My Hooben T-55 Progress

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Marc780
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Fitting the hull metal reinforcing plate

Post by Marc780 »

I'm waiting for several battery electrical adapters now. The tank wiring only comes with a Dean's adapter and all my batteries are Tamiya connectors. All I have left to do before a test run of the transmitter and motors is to connect the battery, which I don't want to do until I have the proper battery adapter first.
The schematic is fairly straightforward and seems very similar to the Heng Long 2.4 Ghz systems. If it works with the same reliability as theirs that'll be great, even so I'm wondering what I will do if after all this the Hooben R/C gear I paid extra for does not work!?
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I got the "Hull reinforcement plate" for DKLM for $45 and thought I'd fit that in the hull now. There are some plastic moldings in the bottom of the hull, that serve no purpose except stick up and have to be ground away before the plate will fit inside. I couldn't use the screws that came with it, sometimes I wonder if these designers ever even examined the parts before they design them how they do. I replaced the screws that hold in the suspension blocks with longer ones. With the longer screws, the plate is a few mm off the bottom of the hull and not fitting flat, which is not possible anyway, due to the concave shape of the hull. I thought I'd paint the plate before it was installed too, couldn't decide between gray, black, or tamiya white primer and finally decided this dark green would hide fingerprints best.
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You can see the motor mounting plate in the image above and it is different from any other motor mounting system I have seen before. The plate mounts over stand-offs, just like the kind of stand-offs in our computers to hold the mobo away from the metal case. There are 6 stand-offs that mount in the floor of the hull, over which you place the plate and secure it with nuts. It works pretty well, especially since you can pre-mount one of the motors before installing the plate in the hull... but the second motor you have to mount the hard way i.e. ship-in-a-bottle type assembling. As luck and Asian engineering would have it one motor mounts roughly like it is supposed to using 3 screws. The second motor was a tougher proposition and only ONE of the mount screws lined up. So at least one more will need to be drilled, with their corresponding nuts getting glued in on the bottom of the plate.

One thing I learned pretty quickly, while assembling this tank is not quite as bad as I initially thought it would be, it will still require plenty of fitting and refitting. So now I never bother installing anything "permanently" as whatever it is, the part will be coming out again for more work at least one more time!
Last edited by Marc780 on Sat Nov 02, 2019 2:29 pm, edited 1 time in total.
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Wiring for first run of the motors - will the R/C system wor

Post by Marc780 »

The adapter for the battery came so now there were no more excuses, it was time to hook up the R/C to see if the motors work! I haven't hooked up anything else for the tank yet, I figured if i can't at least get the motors to work with this Hooben system there was no point. The battery adapter that came with it was Deans, so I needed an adapter for Tamiya

I put the batteries and powered up everything, tried the R/C controls and nothing happened. The diagram called for binding, the only binding wire I had was Heng long which didn't fit. I just shorted the pins in the TCU (the square control box with the wires coming from it)for the binding cable with a screwdriver, pressed the controls, voila, motor spun!

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The next chores will be tearing into the turret, and starting work on the upper hull - along with adding more screws to the motor mounting. I definitely needed to hear the motors run though, just to know for certain I'm not spending all this time and effort on a static model!
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43rdRecceReg
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Re: My Hooben T-55 Progress

Post by 43rdRecceReg »

Following with keen interest. :thumbup: The educational value of seeing someone confronted with problems, and finding workable solutions to them, is great indeed. :D
"Get your facts first, and then you can distort them as much as you please"- Mark Twain.
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Rad_Schuhart
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Re: My Hooben T-55 Progress

Post by Rad_Schuhart »

Hi Marc, please tell us how did you solve the horrible sprocket offset. As stock, it is almost like the king tiger!
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General Jumbo01
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Re: My Hooben T-55 Progress

Post by General Jumbo01 »

43rdRecceReg wrote:Following with keen interest. Image The educational value of seeing someone confronted with problems, and finding workable solutions to them, is great indeed. :D
I'm sure this is helping us all with our marriages :(


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Marc780
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Re: My Hooben T-55 Progress

Post by Marc780 »

Now the tank can move under it's own power, I turned my attention to the turret elevation and recoil mechanisms.
The barrel recoil is something I decided I can do without, even so since the capability is there it seemed a waste not to at least try to get it to function. The problem is the designers dropped the ball here since their line drawings do not completely match the parts you are given. Some parts such as suspension components and springs, you actually get one or two more than you need, other parts are missing. This is maddening, but not exactly unexpected, thus my low expectations for this kit.

