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Pompoms, part IV

UPDATE 27/12/14

Right, my previous pompoms were just perfect if it weren’t for the corrosion of the solder (flux, probably). The parts were re-etched and the 100-part pompom is on its way. This weekend I finalized the guns themselves.

It’s very easy actually. Prefold the photoetch part with the small photoetch tool and find out it is far too crude for fine work. Find a part of brass strip to finalize the fold. Add evergreen strips that should be the right size. Be dissappointed that they are not and file all parts to the correct height using a filing jig. Replace jig from time to time. Place the part in a small jig and use the drill press to drill in the placeholder for the barrel. Be disappointed that the Proxxon drill press is unable to drill consistently, but be happy you added a photoetch part that acts as a drilling jig. Hold the part with tweezers during drilling so that the drill will not exit the part sideways. Place the guns in another jig and add a small strip on the end. File a fillet to the end of that block. Thoroughly check the gun for CA spots and clean. Add some putty to the end and sand smoothly. Find out that Tamiya putty is no longer sold in Europe and order from Singapore. Wait for the shipment while Vallejo putty disappoints you.

Because the process seems fairly repeatable I made enough guns for HMS Hood and for my next project (oh yes). Repeat the above at least: 78 times.  Loose mind, despair, find will to live and continue. Fairly straightforward scratch building.

So here is half of them; these guns have a small lip to act as a spacer when added to the gun block that hasn’t been soldered yes. The barrels are on order. The mounts themselves are coming along nicely!

UPDATE 27/7/14

The main gun housings were soldered today with 5 etched parts for each housing: the housing itself, a center shelf that holds the upper guns, one top detail part and the two-part elevation gear parts. The housing part is sort-of self-interlocking, making it easy to hold without the risk of squeezing it with my tweezers. Soldering was quite interesting as applying heat means that some bond will release at another location (the part measures 3.3 x 2.6 x 1.9 mm only). The gun housings are supported in the center for which I made some etched part filled with styrene; the result was 0.1mm too wide and the housings ended up about 0.05mm too wide each, meaning that the sum of thee parts was 0.2mm wide and it didn’t fit. I wasted some time making the center parts fit anyway but I’ll have to add a new styrene part for that.

UPDATE 3/8/14

There’s a small coolant overflow cone at the end of the gun block (beautiful custom work by MASTER). I added some 0.2mm wire to either side and soldered it together so that is also works as a spacer for the two gun block halves. With some tape it’s easy to position the parts and add some solder. The first specimen was used for the general dimensions. The two wires were cut after soldering.

The gun blocks were glued to the center support after having spent 5 minutes in the ultrasonic cleaner. Fortunately, the part is now 4.5mm wide and fits the mounts. There are still a few more etched parts to keep the gun blocks together but I have to wait for the barrels to arrive. Now that some styrene is added to the model I can no longer solder and the part is delicate with superglue only until the mounts will keep the gun blocks in place.

UPDATE 10/8/14

While Tiberius the Famished kept the etch set warm, I started adding the custom barrels that meanwhile arrived. You could say that the image shows how small the etch set really is, but Tiberius is a particularly large Norwegian Forest cat.

The work by Master is as good as ever and fits the tiny pompom models well. I had to do some post-drilling by hand of the styrene guns to clear all the ‘chips’. Note that the conical flash suppressor that is ever present on all pompom models is absent; HMS Hood did not yet receive the upgrade to the pompoms and the barrels are thus plain and simple. The bottom row of pompom guns have a small lip below the barrel; this is a spacer for the correct offset of the outer barrels. One gun block was finished today but another one fell apart during handling; I hope to finish the rest soon. I learned the hard way that once parts start breaking up it is a good moment to stop.

UPDATE 17/8/14

All the gun blocks are all done; the guns were inserted and final detail was added. The cooling lines to the guns are partially added; the pipes running to the barrels themselves where eventually ‘canceled’ was it was too small to do repeatedly nice. I gave the models a coat of paint. I found out that out of the four premixed colors two batches again went bad and turned into sludge. The others, same ingredients but in a different ratio, are just fine. If anyone has tips how to improve the shelf life of premixed Humbrol to more than 2 months, let me know!

