The main anti-ship gun for type VII U-boats until 1943. U48 sported one on her foredeck for most of her service (war patrols and later as a schoolboat until 1943).
The idea: the gun offered in the kit is rather inaccurate and its dimensions are more appropriate to represent the 10.5 cm gun of the type IX boats models (also produced by Mirage Hobby). I therefore decided to build U48 gun mostly from scratch (only keeping the original gun mount, appropriately reworked). My references for scratchbuilding the 8.8 cm gun are:
a) The following books:
German Naval Guns 1939-1945 by Miroslaw Skwiot (a). The book is magnificent and a real must if you want to have an in-depth look to german naval armaments of WW2. It features detailed information, beautiful artworks, technical drawings and hundreds of fine pictures. Mr Skwiot is a real autohority on the subject.
Super drawings in 3D: The VIIC Type U-Boot by Waldemar Goralski and Mieczyslaw Jastrzebski, Kagero Publishing (b). A fine manual with noteworthy information and stunning 3D artworks by Waldemar Goralski.
U-Boot VII Vol.1 by Marek Krzysztalowicz, AJ- Press (c). Great information, pictures and 3D artworks by Waldemar Goralski (“early” artworks when compared to the ones contained in Super drawings in 3D:The VIIC Type U-Boot but still beautiful artworks).
b) The 54 mm kit “Type VIIC U-boat deck gun” by Andrea Miniatures (Ref S5-S10). An excellent kit that I have in my stash from the early 2000s, actually a Christmas present from my brother which I haven’t been able to build yet and which, am afraid, will wait long before being dealt with. Nowadays it helps me to understand the 3D shape of the gun and its details. And what an invaluable source of help! I have already measured and converted to 1/400 scale all the gun components and made an action plan (this says it all!): I will divide the gun in 5 different sub-assemblies: gun mount, barrel, breech, superstructure, lateral arms.
I started my work by separating the gun mount from barrel, breech and superstructure (a), then I sanded away all the detail from the mount, carved it appropriately, filled a few holes/irregularities, reshaped the rear pedestal fairing with epoxy putty and added what I nicknamed the “lateral ears”, made from 0.2mm-thick/0.25 mm-wide styrene half disks (b,c). The “lateral ears” (aka the trunnions, as EJ Foeth – ontheslipway.com – kindly suggests me), were then shaped in situ with fine sandpaper. I finally drilled a few holes: the one on the frontside of the mount, for the tampion-holder (e), the one on the starboard side of the fairing (0.2 mm wide, cheeky monkey), (d) and the holes for the lateral arms, which must allow the lateral arms to be parallel to each other on both sides and to be perpendicular to the vertical axis of the mount (not an easy task) (f).
One word about the rear pedestal fairing shape: according to M Skwiot there were three different versions of the rear fairing and I found evidence that U48 sported the fairing version pictured below (“a” in the technical drawings)
thanks to details that I hunted down in two rare pictures of U48 (below, the magnified details):
At the end of an endless work which lasted many hours/modelling sessions I test-fitted the gun mount on the Uboat foredeck only to realize that it was over-dimensioned for 1/400 scale (so very bad of me). Luckily, in Revell 1/350 VIIC kit (also part of my stash) there was a gun which is slightly under-dimensioned for the 1/350 scale and looks much more proportioned for 1/400 scale than the Mirage Hobby part. I started all over again with the same process I illustrated above for the Mirage Hobby gun mount. Below, the carving/shaping process has just begun on the original part by Revell (in the window):
and here’s the result of my work:
The new and the old mount compared:
The actual dimensions and the 1/400 mount compared to the 1/32 one by Andrea Miniatures:
There’s still a lot to do before I can say the gun mount is completed but I am happy things have started to move again!! (to be continued)
Pedestal (November 2015)
A composition of telescopic tubing of different calibers and materials (a=0.7 mm/brass, c=0.9 mm/brass, d=1.2 mm/plastic) and an aluminium disc (b) were positioned on the Mirage Hobby PE representing the round bolted baseplate (f). I added the toothed rim (e) which i have worked out from a PE catwalk from L’Arsenal, adequately trimmed and filed. Below: the real thing (window), the predestal alone (top left) and dry fitted to the deck’s anti-slip web PE from Mirage Hobby (bottom left). This is just a preliminary work and the parts are only dry-fitted. I think there’s still room for improvement and I am currently working on it, so stay tuned for a Part 2. (off the record: I am disappointed with the new WordPress policy of denying the uploading of clickable images that can be enlarged to their bigger original size)
Pedestal Part 2 (December 2015/January 2016)
After two months of hard work am finally happy to show you the improvement I had promised: the toothed ring (?should i call it the pedestal toothed fairing) was improved, the bolted baseplate was sanded flat and the pedestal was drilled twice. It took more time than I had originally thought (2 months!) because of the few modelling sessions i was conceded by work (an average of 4 per month) but most of all because the toothed ring was extremely difficult to make and when I had completed (an almost perfect) one, it pinged off to feed the monster carpet, causing a major blow to my morale (hehehe Yess!) and I had to start all over again. Let’s see the improvement in detail.
