Max-U52

Those plastic posts really aren't strong enough for any gearbox. They'll start to crack and then the threads strip out and then it's a big problem. I think it's way better just to drop a few pieces of tubing on them right at the start instead of trying to do a major repair later on.

Kanyhalos

You are right. Thanks for the heads up. I'll see what can I do.

Lord Haw-Haw

As always good advice maxu52.
I put styrene tubing w/ ca on ALL stand-offs, even this styrene makes a world of difference. And ca 6-32 (4-40?) flat washers on top of the lower hull's screw bores/posts (helps screw heads from pulling through or cracking the plastic) and sand the a-joining threaded stand-off's shorter to keep a tighter then factory sandwich fit -helps with glacis plate gaps.

Also, a few drops of slow set (seconds) thin ca down the thread hole and use a needle (quick up & dwn circular motion) to ensure it's on the threads and not pooling on the bottom of the bore makes an easy thread refresh/repair process -don't add to much to the bore volume as that it will crack from expansion. Those self tapping screws are for production costs* and not for routine maintenance. Taigen and their quick release upper hulls (not M26) solve this.

Converting the HL to a Taigen quick release when model type allows is an option or do the magnet deally-wog.

*having a threaded metal insert and machine screws would nice but when they fail it'd be a more difficult repair ...imagine a loose insert on that last of the 6 hull screws your removing The self tappers just fall out because of thread failure an easy fix.

Kanyhalos

How much is the inner diameter and height of that brass tube?

Kanyhalos

My gearboxes have arrived with Deutschepost.

http://postimg.org/image/lui0l1n6b/

I will have to think about how can I strengthen the plastic posts on the lower hull. I'm thinking about using bakelite cubes that I drill in center. We'll see.

Max-U52

5.5mm ID tubing is available at most hobby shops. It usually comes in pieces two to three feet long and you cut it to fit.

Kanyhalos

And what kind of hobby shops I should look after? What are these tubes are used for in common purpose?

Kanyhalos

I am completely pissed off right now. I've got these gearboxes from rctank.de. That Domnique guy said that it is for metal lower hull, so 2 out of 6 screws are in different position, so I either drill new holes on the gearbox holder plate, or make 2 new mounts. That would be fine I said, and I ordered it.

But it's totally something else... actually the left gearbox fits perfectly to the hull with all 3 screws, but the right gearbox doesn't fit at all, every 3 screws are in different positions.
I am unable to drill holes, that's why I ordered this piece of junk.

I will never buy anything from rctank.de anymore. People who are selling in english should learn english first. I'll see what can I do myself, but I'm thinking about fileing a complaint against them in PayPal as false advertisement.

Yup, I'm angry.

Ex_Pat_Tanker

Pah co chu puk

Do you know anybody who could drill the holes for you? Could you locate where they need to be drilled for that person?

Two options are to drill the gearbox metal to fit the plastic tank, or drill the bottom of the tank hull to fit the holes in the gearbox metal. To drill the metal just put paint on the plastic stand-offs and set the gearbox in place. Lift it back out and the paint on the metal will show where you need to drill.

Kanyhalos

If I'd use the painting method, there's a problem. Since there is not a single position where I can fix the plate with at least 1 screw, then the drilling wouldn't be precise. I mean that it's enough if I misalign it with 0,1mm.
That way the tank might start to go leftwards or rightwards. I can borrow a drill or suggest one of my colleagues it's not a problem anyway.

Kanyhalos

I have figured out that the bottom plate of the 4-1 right gearbox and the stock HL left gearbox are mirrors of each other, minus the 3 additional holes.

This way I can mark for drilling easily.

http://postimg.org/image/4bbcekt5f/

http://postimg.org/image/vq4go1ko5/

Lord Haw-Haw

Are those delrin inserts?

Add these if you don't already have to your tool box:
http://www.harborfreight.com/28-piec...-set-3577.html

Kanyhalos

I didn't know that such tool exists. Interesting. The right gearbox on the picture is stock HL with plastic inserts ( I dunno if its POM or whatever) and the left one on the picture is the Taigen 4:1 gearbox with brass bushings (if this was the question ). Tbh I never heard the term "delrin insert" before, I had to google after it.