UPDATE 2/9/14

One down, two to go. Soldering the sights was tricky, holding the PE part with tweezers in one hand and the soldering iron in the other… still have to add that curved bar from the portside sight to the guns but I think I’ll glue that one having spent too much time trying to solder it.

UPDATE 20/10/14

I wouldn’t want to leave the impression no progress has been made, even though most weekends have been quite busy, including a visit to the Small Scale Convention at Heiden, Germany, where the unfinished Hood was on display. There were many stunning models by the IG waterline group and the ‘German gamblers’ to study. One visitor wondered if the Lion Roar pompom set tempted me into building the rest of the ship myself? Well, it’s a bit more weird than that!

The pompoms have received some attention; here you can see one of them in my “high tech” clamping mechanism ready for some soldering of the rear railing. I have to add a few more lines of the hydraulic system and the base of the guns and then I can move on to painting.

UPDATE 27/12/14

Done! One picture with flash so they look awful, but it is snowing and light conditions plus a bad camera make bad pictures.

Aft searchlight platform

The site is back up and I’ve enabled comments with the usual comment filters. I have a few side projects going on and some are nearly finished but I decided to post more unrelated images instead of ripening the posts on oak for a year…

Actually, I updated my blog to take my mind off my cat Mouse, Slayer of Photoetch, who was put to sleep today. She was only 10 year old and suffered from a tumor in her nose that suddenly grew very large starting to push out her right eye; for three months we thought she was fighting an infection as the X-rays were clean and she was finally getting better, but apparently not. We buried her in the garden close to one of her favorite spots. Good bye my friend.

I bought a new airbrush over a year ago, a Harder & Steenbeck Infinity (perhaps I’ll make a post later why this airbrush is really fantastic) and experimented with various paints, thinners, airbrush settings, oil washes and filters. The goal was to mimic the blue-grayish AP507B that Hood was painted with. I tried water-based paints but I think they hate me. I just cannot apply these paints to the smallest parts without suffering from tip-dry, overspray or grainy surfaces. Enamels are so much easier to use and cleaning the airbrush afterwards takes only minutes. The White Ensign Model colourcoats offer a premixed AP507B and spray beautifully although they are slightly less resistant than Humbrol when sprayed on PE and resin (might just be me). However, WEM suffered a few problems with restocking and as I (think to) know that several of their colors (based on the Snyder and Short color charts ) are wrong, so I decided to experiment with mixing. My local hobby shop had an old binder by Humbrol called the Colour System that had a few recipes and using Humbrol 34 (white), 77 (navy blue) and 140 (gull grey) in a 1:1:1 ratio is an excellent match for AP507B. (This doesn’t mean those color charts shouldn’t be in your collection).

Perhaps the result is a bit too dark, but the overall effect is nice, especially compared to the single coat in the previous image. The sides are sprayed with AP507B, and the top and bottom surfaces with a coat with more white and blue respectively. I added some filters and drybrushed in pure white (artist oils) and added some additional (artist oil) highlights in black, umber, and probably a few colors more. I want to emphasize all details without giving the idea of a severely weathered ship; HMS Hood was painted about a week before she sank. I have to experiment with the deck colors a bit more (wood) but I’m about ready to start painting the hull.

The old aft searchlight platform (ASP) was damaged during cleaning up for painting and needed to be replaced. I drew the part in CAD first. It’s both a building manual and a note combined. The old AOTS shows this platform in several views but the measurements do not agree with each other. So, the CAD file is my ‘new’ reference’ and I think I’m going to do this more often. I even drew in what styrene strips go where and assembly is then very fast. ish.

The lines were scribed in styrene using a steel ruler and the depth probe of the calipers. Very easy and very accurate. The two cylindrical parts of the top floor of the ASP do not have doors and as all pictures seem to indicate this area was open I decided to leave it open on the sides as well as on the aft bulkhead. However, cutting out doors and then folding the plastic won’t work, so I first folded the part around (lathed-to-size) rod, boiled the part for a while, and then cut out the door and added the slanted interior. Tricky but it worked.

The front bulkhead fits the top floor excellently. Caliper and CAD work give good results. The previous variant of the ASP had the bulkhead glue onto the deck, now it is glued against the deck. Can’t remember why I made this bad decision for the previous version, but it resulted in the part being tossed.

