The Sd.Kfz 251/6

Joined: February 27th, 2005, 7:41 pm

August 19th, 2016, 2:36 pm #21

in multiples, you could make a quick rump mold set from bathtub caulk and cast the AFV Club interior parts in a clear resin, especially useful for the armor glass vision blocks. These are molded in solid plastic in the AFV Club kit.
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Joined: June 9th, 2015, 11:35 pm

August 20th, 2016, 12:22 am #22

Bruce, for making multiple copies of small parts, I often use a method I can "mash molding".

I mix a wad of epoxy putty, slightly flatten one side and, using plenty of talc to avoid sticking, stick the part I want to reproduce in the putty - like an open face mold.

When the putty cures, I pop out the part, and I now have a very rigid, open face mold (to get the part out, it can help to glue a styrene rod to the back of it).

To make the duplicate parts, I take lengths of sprue tree, heat them over a candle until I get a blob of molted plastic at the end, then shove/mash it into the mold and let it harden. Pull it out, cut off the excess sprue and make the next one. You can make bunches quickly, and if you use the sprue trees from the kit you are building, the duplicate parts are even made from the same plastic.

For the AFV spare vision blocks, this method would be ideal.
Kevin Townsend
from the garden paradise of southern New Jersey
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Joined: February 27th, 2005, 7:41 pm

August 20th, 2016, 2:46 pm #23

I will be saving this post for future evil reference..... I am doing something somewhat similar for casting marks - I apply the Archer 3D casting numbers and /or marks to a small sheet of thick styrene sheet as they would be on the model. Then I use bathtub caulk to make a flexible mold of the markings, and any time I need particular numbers r marks for a model, I just run some putty or epoxy into the caulk mold and pop them out and apply them to the model sections. It saves time making up all the numbers each time you need one, and for bogie truck towers and transmission covers, where the part numbers are the same for each type of item, it is much more convenient, and I need to save all the time I can.....
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Joined: June 9th, 2015, 11:35 pm

August 20th, 2016, 3:12 pm #24



While fixing the Bandai might not be the best way to get an Ausf B, it is a way... I never said I was normal.

https://www.youtube.com/watch?v=yH97lImrr0Q

So how is my monster progressing? As we saw a bit earlier, a first step in resolving the shape issues on the Bandai hull—as well as correcting detail issues on the rather poor Bandai suspension and running gear, The bottom area on the Tamiya hull will be cut away and used to replace the bottom part of the Bandai hull. This is an easy cut, with the bend in the hull (at the point it goes from vertical to angled) being used as a guide. To make the cuts, I scribed carefully with a new, sharp hobby knife blade. This is more exact and less damaging than trying to use a saw or Dremel—although it takes more time. The key is making sure the cuts are straight so it mates better when the parts are swapped.




1. The Tamiya piece cut from the hull. To help ensure a good fit later, it’s important to make the cuts and straight and even and possible.

2. As we have seen, a comparison of the Bandai hull with the plans from Panzer Tracts indicates the angles where the rear joins the side are not quite correct, so in addition to removing the bottom of the Bandai hull, the rear is removed, too.

3. Prior to grafting on the Tamiya hull, the Bandai upper and lower hulls were temporarily attached with tape. This will help ensure that when the Tamiya/Bandai parts are glued, the Bandai lower hull walls will retain the correct alignment and the correct angles.

4. The Tamiya hull parts glued in place. As great care was taken to get the cuts straight and exact, the pieces join together with a very clean joint (at least at the rear where the hull shapes are most compatible).



5. Before the glue cures, test fitting with both the sprocket and idler wheel (with some track links attached) was done to ensure proper clearance under the fenders. The alignment of the lower hull pieces was slightly adjusted to ensure the correct fit and spacing. If the idler and sprocket fit ok, so too will the rest of the wheels and tracks.

So far things are going so lovely, I feel like a song!

https://www.youtube.com/watch?v=w1FLZPFI3jc

And, like our song, while things started well, there were some issues that arose the further along we went.




6. The Tamiya front portion was filled in place on the Bandai hull, the fit was not as good here, and some plastic/putty work will be needed to correct this area, but it’s not toooooo bad.

