Armortek

I spent some time with the driver's and right side armored doors. I was looking to add either the cast metal latch details, the latch that secures upper and lower panels together; or make functional versions.

I quickly became apparent that no matter which option I chose, neither would fit where they needed to be because of the upper steel cross member.
It took a while but I finally found an image that showed this area which is set in a bit.

Not wanting to chop and whittle my way into a corner by altering the kit parts, I first decided to scour the web looking for the curious miniature
steel angle as the one used in the kit but finding none. So door number two was to cut a section of square steel tubing. I received two lengths of angle for my efforts and milled and ground them as needed. For the left and right hand cross members I introduced a slight bend to allow the clearance needed for the latch works.

At for the latches themselves, the biggest challenge was to make a long slot just wide enough for a small handle to pass and the latch bar to slide freely. Alignment of the top and bottom sections wasn't quite trivial.

There's actually some level of detail yet to added but it's very hot in my garage these last days.

Jerry

Between hot days here I've continued to work on the small bits surrounding the cab doors, all the various latches and related bits. I wanted to
make these functional as I mentioned previously and happily I've been able to do that while being able to use materials that are not out of line
with the overall scale proportions of the originals. So there's that.

The one disappointing aspect of this project remains the tracks, unfortunately a key aspect that really dictates the overall tone of it all.

I attempted to modify one of the tracks, actually the roller chain basis to not have the retaining clip as the longer pins were causing grief.
I had feared and that fear became a reality that the master link pins were/are a very hard steel, not surprisingly so, that resisted my attempts
to form rivet heads thereby eliminating the need for the retaining clip and the added length of the pins in one stroke. In essence I ended up damaging
one of the two tracks as the efforts did not hold up as expected. I believe if I had thought of this before assembling the track with rubber loops I could
have tried to anneal the pins and attempt the riveting then however you know the nature of hindsight...

The second track issue which really surprised my while I'd heard of it and actually seen it prior is how quickly one of the track loops split at the the 'ribs'
not once but in two places on the left outer loop. This was on the intact track on which I'd not tried my master pin modification. Unlike other challenges I don't believe I have a cure for this yet. I believe the root causes are far too rigid rubber loop and the roller chain basis is far too coarse putting enormous stress on the rubber when bending around idler and sprocket. This failure occurred after less than 20 minutes total run time and at very low speeds- albeit at maximum throttle- the best speed the machine is able to muster.The assembled tracks are far too rigid to purpose in my opinion. This stresses the rubber to the breaking point and it puts such a load on the motor as to barely achieve any realistic speed. The ESC rated to handle fairly high current levels gets very hot, too hot to touch, after a short time in operation.

All this has been disheartening but my enthusiasm for this model remains; it is such an unusual, interesting machine; I wish further developments had been made for this. I'm probably going to cut short my detail work on this after a while and leave it to the side as I decide what to do about the track issue; whatever the solution is it won't be a quick, over night sort of thing...

Jerry

I've had a number of conversations with fellow owners of the US half-track. All have some level of concern for the tracks. To use the chosen
lyric of all fatalists everywhere; 'it is what it is'.

As soon as I knew something needed to be done my first inclination was to think, 'Hmm.... can I reproduce a miniature track using scaled down
methods used for the original?' The answer being 'possibly' also brought with it probably a good long project with much trial and error to find properly flexible fine steel 'rope', making a vulcanizing mold (not that difficult), how to heat that mold then how to make the guides, attach them and everything else that goes along with it. So I decided to save that idea as a project for when I've run out of other projects....

Right on the heels of that though was 1) using industrial tooth belts, or timing belts if you prefer followed by 2) 3D printing the belt using TPU filament.

Door number 2 requires STL file for the track which is extant and finding a fellow modeler with a printer of sufficient capacity, minimally 400 x 400mm or purchasing the same. This thought is still being pursued.

That leaves Door number 1, timing belts. Seems like a viable option all things considered. in parallel I cast about for for belts of appropriate dimensions and once I determined that I sent off for two.

For a task like this I consider it from the most basic implementation and add features or modifications there as needed as it goes into test.

The belts arrived today, after several annoying delays, rendered largely moot however due unbearable heat in my shop (108F) over the last week..

Without anything else I tore open the packages and proceeded to fit them to the model, just as is; they were just snug enough to fit as I'd planned;
no adjustment to the track tensioner. No guides. No relieved center section of the belt to remove teeth from the central 9-12mm as would be appropriate for a more 'scale' appearance. The belts are 53mm wide- nearly identical to the OEM tracks.