The old ASP had to be removed with subtle force from the deck part. A few positioning pins were added for easy fixing later.

The rest of the part is now simple a matter of stacking. I started with a core of several layers, added the sides, and puttied everything smooth. At least the forward corners (well aft actually) of the ASP are now round as they should be.

The wings for the two lower searchlights are very delicate. I never met a circle cutter I liked so when I need to carve a circle (or in this an arc) I make a disc on the lathe to be used as a template. The wings were added using a small template for both the right height and angle. I used some tape to get an ‘exact’ measurement and added the bulkhead cut to size and small strip later. Note that I add that strip on a flat surface; otherwise it will never look right.

Existing detail was transferred; some railing, stairs, Carleys and ammo lockers. The structure consists of two parts for easy painting and is still very open.

TO BE UPDATED

The structure and searchlights are now painted. The fog light still needs to be assembled so no pics yet.

Funnels, Part II

Continuing from part I

With the soldering going so well I decided to solder on a bit more and had some parts redesigned and etched.

Some minor detail was added first. The two ladders on the inside of the funnel are placed with a jig so that the gantry will link up to it nicely. The ladder is by Aber, one of the few commercial products I have used (I’ll probably use my own ladders in the future). The steam pipes cluttered around the funnel are made from rod; drilled in, chopped up to give it that knuckle on the end, and fixed with brass wire. That is, I didn’t glue the pipes to the wire yet to avoid handling damage in that area.

Note that there is a bit of damage on the aft funnel that was later patched up; a nice piece of detail to add. The top left image also shows the typical Royal Navy approach to painting the ship; they do not use the foot rails found on axis battleships with a series of pulleys and planks to stand on. It doesn’t seem very safe but it does save you building an awful lot of these foot rails. The pulleys are etched parts, folded once.

Here’s a sketch of the funnel cage.  The crew could access the funnel from below, climb to the top and fix an awning to the cage (but usually did so only when the boilers were out). I made this small drawing in Autocad of the funnel cage with a series of 0.2mm holes for the supports of the cage and for a few pins to hold the cage in place. A ring goes around the funnel cap supporting a series of arches. One large grande arche is on the ship center line. I decided to make a drilling template for the supports and support pins.

The inside of the funnel isn’t as perfect as I’d hoped and deformed a bit with all these layers of plastic going around it. Perhaps all these brass wires in the inside are a bit too taut. I already botched up fitting several well-executed gantries so I came up with a disposable fitting template to check the goodness of fit; should have come up with that earlier!

The soldering of the gantry itself was slightly tricky and I had to tape the parts down at every step. I added the solder like I’d normally add CA; a few spots to fix the part, with a line of solder when it’s more or less in place.

Now the template for the cage. I bought a pin chuck to hold the 0.2mm drills. When I put the pin chuck in the Proxxon chuck (Röhm actually) and dutifully fixed the chuck with the key at all three positions as my tool shop ordered me to do, the pin chuck was not centered correctly; I really had to try, try and try again until it was finally worked. I even bought a new chuck so that I now have a nicely centered chuck/pin chuck combination never to be separated. I made a picture of the spinning drill as proof it finally worked. I started with the drill protruding only a few mms from the chuck but the drill will usually walk away slightly—drilling off center—and the drill will break when the chuck is near the work piece; I lost three drills before I figured this out. So, I finally had the drill sticking about 1 cm or so from the chuck so that it could flex. The result is shown at right after drilling and with the positioning pins. The tubes at the center are supports for the arcs of the cage, made from aluminum so that the brass wire won’t be soldered to them.

I had some room to spare on my last etch so I added a folding template for the ring of the cage; the brass was far too stiff to use this template but it did work to check the shape. I started by rolling the handle of my X-acto knife over a 0.2mm brass wire until the diameter was correct. With some pressure from a pair of pliers I added the parallel center until the shape was more or less right. The wire was transferred to the jig, held in place by tape and the supports were added one by one. I started opposite where the ends of the ring meet and cut the ring to size only when nearly all supports were in place. The positioning pins could then be removed.

