Sd.Kfz 165 Hummel scratch + HL electronics

[MonsieurTox]

Great progress.

I am curious to see how you will manage the gun shield. It was the most complex area to model on mine.

Thanks Louis, I am considering several options.

The first one would be the easiest, print it in resin. Result would be perfect with no sanding and I could incluse the attachment points with bolts and nuts for the linkages to the gun.

The second would be to vacform it over a hand sculpted or 3D printed buck. That's my favorite because I can get something very thin yet very strong and keeping its shape in styrene.

The problem is that my vacforming tool is 600x400 mm, way too big for that job. I have built smaller ones in the pasts but I dont know where they are after 2 moves I'm too lazy to build another and drill thousands of holes.

The third option would be to use the Bandai parts. I would have to trim them of course to rescale them from 1/15 to 1/16 but that would work. Parts are a bit thick though.

Making the shield is quite challenging, and I am even more concerning attaching it strongly to the gun.

Another concern of mine is too get the correct anti skid plates for the fenders (dotted) and for the combat compartment. I have a plan for that, I'm going to accurately 3D model each type of antiskid plate and 3D print a master that I will mold and get thin (0.3mm at max) resin castings.
I may also do it the real way and emboss some thin aluminium sheet with a 3D printed roller with the correct pattern. I may try both ways. I would really be able to do embossed aluminium stuff...

[lmcq11]

Yeah, quite a few challenges;
- getting the thin shield angles and curves right, keep them that way, and do it twice for both sides
- if you want rotation, its very difficult to find the angle that make the shield rotate while ensuring the shield is flush with the side armor as it rotates, with consistent spacing.
- those thin and curved attachment brackets, some deep inside
- how to anchor the gun and keep the shield together with the force of the heavy recoil

Hummel gun shield

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Hummel gun shield

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Good luck

[MonsieurTox]

Yeah, quite a few challenges;
- getting the thin shield angles and curves right, keep them that way, and do it twice for both sides
- if you want rotation, its very difficult to find the angle that make the shield rotate while ensuring the shield is flush with the side armor as it rotates, with consistent spacing.
- those thin and curved attachment brackets, some deep inside
- how to anchor the gun and keep the shield together with the force of the heavy recoil

Capture31.JPG

Capture30.JPG

Good luck

Happy New Year !

Thank you for the pics and advices Louis, yeah it's quite a challenge ! I think I will finally use a fourth option I did not think off earlier. Will use 2 laminated 0.3mm thick styrene. Going to use chemichal bond which will soften the 2 layers until the plastic become hard again, I will let them around a buck with the correct shape. It's a bit the same thing than doing curved stuff with laminated wood (except we're not talking solvent to soften the material but steam in the case of wood). The parts will retain the shape once perfectly cured. I haven't done the maths yet but 0.6mm thickness seems to be OK. Lets see if thats work !

[MonsieurTox]

Hello guys, it's been a long time I haven't posted but it doesnt mean I haven't made progress on the Hummel !

I actually did a lot of small works on it, Im moving slowly but I am also working on other tanks at the same time.

On the Hummel and on several other german tanks like the Panzer IV, they used semi perforated right angle brackets all over the tank. Of course none of them have the same hole diameter and spacing, it would be too easy.

I decided to make them in styrene using the mill to drill the holes and then finishing with the hobby knife. And made the several styles and sizes used on the hummel.

I made the fender in styrene. I used Aber dotted pattern (PP03 if I'm correct) to put on them, unfortunatly I had the bad idea to use strong double sided tape but it was not that strong haha... after some days in my hot veranda they started to came off partially, I decided to removed them and I have been very careful doing that because the bond was still strong in the center but the PE is so thin that it has been damaged (creating some kind of "waves" on the plate). I tried to straighten it as good as I could and I glued it back with CA.

I then worked on the ammo box. Once again I used the mill to get evenly spaced and aligned holes, the square ones have been cut by hand.
This the first box I made, the proportion was a bit off (slightly too large and not deep enough). I built a second one.

Here's the final box :

You can notice in that last pic the textured floor. I found a nice facebook page of guys restoring a Nashorn with plenty of pics (too bad I did not know it earlier !). There were some great pics of the original floor plates showing the exact pattern (same as the Hummel of Saumur and probably that every Hummel/Nashorn), I have been able to find the right size of those squares and the I cound them to get the right numbers . Well I modeled that textured floor in my 3D software, it was a very heavy file !