Just as is.

I was very encouraged that this has a chance to work with hopefully minimal alterations to belt or model and looks 'decent' as well. Yes, in the brief
test the left side belt wanted to work its way off but that was fully expected with no guides.Oddly the right side belt never moved from its lateral starting position. I will take my time deciding how to mount guides that will also engage the existing sprocket but I will try locktite 410- my experience with the steel /rubber bonding capabilities has made me a believer. We'll see how that works but I have other ideas in that regard as well.

Jerry

I don't consider myself a good modeler, I have my moments but on the whole I build fo me and what makes me content if not happy.

What makes me sad is when a model doesn't run well. I expect two things mechanically: run reliably and run well. Nothing less will do.
I actually don't run my models often these day; especially these out sized 1/6 scale jobbies... but when I do I expect them to run when
I want them to.

The M2 did not meet expectations in its original form.

I knew I needed to do something about the tracks; that was clear. I investigated how full sized ones are made and even contacted the fellow behind the company here in the US making new full sized tracks. An interesting process that could in theory be miniaturized for our models but at present I wasn't
that ambitious.

I wanted a solution that would 1)require minimal or preferably no modifications to the model 2) low cost (cause I'm basically cheap) and 3) minimal
effort to prepare.

From the beginning my thoughts ran to using some combination of or modification to toothed or timing belts. Once I determined the correct inner
circumference or length of the belt it was a question or purchasing a few to have a look. I purchased 5mm and 8mm pitch belts with the consensus
that the 8mm versions looked more the part; more like an original track. Oddly the 8mm versions were less costly than the 5mm.

Next came the question of track guides. In the interest of timeliness I fixed on bonding the guides which I would make out of rubber using the redoubtable Locktite 410. Wanting 1/2 round 8mm ( 5/16") half round and finding none I made a tool to split solid rubber 'rope' in half cleanly.

Now came the chore of mounting the guides. After preparing the belts and the guides came the challenge of establishing the correct pitch to engage the existing roller chain sprocket (remember requirement #1 above?). After some wrangling and a wrongly made fixture I got something to try.

Here is the initial test:



(Yes that's me uttering the 'ouch'! as I ran the model into myself... tough to film and drive by one's self...)

I recognize there's more modifications that may be made to the belt to improve the look, removing the central portion of the belt to better simulate the original track belt for example. The video represents what is still a POC state. It works. I used the 5mm belts because that's what I began with. The 8mm is substantially heavier and no doubt will look better. The model's motor is much happier moving these belts as is the ESC.

On the whole I'm pleased for now there is at least one more alternative until a better solution is made.

Jerry

Like you Jerry I need a model to run well rather than be totally authentic scale wise. Looks like you've found a good compromise there. I must admit I tried a number of track solutions, including timing belts but these seemed to wear very quickly on hard surfaces (not designed to take weight) albeit they were relatively cheap. Abandoned in favour of ally tracks as per previous post. You'll crack the problem I'm sure.

Peter Silcock wrote: ↑

Thu Aug 08, 2024 11:16 am

Like you Jerry I need a model to run well rather than be totally authentic scale wise. Looks like you've found a good compromise there. I must admit I tried a number of track solutions, including timing belts but these seemed to wear very quickly on hard surfaces (not designed to take weight) albeit they were relatively cheap. Abandoned in favour of ally tracks as per previous post. You'll crack the problem I'm sure.

I can't say I didn't consider track wear as a requirement point. Again the amount of use came into play and essentially outweighed it. As I do my own foundry and machine work as well and have cast tracks before, I considered your solution. To be honest drilling or chasing out track pin holes
has to be one of the more mind-numbing exercises one can do next to watching American football or golf on TV.

Looking at the situation as a Venn diagram with wear (longevity), appearance and cost as three intersecting bubbles we can all realize anything
we dream up is going to compromise all of these. Add in flexibility as a consideration in deference to the drive system.

Even an ideal miniaturization of the original track system probably wouldn't likely offer great longevity but as I've read of the originals in WWII while
the official lifetime expectation was between 1,500-2,000 'combat miles' I've read of latter day tracks made with better materials lasting 6,500
miles. It would be down to rubber material used with flexibility versus strength versus wear-ability.

Like anything else your mileage may vary.