The nuts that hold in the turret elevation mechanism were round head and needed to be the countersunk type, since the whole works gets screwed to a plastic piece, which in turn gets glued to the turret floor. So another trip to the hardware store to get the right screws was in order. If you build this tank, if you aren't on a first name basis with the people at your local hardware store you will be after.
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The way the barrel is attached inside the turret is puzzling, some parts have to be glued together with nothing to guide you how the orientation should be and its impossible to hook up things and test them until everything's permanently assembled. On a couple parts I realized I had glued the parts wrong and needed to hurriedly pry them apart before the glue set! Fast setting glue, like the JB Quick weld I was planning to use but haven't so far, is not what you want to use for most of this project. Except for parts that are more or less impossible to assemble wrong like the fender fuel tanks and the like.

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I'm almost to the point I can hookup the turret and test the function. As long as the gun elevates I'll be happy with that, but if it turns out the recoil function is flawed in any way I'm moving on to the traverse mechanism in the upper hull.
Last edited by Marc780 on Sat Nov 02, 2019 5:32 am, edited 1 time in total.
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Re: My Hooben T-55 Progress

Post by Marc780 »

Now i started work on the turret functions. This T55 has elevation and traverse of course, and it has gun recoil with an additional servo in the turret. The motors for the first two do not have the wires soldered on, so you have to do it. The gun recoil servo has an R/C aircraft type servo with 3 pins, so that just gets plugged in to 3 pins on part #9 "Pinboard" as it says on the schematic.
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After powering up and trying all the controls, all of them function, even the recoil. Now I can add them into the turret, finish up with the fine details and close up the top and bottom turret pieces. That's going to take a lot more work, especially since I noticed a few more parts missing - the roller units that the turret pivots on, for one thing.

I did find you can order missing parts direct from the Hooben site. I emailed them for what I thought was a missing part, but later realized was just a mistake in reading the schematic (#9 "PINBOARD" ) and they told me it is $30 for a replacement. They are not cheap but still, the parts are available.
Last edited by Marc780 on Sun Nov 03, 2019 1:23 pm, edited 1 time in total.
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Re: My Hooben T-55 Progress

Post by Marc780 »

Rad_Schuhart wrote:Hi Marc, please tell us how did you solve the horrible sprocket offset. As stock, it is almost like the king tiger!
Sprocket offset? I haven't even gotten that far yet, right now I'm just happy all the motors respond to the transmitter! I guess that's something I'll deal with when I get to it? I'll probably search the forums to find out how others fixed the problem on similar tanks, although now that I know i have this problem to deal with I can't say I'm looking forward to it lol

...So I am ready to do a function test of the turret motors soon. The elevation and recoil servos need to be fine-tuned and made as perfect as I can get them before I seal everything up in the turret! But the design really seems to have not been thought through completely and calls for re-engineering by the end user (the unfortunate soul trying to build the tank, that is of course, yours truly).
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Take a look at the drawing (the one helpful thing that Hooben engineers include with the tank... the line drawings are excellent for the most part, even if the parts shown don't always match with what comes in the box!)
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The problems with making the barrel recoil function work are becoming a real issue (If anybody with this tank has any tips on how they overcame them I'd like to hear them!) The part "TF4" is a simple bronze bushing that gets glued inside the plastic part "TF2". The plastic barrel extension "TF3" is supposed to slide backwards and forwards inside the bushing when activated by the servo "TG3". The drawing tells you (in the detail to the right of it) to glue the bushing inside the rearward part of TF2. But the bushing is too big to fit there unless you drill it out, won't work that way, and the only place the bushing will fit is in the front part of TF2. Moreover you really need two bushings to properly support the barrel extension otherwise the barrel droops too much. It seems the designers once again have made something that does meet the bare minimum requirements (since yes, the barrel will recoil) but needs a whole lot more refinement - which the designers have just left for the end user to fix.

