HL T72 Problems

[dai phan]

Hi all,

I have not had much luck with my 2 latest HL tanks. I just got the T72 with 360 degree rotation. However every while it would not complete a circle and clicking noise appears then stops. I open up the tank and I saw nothing that could impede the motion. I checked and recheck to make sure nothing got in the way then close the tank. It would work for a few rotations then the problem starts again. Also BB function now stops working. No cannon sound, no recoil nothing. I start to lose faith in these HL tanks gals and guys... Dai

BTW: I found a broken lug where the screw goes into. Now I only have 5 screws to hold the tank down.

[oldwolf]

Just a guess based on what you describe, it sounds like one or more wires, probably involved in running the airsoft cannon shooting a bb, has been getting "wound up" as the turret rotates. At first it was bringing the turret to a halt and after a while it either pulled a connector loose or broke a wire.

[dai phan]

Hi all,

I found many problems. Both of the wires connect to CN 10 ( BB) were off the plastic insert that goes into CN10. I used tooth pick and reinsert them back in the socket. Quite difficult but I got the BB /cannon sound to work. Will ask Toucan to send me a new connector. There are two cracks in front of the tank and looks like someone drops the tank because one of the screw lugs broke away from the mount at the same area. I repaired by using CA and epoxy but now the idlers are at an off angle. Out of Heng Long tanks, one has motor issue that needs replacement (Panther G), one has defective rear light that needs replacement (T99A), and this with cracked hull. Will the cracked hull although repaired with epoxy pose a future problem? Should I ask TH for a new tank? Thanks Dai

[SoCalBobS]

Rubicon has some good info about the T72 quirks, maybe some solutions. Mine is fine for now, but if/when I need it, I'll install a second party metal cross axle. Can't remember the brand offhand.

[Rubicon99]

Hi all,

I found many problems. Both of the wires connect to CN 10 ( BB) were off the plastic insert that goes into CN10. I used tooth pick and reinsert them back in the socket. Quite difficult but I got the BB /cannon sound to work. Will ask Toucan to send me a new connector. There are two cracks in front of the tank and looks like someone drops the tank because one of the screw lugs broke away from the mount at the same area. I repaired by using CA and epoxy but now the idlers are at an off angle. Out of Heng Long tanks, one has motor issue that needs replacement (Panther G), one has defective rear light that needs replacement (T99A), and this with cracked hull. Will the cracked hull although repaired with epoxy pose a future problem? Should I ask TH for a new tank? Thanks Dai

The clicking when the turret is turning is caused by something catching and binding. The T72 has a ton of wires crammed into a rather tight space and it is easy for them to catch as they move around inside the hull. The 360 rings are not full proof and do have a number of random issues from time to time.

The forward lower hull cracks are common and happen often because of the weak design. Usually though they happen on tanks that are run hard outdoors and take some time to develop. Seeing them on a new tank or “indoor” tank is more rare.

There are a few fixes that strengthen the forward hull section and solve the cracking issues. Some easier and cheaper then others.

Adding epoxy alone will not solve the problem. The material used in HL hulls does not allow epoxy to bond well to it especially in high stress or areas of high torque loads. The cracking areas are both. I used two steel wire bracings running along the outer hull anchored at two points through the hull to address the stress issues then imbedded them in epoxy to further strengthen them and “tie both together” The epoxy and steel wires act kinda like cement and rebar.

This method is cheap, easy and fast, yet highly effective! Trust me I beat the living SH*T out of my T72s and after doing the above fix have had no further cracking issues. Oh and even with the side skirts off on my tanks no one has noticed the reinforcement because they are painted over and largely hidden behind the idlers and #1 road wheels. With the side skirts on it is not be possible to see the reinforcement.

[dai phan]

The clicking when the turret is turning is caused by something catching and binding. The T72 has a ton of wires crammed into a rather tight space and it is easy for them to catch as they move around inside the hull. The 360 rings are not full proof and do have a number of random issues from time to time.

The forward lower hull cracks are common and happen often because of the weak design. Usually though they happen on tanks that are run hard outdoors and take some time to develop. Seeing them on a new tank or “indoor” tank is more rare.

There are a few fixes that strengthen the forward hull section and solve the cracking issues. Some easier and cheaper then others.

Adding epoxy alone will not solve the problem. The material used in HL hulls does not allow epoxy to bond well to it especially in high stress or areas of high torque loads. The cracking areas are both. I used two steel wire bracings running along the outer hull anchored at two points through the hull to address the stress issues then imbedded them in epoxy to further strengthen them and “tie both together” The epoxy and steel wires act kinda like cement and rebar.

This method is cheap, easy and fast, yet highly effective! Trust me I beat the living SH*T out of my T72s and after doing the above fix have had no further cracking issues. Oh and even with the side skirts off on my tanks no one has noticed the reinforcement because they are painted over and largely hidden behind the idlers and #1 road wheels. With the side skirts on it is not be possible to see the reinforcement.

I tidied the wiring and still turret problem. I see the problem is internal because BB/recoil stopped working and no wires are in the way when turning . Now no BB and no recoil. I will have to ask TH for a refund or credit. Dai

[Rubicon99]

I tidied the wiring and still turret problem. I see the problem is internal because BB/recoil stopped working and no wires are in the way when turning . Now no BB and no recoil. I will have to ask TH for a refund or credit. Dai

I would bet that issue is related to the thin 360 wires. Have you tried using the “non” 360 wiring for each effected system plugged directly into the MFU?

