Heng Long 3958-1 IDF Merkava IV basic version to metal upgrade

[keilau]

The issues of mounting a Hooben sprocket to a Heng Long IDF Merkava Mk4 is not complicated. But there is no instructions manual to tell you what the problems are and how to fix it step by step. The Merkava is a large modern MBT. The adjustment that HL made to accommodate the large Merkava chassis is not good engineering.

The Merkava has a chassis wall to wall width of 12.8cm. (pic #1) My next biggest HL tank, the Leopard 2A6 is 12.0cm. The 8mm difference is very significant. HL have 49mm and 59mm motor shaft lengths for their gearbox. (pic #2) HL did not make a longer motor shaft for the Merkava, nor change the gearbox mounting to sidewall. As a result, the Merkava has only about 5mm motor shaft for sprocket mounting. pic $4 (By comparison, most other HL tank have 10mm bare motor shaft or longer. The sprocket D-shape tube is typically 8-10mm.) HL extends the Merkava sprocket tube as far inboard as possible. There is thick padding on sprocket hole to allow tightening to the motor shaft. The HL sprocket works ok.

After I first install the Hooben sprocket as is, it runs. But the sprocket had a lot of wobbling and fell off after a few minutes. After a few hours of examining and measuring, I found 2 problems. The Hooben sprocket expects a motor shaft that would be 5mm longer. The HL motor shaft left a 5mm gap between the top of the motor shaft and the bottom of the sprocket mounting tube. It is impossible to tighten the mounting M3 screw without cracking the sprocket. The Hooben sprocket mounting tube is recessed into the body by 2mm, leaving a short 4mm contact surface between the motor shaft and the sprocket.

My solution is very simple. I stack 2 pieces of 7mm OD nylon rings to the bottom of the sprocket mounting tube. I cut off a small piece to make the rings D-shape. It allows me to tighten the M3 mounting screw. It seems to run extended period fine without anything getting loose. The Merkava runs smoothly and drives well on the Hooben nylon track.

I am not happy with the fact that the motor shaft and sprocket tube have only a 4mm contact surface. I cannot figure out a better solution without making new hardware. My ideal solution is to find a 5mm longer motor shaft for the gearbox. It is what it is. If the Hooben sprocket falls off again repeatedly, I will have no choice but to revert back to HL track and sprocket.

[keilau]

I’m glad that worked for you.

Yes, I made enough mod to get the Hooben track and sprocket work on a Heng Long Merkava Mk4. I modify the sprocket and did not touch the HL motor shaft.

What I really want is a 3D printed Heng Long sprocket with 13 teeth. I will illustrate this more later.

[RichJohnson]

I’m glad that worked for you.

[keilau]

It took me another working day, but I get the Hooben nylon to work properly on the Heng Long IDF Merkava Mk4. I can state without reservation that it is the best track for the HL Merkava. You can easily see the difference in a closed pin track vs. an open pin track (lower). The Hooben track pattern is Merkava early Mk4 and quite different from the HL track.

The Hooben track works only with the Hooben sprocket which has 13 teeth vs the HL's 15. But the Hooben sprocket was not designed to work with the HL gearbox. It wobble and fall off. It took me a whole day to figure out the problem. Once I identified the problem, the fix to make the Hooben sprocket to work on a HL gearbox is simple and easy to implement. I am working on a longer post to describe the problem and how to fix it.

[RichJohnson]

I’m glad they fit for you. That was a big gamble. Especially permanently modifying your shaft to the double D end, which I swear I stated somewhere back in the thread. The hooben fury Sherman is that way too. Same tranys. As is my hooben leopard 1a5.

[keilau]

As long as the OD of the Hooben and the HL motor drive shaft are the same. It is possible, if not easily, to make it work. And I intend to try. Waiting for the Hooben Merkava nylon sprockets.

I received the Hooben nylon sprockets for the Merkava Mk4 today. As tank_me warned me, the Hooben sprocket comes with a Double-D motor shaft hole while the Heng Long motor shaft is a single-D cross section. The Hooben sprocket ID and the Heng Long motor shaft OD are both 7.88mm. So I set to work.

I used an 8volts rotary tool with a 6mm cylindrical stone grinder, a small round metal file and a jeweler's file set to convert the sprocket to a single D configuration. The sprocket resin is relatively easy to work with. I worked slowly and used a spare HL gearbox to test fit every few steps. Each sprocket took about 10 minutes for the conversion. The Hooben sprocket hole is a tight pressure fit to the HL motor shaft, a very desireable situation.

I replace the HL Merkava plastic track with the Hooben nylon track. With the Hooben sprocket, the change over is easy. I test run the Merkava with the Hooben nylon track on my 2x4 dynamo. It runs smoothly with no excessive vibration. I call it a day.

Tomorrow, I will subject the Merkava to a series of run on solid floor and on carpet to evaluate its driving quality. If the sun comes out and the lawn is dry, I may do an outdoor run too.

[Evan D]

I am very happy with the Merkava.

[keilau]

If you are still looking or just for future information the CS tracks and sprockets for the HL Merkava are now available on EBay.

I have a set coming for another IDF project I am working on.

https://www.ebay.com/itm/285657502583?hash=item4282839377:g:5JAAAOSwYv1lp3d4&amdata=enc%3AAQAIAAAA4Pogs51Y0EAgChdXri9HQm4BvAv8vlA9bB8WfwachukLLmko3caMFLyJ1DjxN7PK0P5jmio5En3afNKdZAHbuY5dEBbZa%2FIbArYAwWPPOyuce9y7iNJ0xmIGNnP3ymg8q9ZS4TH%2BnsEuLEUPy2ieeCqMiWegLY0KTY2Kz%2BGRRhEH71cLgOzWyb%2Fg9NK3coqISmjUpn8SnaS8Tzut3joUYkxsiV%2FUneWV%2FFYnyj2a1ik1A4LihBavBBNRaEp%2FmIR9HZNP11YG0oMgY9SL02CO9nHL%2FYdT9G8j099LD09YAVtD%7Ctkp%3ABk9SR_La4p-lYw

I am still waiting for the arrival of the Hooben sprockets and hope to make the Hooben nylon track to work with the HL IDF Merkava Mk4. The exposed pins of the HL CS-3958-MetalTracks make it look unrealistic.