Another example of poor design work here is evident. Notice the 3 plastic parts in the lower drawing called "Y4". These are 3 plastic blocks parts glued together onto the barrel extension. They are obviously meant to function as a guide or "track" so the barrel doesn't twist laterally as it recoils. But the fit is much too loose for it to function that way and they do nothing to keep the barrel extension from moving to the right- so i deleted those parts. Even worse, the barrel extension fits so loosely inside TF2 that it droops noticeably. I figured if I had another bushing like TF4 I could bore out the rear hole on TF2 and glue it inside. But after yet another trip to the hardware store there was no bushing, not steel, nor bronze nor aluminum, even close to the size needed. Although I can always make my own bushing with JB Weld (it dries hard enough to be machined) I'm getting very close to just gluing the parts in place. The parts fit is too sloppy, the barrel flops around and droops too much, the barrel recoil is very cool but impractical as is, and the whole functionality can easily be done away with.

Anyway today I began gluing some of the exterior parts to the hull and turret and I used 3 kinds of glue: Gorilla super glue gel, Gorilla clear, and Tamiya thin cement (the kind with the bottle and brush). The Tamiya works best for gluing small parts that aren't stressed. I use the super glue for gluing things fast, then i reinforce it by brushing the Tamiya glue around the edges. I use clamps wherever I can, which isn't often, due to the irregular shapes of most of the components of this tank.
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As you can see, this tank is a lot of work! I am going to have to go back and re-do many things and I can't say this tank is even close to being finished. I want to do a test run with everything hooked up, the tank running and with the turret attached to the hull. I can tell this tank is going to require a lot of fine-tuning and will never really be "finished" - but that's clearly the nature of "THE BEAST" (which by the way, is the title of the best - not to mention only - movie starring this T55 tank ever made!)
Last edited by Marc780 on Thu Aug 20, 2020 7:22 am, edited 3 times in total.
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Re: My Hooben T-55 Progress

Post by Marc780 »

I'm getting closer to finishing the turret functions and closing it all up. I did a function test on the elevation motor and it worked fine.
I was still not even close to fixing the barrel recoil function. I hated the amount of play in the barrel, it flopped around too much and there's no way to fix it to where I'm satisfied. As a last resort I cut shim material from a soda can and tried shimming the barrel at both ends to reduce the huge amount of play.
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The shims got most of the play out, but after that the servo wouldn't pull the barrel back and forth. Since I'd never be satisfied with the function, I gave up, gave in and glued the barrel solid. So although I didn't like doing that, I felt i could do nothing more with it.

I glued on the front and back hull plates. I really should have waited to prime the hull since I had to scrape off a lot of paint before gluing. I also glued on a lot more of the small parts onto the upper hull, the fuel tanks, tool boxes and other stuff. The next chore is to hook up the lights and turret IR searchlight.
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Last edited by Marc780 on Sun Nov 03, 2019 1:22 pm, edited 1 time in total.
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Rad_Schuhart
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Re: My Hooben T-55 Progress

Post by Rad_Schuhart »

Marc780 wrote:
Rad_Schuhart wrote:Hi Marc, please tell us how did you solve the horrible sprocket offset. As stock, it is almost like the king tiger!
Sprocket offset? I haven't even gotten that far yet, right now I'm just happy all the motors respond to the transmitter! I guess that's something I'll deal with when I get to it? I'll probably search the forums to find out how others fixed the problem on similar tanks, although now that I know i have this problem to deal with I can't say I'm looking forward to it lol
Yep, before working on the turret I think you should focus on that first, lol. The sprockets are offset. I mean, are not aligned with the roadwheels, so it will cause throw track every 10 seconds, lol.

I planned to shim the wheels, but one shim is not enough, and two makes the roadwheels to bee too out, and the grub screw wont have enough flat part to fit.

Anyway considering doing that puts the wheels outside the fenders (and it should NOT be like that) the only thing we can do, is to machine the motor axles and remove 1 or 2 milimeters...

And yeah, recoil is a pain, lol
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