'FL.... M

Share this post


Link to post
Share on other sites

Zvezda way better as You can see, but not without errors, especially the aft fuselage too narrow, but the RV fuselage, spin and canopy are absolute off. The blueprints not in 1/72 (1/73-1/74), Sorry.

I totally agree. I am building both right now, and RV has a very strange shape. I fact, I started the Zvezda build just to check if RV's MiG really could be as strange as it looked, or if I had lost all my knowledge about the shapes of a MiG-21...

Edited by Bjorn

Share this post


Link to post
Share on other sites

Hello,

I followed this thread from the beginning as the same question kept me busy for a while. Having both Zvezda’s MIG-21bis and RV’s MIG-21MF, I prefer the RV offering as being better in outline except for the intake area. Correcting RV’s intake area and the riveting is well within my modeling skills, while Zvezda’s undersize rear fuselage is not.

I base my conclusion on the Czech 4+ plans included in their Mig-21 book. I also own the WWP MiG-21 book and plans and thought first the WWP plans are better. Main differences between the plans are the fuselage widths and horizontal tail span and angle. So the question was: which plans are more accurate?

It happened that an Ex-Czech MIG-21MF is a gate guardian of a local army shop (I live in Switzerland!) so one day last summer I packed my camera and visited this place. There is almost unrestricted access to the plane so I took some pictures from the front and rear fuselage. To have some scale evidence I tape a plywood rectangle 223x385mm on the airframe.

Back at home I dimensioned the pictures to 1/72 scale and the 4+ drawings are almost spot-on in outline. The WWP drawings show a fuselage side profile which is far too fat.

Enclosed are some pictures in High-Res so that everyone can make his/her own conclusions. Remember, the tiny plywood rectangle belongs not to real aircraft.

Regards,

Martin

P1030912_zps05380deb.jpg

P1030910_zps83ce480a.jpg

P1030907_zps886c2414.jpg

Share this post


Link to post
Share on other sites

Hi all,

 

I am re-launching this one :).

 

I really want to build a PF (actually a FL). I can source a spine that may not be perfe t but it could be a good base for improvement. I also have a PF canopy and cockpit set. So with that in mind could I convert a Zvezda bis succesfully? What would I need to consider?

 

i am impatient waiting for Eduard, sadly ... 

 

Thanks,

 

Martin

Share this post


Link to post
Share on other sites

Just a thought, Zvezda PFM could be better starting point for a conversion?

 

Off the top of my head, you will need at least F-style narrow chord vertical fin, different pitot, exhaust nozzle / engine and ventral fin. Don't fit the outer wing pylons. The wheel hubs would also be different, but Zvezda bis kit only includes the early style hubs appropriate for PF. There are probably tons of small differences in panels, AoA probes and antennas.

Share this post


Link to post
Share on other sites

The Zvezda PFM may be a better starting point but this kit has 2 problems: the accuracy of the front fuselage is not great and most important, it seems to be very hard to find

Their bis is better, but to convert this into an FL there are a few more things that need changing. Off the top of my head the intake of the bis is wider and the fin needs modifications as the spine blends into this part. The FL had the wider chord fin so this does need replacing. Agree that there are likely a lot of other smaller differences...

Share this post


Link to post
Share on other sites

Oops, I just sold a Zvezda PFM! ;(

 

Martin

Share this post


Link to post
Share on other sites
13 hours ago, RidgeRunner said:

Oops, I just sold a Zvezda PFM! ;(

 

Martin

 

Actually I truly believe it isn't a good basis for anything. It is very out of shape. I think the Zvezda Bis is a better way to go. 

 

Thanks Apex. as I said, I have the spine and a wide chord fin (for a FL) plus pitot, vac form canopy, cockpit set, etc. I naturally wouldn't use the outer pylons as the FL didn't use them. I also have a couple of centreline guns. 

 

I may may give it a try. I can't wait for Eduard. They are backing the wrong horse in this race with their MFs.

 

Martin

Edited by RidgeRunner

Share this post


Link to post
Share on other sites

Having looked in to this a bit more I think the Bis wing needs some modification to get it to a PF/FL. Other than that, having compared the scale drawings in Yefim Gordon's MIG-21 book, I think it is possible to do this and get it reasonbly  accurate.  The nose intake  - by the way, looks the same for the PF and the Bis.

 

Now you MIG-21 experts - shoot me down ;)

 

Martin

Share this post


Link to post
Share on other sites

Hi RR and all,

 

Bis intake is bigger in diameter than MF. More powerful engine needed more air. If you compare pictures of the MF and the Bis shorter intake lip can easily be seen than in MF. Also front part of the fuselage is slightly more bulbous.

 

An alternative to get a PF is also a Bilek PF. Difficult to find but one of those underrated kits.

 

Cheers,

 

AaCee

Share this post


Link to post
Share on other sites
6 hours ago, AaCee26 said:

Hi RR and all,

 

Bis intake is bigger in diameter than MF. More powerful engine needed more air. If you compare pictures of the MF and the Bis shorter intake lip can easily be seen than in MF. Also front part of the fuselage is slightly more bulbous.

 

An alternative to get a PF is also a Bilek PF. Difficult to find but one of those underrated kits.

 

Cheers,

 

AaCee

 

Thanks AaCee26. I guess I will need to wait for a good MF! ;)

 

Martin

Share this post


Link to post
Share on other sites

Hello!

 

This is not an answer to the original topic. Just wanted to say something about MiG-21 BIS (produkt 75b) shape compared to MF and such.

 

MiG-21 BIS has forward fuselage centerline tilted down 3 degrees from rear fuselage & engine centerline. That is why BIS fuselage lower edge line is practically straight from nose wheel well to the fuselage joint line behind wing trailing edge and somewhat behind, even. Any model trying to be BIS should show this attribute. Also BIS intake lip outside is curved (to minimize pressure losses in the attached sonic vawe? Graham Boak might know more?) while MF PF, PFM etc have it sharper. Their fuselage lower line also seems to beging to curve upwards to the nose much earlier, somewhere near the cockpit rear wall. Intake diameter is indeed different, but that may be because of the radar size, too.

 

BIS spine is one huge fuel tank (number seven). Undeneath one can find a fuselage similiar to the ealier F types. Rudder puhsrods go on the spine, too. If someone has MiG-21 MF manual I would like to know if it gives tilt angle for the forward fuselage and does it differ from BIS.

 

 

Cheers,

¨Kari

Share this post


Link to post
Share on other sites

I'm not sure whether you can find a single item common for the F-13 and Bis. Frankly speaking the biggest change in MiG-21 family tree happened with introduction of the -21PF.

And this was not only due to the enlarged intake and nose cone, but also due to the totally new main undercarriage (not only larger wheels, as every single part was new there - struts, oleos, covers and even the wing and fuselage bays were relocated). When I have some free time next week I'll try to take some measurements at the Polish Aviation Museum collection. They have more than dozen of variants exhibited, ranging from F-13 to Bis (and including PF, FL, PFS, PFM, M, MF, RF and 4 or 5 five trainers). IIRC the changes you described for the Bis should be introduced a little bit earlier as externally Bis looks almost unchanged from the MF.

The only later -21s having anything common with the F-13 were the slim-nosed trainers and Chinese J/F-7s.

Cheers

Michael

 

Share this post


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

×