With the price of the materials involved I can make these once each year and would still be happy but my feeling is the longevity may well
surprise me. The belts are fiber or cloth re-enforced rubber and the M2 isn't that heavy of a model- I can lift it easily - it seems to weigh less
than one of my 1/10 scale Panthers.

I'm likely going to make some improvements to the way I assemble these and perhaps make a tool to remove the center of the belt teeth but that isn't a priority. The model runs well, looks passable and that was my goal. I invite others to make improvements to the approach.

Jerry

Here is a local fellow who models a Hägglunds tracked vehicle. The prototype also has rubber tracks, but the model uses 3D printed tracks - tank style. Seems to work well. The picture is from this video:
Build log: https://forumet.minipansar.nu/viewtopic.php?f=6&t=2401

Christoffer Ahlfors wrote: ↑

Thu Aug 08, 2024 8:50 pm

Here is a local fellow who models a Hägglunds tracked vehicle. The prototype also has rubber tracks, but the model uses 3D printed tracks - tank style. Seems to work well.
Markering_237.png

The picture is from this video:
Build log: https://forumet.minipansar.nu/viewtopic.php?f=6&t=2401

Quite interesting Christoffer. There's always something new to learn; I'll stop learning when I've gone on to the Tank Shed in the sky...

Jerry

Seeing as I have at the very least a pretty good interim solution to the M2 Track situation I can resume work on the model and get around to some of the other things I wanted to do.

One of those was to make proper upper and lower covers for the main gearbox. I saw that there was a steel piece which I assume was intended for the purpose of forming a cover of sorts for the gearbox but this seemed awkward and I've consigned the steel to my metal bits storage: I never throw anything away in the believe that someday perhaps possibly maybe a particular bit of metal will come in handy...

I located other bits in that storage box ( or actually 'boxes'- there are several - all far to heavy to move) this time being pieces of ex-IBM 3890 MICR check reader aluminum from years ago which was just the ticket. I'd thought briefly of making a pattern and casting these but thought better of that with the knowledge that I only need one set.

So after making a disproportionate pile of aluminum shavings I had usable covers. The need to properly shield the guts of the gearbox was made apparent after my brief run in my from yard. 1)various bit from my yard tried to gum up the works and 2) the grease I'd put in the gearing flew out and is gracing my front yard, I assume as small flecks somewhere. I used 2mm socket head caps to fasten the covers, mostly and a few SAE 1-72 hex heads for a lower thin secondary cover just because. Looks really weren't my primary concern. After final cleaning I sealed the assembly with black silicon rubber, packed it with good quality grease and mounted the lower cover, which because of the large driven gear can only be installed once the gearbox is mounted in place, and sealed it.

If you recall from earlier on in this thread I had also sealed and packed the differential gear as well, having made covers for it.

Upon running model it seemed smoother, having grease that can't easily escape now as well as somewhat quieter. I'm sure given that grease is, well greasy, slippery stuff it will ooze and leak somewhere but at least dirt won't easily get in.

So on the whole it came out well.

Jerry

I've been side tracked by several issues with my flock of Parrotlets; small (30-32grams) but mighty ( they're devoid of any concept of relative size)
little friends I share my home with One who's been ill for months but has made a remarkable come back in the last weeks- I need to administer 4 medications daily.... And sadly another one of the boys who escaped his travel carrier just as I was leaving their doctor's facility.... he has yet to be found but I remain optimistic.... siiiiigh...

I've also had to dodge the heat and unusual humidity here just within the last day or so I returned to my M2 work. I've found the M2 has become a most enjoyable model; for one thing I can easily lift it and my ersatz tracks seem to work quite well, so much so I've found myself running it all over my back and front yards.... So I have to keep it in one place long enough to actually work on it.

I've long realized that while I really admire the detail work of others only so much of that will fall from my hands; some bits are must haves while others... not so much. One thing I had to do was remove the folded metal gaps of several parts. These being the side mine racks and rear fuel tanks. I brazed these and filled any irregularities with Devcon steel. I plan to do a similar thing to the two large stowage bins; the seams just bug me. There are others that bother me to lessening degrees but I'll likely leave them. At some point in my detailing I take either creative license or flights of fancy sometimes both at once..when making bits.

While I had the fuel tanks stripped I couldn't resist making fuel caps- not completely accurate depictions but they'll serve as place holders for now until I find a good photo of one.

After I braze away on the stowage bins and re-install them I have to work on seats for the driver and passenger as well as for the crew compartment; it's just too barren in there, can't avoid it....


Jerry

I was able to keep myself from playing with any model and actually do some work....

