The Panther Cupola is almost finished. I have had some problems figuring out how to fit the periscope mounts into the cupola. The initial idea was to have a series of pins fitted to the cupola for the mounts to hook on, this however proved to difficult to achieve. I have reverted to designing the mount holders the same as the real ones. The problem I had to over come was casting the tabs into the cupola base. These could have been cast as part of the cupola in resin, difficult but not impossible, this would have meant having a collapsible interior mold to be able to remove the cast parts. However I do not think the resin cast tabs would be strong enough to support the mounts under the pressure required to hold them in place. The alternative is to have a metal cast ring with tabs that can be screwed to the base of the cupola. This is what I am working on and following is were I am at.
First I had to make a master of the base ring to fit the cupola base. Near impossible to machine a accurate fit. So I made a mold of the base and cast a resin copy.
The resin copy now has to have the tabs fitted as shown in picture. I have also included a not to scale drawing of how the mounts are fitted. The periscope was fitted with the rubber gasket and held in place by the box mount, with the release lever in the locked position the mount bolt was tightened on the mount tab until it was firm. To remove the periscope the release leave was moved to the unlock position, a cam system released the pressure on the mount bolt and the periscope and mount could be removed.
It is not possible to make the scale model work like this, but my design is close. The rubber gasket will act as the pressure for the mount and the periscope and mount can be fitted the same way as the real one. The big problem here is the make the cupola and base ring to match and also achieve the correct distance between the inside surface of the resin cupola body and tabs on the metal ring. First I have to make the metal base rings, then using a metal ring, machine the base of the master cupola body until the two match and the distance between the cupola surface and ring tabs match the size required to fit the periscopes and mounts. Once this is done I can finally cast the cupola body. The resin I use has only a .002% shrinkage so this will not be a problem.
I have also test fitted the photo-etched head rest ring, these are bolted in place and cupola bodies will come with predrilled holes for mounting the ring.
All other parts for the cupola, periscopes, armored periscope covers, periscope rubber gaskets, periscope mounts, rubber head rests and ring, hatch cover arm and interior hatch cover lifting parts are completed.
I know this has been a long haul for those that ordered to cupola, I hope you all think it is worth the wait. I try to achieve the best possible products for customers and sometimes this takes a lot longer than you and I would like.
Regards
Mike