The arcs were bent into shape and checked against a high-tech drawing. The grande arche was added first, followed by the other arches. Note that the ends of each arc have a 90-degree bend; this allowed me to temporarily tape the arc to the jig and keep the direction of the arc upwards; otherwise it will just fall over all the time. I fixed the end of a single arch to the grande arch, fix the arch to the ring, and reapply to both ends in succession. By doing this, there is no stress in the solder and when I apply heat to the center they do not change position (much).

Afterwards three etched parts were added on top of the intersections of all the arcs. The difficulty was not so much avoiding the desoldering of all arcs but aligning the etchings themselves. The cage could then be lifted from the jig. One cage was damaged beyond repair at this phase. One cage took between five and six hours to make; this time was mainly spent looking through the Optivisor and handling the parts with tweezers and the soldering iron until the alignment was to my satisfaction (which is never, naturally).

These funnels took more than a fair amount of planning and experimentation but now have a level of detail that I would not have thought possible a few years ago (cage and gantry are not fixed yet in this picture). The soldering allows for much better and clearer work than using super glue and it is much easier to correct.

Cordage and Hawser reels, Part II

Continuing from part I

I’ve been exercising with soldering lately. I thought things were going wonderfully at first and I made a few fully soldered pompoms. Unfortunately, after a week they started to corrode and after a month parts started falling off. Repairs didn’t work and even superglue did no longer adhere to the metal at all (this never happened before!). I used the corrosion-free Tix flux that may have been the problem, either as I didn’t clean the parts properly afterwards or it simply isn’t corrosion free as some modelers on railroading forums claim? I don’t know really, but after a period of mourning for my pompoms I gathered my strength and I replaced all my soldering equipment and consumables. I finally found a nice Australian web shop called DCC Concepts with a nice how-to on soldering and their own range of solders and fluxes. They claim to have a no-clean non-toxic flux that I wanted to try and this solder/flux from DCC works really well. In the beginning I had some trouble as it didn’t run as smoothly as the Aber/Tix combination; however, that combination ran so well it ended up in a very very thin layer and a poor bond. I just have to be a bit more careful in the amount of solder I add for each joint.

I practiced on a new batch of cordage and hawser reels before trying the far more complicated pompom. I already made a batch but I had so much trouble gluing these parts together. If some part broke off during the final stages of construction, I really couldn’t repair it and had to start over. Understandably, the failure rate was very high.

1. Piece of MDF used as a disposable workbench.
2. Bottle of flux secured in a hole drilled in the MDF. It does really help avoid knocking the bottle, which I did when working with the Tix flux earlier (Staining the modelling table). The first day I constantly found myself wanted to shift the position of the bottle but now I’m used to it not being able to move.
3. An old brush for applying the flux.
4. A bag of parts to be soldered.
5. The DCC Saphire solder.
6. Stock rod, tube, and wire. This brass from Scientific Wire can actually be soldered, in contrast to winding wire I bought that has a coating.
7. A drill to open freshly cut tubing.
8. A toe-nail clipper for cutting (thin) rod and wire.
9. Calliper.
10. Assortment of files, knifes and tweezers.
11. Part storage area outline.
12. Soldering station by Weller with a variable iron temperature.
13. Soldering iron with the finest tip in the Weller assortment of fine tips.
14. Alcohol for pre/post soldering cleaning.
15. Bowl with alcohol to finished parts.
16. Maximum magnification Optivisor to check the bonds and quality of filing and such.
17. Tramin 2011 Pinot Grigio from the Alto Adige. Hensel 2011 Grauer Burgunder will also work. Soothes the nerves before soldering, dampens disappointment when parts spontaneously disintegrate, raises spirits when things finally go according to plan.

Now, I am not going to follow all the advice normally given for soldering work. For instance, I do not have an abrasive pen to clean the parts as the parts are much too small; holding them without damage is enough of a challenge already. Pre-tinning a part is often risky as you can clog delicate parts but sometimes works. You also can’t really pre-tin the soldering tip because the amount of solder you need is so small. Top-left shows a tiny chafing chipped from the solder. Now, slice is halved, and if necessary cut it two again. You can pick up the solder with the tip of the iron; you can see a tiny bead (top right. note that this is the smallest soldering iron tip that Weller sells with a 0.4mm tip). This works very well for applying a minute amount of solder that is sometimes already a bit too much. The bottom images show a tiny 0.5mm tube soldered to a 0.3mm wire; the wire centers the etched parts and the tube acts a spacer. I add flux to the wire, pre-tin the wire (no harm here), slide over the tube and add heat.

