Imex-Erik

Grind away my friend. I have plenty of those shafts in both long and short versions. Get a belt sander if you can, should only take a few seconds with it. If you mess it up just let me know

philipat

Good to know.

Max-U52

If you can find a place with a lathe it will only take a few minutes. Tell them they don't even have to indicate, just touch off at the end and peel 40 thou off the face. If you do have to send them here it will take me about 3 minutes per shaft to fix them, but you'll have to pay shipping both ways and I think it would be much better to try and get it done locally. If someone walked into our shop and wanted me to do that I'd either do it for free or charge them just 10 dollars. If you can find a lathe hand there it should be a lot less than shipping them here. But if it comes to it, send them and I'll have them in the mail going back the very next day after they get here.

Another idea is to do it with a dremel and a drill. I have a couple shafts layin' around so I'll make you a video after work tonight.

Max-U52

Hey Philip, you may find this helpful. Or not, one can never tell these days.

https://www.youtube.com/watch?v=TP8ki7GEuLg

philipat

Thanks for the video, Gary. Once I get the idler adjusters back, I'll be able to make a decision on what needs to be done.

I tried doing something similar where I chucked my return roller axles in my Dremel and then tried touching a metal file to their heads to reduce the diameter. (they were too wide to allow the outer half to seat on the inner wheel...same problem you had) But, for some reason it didn't file down evenly. One side was filed and the other wasn't. Did I not chuck it tightly enough?

philipat

More progress on wiring the tank. Actually, I’ve finished the wiring setup. In a nutshell, the setup includes:

- UV LED in turret to “charge” glow-in-the-dark airsoft BBs.
- JST plugs to make it easy to separate the parts
- 360[SUP]o[/SUP] turret using a ½" slip ring (12-wire)


Discussion:
UV LED in the turret. I basically did the same thing that Perry S. did with his setup (http://www.rcuniverse.com/forum/rc-t...rsoft-bbs.html). My only challenge is that the LEDs don’t seem to be working. I’m not sure if I’m not supplying enough voltage or if they’re defective. I have new LEDs coming from an eBay vendor that tested them using 3V batteries; so, they should work on my 3.1V circuit. But, I installed everything so that I could get the rest done.

JST plugs. I used two sizes for this. Inside the turret, I used two sets of 3-pin miniature plugs. One set for the LED circuit and one set for the gun-and-elevation circuit. Soldering these to the slip ring’s wiring was a challenge because they’re so small. But, the slip ring’s thin wiring helped to make it a little easier. Be careful to note the color scheme (each wire has a different color or shade of color) so that you don’t cross circuits. Label bundles as you go. The 8-pin plug with side plugs came from Aliexpress. It’s an awesome piece of gear. Note that you need to order the right plug setup or it might come without the 3-pin plug for the LEDs. The pictures are the same for all tanks; so, ask. They were responsive when I had questions afterwards. Fortunately, after Erik let it out that they use JST-XH plugs for Taigen/HL, I ordered about 10 male/female sets (one side has pig tails). So, I already had some 3-pin plugs on hand that go into the board (no pig tails on this side...is the the male or female?) Just be careful soldering them to the board. Best way is to use the soldering iron to pull the solder away from the small holes in the board where the plug goes. Then solder the plug to the board. The 3-point junction board I used in the turret wasn’t absolutely necessary, but it made it easier to solder things together, especially since the LEDs all share a common positive and I figure I will probably have to replace the LED later. You could just go straight to soldering wires in a 3-way setup. I’m still working my soldering skills; so, this was easier.

360-degree turret. I always wanted one of these. I saw several innovative ways of doing it a few years ago, but couldn’t replicate it. Then, I finally saw Max-U52's video on how he installed Taigen’s setup. I figured I could do that. I used a 12-wire setup because I couldn’t find an 8-wire setup. I needed 3 wires for the LEDs, 3 for the gun and elevation, and 2 for the airsoft gun sound-and-recoil trigger. If you have an antenna in or on the turret, you would need an additional wire. I don’t know how many, if any additional wires going into the turret will be needed with Taigen’s recoiling airsoft gun, but I have room for growth. (Note: Taigen’s setup wouldn’t work because they only provide 7 wires on the slip ring for the setup that supports airsoft and a turret machine gun.) I glued the slip ring into the rotation ring and drilled a ½" hole behind it in the turret floor. The rotation ring’s were made by mating another rotation ring to it and filing out the teeth. It looks a little crude, but the rotation motor and gearbox didn’t seem to notice.

