Project Firefly. (Or "Why We Can't Have Nice Stuff")

[Rob1970]

I -was- planning to do some relaxing today. Which involved browsing shop online. In one shop I found a LED for a coax mounted MG. Large LED, long optic fiber. Interesting enough... and then I realized that in my stash of various modeling project gubbins I have a load of tiny pre-wired and pre-resistored SMDs in various colours.


And I mean -TINY-


A bit of heatshrink around it to make the tiny wires durable enough to pass through the mantlet...


... and pass it through. A little stub of styrene 2.4mm tube over the end. I will detail it for the final version and paint it a nice shade of gunmetal. For now a sharpie will do...

Yesss...

To Be Continued...

TTFN,
Rob

[Rob1970]

This was an experiment... in welding.


After some practice on some scraps of ABS, I took my 3D-pen and some ABS filament and went to work on the Firefly hull to mend those "welds" Heng Long did. And... well... I'm not dissatisfied. When all was said and done, and I took a sanding stick to the new weld beads they looked like... well... ground down weld beads. I'm sure a lick of paint will hide a multitude of sins...


I mean, I've seen worse...

To Be Continued...

TTFN,
Rob

[Sappo]

I've tried doing the same thing but had no luck. Probably just too damn shaky, yours is looking great

[Rob1970]

Well, it took some practice, and steadying my hand and the tank and the 3D-pen in an awkward grip to keep everything steady and even. But once I had the rhytm going it came out okay. Had to redo a few, and the filament doesn't bond all that great with the tank plastic at first so I managed to rip the bad weld out. When all was to my liking I hit it all with MEK to seal/melt them in before I started sanding.

[Rob1970]

It's been slow going the past few days. Damn life and damn wi... uhm... chores around the house kept interrupting. But today I had a very welcome visitor; the UPS Guy!!!

The stuff I ordered from Forgebear last Friday came in... and maaaaan, it's awesome.


I mean, those duckbills look the dog's bollocks, the cat's miaow and probably several other mammal's assorted bits... I dressed up the dame with all the assorted bits to come just for the look, ya know. Show off her new gams

I just want to state here for the record; Dave of Forgebear's is a gentleman and a scholar. A vendor above par, with the healthy disdain for the tax man I have come to cherish in the British. HUZZAH! HUZZAH! HUZZAH!!!

(And no, he did not give me a discount...)

To Be Continued...

TTFN,
Rob

[Rob1970]

One question...; WHY DID NOBODY TELL ME ABOUT THE JOYS OF MILLIPUT!?!


Man, that stuff is nice... made a few castings of fuel filler caps and air vents...


I made the hoods from Shapeways a bit narrower and rounded the front. Glued on and filled the gap between the hood and the glacis with Milliput. Then added the front MG bump and added armour to that bump and the two plates in front of the hoods. And then did welds with more Milliput. Awesome stuff, and once I got to know the best ways to get the best results, it is a joy to work with.

Seriously, somebody could have told me about Milliput 40 years ago...

To Be Continued...

TTFN,
Rob

[Vaseline]

I use a product called Apoxy Sculpt. it was easier for me to acquire than the Milliput.

[Rob1970]

A little more done, all the little jobs that need doing and I've been putting off...


Getting the IR transmitter back into the mantlet. Space is tight, so I decided to put it above the post that holds the shield to the mantlet. Elevation of the gun is just allowing me to use the same slot as the post...


Connector for the little IR mushroom got moved to the commander's hatch. Not the neatest job I've ever done, but I'll tidy that up later.


A video on Youtube showed someone who made the spotlight work, and used the WiFi 6volt power to switch it on and off remotely. So... why not?


Now, today's Grand Prize Question; where does this go? I found it after disassembling the gun, and I found it on a few sites listed as "Heng Long Sparepart rubber for shooting unit sparepart"... but where does it go?

To Be Continued...

TTFN,
Rob

[Vaseline]

Its the hop-up bucking for the airsoft unit/barrel It keeps the bb from just falling out the barrel and provides the airseal around the bb so air doesnt just blow past it. In a more sophisticated or dedicated airsoft application it would also provide a backspin on the bb for longer range. You know, its been a while since Ive had a unit apart without binning everything inside it, but it goes at the end of the barrel inside the airsoft mechbox...