Toothed fairing. Curiosity: the real pattern of the “teeth” was somewhat peculiar. The “teeth” were arranged in groups of three at the cardinal points (picture below,a, ovals + b,c) and there was only one “tooth” per quadrant (a, square + b,c) for a total of 16 teeth distributed all along the circumference of the fairing. Miroslaw Skwiot gives the correct pattern in a technical drawing shown in his magnificent book. I verified the correctness of the pattern studying many original photos (it was particularly hard to find pictures showing the “triplets” at 3 and 9, but i eventually found a pair, c, arrow) and thought to share this information to provide a handy tip to those modellers who want to represent faithfully the gun in bigger scales (I am thinking of 1/72, 1/32 scale and the recent 1/48 U-boat releases), since the toothed fairing is a detail often ignored by many modellers. No, I am not that insane to reproduce the exact teeth pattern in the 400th scale (even if by mere chance I got very close to it! 🙂 )
The toothed fairing was made from a section of 0.08mm-thin brass net by Flyhawk, which was filed-to-size and shaped over a drill bit to obtain a ring of 1.5 mm. The height of the teeth is 0.06mm and so is the one of the frame, for a complexive height of 0.12 mm. I added two 0.08 mm-thick/0.13 mm-tall styrene crescents at 12 and 6. They were thermo-formed over a 1.5 mm drill bit and given a sloping lateral profile. The gluing phase was the most difficult part of the work and obtaining a stable joint without the bulking effect of the glue was particularly tricky. Unfortunately I had no luck with extra-thin CA and the pieces were eventually glued with diluted Gator’s Grip glue after several attempts.
Then, I sanded off the bolts from the outer ring of the round brass baseplate (above, right) to make sure to have an even surface for gluing the toothed fairing.
Finally I drilled two 0.15 mm holes on the 0.3 x 1.2 mm plastic tube representing the pedestal. The Jigster and the canal root files allowed me to obtain a smooth result.
In fact there’s photographic evidence that there were two holes on U 48 pedestal at 4-5-ish and 7-8-ish. It’s been speculated that the holes were meant to allow lubrication of the pedestal mechanism, since they were provided with caps that had probably been removed or gone missing on U 48 (you can follow the research behind this finding in my U 48 thread on the AMP forum: http://models.rokket.biz/index.php?topic=858.0).
I test-fitted all the components of the pedestal to have an idea of the result, which I think is way better than the initial work.
The 8.8cm gun had two couples of lateral arms:
two “Controls and Gearing arms” for the elevation and traversing control wheels (a); two arms (b) from which the braces for the elevator’s safety harness (c) and the traverse number’s safety harness (d) branched. Each of these braces had “Lambda” joints and “T” joints (circled). I started my work from the braces (c,d) and precisely from the Lambda joints. First of all i brought to 1/400 scale the dimensions of arms and braces. Without giving in to AMS (Advanced Modelling Syndrome which, am afraid to admit, has been affecting me for a looong time) a suitable caliber to represent the “controls and gearing arms” (a) in the 1/400 scale can be 0.3 mm and 0.25 mm for the lower arms (b). 0.3 mm (brass or other alloy) tubing are the smallest tubing you can get on the market. I chose Albion Alloys brass tubes, which have an inner diameter of 0.12 mm, they are an excellent product. Since 0.25 mm tubing are absent from the market I had to obtain them from 0.3 mm tubing by reducing their caliber. I used a cheap supermarket diamond file which I rolled over a tubing section placed on an old CD. The tubes must be fitted with a 0.1 mm rod, to avoid their deformation. Remember to wear a facemask and disposable gloves, and to wash file and CD with soap when you have finished. The tubing can be reduced to an even caliber by rolling the file over the entire tubing surface with a left-to-right motion. (the tubing in the pictures is bigger than 0.3 cal for demonstration purposes). I warn you, the procedure is long and tedious, so arm yourself with patience; the technique, on the contrary, is effective to get the desired result.