The two etched parts are cut from the fret, sanded and put in the “storage area outline”; they are so small and difficult to find that putting them on the same spot actually helps. Now, I drilled in a small 0.3mm hole on the base plate so that I can plug the 0.3 wire through the etched part (top center), add some flux and then heat while gently pushing the tube down with fine-tipped tweezers. The part is both held in place and aligned at the same time. It can help to use to Optivisor to see if the solder is really flowing; if the connection is bad the part will probably fall off anyway. The long end of the wire is clipped and the other etched part is added. This is more difficult as they need to be aligned with respect to each other and there is some risk of the first part getting loose, so some trial and error is required.
My cheap model pliers weren’t any good for clipping wire (most modeling tools aren’t) but my beautiful Zwilling toenail clippers were just perfect for the job. Afterwards the excess wire (nearly nothing) was filed off; this is a tricky part as it’s very easy to catapult the part if you’re not careful (need better tweezers). Afterwards the etched parts were folded. Here the optivisor came in really handy, showing me if I held the tweezers properly over the fold line. The image bottom left shows a poor example, risking folding over a hole present in the part. Bottom right shows a finished cordage reel; 2.5mm wide.
The hawser reels presented a much greater challenge; I needed to make drums with a 0.3mm hole for the center wire to align all parts. However, I haven’t been successful drilling in these small holes in brass. I started with a center drill of 0.5mm, giving only a gently tap to the end of the rod, but the small drill often wandered anyway. Even when the hole was centered perfectly the drill breaks, even when I drill very carefully using cutting oil and cleaning the drill every few tenths of a millimeter. Anyway, I gave up and ordered some stock tubing from Albion Alloys with a 0.3/0.5 inner/outer diameter. Drilling in a 0.5mm hole is very much easier and the tubes are very easy to cut to length

Making small brass tubes is now fairly easy for me. Setting the late at its highest rpm (only 3,000) I start with cutting the end of the stock brass (1) and cutting the rod to the correct diameter in very small steps (2). I bought some stock rod from Albion at the right diameter but I lost it… Next I position the 0.5mm hole with the center drill but I do not drill the hole yet (3). I change the cutting tool for the parting tool (the quick change tool holder is the best upgrade for the lathe). I position the parting tool, release the rod,push the rod back with the parting tool and fix the rod again in the chuck. This is my primitive way to reposition the parting tool at zero (4) and make a small groove with the parting tool (5). Then I apply the square flat file; I put the lathe in reverse so that  the file isn’t catapulted into my eye when I accidentally hit the chuck with the end. I think this is much safer (6). I continue slowly with the parting tool (7) and capture the small tube on the end of the drill (or center drill). I usually make a batch of them before reinserting them in the chuck (9), apply some cutting oil and drill them through.

I took a few images of the largest hawser reel, consisting of 2 tubes and 7 etched parts.

The top four images show the small drums added to the 0.5mm tube. The tube is much to long but when the to tubes are soldered to each, I insert the part in my hand-held drill and cut the tube by hand. A small 0.3mm wire is then put through the tube. The etched parts at the side are actually three parts, so that I could capture a bit more detail. The first parts fit into each other and need to aligning, but the last part is held in placed by an old broken-off 0.3mm drill.

Like the cordage reel,. the hawsers are fixed to the bade plate and the parts are all soldered into place. This is a tricky part because all the parts get desoldered; I apply pressure with fine-tipped tweezers while the solder solidifies. The part is checked to see if everything still aligns nicely and of all the feel touch the deck properly; if not, the part is heated and realigned. The 0.3mm is then trimmed and filed smooth.

The small model is clamped into the caliper and a 0.15mm brass wire is soldered into place, cut to size and filed. If the rod breaks off during filing, then the bond wasn’t any good. Although the flux is sold as no-clean flux, I threw the parts int he ultrasonic cleaner anyway. This cleaned up the parts and improved the bond between the final two parts superglued to base of the small models.

Not the best picture, bit it givens a nice impression of the range of reels to be fitted to the model. Why doesn’t the reel at the center doesn’t have those two wires? Must be a failure I didn’t throw out.

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