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CarLos

Hudson to Lodestar conversion?

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Some time ago (some years ago) I read an article in some website about converting an Airfix Hudson into a Lodestar. Unfortunately I didn't save it then and a fastidious search didn't surface it. Can someone help?

I know, there is the Special Hobby kit, but it is rather inaccurate.

Carlos

Edited by CarLos

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I have an old Airfix magazine article on that somewhere, but I'd say a better bet is converting a Minicraft/Academy Ventura. Nils Mathisrud did that one in SAM a while back. The wings and fuselage are much much closer than the Hudson.

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Thanks Dave, but as i read somewhere the Airfix Magazine article uses balsa plugs and the other I remember used plastic card to expand the Hudson kit (as the model 18 developed from the 14, by the way).

I have the Minicraft kit for the purpose but it also has its problems, namely a rather too slim fuselage.

Do you mean the article in this magazine? http://www.payhost.net/modelling/acatalog/...April_2006.html

Fortunately I have the mag but forgot about the article. I'll have a look, even if he uses 1/48 kits.

Carlos

Edited by CarLos

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No, he did it in 72 in SAM before that - checking, it was April 1990!!!!! That makes me feel old!!

Westland Scout/Wasp as Aircraft in Detail

Edited by Dave Fleming

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I don't think I have that number. If you could scan the article I'd very grateful.

No hurry, I am occupied with a Bristol Freighter and an Albatros D.VII.

C

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No, he did it in 72 in SAM before that - checking, it was April 1990!!!!! That makes me feel old!!

1990 ?? That makes me feel old! :)

Well, I have modelled the Lodestar three times (so far). First was a 1/72 conversion of the Academy/Minicraft Ventura kit, using Airfix engines and wing sections. That must be the SAM article. Next was 1/48 scale, combining the Koster Ventura kit and the Sanger (if I recall correctly) Hudson. Finally I did the 1/72 scale Special Hobby kit nearly out of the box (I opened up the wing slots and made new wheel well interior).

I still have a couple to go, both in 1/72 scale. For the next I will probably use the Special Hobby kit, but use the wings from the Academy/Minicraft Ventura. The Special Hobby Lodestar is not 100% accurate but, unless I compare it with the Arctic Decals drawings, I think it looks quite right. It would be quite a lot of work to convert a Hudson model, as most of the fuselage (aft of the cockpit) has a different shape. The wings are different as well.

I have copies of the articles, if you have not got them already.

Nils

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I know, there is the Special Hobby kit, but it is rather inaccurate.

Could you please point out to these inaccuracies? I have the kit and would like to know what should be improved. Thanks.

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I have copies of the articles, if you have not got them already.

Thanks for dropping by! I'd appreciate the SAM article. You may send to cacarr1960 (at) gmail (dot) com.

It was Mika Jernfors who showed the SH fuselage superimposed to a plan. I don't think I could live with that!

However the several models I saw are very nice, including yours.

C

Edited by CarLos

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Could you please point out to these inaccuracies? I have the kit and would like to know what should be improved. Thanks.

I'll ask permission to share the drawing here. However I just compared with the side view from Peter Marson's book (this one) and the differences are not great.

Carlos

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I think Mika's drawings are based on drawings made by Timo Aalto and published by IPMS Finland 1983. The differences between kit and drawings could mean that the kit is wrong, but it could just as well mean that the drawings are wrong. Unless you know the accuracy of the drawings, the comparison doesn't mean a lot.

Nils

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I think Mika's drawings are based on drawings made by Timo Aalto and published by IPMS Finland 1983. The differences between kit and drawings could mean that the kit is wrong, but it could just as well mean that the drawings are wrong. Unless you know the accuracy of the drawings, the comparison doesn't mean a lot.

Nils

Mika sent me an e-mail referring that the drawings were "based on the original station plan drawings and also on the measures taken from a preserved plane in Finnish Aviation Museum".

SpecialHobbyLodestarfuselage_sm.jpg

This is one of the original drawings:

L18_profile_sm.jpg

Mika just sent me an update with more drawings, allowing me to share them. I must re-size them for the forum, I will do it later.