This way i obtained smaller caliber tubing sections for the lower arms and lambda joints (0.24 mm), which I cut to size and then soldered. In the picture below: 0.3 mm brass tubing (a); 0.1 mm rod (b) to represent the braces; 0.20-something mm brass rod obtained from 0.25 mm rod to fit Albion Alloys 0.4 mm-cal tubing (d); 0.24 mm-cal tubing obtained from the reduction of 0.3 mm tubing (c), then cut-to-size (window) and reduced to desired length by filing (the entire process of caliber reduction + cutting/filing-to-size is time consuming and rather boring).
One word about the “Lambda joints”: the angle between the branches of the joints is 60° in the technical drawings, 3-D artworks and original U48 pictures (a propos of pics, a Thousand Thanks Dougie Martindale!).
I am still a bit puzzled about the angle of the “Lambda-joints” for the traverse number safety harness brace: while the artworks show an angle of 60°, a close-up pic from U48 seems to show a steeper angle, but perspective might be deceptive in this case. In any case, consider an hypotetical steeper angle for that brace if you plan to make one and let me know what are your conclusions about that. I sticked to the artworks and soldered all the four “Lambda-joints” with an angle of 60°.
The soldering of the “Lambda joints” is one of the most difficult modelling tasks I was ever faced with. I used the “hot-blower and Koki solder paste technique” very well described and perfectioned by “Siara” Musialek and Glenn Cauley (check their outstanding modelling threads on the AMP forum: models.rokket.biz). I use a cheap butane blower, although I recently purchased the Dremel Versatip butane soldering iron, but i haven’t used that yet.
My faliure/success ratio in soldering very small parts with an angle of 60° with this technique is about 5 failures/1 success and that’s very frustrating because every time you fail you have to file-to-size the sections + align them properly time and again, and this alone requires time. The result of my work:
I know, the joints are not 100% perfect, but consider that the camera magnification is merciless, and bear in mind that the joints are barely visible to the naked eye, even at close distance (and even with an optivisor). I think what matters is giving an idea of what you are trying to represent. After all, aren’t we modellers some of the finest cheaters? I think i will ignore my AMS for once, the risk of re-doing the entire process is to get bogged-down by the lambda joints for an indefinite time and not move forward. (to be continued)
Safety harnesses and vertical braces (May 2015)
The vertical sections of the “T-joints” come from 0.25 mm-long sections of 0.21-0.22 mm-cal brass tubing. Obtaining a smaller caliber than 0.21-0.22 mm (from the original 0.3 mm) through reduction proved to be impossible: the tubes have their-own breaking point and when this is reached they just disintegrate under the file. The end-run sections are just o.15 mm long and preparing them was pretty painful. The picture below shows the sections dry-fitting 0.1 mm-cal rods. They will be assembled properly and glued to the harnesses once the rest of the gun is done, to make sure the correct proportions are respected.
The safety harnesses come from two lateral sections of 0.23 mm-cal brass rod, appropriately bent and shaped through filing, glued to a central section of 0.2 mm-cal rod. Yes, glued, i didn’t want to take my chances on soldering this time. Preparing the parts was very time consuming and a bad soldering would have meant starting all over again with the preparation phase (and an almost-sure nervous breakdown). I used very thin Rocket CA glue and reinforced the joints with diluted Gator’s Grip glue. The picture makes them appear more bulky than they really are.
(to be continued)
“Lower” lateral arms (12/03/2015)
I managed to solder 0.25 mm-cal tubing sections approximately 1 mm-long with 0.24 mm-cal sections 0.3 mm-long to obtain the arms (which, i must say, are almost invisible). This time I was lucky: only 1 failure and 2 successes with soldering! After soldering I polished the joints with fine sandpaper and test-fiitted the arms to the gun mount, just to get an idea of the result. Not bad at all! Wish I had some 0.2 mm cal tubing with an internal lumen of 0.1 mm though, the final outcome would have looked perfect.