7. The incorrect rear hull shapes were fixed with sheet plastic. Take care to get a good, straight joint so it will be easier to smooth later. In this photo, the side pieces are glued, cured, and sanded to shape. This was done by constantly fitting the upper hull until everything lined up and was square. Here, the back lower piece is glued in place, but not yet sanded. Tip: As we see here, sometimes it's best to cut the piece slightly oversize and sand to final shape after curing. This ensure perfect fit with no gaps.

Speaking of gaps... Any issues on the outside of the hull can be fixed with putty after assembly, but before painting. However, the inside of the hull will need painting prior to assembly, so I'm taking care to ensure interior fit is perfect and gap free.




8. The front axle was loosely fitted in place, along with the wheels. So was the completed track/road wheel assembly. This was done to ensure proper alignment of the mated hull pieces and to make sure the vehicle would sit level on the ground. So far, so good (of course is what the optimist yelled out when passing every floor after he fell from the roof of the 80-storey building). The only (minor) issue is that the Tamiya front wheels are slightly larger than the Bandai wheels. Therefore, proper alignment of the axle under the fender is vital to make sure the fender does not foul the wheel. If, as I get to the point where suspension bits will be permanently attached, the wheel ends up looking a bit too large, I may turn the wheels to about a 30 degree angle to sort-of hide their size.

So the first step is pretty much complete with no major issues or problems. But I'm sure that sooner or later Frankenstein will meet the blind priest:

https://www.youtube.com/watch?v=sXGzO2aDDRU



To this point, I haven't done much with the upper hull, but I did remove the incorrect antenna mount and bullet splash rail.
Kevin Townsend
from the garden paradise of southern New Jersey
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Joined: June 9th, 2015, 11:35 pm

August 20th, 2016, 3:15 pm #25

I will be saving this post for future evil reference..... I am doing something somewhat similar for casting marks - I apply the Archer 3D casting numbers and /or marks to a small sheet of thick styrene sheet as they would be on the model. Then I use bathtub caulk to make a flexible mold of the markings, and any time I need particular numbers r marks for a model, I just run some putty or epoxy into the caulk mold and pop them out and apply them to the model sections. It saves time making up all the numbers each time you need one, and for bogie truck towers and transmission covers, where the part numbers are the same for each type of item, it is much more convenient, and I need to save all the time I can.....
...but only if you have a very solid, rigid, mold. Otherwise the act of mashing would distort the mold. That's why I use a blob of epoxy putty. In fact, I'll probably use the method on this conversion. If so, I'll try and remember to photo-document my process.
Kevin Townsend
from the garden paradise of southern New Jersey
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Joined: June 9th, 2015, 11:35 pm

August 26th, 2016, 7:13 pm #26

Now that the bottom is fixed, time to turn attention to the back. The lower rear hull joins the sides at the wrong angle. So… the rear portion of the lower hull was cut away as we have already seen.



1) With the hull halves taped together, the lower hull was extended with sheep plastic until the joint at the rear was vertical. The rear bottom piece was also put in place. When doing work like this, I always make the new plastic pieces a bit oversize and do final trimming and shaping after they are glued in place. This ensures perfect fit.

2) The lower back piece was glued on the correct angle. This caused the top joint with the upper hull to have a variable-sized gap along its whole length. A length of plastic strip was glued on top of the lower hull piece and sanded until it was level and the hull top fit flush. Note the upper hull should slightly project over the lower hull – there should be a slight step on the angled piece instead of a perfectly flush joint. At this stage, I am not as concerned about the fit of the joints on the outside of the halftrack – this area can be fixed with putty after the hull is glued together. But I am concerned that there be no visible gap on the inside since the interior will have to be built and painted prior to the hull being glued together. At this point, I am happy with the shape of the lower and rear hulls.



3) Time to fix the nose! The angle of the top nose piece is waayyy toooo steep. It should be closer to the vertical. Fixing this will also require the top vent be moved slightly forward. So, the top front piece and the vent were cut from the hull.

4) and, using a sheet plastic backing to ensure a good joint, were glued into the proper place at the correct angle.

5) Note the front top piece should overlap the lower piece – there should be a noticeable step where the top portion meets the lower portion.

6) And the gap was simply filled with Magic Sculpt epoxy putty. A swipe with a damp finger smooths it nicely.