Cheers

Carlos

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Here are more drawings, thanks to Mika Jernfors. As you may read in the following review, Mika's decals are good both for the corrected and uncorrected kit fuselage: http://www.internetmodeler.com/2008/decemb...c_lodestars.php

LodestarFinandrudderdimensions.jpg

Lodestarfuselagestructurediagram_sm.jpg

Lodestarstationplan_sm.jpg

Lodestarstationplansright_sm.jpg

Lodestartaildimensions_sm.jpg

I will scale the drawings to 1/72 and lay in the Academy Ventura and the Airfix and Italeri fuselages to see what's the best way to have a Lodestar.

If someone wants the drawings in its original size just send me an e-mail.

Carlos

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Manufacturers drawings are not neccesary "accurate" when it comes to shape. Their purpose is to show the points/lines where the various measurements are given. The Supermarine Spitfire factory drawings are good examples of this, and I have seen the same on other types/manufacturers' drawings. The measurements themselves are however the keys that should be checked. If you have a specimen of the aircraft at your local museum, it is up to you to make your own measurements. This is not an easy task though. Fortunately there is a Lodestar at my "local" museum, however I have not made any measurements yet.

The best way to correct the Special Hobby kit, according to Mika's drawings, is, I think, to split the fuselage from the the nose to the tail, on the lower side of the wings, and add the missing fuselage height. The cabin windows should also be moved forward. That is, if the drawings are accurate (and the kit is not).

Nils

PS. I must add that I know Mika quite well. We have met at SMW a couple of times, and next year we plan to share a sales stand (together with Ruben Husberg -Lima November - under the name Nordic Decals).

Edited by Vingtor

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Manufacturers drawings are not neccesary "accurate" when it comes to shape. Their purpose is to show the points/lines where the various measurements are given.

Agree... However, in the case of the stations side view it is detailed enough on the windows positions and spacing, for example - and in this aspect the SH kit is rather incorrect in the spacing between the 1st and 2nd window. I have no reason to doubt in the stations figures (as far as I know it wasn't drawn by Wylam...) so I will use that drawing as a basis for a correct fuselage (made from the Minicraft Ventura, I'm now convinced that it is the best choice).

The distance between the 6th and 7th windows possibly depends on the door width - in most photos I have the door is larger and the distance is smaller.

Carlos

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Nils is right about the drawings. When drawings were drawn by hand, the only purpose of the drawing was to show the shape and configuration to help the workmen interpret what the part was going to look like. They weren't necessarily drawn to scale as that would be timeconsuming and yield no gain: The only thing that was correct were the dimensions and tolerances on these drawings. If you needed to know a particular dimension (say it had accidentally been left off the drawing), then it was positively forbidden to measure the drawing. The station diagram therefore only proves one thing: The location of the structural members and can be relied on to use as a basis for measuring the lengthwise location of features. The drawing of the fin and tailplane may work out to be close, but your best bet would be to redraw these in a CAD system where your input would be the dimensions - though Mika may have already done this. On CAD systems, you "draw" the part to full size using the actual nominal dimensions, and when producing the 2D drawing, you should then be able to take the accurate dimensions from the drawing. However, even drawings made in 2D CAD may not be accurate if the purpose of the drawing is more of a general arrangement than for parts manufacture. Every part of an aircraft or missile launcher would have to be drawn, but retrieving all these parts from the drawings database and assembling them in a new drawing to create a GA drawing takes a lot of time, and for the purposes, is pointless. Therefore, the CAD designer making these manufacturer's drawings would take the easy option and draw something that looks about right and then edit the dimensions to show the true values.

3D CAD is a different kettle however, as each part has a "perfect" CAD model from which you can extract drawings that show the true configuration of the part in any view you like. Even so, there are many parts to hide before you can make a GA of an aircraft from a complete set of 3D models, so unless you *know* that a drawing has been created from the 3D data, I would treat even manufacturer's drawings with suspicion. A litmus test would be to see if the dimensions and proportions match. For example, calculate the ratio of the wingspan to length in the plan view - does the drawing match this ratio? Is the length of the fuselage in the sideview the same as in the plan view? Is the wingspan in the front view the same as in the plan view? If even the views don't match, why put your faith in the drawing?