Controls and Gearing arms (10/04/2015)
0.25 mm-Cal sections, 0.25 mm-long (these were tough to make!) were soldered to 0.3 mm-Cal tubing (slightly longer than the needed length of 0.7 mm, just to make the handling easier) with the usual technique. Two failed attempts, 2 successful soldering this time. Unfortunately I had to solder the brace for the traversing control wheel to the traversing arm and to the elevation arm to avoid dealing with a possible solder-related clogging of the traversing arm lumen. Nevermind, the control wheel brace will be trimmed to the correct length afterwards, and the elevation arms will be trimmed-to-size by filing after proper test-fitting to the gun mount. The distance between the outer margin of the traversing arm and the distal edge of the elevation arm (arrow, a) varies from a few tenths of a millimeter to nil depending on what reference source you follow (artworks by Goralsky, (a); artworks/technical drawings by Skwiot (b); Andrea Miniatures kit (c)) . Original pics don’t help much, since that area was rarely pictured from a close distance with the right angulation. I soldered the tubing sections with virtually no distance betweeen the edges but I am tempted to add a 0.13 mm-thick roundel at the end of the main arm, I’ll think it over.. In the meanwhile enjoy the result!
The elevation and traversing control wheels should have a diameter of approximatively 0.6 to 0.7 mm, depending on what reference source you follow. I had taken for granted that I could use some photoetched handwheels included in a set by Tauro Model but unfortunately size doesn’t always match with quality: the smallest handwheels in the set are thick and coarse (a). Since designing my own PEs with Autocad to have them produced elsewhere is something I am still unable to do (but I will in my next life, promised), I decided to make my own wheels from old-fashioned scratch after performing a feasibility study. Using copper wire and a cross-shaped section of fine brass railing to obtain a “full-metal” wheel doesn’t allow to reach a convincing result (b); reducing the size of the cross arms through filing is very time consuming; soldering is not an option either: I tried and it’s just not feasible with the soldering technique I commonly use. Gluing is the only other possibility left. I used Gator’s Grip glue successfully. In the end I decided to use a cross-shaped section of fine plastic net that I obtained from a ribbon, which I glued into a roundel made with 0.1 mm copper wire (c). Once I realized the feasibility of this technique I opted for 0.6mm diameter roundels made with 0.08mm-thick copper wire (d). The technique is straight forward: put the small cross (appropriately trimmed to fit into the roundel) into the roundel and apply a drop of very diluted Gator’s Grip glue with a fine pointed brush, “sucking” off the excess of glue with a thin strip of blotting paper. Gator’s Grip Glue is just amazing, fast drying and with a good bonding quality. Non toxic, thins with water, dries to a completely transparent finish.
I am pleased with the result. I managed to make eleven wheels in an afternoon (the same amount of time I spent for making just one “full-metal” wheel). I will choose the best 4 of them for the Controls and Gearing Arms. Notice the residuals of glue in some wheels, they are completely transparent and invisible to the naked eye, however i’ll try to clean them up. The wheels still miss their knobs, that will be added in due course. Below, the actual dimensions.
(to be continued)
I made the recuperators from 2 x 0.3 mm-cal brass tubing sections which were separated by an interposed brass railing section. The three pieces were soldered together with the usual technique to obtain the tray. The tubing sections were then fitted with 0.1 mm wire and the tips of the recuperators were shaped with Tamiya epoxy putty (arrow). I painted the recoil tray with diluted Gators’ Grip just to make sure the putty tips are secured properly to the rest of the tray. This caused some debris to form (invisible to the naked eye but clearly visible on the magnified image at the left end of the cylinders),which has already been taken care of.