7) Still, to make sure all is perfect, I sprayed the area with some black and examined it from all angles under a bright light. Areas that weren’t perfectly flat, or that exhibited a visible line between plastic and putty were lightly sanded. Note the scribed radiator cover has also been filled in with putty. This should be a cap that stands proud of the surface and will be added later.

8) Since I’ve already sacrificed a Tamiya kit for the conversion, I’ll use the appropriate parts from the Tamiya interior. On the floor, the front seat mounts and under seat stowage bins were cut away and replaced with sheet plastic. Don’t worry that the tread plate pattern isn’t there. These areas will all be under seats and will be all but invisible on the finished model anyway.

9) The floor and dash are nearly perfect fits. Only small wedges at the bottom of the dash (indicated by the arrows) needed filled. Again, a swipe of Magic Sculpt followed by a damp brush took care of the gaps.

While it’s not shown, I also cut the rear door out of the upper hull piece. I’ve decided I want to pose the doors open. Although this will be more work, I won’t be happy unless I have open doors, so it’s going to get done.

Kevin Townsend
from the garden paradise of southern New Jersey
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Joined: June 9th, 2015, 11:35 pm

August 26th, 2016, 7:14 pm #27

The Monster Mash

I mentioned what I call “Mash Molding” a few posts ago. As promised, here’s a brief tutorial.



1) I make a mold by pressing the part into a blob of soft epoxy putty. I use Magic Sculpt, but any would work. In fact, any medium that dries hard will probably work just as well. I use plenty of talk to make sure my part doesn’t stick to the putty. In this case, I’m using a “tractor” style seat left over from the Flakvierling that has provided parts and figures for a couple earlier conversions. Note I glued it to a length of styrene rod for easy handling. The putty is now allowed to fully cure.

2) To make the part, heat a length of sprue tree over a flame. Instead of heating at a joint or middle of a length for stretched sprue, I head an end. Rotating the part to ensure evenness. Don’t let it bubble and boil or you will get a poor part. Just let it nice and soft, almost molten.

3) Then just mash it into the mold (this is why I use the term “mash molding”). Allow the plastic to cool. This only takes a couple seconds.

4) Pop it out and you have your part.

You can make a bunch of parts quickly with this method. It works for small, simple, one-sided parts only. Part quality varies fromt perfect to bad, but the bad ones can be tossed or remelted. The advantages are the ease and quickness of making parts and the fact they are the same plastic as the kit. The little bit of putty needed is quite cheap compared to casting/molding materials and most of us have an endless supply of plastic sprues.
Kevin Townsend
from the garden paradise of southern New Jersey
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Joined: June 9th, 2015, 11:35 pm

August 26th, 2016, 7:18 pm #28

As you can imagine, I've amassed a large amount of data about this vehicle.
In my obsessive/compulsive way, I've tried to smash as much information as
possible into a simple chart. (Well, simple to me, anyway). So here, for
your perusal, is my first hack. If anyone wants a better copy that these
photos, I can you the five-page pdf. Just let me know. You can reach me at


Kevin_townsend1961ATyahooDOTcom

















Any ideas or inputs, let me know. Enjoy.
Kevin Townsend
from the garden paradise of southern New Jersey
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Joined: June 9th, 2015, 11:35 pm

August 26th, 2016, 7:46 pm #29

Most of the little avatars on the above chart come from this website:

http://www.pietvanhees.nl/251/

Which is a pretty good source of information. A couple of the avatars I made using those as a basis.
Kevin Townsend
from the garden paradise of southern New Jersey
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Joined: April 27th, 2005, 1:33 pm

August 27th, 2016, 4:22 pm #30

Looks like your Fanken-kitting is coming together wonderfully! I have a few of the old Bandais lurking, and this article is the solution to building acceptable models out of them. The resection on the hull certainly turned out treat, I will start looking for a source for Tamiya sprues, looks like you needn't use the whole kit. Still thinking about a way to save that Bandai logo though 😂

I like the smash mounding tutorial - have you tried the boil and squish instant mould compound? It works with epoxy to cast the parts - I use JB Weld Quick Cue. Used it on my Pz. III H for the visors and vision block covers.

Konrad
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