[Rob1970]

Its the hop-up bucking for the airsoft unit/barrel It keeps the bb from just falling out the barrel and provides the airseal around the bb so air doesnt just blow past it. In a more sophisticated or dedicated airsoft application it would also provide a backspin on the bb for longer range. You know, its been a while since Ive had a unit apart without binning everything inside it, but it goes at the end of the barrel inside the airsoft mechbox...

Weeeeelll.... I think I have figured it out, with the viewing of about 30 videos on Youtube on the subject, with 1 (One) delivering a smidgen of useful info.

It goes like this... (excuse my awesome MS Paint skills...)

In this cross-section, the orange bit is a small plastic barrel which grabs the main aluminium barrel. At the back side there is a little lip that stops the ring/gasket (in red on the drawing) from sliding further back. The barrel should only barely touch the gasket. So it goes in about 10mm.

Which means the rear end of my Firefly barrel needs to be shorter... and the part where is gets fatter needs to be cut as well. Oh joy... machining without a lathe...

*deep breath*

To Be Continued...

TTFN,
Rob

[James]

MS Paint for the win! Well done.

[Rob1970]

A deep breath, a really fine but sharp razor saw and a short prayer later...


First shifting the thick end up (as it turns out) 3.5mm. Slow cuts along the thin end of the barrel into the thick end, which I already scored all the way round at the right spot. So it's cut from the back, cut from the top, cut from the back again... until I was almost all the way around, and then a very fine keymaker's file did the rest.


The thin end that goes into the airsoft mech box I shortened in stages. Cut and sand, re-assemble, test fire, disassemble, cut again, re-assemble, test fire.

Did that until the gun fired fine, except by now the gasket had gotten a small tear and I was losing some power. But new gaskets have been ordered, and I probably need to fatten up the thin section juuuuust a tiny bit to make it more snug. That I will do with layers of CA, but only when the gasket is replaced.

But there is hope...

To Be Continued...

TTFN,
Rob

[Rob1970]

Let's talk about welds. Awesome welds...

\

*sigh* No, internet. Awesome Welds... not Orson Wells... altho he was awesome...

As you could see earlier in the thread I did some weld beads with my 3D pen. This pen is an -original- first issue 3Doodler, which I bought from their kickstarter campaign. The first ever 3D pen. Big, bulky... not the lightest.

I was having some trouble getting nice beads in some of the tighter corners, when SWMBO casually remarked; "Didn't you also have a smaller one?"

And yes, I do... picked up on AliExpress a while back, and put in a drawer... forgot all about it.

This one; https://www.aliexpress.com/item/33020992274.html. Awesome little thing, with a very pointy ceramic nozzle and it can be set to various speeds and temperatures.

So I decided to try it out in a new way. Stick-on welds beads. So... experimenting we will go...


I have a strip of 1mm thick copper, as a heat sink...


Wrapped it in normal paper, two layers on the top and some pencil lines to guide me. The extruded fillament will stuck to the paper just enough to keep it in place, but the work will peel off.

A little experimenting with temperature and speed with which the pen feeds the filament later, and we are ready to go. Drag the pen back with a little back and forth judder (and a tight zig-zag for the wider beads) and with some practice I got some very acceptable weld beads... Now, I have plenty of filament scraps (PLA only, more on that later) so I can was a lot to get enough good bead to work with.


Narrow and wide beads. With a good flow in my motion I can get up to 5 inches of nice steady weld bead, and when you peal them from the paper the bottom is flat and ready for glue.

These were done with PLA wich does not glue to ABS all that well. CA glue would work, but a friend of mine does do a lot of work with ABS in his 3D printer, so he's mailing me a load of scraps. Those should weld up a treat to the ABS of the Heng Long hull with some MEK.

Next experiment; making inside corner weld beads, as soon as I find some 10x10 (or smaller) aluminium angle strip to use as the angles heat sink. I am sure I've got some -somewhere-...

To Be Continued...

TTFN,
Rob

[Rob1970]

This was a triumph.
I'm making a note here; "Huge success"
It's hard to overstate my satisfaction.

I can indeed make inner corner weld beads that look pretty darn convincing.


All it took was a small piece of aluminum 10x10 corner profile lined on the inside with painters tape. Work like a charm. And soon I had a tankload of weld beads... At slow feeding speed I could even make very small ones.