I sealed up the main stowage bins, brazed the one end closed and actually added a 'real' end the the other by brazing in a steel panel.
Cu-Ag braze for tacking mostly followed with soft solder and Devcon 50% steel for filler. Same as with the other parts. I think they came out alright.

When I got the kit the detail parts for the headlights were mostly there although broken. So I cleaned up the headlight units and added a new
aluminum shaft/mount that's hollow. My intent was even with the night driving cover to make these function, which I was successful doing but
in the end decided against, for the present, due mainly to the unreliability of the LEDs I have in hand. I'll revisit this when I source more appropriate LEDs. I made the headlight assemblies so that they can be disassembled. Some of the parts that were broken was one of the brush guards. Having had the perfect sized piece of thin steel left over from when I made the angle steel sections for the rear 'coving' previously I used it to form and braze
steel brush guards that I attached to the headlight brackets with 2mm hex head screws. They came ok also, they look the part. I'd actually ordered new bits from Mr. Dibb but decided to save these for other projects.

I've got to get back to the dashboard. It will be good to keep me going while I await other parts from Mr Dibb.

I really hope the powers that be at Armortek re-issue this cutie, there are several more variants I'd like to build.....

Jerry

I've been tinkering and making odd and ends bits. Got to something I've wanted to do for a while: make windshield panels and the hardware
for holding them in place.

Fortunately I still have a small supply of the beautiful tiny, functional wing nuts (butterfly nut, Flügelmutter) once sold by WECOHE.

For this I chose the 1,2mm size. When they cast these they actually had cast them with the threads in them but they need a little 'chasing'.

My panels are perfect nor is the hardware but surely all this is better than nothing at all. As seen in the photos there is still cleanup, resizing of various
parts and trimming and fixing the 1,2mm studs on the windshield frame. And of course painting, I found that as with many things needed to scratch build any bits, raw materials are becoming increasingly difficult to find. In this case small size 'U' profile brass lengths. Fortunately I still had some from when K&S, a U.S. supplier used to carry them. Sadly K&S is nothing compared to what it was years ago. Going forward for tasks like this I'm afraid I'll have to turn to Europe and metric sizes, which I'm ok with but sad. Same reason why I use almost exclusively metric threaded fasteners- all the good suppliers that once carried the SAE counterparts have gone the way of the winds...

The other thing I did was re-program and install a Benedini mini V2; Thomas sent me a M2/M3 sound set and it works a treat. Sad that he is no longer
able to offer his sound cards. So I'm able to fit receiver, esc, sound card, 24v battery, homegrown power panel (with relay and teeny-tiny voltage meter!), fuse and speaker all in the engine bay and there's still some room left...



There it is.

Jerry

I was hit by some mysterious bug over the last several days, that gave me a fever but little else, quite odd, seems gone now but put a crimp
in my modelling efforts.

Managed to rebuild all my led lights after believing the laws of physics wouldn't apply to me - attempted to operate LEDs that require
2.2v max ( Reds) and 3.2v max ( warm whites) on the 4.87 volts output from the Bendini card...

"Oooo look how bright they are"
"Jerry, why did they all go out- did you do that?"
"Never mind that look over here at the new pliers I bought today...."

So after knuckling under I brought out the new "Happy, Best 1,400 piece Every Resistor you ever wanted" Kit

The formula is Resistance = (available max voltage - LED operating voltage) / current rating for the LED

My LED supplier happily also specified the correct voltage range and current rating so the calculation was simple.
I picked the appropriate resistors and wired one into each light circuit as I like to keep them all independent as you never know.....

So actually having to rework all 4 lights, 2 fronts and two rears ended up with the lights working much brighter than previously so
that was good.

Unfortunately photos taken in the dark are neither very good nor exciting so I'm only including one rear shot, the fronts compete with the fiercely
bright blue LED from the ESC giving the engine bay a rather eerie look in the dark... Also I've finally proven to myself that it's impossible
to operate a model in the pitch dark and try to make a video at the same time; a small plant near my walkway can attest.. There were a few choice
words uttered as I fumbled about which for decorum's sake I'll keep out of the thread..

I received a parts package from Mr Dibbs that I'll be exploring shortly as well as some other options which I'll discuss in a future installment
but these are for the interior, seats and the like.

I will be turning my attention to the interior now.

Jerry

Just out for a short drive on a sunny day...

For most of it I just used what the camera showed me to drive the thing, mildly unnerving but made it back in one piece.



Jerry