Watch it in action:

Max-U52

As the little guy said after he watched Conan kick the crap outta the bad guy, "That's exactly what I would've done".

Great job in a tight space, Philip. I haven't tried the tiny JSTs yet. In fact, I just got a proper crimping tool. As for male and female, the way it was explained to me is the plugs you have to crimp are the female, and the ones that look like a socket (that I thought should be female) are the males. So the two in the lower left of your first photo are female. That seemed backwards to me, but when you look into the other one, the socket one, the pins are in there and the pins themselves are kinda phallic and they insert into the metal pieces you crimped, so I guess that's how they decided which would be male and which female. Like you, I picked up a bunch of JST plugs and they're very, very handy to have! Being able to unplug for future maintenance will really pay off.

Having tracer BBs is something I've wanted to try for quite some time now. I still have the 12 wire slip ring that came with the mato/clark package and I think I'm going to try this mod as well, Philip, so if imitation is the sincerest form of flattery than consider yourself flattered.

As soon as you get the UV LED thing straightened out please let me know which ones to buy, and thanks for doing the legwork on this one.

strmnd54

Congratulations on the 360 turret...
Once you spoil yourself with it; you won't go back to the old way...

philipat

So, I've spent the last few weeks ordering and testing UV LEDs trying to sort out something that would work. And, I'm still working on that. I found some that hit the sweet spot in terms of voltage, but the current doesn't seem to be enough. I'll need to get some sort of a meter to test my circuits. Anyone know what I need to test current and voltage? Needs to work in terms of mA. Electricals are not my forte.

But, in the meantime, I got my TC back from a buddy that was painting him for me. KSOC kindly provided me a TC, "Otto". In putting it together I realized it was designed to have a hand in the air (actually holding the open hatch on an early Tiger I cupola). But, it reached way above the split hatch on a PzIV Ausf G. So, I used some putty and micro files to reposition the arm and blend it to look natural. Once I got it to where I thought it looked right, I gave it to him for detailing and painting. Of course, just like he did with the PzIII TC, he did a great job. Getting it was a little like Christmas, but in June.

• My work:

• His progress photos: https://picasaweb.google.com/1047456...C?noredirect=1

• Sitting in the turret (looks like the TC got a rare trip to the factory to check out his tank as it was being built):

Jhdumas

Wonderful !!!!! where did you get the Fender plate? Apparently its a thin piece affixed to the top of the existing fender..once you have prepared the original fender.....

philipat

Thanks. I've had a busy summer, but I should be able to get back into this build soon. Really just need to figure out the running gear.

Post 46 gives the specifics for the tread plate that I used.

My father got went to Mainline Hobby with the dimensions for each tread. He bought that one and mailed it to me. You have to sand the fenders smooth and then glue the tread plate to the fenders. The plate is only about .5-mm thick.

Jhdumas

Thank You!!!

philipat

So, after a long summer hiatus, it’s time to get back down to work. The flat, brass gearboxes (5:1 ratio) will fit on the standard HL posts. However, the two parallel gears nearest the final drive gear stick too far up to allow the gearboxes to be raised. If you raise the gearboxes, those gears rub on the upper hull. So, I figured that I’d try the new Mato gearboxes with the steel gears and ball bearings. I also figured that if the mounting plate fit in the PzIV, then I might have an easier way of lining everything up.

I ordered the gearbox set from eBay. They were a little cheaper than buying from Mato, but shipping took a lot longer since they were coming from China. I took them out of the box to inspect them and noticed a few things.