Many of us that have been into tanks for a while don’t use the 360 “slip joint” wire system. Just to many glitches and far to much wiring. We just slightly lengthen the exciting stock lines, tie/rap them in a neat bundle and call it good. This allows for up to 5-10 full 360 rotations. Just have to reverse the rotation now and again. Far less complicated and far more reliable than the HL “slip joint” system.

[dai phan]

I would bet that issue is related to the thin 360 wires. Have you tried using the “non” 360 wiring for each effected system plugged directly into the MFU?

Many of us that have been into tanks for a while don’t use the 360 “slip joint” wire system. Just to many glitches and far to much wiring. We just slightly lengthen the exciting stock lines, tie/rap them in a neat bundle and call it good. This allows for up to 5-10 full 360 rotations. Just have to reverse the rotation now and again. Far less complicated and far more reliable than the HL “slip joint” system.

I will wait to see what TH has to say. I don't want to be sent a bunch of wires then said " you are covered under the warranty" . I am still learning and not ready to do full blown maintenance. Dai

[Rubicon99]

I will wait to see what TH has to say. I don't want to be sent a bunch of wires then said " you are covered under the warranty" . I am still learning and not ready to do full blown maintenance. Dai

It really is easy work to do. HL tanks are super simple to work on when compared to R/C cars and trucks. Once you start working on them, upgrades and modifications come easy and simple breakages are no longer big issues. I would encourage you to try. It makes the tank hobby so much more fun when you can fix and upgrade all your own tanks.

[dai phan]

It really is easy work to do. HL tanks are super simple to work on when compared to R/C cars and trucks. Once you start working on them, upgrades and modifications come easy and simple breakages are no longer big issues. I would encourage you to try. It makes the tank hobby so much more fun when you can fix and upgrade all your own tanks.

So in my case what shall I ask TH to do? A new lower hull and possibly a new BB unit? Dai

[Rubicon99]

So in my case what shall I ask TH to do? A new lower hull and possibly a new BB unit? Dai

New lower hull YES. But the new one will have the same issues in time. Just no way around it.

BB unit maybe, maybe not, it might be the MFU. Why I recommend testing using the non 360 wires. The T72 has all the stock non 360 wires stuffed into the turret. Find the stock “thick wire” I think it’s the red\black(?) pair for the BB until (motor) unplug it from the 360 harness and then plug it directly into the MFU. Then test fire it. If it doesn’t work then there is an MFU issue.

In which case you will need a new MFU.

[dai phan]

New lower hull YES. But the new one will have the same issues in time. Just no way around it.

BB unit maybe, maybe not, it might be the MFU. Why I recommend testing using the non 360 wires. The T72 has all the stock non 360 wires stuffed into the turret. Find the stock “thick wire” I think it’s the red\black(?) pair for the BB until (motor) unplug it from the 360 harness and then plug it directly into the MFU. Then test fire it. If it doesn’t work then there is an MFU issue.

In which case you will need a new MFU.

There are 2 CN10 slots. One on the MFU with the connectors came off and put back (THIN WIRES). There is a small board with thicker wires. I took the connector from the small board ( THICK WIRES) and plug into the MFU. Now I have BB/recoil function. So what does the connector with THIN wires do? I am asking TH to send me new top ( broken screw lug) and lower hull (cracked) and I will repair. I think it is important that I learn the engineering so I can handle if I am going to be in this hobby for a while. Dai

PS: the T90 shares the same lower hull. Expect it to have crack issues too?

[Rubicon99]

There are 2 CN10 slots. One on the MFU with the connectors came off and put back (THIN WIRES). There is a small board with thicker wires. I took the connector from the small board ( THICK WIRES) and plug into the MFU. Now I have BB/recoil function. So what does the connector with THIN wires do? I am asking TH to send me new top ( broken screw lug) and lower hull (cracked) and I will repair. I think it is important that I learn the engineering so I can handle if I am going to be in this hobby for a while. Dai

PS: the T90 shares the same lower hull. Expect it to have crack issues too?

Sounds like you are on the right course of action with the MFU and BB unit.

Yes the T90 uses the same lower hull and will have the same issues.

[dai phan]

This is what I need to replace the thin detached connector? It is thicker than the original wires though... Dai

[dai phan]

Sounds like you are on the right course of action with the MFU and BB unit.

Yes the T90 uses the same lower hull and will have the same issues.

Every now and then I get BB action/cannon sound but no recoil !!! Is this related to the MFU issue? Dai

[Rubicon99]

Every now and then I get BB action/cannon sound but no recoil !!! Is this related to the MFU issue? Dai

Long explanation needed to just answer both yes and or no. Depends some factors I would need to know.

[dai phan]

Long explanation needed to just answer both yes and or no. Depends some factors I would need to know.

Sometimes body recoil works then suddendly stops. Now nothing, just BB sound. Dai

[dai phan]

I have been talking to Toucan and either they will ship me the new hulls, BBs, main board or perhaps send me a replacement tank as I requested. The earlier option takes 70 days to reach to the US. I think it is wise for the new tanks owners to open the tank and see what inside before driving or adding details. Dai

[dai phan]

Ok guys,

Toucan agreed to send me new hulls (upper/lower, BB unit and MFU). This will give me a chance to see and familiarize the mechanics of these tanks. I have heard some reinforce the front end of the tank home made or even kits are available. The large search lights are begging for upgrades so any inputs on this upgrade will be appreciated. Thanks Dai

[quitcherbitchen]

Look at Stanlley's website for stiffeners. RCTANKLEGION-youtube. He has a whole tutorial just for this tank. Looks like it flexes a lot. You could probably source all the aluminum yourself. He as custom versions for other tanks that look very cool and are drop in almost.