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| Messages | 22309 |
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| Subject: | Re: Stirring another pot...or why do we settle for closed guide horns? |  |
| Date: | Jan 5, 2003 |
| From: | Chris | |
Andy Herbert wrote:
>OK, I was looking at a variety of kits, and remembering how often I've
>read that the kit supplied tracks are great except for solid guide
>horns. This has been passed off as 'impossible to have open guide horns
>because of the molding process', or some such.
>
>I have the DML T26. The tracks have open guide horns. Alan's PzII tracks
>have open guide horns. MK can do it, right?
>Why do we get three beatiful Panther kits from DML, all with solid guide
>horns for the tracks? Is it something about the number of guide horns on
>the tracks? Would it be more expensive to have accurate tracks?
>
>Just curious.
>
>By the way, I received both the DML Panther A kits for Christmas.
>WOW!!!!!!!!!!!
>
>Andy
>
>
>
Andy -
Look at the Alan and DML tracks, and you'll notice that the hollow in
the guide horn has a hole in the body of the link right under it. The
piece of metal (it's actually a permanent part of the side of the mold
that has the impression for the tread) that keeps the injected plastic
from filling that hollow goes through the hole when the mold is closed.
This doesn't increase the cost of the mold directly, but it can result
in trouble separating the mold and releasing the frame and parts cleanly
(resulting in ejector pin marks and sink/shorts to get the darn things
out of the mold). The Panther track links have this hole beside rather
than under the guide horns, and the horn itself is closed both top and
bottom, so there is no place for that piece of metal to go through.
In order to mold these links in plastic, the mold maker has two basic
choices. He can mold the guide horns separately, which would require a
larger or an additional mold (increase his costs substantially) and
would leave modelers with two small pieces to cut, clean, and add to
every link (decrease their pleasure and his future sales), or he can
make a multi-part mold. A multi-part mold would have to have four parts:
one surface of the mold would carry the impression for the tread of the
link, and the other surface would have to have three pieces (a center
which would retract straight out and two side pieces which would have to
be pulled to the side) to make the top and guide horns. This would leave
a very flat surface on the guide horn side of the link, which would not
usually be accurate and about which modelers would complain. This would
also be a very expensive tool to make, and the resulting links would add
to the price of the kit only a little less than what modelers would pay
for after-market tracks, nearly doubling the ultimate price.
When the guide horn has a natural hole under it, conscientious
manufacturers probably should provide hollow guide horns when they mold
individual links (I am not a great fan of individual links). Using
multi-part molds for Panther-type links would put the kits out of the
price range of so many modelers that the manufacturer could not project
enough sales to justify the costs of tooling. That risk is what
after-market entrepreneurs are willing to take when they plan their
releases.
Best in modeling,
CTew |
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