- They appear to be pretty solid and the gears seem to be decent steel.
- The gears do rotate independently on the shafts and the shafts can also rotate in their bearings.
- The ends of the motors that come with the gearboxes are knurled, making it more difficult to remove the pinions. (Note: on the up-side, the knurling should give the set screw a better surface to grip and hold the pinion firmly on the motor shaft.)
- The gears seem to bind some, particularly the final drive shaft. I couldn’t spin the drive shaft with my hands.

So, the first thing to do was to free up the drive shaft. Once I loosened the set screws on the final drive gear and the shaft’s collar, it turned freely. I can’t really move where either of those sit on the shaft because there are holes drilled into the shaft for the set screw to sit. (Good for being solid, bad for minor placement adjustments.) So, I filed down the collars and final drive gears for both gearboxes using a large file. I trimmed down their thickness by .5 - .75-mm. Now, the spin freely.

Jhdumas

AWSOME!!! Thanks

philipat

The gearboxes spin much more freely now. However, there was still some binding and it looked like some of the intermediate gears might be too close together and were rubbing on each other. So, I filed down the brass spacer rods a little and inserted a couple of M3 washers to create some space between the gears.

They’re better now. But, there is still some random binding when it will be noticeably harder to spin the gears by hand-spinning the drive shaft. Or, when the gears will suddenly slow and stop after letting them spin freely. I’m not sure why that is, but I think it might have to do with rubbing on the brass spacers. I hope that goes away with some run-in.

philipat

One of the reasons I’m interested in the Mato gearboxes is that they come with a mounting plate, which would add some rigidity to the lower hull, particularly in the front. I originally asked Mato if this would work on the PzIV, but was told it was made for the Tiger I. I remembered someone else saying that they had used the gearboxes in their PzIV. So, I figured that I’d get it and try it out. The plate fits perfectly. It has four holes in the corners where the plate bolts to the stock gearbox mounts. There are also holes for the plastic nubs that the stock gearboxes use as alignment nubs. The gearboxes bolt into the metal plate and keep them aligned correctly.


Nice thing about the Mato gearboxes in the PzIV is the front gears (nearest the drive shaft) are low and they rise going backwards towards the motors. That allows me to raise the gearboxes without having the gears rub on the upper hull. However, it did cause the motors to bump into the 8-pin plug in the upper hull. So, I’ll have to relocate that plug. Also, the high-low motor configuration should allow me to install different motors and experiment with Speed400s, 480s, or 390s (if I can find any of those...banebots.com is out).


As far as the plate goes, it fits perfectly. It also adds about 1.5-mm to the sprockets’ height. So, I can use a couple of .75-mm M3 washers to bring it up a total of 3-mm without rubbing the gears on the upper hull or the tracks on the upper hull. However, it seems that the sprockets stick out about 2-mm too far. To make the tracks line up with the sprockets I’ve used 2-mm aluminum spacers on the suspension and 1-mm aluminum spacers on the return rollers. I’ve test run it a couple of times without the upper hull and everything works well. Adding the upper hull results in some rubbing from the edge of the tracks against the small lip on the edge of the fenders. The tracks barely clear the inside of the mud flaps, but they’re doing okay. I’ll have to look into shortening the drive shafts by 1 or 2 mm. Can’t be too much because the outer edge of the tracks was just inside the fender lip on the real tank.


Note: if you’re using Taigen or HL tracks you may not rub against the lip of the fenders. I’m using Impact tracks that have a small knob at the outer edge of each track link that simulates the link nuts.

Jhdumas

This a wonderful build.... I plan on doing a similar build... I hope I have the same level of commitment and degree of success as you....Thank You, Joe

Rebel 1

Truly a great work in progress!!! I have one of the Harbor Freight Lathes, so truning something isn't a problem at all. I wish I had a milling machine though. One day I'll use this thread to build one for myself. The Tigers are nice, but this is my favorite next to the Panther. I love the secondary armor plates. When I was young I had every Revell German tank kit they made. A couple of their kits had extra armor plates. I would heat up a nail to add a few holes to make it look like battle damage. Those were the days.