[Rubicon99]

Hooben is sending the nylon sprocket set now. I should have them in about 2 weeks. I will try to find a way to fit them on the Heng Xin motor drive shaft.

If you are still looking or just for future information the CS tracks and sprockets for the HL Merkava are now available on EBay.

I have a set coming for another IDF project I am working on.

[keilau]

Which means $30 for the nylon sprocket pair and $80 for the metal pair. I am ordering the nylon sprocket pair.

Hooben is sending the nylon sprocket set now. I should have them in about 2 weeks. I will try to find a way to fit them on the Heng Xin motor drive shaft.

[RichJohnson]

Here are some pictures of the different track. The Mk4 has angled notched corners on the pad ends and the 4M has the rectangular bar cleat design.
Also best pic of a sprocket I found quickly and some pics of green merks circa early 2000s.
I will look around for more or better pics.

[RichJohnson]

He does amazing work but the final quality of his file still leaves alot of line resolution. I had JVM run a few leapard 1 parts from his kit, I paid the 18 bucks and Rubicon and I reviewed the parts and were disapointed at the quality even off their high resolution resin printers. So I gave up on his designs for now.
Might be worth buying just for his track though....
Let me find the pics of the track for the merkava.

[tank_me]

That metal track is sick! That is the track of early merkava tanks like the 1,2,3. I have a kit to build a mark 3C from Sol. I think I will go buy this setup.
Also, its the same track the idf used on late Magatch tanks.

I know you aren't a big fan of Inkor's designs, but he has the early track available on the Merkava 3D and the recently released Magach 6B.

https://cults3d.com/en/3d-model/various/merkava-3d

https://cults3d.com/en/3d-model/various/magach-6b-gal

[keilau]

I probably do but I have to dig through about 1200 pics lol.
Keep in mind that those are two different tanks. The Mark 4 and the Mark4M with trophy look similar but are different tanks even the track they use is different.

Do you have any reference that the Mark4M has a different track than the Merkava Mk4? Most material that I've seen said that Mark4M is developed from Mark4 by adding the Windbreaker. I am no expert of the Merkava and am eager to learn more.

[RichJohnson]

Sure... https://item.taobao.com/item.htm?spm...d=740594040032

The site is all in Chinese as far as I can tell. Google translate only goes so far with the site. Never dealt direct with Taobao personally.

And the overall link:

https://canshuotoys.world.taobao.com/category-1034104084.htm?spm=a312a.7700824.w4010-871832117.12.580b3809O9F8jv&search=y&parentCatId=9 42113096&parentCatName=%B2%D3%CB%B8%CC%B9%BF%CB%BD %F0%CA%F4%C9%FD%BC%B6%C5%E4%BC%FE&catName=%CC%B9%B F%CB%BD%F0%CA%F4%C9%FD%BC%B6%C5%E4%BC%FE#bd

That metal track is sick! That is the track of early merkava tanks like the 1,2,3. I have a kit to build a mark 3C from Sol. I think I will go buy this setup.
Also, its the same track the idf used on late Magatch tanks.

[RichJohnson]

I probably do but I have to dig through about 1200 pics lol.
Keep in mind that those are two different tanks. The Mark 4 and the Mark4M with trophy look similar but are different tanks even the track they use is different.

[keilau]

The Hooben Merkava sprocket has 14 teeth, but the Heng Long sproket has 15 teeth. Do you have a picture that allows you to count on the real tank sprocket?

[keilau]

A full metal chassis for the Heng Long IDF Merkava at USD$236 is an excellent price. The oversea shipping may be more than the item! (That's usually the case at AliExpress.)

https://item.taobao.com/item.htm?spm=pc_detail.27183998.202208.2.7dab7dd6amZWK1&id=759242737621

Their metal track is the HL metal track. The open pin design is unrealistic. I am waiting for Mato to offer a better looking track for the Merkava.

[tank_me]

Do you have a link to this listing? The early merkava track looks really interesting.

Sure... https://item.taobao.com/item.htm?spm...d=740594040032

The site is all in Chinese as far as I can tell. Google translate only goes so far with the site. Never dealt direct with Taobao personally.

And the overall link:

https://canshuotoys.world.taobao.com/category-1034104084.htm?spm=a312a.7700824.w4010-871832117.12.580b3809O9F8jv&search=y&parentCatId=9 42113096&parentCatName=%B2%D3%CB%B8%CC%B9%BF%CB%BD %F0%CA%F4%C9%FD%BC%B6%C5%E4%BC%FE&catName=%CC%B9%B F%CB%BD%F0%CA%F4%C9%FD%BC%B6%C5%E4%BC%FE#bd

[RichJohnson]

Since this is just a general HL Merkava post, the folks on Inkor's Discord server pointed out there might be a new metal Merkava chassis from Canshuo and it seems to have the proper spring suspension:



After looking at all the things on the Taobao site for Canshuo, I realized that all those new metal parts for the Abrams and such were made by them. The parts bags have CSxxxx on them...assuming for "Canshuo". The gearbox at the bottom looked interesting.

Do you have a link to this listing? The early merkava track looks really interesting.