Recoil tray take two (Oct 2015)
After a forced stop due to an unusually hot summer and too much hospital work I am finally back. Re-did the recoil tray since test-fitting the one I had already completed to the gun mount proved to be unsuccessful due to a few tenths of mm too many (the soldering was too bulky and made the tray too wide). This time I spaced the recuperators with a 0.13 mm styrene spacer, gluing the ensamble with Gator’s Grip glue. Here’s the result:
Part 1 (November 2015)
A piece of styrene measuring 1 x 1.3 x 1.5 mm was cut, shaped, drilled and carved to represent the main frame of the breech. The most difficult part was shaping the U-shaped breech ring and the housing for the breech-block. I corrected minor errors with epoxy putty which was preferred to toluene-based fillers because of the potential risk to melt or deform the flimsy walls of the breech housing from the use of the latters. The breech still needs to be completed with the breech block (am studying the feasibility of making one), various levers and rods and the fore top fairing, which i hope I’ll be able to complete soon. The preliminary results:
Part 2 (February to April 2016)
I’ve been through difficult times lately and now I am slowly recovering. The last few months saw just a handful of modelling sessions during which i was able to sculpt a breech block from a very thin strip of styrene (0.3 x 0.3 x 0.5 mm) to fit the breech block housing. I have also drilled very small holes onto the breech sides to host the various levers/rods that were there in reality. Drilling holes in the right places on such a small surface proved to be quite a task and more than once I had to fill the misplaced holes with epoxy putty, wait for the putty to cure, sand the repair flat and then re-drill the holes until I was satisfied (a pretty silly work). It took time (no pictures available at the moment, I’ll shoot some as soon as I am able to complete the breech top fairing). Am afraid to tell you that I am facing another forced stop of my project due to “real life interfering with progress” once again. No worries I won’t give up, I’ll be back at it sooner or later. In the meanwhile enjoy my meager progress:
Part 3 (April 2017)
Hi, it’s been a while. I’ve not been well and am just recovering from an operation. The pros: i have some more spare time to reconcile with modelling. When i was unwell and in an hospital bed i thought i really had to start working again on my project and and try not to leave it unfinished. So: the shipyard is open again (?should i say the gun factory 🙂 ) and some little steps forward have been made. I added some details to the breech (port side: 0.05mm copper rod trimmed and shaped, starboard side: 0.08mm rod), which have been dry-fitted for scenic purposes. The port side lever will be trimmed a bit and the other flat detail aft of it added. The horrific hole has already been taken care of. Well, i hope to be back on track, but i wouldn’t bet all my money on that. I’ll try my best to keep this project alive, health and spare time permitting. Glad to be back! Enjoy the results:
Breech fairing (April 2017)
The breech fairing had several subvariants: “squared” (a), “multi-faceted” (b), “flattish” (c) etc, as i had the chance to observe in the hundreds of pictures i have studied. There are different possibilities to build one from scratch but in the 400th-scale priority must be given to materials causing less bulking effect, thus narrowing down to three different materials: styrene sheets (minimum thickness 0.13 mm), CA-soaked paper (about 0.1 mm thick, it can be sanded to some extent) and aluminium foil (0.01mm-thick). I opted for aluminium and managed to cut a trapezoid to represent the fairing. I found that working with aluminium in such a small dimension and thickness is pretty difficult because alu gets crumpled or perforated very easily by tweezers and blade. So, not many chances to craft the subvariants of the fairing but rather trying to make do with what you get. Making and bending the lateral “wings” was particularly tricky.
Here you can see the actual dimensions of the fairing dry-fitting the breech. The fairing will be given a sloping angulation of the forward free-end once the breech is connected to the barrel. The arrow points out the fore hole on the starboard side of the breech which was moved forward to get a look closer to the real thing.
BARREL (April 2017)
The 8.8 cm tube had a slight variation of the outer profile with a decrease in size at the middle-last section of the barrel and a sloping slight increase in diameter at the muzzle. The scale effect must be considered here, because as you may see in the pictures below, the caliber of the tube looks like it’s even and perfectly cylindrical when seen from a distance, something to be kept in mind when dealing with small scales such as the 400th.
I used three telescopic sections of Albion Alloys brass tubing with a caliber of 0.4, 0.6 and 0.8 mm, measuring different lengths that were taken according to the technical drawings by Miroslaw Skwiot. The bottom surface of the bigger section was sanded flat to host the recoil tray (a), and the middle section was left slightly longer than the actual dimensions to connect to the breech and host a perforated ring which was present just fore of the breech. I crafted 2 different rings: a brass ring some 0.25 mm-long obtained from the fret “1/700 perforated beams” from L’Arsenal (b,c) and a thinner 0.18-ish mm-long ring obtained from 0.01mm-thin aluminium foil (d) which i perforated with a 0.06 dental root file. The alu ring is really flimsy and difficult to manipulate as it is nearly invisible. I still have to choose between the two. I like the clearly-visible holes on the brass ring but the bigger dimensions of it when compared to the alu ring just got me thinking.
(to be continued)