Keep up the great work, I'll continue to follow this thread.

philipat

Thanks...glad you're enjoying it. Hoping to make more progress during some time off during the holidays.

philipat

So, I’m still working on the lower hull, particularly the drive gear (gearboxes, transmission covers, motors, etc). Right now, milliput is hardening and JB Weld is curing. So, in the meantime, I rebuilt one of the antenna tray brackets that broke off somewhere along the way. The first time I built it, I glued everything to the surface. This time, I drilled into the plastic to embed everything. Work done:

- 2-mm hole drilled for the bolt mount at the top of the bracket.

-The bolt mount was made using 2-mm styrene rod with a .8-mm hole drilled for the bolt. I sank the styrene rod into the hull side by 2-3 mm.

- .8-mm hole drilled for the bottom bracket’s bolt.

- bracket was made using F-1x-3 brass strip from www.specialshapes.com.

- all epoxied in place using JB Weld.

Suggested work order:

- Shape the primary bracket and cut and drill the styrene rod.

- Use the primary bracket to line up the hole for the bolt into the hull for the support bracket. Drill that hole.

- Make the support bracket (do not cut to length yet).

- Drill a .8-mm hole in the bottom of the main bracket (bottom = where the bottom of the antenna tray rests in the bracket).

- Line up the support bracket it under it and use the hole as a guide to drill a .8-mm hole in the support bracket. Cut the support bracket to length.

- Glue/epoxy the support bracket to the main bracket. Insert a .8-mm hex head bolt through the hole. Let epoxy harden.

- Cut the protruding bolt so that the antenna tray sits flat in the bracket (basic Tamiya side snips will do it).

- Epoxy the assembly (styrene rod in hull, main bracket to rod, support bracket to hull) to the hull as a single unit. Use .8-mm bolts in the support bracket (to the hull) and the main bracket (into the styrene rod). Use the antenna tray to fine tune the bracket placement.

Hopefully, this way it will last longer than my last effort.

philipat

Finding gearboxes that would allow me to raise the sprockets by 2-3 mm has been a challenge for me. The Asiatam/Taigen flat gearboxes (aka dual ratio aka 5:1) fit the HL screw pattern, but can’t be raised more than about 1-mm before the large, coaxial gears rub the inside of the upper hull. Also, because the PzIV hull is so narrow, they can’t be fitted with a 380-sized motor. So, I wanted to try the Mato gearboxes. I decided to spring for the newer steel gearboxes (version 4.0, model MT-193U). The folks at MatoMart said that it would not fit in a PzIV. Not sure if they don’t know or if they don’t want to the liability of a customer using it outside of what it was designed for (designed for the HL Tiger I), but I recalled someone on this forum saying they had used them in their PzIV build. So, I took a chance and ordered a set on eBay (seller: i-love-porcelain-flower...has several Mato and HL parts). The fact that they mounted on a steel plate was also intriguing since the plate could add some rigidity to the front of the hull.

The plate was a perfect fit over the HL alignment nubs and their gearbox screw pattern. It also came drilled and tapped and with the machine screws used to hold the gearboxes to the plate. In essence it fits perfectly. Raising it will also work because the reduction gears are in a falling pattern that matches the slope of the PzIV’s front, upper hull. The only catch is that the motors were hitting the 8-pin plug when it was mounted to the points that HL placed in the upper hull between the driver and RTO’s hatches. So, I had to move the plug by installing new mounts with styrene tubing that would fit closer to the turret gear ring.

I raised the plates with 2x M4 washers that are 0.75-mm thick each. Between the plate and the washers, I raised the drive sprockets a total of 2.5 mm. There is very small clearance between the tracks and the underside of the front plastic mud flaps, but there is clearance that worked well on both the driveway and the front and back lawn. So, I’m happy with where they’re at.

With those emplaced, I can install, or position, the drive shaft supports. These are Tank-Modellbau’s setup that include bearings in them. With everything marked out and test-fitted, I can start making permanent installations of the rest of the front of the lower hull.