Jens

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My relation with drawings is almost a matter of faith... I try to locate references for the subject, compare them between each other and with photos, make my own corrections and then I'll try to stick to that, as it was "the truth". I can invest in that a few hours or several weeks, and I know that the amount of time doesn't lead necessarily to a more accurate model. The ideal to compare drawings is the existence of sharp photos of side and plane views taken from a distance to avoid distortion, but these are rare...

Back to my planned model, I'll stick with the Academy/Minicraft kit that is a good basis. I had the idea that the fuselage was too slim but measures (and comparison to the drawings) say that it is perfectly good. Some photos of the work until the moment:

Lodestar_00.jpg

Lodestar_01.jpg

Thanks to all the help. I am still curious about that Hudson conversion!

Carlos

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What is missing from the station diagrams is waterlines, that would give me more confidence. But really, if you had just one measurement of fuselage height at a known location that would be pretty conclusive. I worry about losses in the reproduction process. There is usually about a 1% variation in the axes in my experience. But those drawings are good enough for me to think it is an 18.

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What is missing from the station diagrams is waterlines, that would give me more confidence.

Waterlines? What do you mean by that?

For dimensions, I always measure the output of the printer and re-print adjusting the percentage setting in Photoshop. I usually use it to print as it allows very fine tuning. And if I scan a square I print a square, once in a while I perform this test...

I advanced a little more on the conversion, but will post photos only tomorrow.

Carlos

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There are more photos in between, but now I'm showing only this. It's beginning to look like a Lodestar!

Lodestar_xx.jpg

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Waterlines? What do you mean by that?

For dimensions, I always measure the output of the printer and re-print adjusting the percentage setting in Photoshop. I usually use it to print as it allows very fine tuning. And if I scan a square I print a square, once in a while I perform this test...

I advanced a little more on the conversion, but will post photos only tomorrow.

Carlos

If I'm not mistaken, "waterlines" are vertical measurements parallel to the horizontal axis - just as "station numbers" are measurements perpendicular to the horizontal axis for the location of bulkheads.

Jens

Edited by jenshb

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Waterlines are horizontal sections. I think the problem with the SH kit is simply it's undersize as a victim of how it was patterned and shrinkage in the submaster stages. It probably started life as a Ventura and went through the same stages as Carlos is doing now. But if moulds are taken at intermediate stages shrinkage almost always takes place. For instance. Take a plan, photocopy it for chopping up to prepare blanks.(1) shape the blanks and make a mould off them.(2) Take a vac or resin out of the moulds (3), detail and make the final mould from this (4) make production parts in the cured mould (5). So there you have 5 potential shrinkage areas which will appear on the boxed model. Take a perfect scale mould and inject plastic into it and the plastic when cooled will be smaller.

John

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So besides removing the turret and doing the windows the Ventura only needs different engines to become a Lodestar?

Is this correct?

This is a plane I did not look into so far ...

Also I once heard the Academy fuselage is 8 mms too long to make an accurate Ventura, looks like this was not correct then?

Edited by occa

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There are more photos in between, but now I'm showing only this. It's beginning to look like a Lodestar!

<cut image of fun modeling project!.

Carlos, this is a 'bump' for you, in case you've made a bit more progress on the Lodestar conversion. I was planning on replicating Nils' 1/48 scale conversion using the Sanger & Koster 'bash' method along with your reference data - thanks for that! However, I'm sure your experience with the 1/72 project would be very useful to anyone attempting a Lodestar 'build'.

Funnily, there is a 'Commerative Air Force' Lodestar located not far from me (~20 miles) here in Norfolk, VA that I've had the pleasure of clambering around in during a public display. That slanted cabin floor must have been fun when handling cargo!

Regards,

Robert

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Hi Robert,

Funny that you ask because yesterday I opened the box after a long time and put it near the Airfix Tiger Moth in my desk. I filled the outside contours with milliput but I made a big mess inside as I used the same milliput as a glue with bad results. I already started scrapping it to replace with my favourite mix of super glue and microballoons. I hope to put more photos next week.

Carlos

Lodestar_16.jpg

Lodestar_15.jpg

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