Kanyhalos

This way I strengthened the fixing posts with some kind of plastic tubes (I think it's a kind of pvc), it fits very tight (can't even remove them with my hands) and it doubled the wall thickness of the posts. This should be strong enough to prevent cracking I think.

http://postimg.org/image/tr4yym0jh/

Kanyhalos

At long last, I successfully finished the installation of the 4:1 steel gearbox. It wasn't so easy, because I drilled 2 holes on the lower plate, but I had to realize that the gears were blocking the way of my screwdriver, so I had to completely disassemble the gearbox and place the parts one by one into the lower hull.
And for the 3rd screw, I installed a hand-made custom pvc mount. I also used Henkel Loctite CA superglue on every posts. One ball bearing was lose and I glued it to the plate.
I also had to expand the holes on the plastic sprocket wheels, because the Taigen screws have bigger diameter then the HL stock ones.

I tested it and it works fine, nothing went wrong. It moves like a real tank, it's slow and is very powerful. I was spinning around with it in a ragged carpet with ease.
However I had to realize that the tank still not going 100% straight in every rpm. But I guess that's the way it is with paired timed motors. It moves fine on medium speed ahead though, I like it.

I will post more info and pictures after I'm done with the testing.

Thank you for all who helped me.

Max-U52

Video, man, Video! We love to watch 'em rollin' along!

Imex-Erik

Congrats! I'm glad you got it working! I was just about to offer a 3:1 and 4:1 plate for you to use as a pattern

Kanyhalos

Here you are Any feedback is welcome Thanks

https://www.youtube.com/watch?v=iDqp...ature=youtu.be

kizwan

That's not go a bit leftwards but a lot leftwards in my opinion. Did you try add one link to each tracks & see if that cures it a little? I think the tracks too tight. Without adjustable idler mount, it's hard to get the right tension on both tracks.

Kanyhalos

I did not try anything yet, I just finished the assembly of the gearbox right before I made the video. I will do more testing, especially outside on rough terrain and grass, and I'll revise the lubrication too. Maybe it has to run a couple of times to break in. I don't know.
The amount it goes leftwards really depends on the speed (rpm).

Ratman0100

As the boys said, don't worry your head about it. Get to work with the screw driver, pull it out, tie a big boulder to it and throw really really far into the river. A video of that would go a long way to making us feel better knowing that annoying contraption had met it maker lol

Kanyhalos

I wish my only problem would be that smoke thing. The black steel 4:1 gearbox drives my tank much worse then the nylon HL stock gearbox. It drives like a shaking hands of an old man every second, like if it would always want to change direction. I don't know what to do. But I'm starting to regret that I got myself involved in Heng Long tanks.

ausf

You and hundreds of dads across the world about 3 days after Christmas.

This is the crossroads of the hobby. You see the potential, you know what you want but are in this trap of HL. It's a false economy, you'll be dropping cash into it to get it where you want, at the end of the day, costing as much, if not more than the high end stuff.

Take my Stug and my journey:

Original tank (two extra Txs sent from vendor over a few weeks)
Mako board for Tamiya compatibility.
DBCR2 for better control and radio.
Metal tracks (plastic kept breaking), sprocket, gearboxes.
reinforce hull.
adjustable idlers.
reposition return rollers to proper spot.
DBCR3 and Benedini, Visation speaker.
Traverse and elevation setup.
redo recoil.
add flash unit.

That doesn't mention any of the cosmetic stuff or hardware, bearings, etc that went into it.

Over a year in time and $1000.

The main thing you should have done was adjustable idler, it's the only way you'll correct the tracking issues.

Kanyhalos

You can see the sprocket wheels wobbling. I might be wrong but I don't see that the axle shaft would be wobbling inside the gearbox. I don't understand. Is this even an issue?

https://www.youtube.com/watch?v=VzOT2DHKsC0