Note: raising the gearboxes required getting longer screws to mount the plate than came with the tank. Good opportunity to upgrade the screws to square holes, which are easier to use.

philipat

One item that needs to be adjusted is to refit the transmission covers so as to accommodate the drive shaft support bearings and the raised drive shafts. To fit over the support bearings, I used a Dremel sanding disk to sand out interior of transmission cover to make room for bearing/reinforcement. Minor adjustments could be made by scraping the inside with a hobby knife. The HL transmission cover uses two locating plastic nubs and a Phillip’s head screw to hold it in place. On one of them, I had destroyed one of the screw points on the hull because the factory had both glued it down and screwed it down. So, I figured this was a great opportunity to make it more realistic and get rid of the screw entirely. So, I made these adjustments:

- Drill out the nubs with 2-mm drill and insert metal nubs by cutting sections of an old clothes hangar.

- Drill out the screw hole using a #1 drill bit from the outside (detailed) side of the cover. From the inside, enlarge the hole with a 1/4" drill bit that sinks about 2-3 mm deep. (I’m using a 1/4" round neodymium magnet.)

- With the gearboxes, drive shaft and support bearing mounted in place, mark out the location of nub holes and the center hole. I used the forward (nearest front glacis plate) nub hole as a pivot point. Then, I found and drilled the second nub hole. With the new metal nubs installed in the transmission cover, I could lock the cover in place and use the # drill bit to mark the new center hole.

- With all holes drilled, I installed a 2x2-mm cylindrical rare earth magnet in each nub hole using JB Weld to keep them there. (Note: magnet orientation is not important in the nub holes because the nubs are steel, not magnets.)

- I filled the center hole in the transmission covers with Milliput leaving a small gap on the inside for the magnet and epoxy. I installed a 1/4" magnet in the hull side and then another one in the transmission cover, securing them with JB Weld. (Note: get the magnet orientation correct in this step or the 1/4" magnets will repel each other and the transmission cover won’t seat against the hull.)

This whole process also gave me the opportunity to glue in the styrene plates that would reinforce the front hull sides. And, I used some of the extra Milliput to fill in some of the hack job that happened as I tried to find the right spot and height for the drive shafts.

Note: before doing any of this with the transmission cover, you need to have the final position set for the gearboxes. This drives where everything else fits - support bearings, transmission cover, hole placement in the reinforcement plates, etc.

Also, I recommend doing this over several days and letting the epoxy in each step harden before moving to the next. Reinforcement plates, then metal nubs, then hull magnets (with cover magnet loosely seating to get the height correct, finally the cover’s 1/4" magnet.

1sgt

Philipat,
When you made your mantlet mod. Did you glue the inner mantlet part in( the part that connects to the airsoft mechanism ) or use the original screws? I'm doing the same mod but may want to change to a recoil mechanism at some time. Just wondering if I drill into the Tamiya putty sides weather it'll hold or not?
Love all the work you have done on your PZ IV and your PZ III.

Strato50

You're doing some wicked detail work here Phil, I really like what you've been up to :P You've gone far beyond the more or less simple "G" cosmetic changes I worked into my own, and it's paying off

I'm happy to see these gearboxes working out, honestly I hadn't seen ANY builds or reference to them although Mato has had their all-steel version out for quite some time. I had a couple sets of their orignal Brass "2.0" gearboxes, and while I did like they and they were quiet, the brass just didn't seem to hold up. I'll have to check them out. "Square hole" screws, Robertsons, invented in Canada! :P Hehehe

Keep up the awesome work, I'll have to re-read this thread in detail again soon :P

philipat

@1st: I used the original screws. I wanted to be able to remove the airsoft gun for maintenance, painting or even replacement in the future. I figure it's only a minor detraction from the realism. If you're using the recoil, you might be able to pull the mantlet closer to the turret. Keeping the airsoft gun forces it out and away from the turret, but I think I saw a build somewhere (probably one of the UK forums) where they used the recoil and pulled the mantlet closer to the turret.

@Strato...Robertsons, eh? I love those screws (much better than Philip's or regular screw heads) and was looking for more selection than just the wood and metal (thread cutting) screws. Would love to find some in a machine screw format...I'll have to look them up and see what other options are out there.

Glad you guys are enjoying the builds. They seem to take me forever to do. But, they're fun to see what I can do.