The print was just a proto to see if it worked, it worked well actually. But I did not properly cured it and it warped over time (and I broke one piece when trying to get it back to shape). I'm going to print new floor plates soon.

[MonsieurTox]

I made the bracket for the elevation mechanism of the gun. In its tracted version, the gun elevation mechanism is on the chassis.

Louis's thread has been a great inspiration, why reinvente the wheel, I'm using here's what he used, the BK-1602 dampers made by BitsKrieg. Very nice parts and the lasercut jig to glue them is great (and it allowed me to checked I glued the suspension with the right spacing ).

I made the track pin pusher or whatever it's called in styrene. There was an early and late version, shape and position were different. Of course I am replicating the late version.

The hooks are from the Trumpeter Panzer IV. I chopped the small bracket from the Panzer IV rear plate and assembled the hook and bracket together, added some detail and glued it to the hull of the Hummel.

[MonsieurTox]

Here are some general overviews.
I 3D printed the shield in resin. I don't know why I designed it that thick but well I don't plan to print another.
I have also 3D printed the angled brackets which themselves have U channel reinforcements. I designed them with the correct thickness this time (0.3 mm).

I've glued several bolts and nuts that I chopped from unvisible aeras of the Trumpeter Panzer IV (kit I am using to build an hybrid HL/Trumpeter Panzer IV, see my other thread).

hummel73.jpg (89.14 KiB) Viewed 593 times

The hinges of the pilot and radio guys hatches are molded and casted from the 1/16 Heller StuG III (kit Im using to make a hybdrid HL/Heller StuG III ).

I found a TK 6.1S which allows me to use servo for elevation and recoil of the guns. Its not as good as other option but it does the job and work well.

That's all for now !

Thanks for watching.

[MonsieurTox]

Hey guys, do you have any idea if a late panzer III sprocket exists in plastic for? I'm using the HL early sprocket and was thinking milling the hub flat and glue the hub with bolts of my Trumpeter Stug Iii sprocket but diameter is not a match? I don't want using metal as I have plastic tracks.

[lmcq11]

Its coming along very well. I like the precision and assembly of the parts. I do not think the Mato metal sprocket with late hub will eat the plastic tracks. The issue is usually the other way around, metal tracks eating the plastic sprocket.

[MonsieurTox]

Its coming along very well. I like the precision and assembly of the parts. I do not think the Mato metal sprocket with late hub will eat the plastic tracks. The issue is usually the other way around, metal tracks eating the plastic sprocket.

Thank you Louis, your build is a great motivation.

OK let's go for metal sprockets then! That's true my Tamiya Tiger I and II have métal sprockets and idler with plastic tracks and I've been using them for a long time with no problem.

Now the other question is, will the Mato sprocket fit the shaft without issue? I mean without having to cut them, and will they fit the HL tracks with no problem?
I've seen some guys having issues with both Taigen and Mato metal Panzer III sprockets and, I believe Taigen tracks haha
Well I'm going to try, for the price, I won't risk a lot and I'll use the metal idler on my son's HL Stug to replace the weak plastic ones.

[lmcq11]

Now the other question is, will the Mato sprocket fit the shaft without issue? I mean without having to cut them, and will they fit the HL tracks with no problem?
I've seen some guys having issues with both Taigen and Mato metal Panzer III sprockets and, I believe Taigen tracks haha
Well I'm going to try, for the price, I won't risk a lot and I'll use the metal idler on my son's HL Stug to replace the weak plastic ones.

It's confusing. From what i have experienced myself with the Shermans, Mato usually makes their metal sprockets in two shaft diameter sizes, one that fit Heng Long shaft size, and one that fit the older Mato gearbox with the smaller shaft diameter, like the one on their M4A1. But the newer Mato gearbox they sell separately uses Heng Long shaft diameter size... When purchasing a Mato sprocket, the vendor usually indicates "HengLong" somewhere in the title or description if it matches the shaft size and shaft length of Heng Long gearbox. If it just says Mato, then its risky. I just fitted a Taigen Sherman sprocket on a Heng Long gearbox, so that combination worked. Cutting the shaft a few mm in length to align the sprocket with the roadwheels is easy. But if the shaft length is too short, then its the gearbox that need to move closer to the armor sides, if possible. But if the shaft diameter is too big or too small, this is when it needs to go in the future build bin for potential reuse.