Perfect size to put around the vents. And the bigger ones were great size for the hatch bumps.


The flat ones laid down nicely on top of the hull... I used the PLA ones I already made and just attached them with CA glue...


... and I pretty much ended up replacing all the milliput welds with PLA self-printed welds... It goes on nicely, and when you have a round bit (like on top of the old bow MG mount) a flick with a lighter will soften the bead and lets you press it in place. With the vents the beads were thin enough to be bend without heat.

So yeah. Happy. I think I deserve cake. I hope the cake is not a lie...

To Be Continued...

TTFN,
Rob

[Rob1970]

So, with the decision to do a complete hull for the Firefly -and- the M4A3 105MM, I need to address the back plate of the Firefly. New door, moving the exhausts and putting on some air filters and a towing thingy...

Also; my ABS filament came in, so I might as well try some of that on the welds on the engine door...


Yes, turns out ABS weld beads are even nicer... I am happily amazed.


yeah, rrrreally happy. The ABS weld beads just blend in on the ABS sheet with a little touch of MEK.

To Be Continued...

TTFN,
Rob

[Rob1970]

(Late) last night I was considering getting a commander for my Firefly, so I went down the rabbithole that is the interwebs looking for a suitable figure. I came across this one from Forgebear, and I seriously considered getting it. He looks all British and proper, great bushy mustache and all...


...and then through the magic of algorithms this video popped up in my Youtube recommendations...

So, if I get this commander figure for my Firefly, it is obviously his first day. And his more experienced crew has forgotten to tell him some very important information... ;D


TTFN,
Rob

[Rob1970]

Slowly getting there...


Got the new engine door fitted, after grinding off the old one and plugging the holes from the old exhausts. The exhausts were made slightly narrower and moved up. Still need to do some weld beads around the hinges.


Also chopped a bit off the top, because it was hitting the top deck. And it's deep in the shadows, nobody will ever see that end. Need slightly longer tubes from the smoker to the exhausts, but if you take off the little bends on the top of the smoker you end up with a couple of very gently curved tubes without kinks.

While tinkering with it all and testing I discovered my smoker wasn't operating all that well. So I removed it and opened it up. Wicked a lot of the smoker fluid off the cotton ball and made the connections to the heating wire a bit more robust then just the little crimping they did. A dab of solder and some heatshrink was all that was needed. After that it smoked like... well... a smoker.


With the top deck on the exhaust just peek out under the rim. Next job; air filters and the towing bar.
The air filters will be scratch-built, still not sure if I will go for the round ones or the up-armoured square ones. And for the towing bar I am also still pondering; just the brackets to hold the leaf-spring bar, or scratchbuild it all... choices.

To Be Continued...

TTFN,
Rob

[Rob1970]

Well, I haven't done much work on the Shermans the past... 5 days, because I've been doing pennance for buying all the tanks. SWMBO calls it "chores that needed doing" and "a garden that needed digging up", but let's not kid ourselves...
Nah, actually she's cool with it all...

Done a little slow work on the rear of the Firefly...


Added weld beads to the hinges of the engine door, and a couple of strengthening-plates. I think that's what they're called... And been tinkering with making air filters. First one is done, and tacked in place with some bluetack while I figure out of I like this version...

To Be Continued...

TTFN,
Rob

[Rob1970]

Funny how busy you can get when you've got tanks... Spent the last few days cleaning and stripping the Tiger I, which is now shipshape and Bristol fashion again. It got a good cleaning and a good rewiring, got the smoker rewired and working with the surprise TK6.0 it was hiding. All it needs now is a slip ring for the 360 turret, and it's another full-fledged runner...

But enough about the wages of sin... still got a little time in with the Firefly...


Air filters, scratchbuild and fitted. They came out nice, even managed to do a couple of convincing wingnuts.

Next on the roll call... towing gear. Still not sure; full setup with leaf spring and hook, or just the brackets...

Opinions anyone?

To Be Continued...

TTFN,
Rob

P.S. anyone know something fun you can do with a Pershing, Tiger I and a broken down Pantiger..? Asking for a "friend"...

[RichJohnson]

Your weld beads are quite impressive. Kudos. Better than my work with putty.
have you tried it right on the model rather than laying them down on paper and peeling and gluing?