Suspension coil spring for Heng Long German Leopard 2A6

[keilau]

I just finished the metal road wheel upgrade on a 2021 Heng Long German Leopard 2A6. The original coil springs seem to be too weak for the new chassis weight of 11 pounds. Anyone knows a source for the right stronger coil spring?

My Pro version HL Leopard came with metal suspension arm, but the arm axles have undersized OD for the road wheel ball bearings. I tried 2 sources of HL parts, but their metal arm all has undersized axle OD. When I purchased the road wheel set, I got it from Toucan Hobby a set without the arms. I use the original HL arm and coil spring now.

Torro recommended using stronger coil spring for the out flanked 4 road wheels, but keep original coil spring for the middle 3. Torro do not sell the stronger coil spring separately.

Your suggestion will be much appreciated.

[Rubicon99]

I just finished the metal road wheel upgrade on a 2021 Heng Long German Leopard 2A6. The original coil springs seem to be too weak for the new chassis weight of 11 pounds. Anyone knows a source for the right stronger coil spring?

My Pro version HL Leopard came with metal suspension arm, but the arm axles have undersized OD for the road wheel ball bearings. I tried 2 sources of HL parts, but their metal arm all has undersized axle OD. When I purchased the road wheel set, I got it from Toucan Hobby a set without the arms. I use the original HL arm and coil spring now.

Torro recommended using stronger coil spring for the out flanked 4 road wheels, but keep original coil spring for the middle 3. Torro do not sell the stronger coil spring separately.

Your suggestion will be much appreciated.

If you already moved the springs to the second whole position and it is still to soft and sagging then consider adding a third position whole. This will greatly increase the spring force.

I have added additional whole positions on several tanks with nearly perfect results. The draw back is the spring life is shortened by ~25% or slight more depending on how hard you drive the tank over rough terrain.

[keilau]

If you already moved the springs to the second whole position and it is still to soft and sagging then consider adding a third position whole. This will greatly increase the spring force.

I have added additional whole positions on several tanks with nearly perfect results. The draw back is the spring life is shortened by ~25% or slight more depending on how hard you drive the tank over rough terrain.

This is invaluable information for metal tank upgraders.

For most tank models, Heng Long make a basic plastic version and a metal professional with some customized version in between.

For the HL Leopard 2A6, the 2 basic variance are 5 and 10 pounds respectively. It makes a lot of sense for HL to design 2 position spring mounting holes I hope the second hole should work for the 11 pounds tank. My metal upgrade is 1 pound heavier than the OEM professional version. The additional weight comes from the Heng Xin gearbox, servo recoil and battery pack. Pictures are OEM vs. upgrade.

[Roaming Gnome]

My Abrams with all the metal upgrades including ball bearing gear boxes is the heaviest tank I have, lightest position was too soft, moved everything to the second and it's been fine. Unfortunely the post for one of the rear suspension arms cracked in half, looking for some suitable thin wall tubing I might use to reinforce the posts on the replacement hull I have, I assume all the added weight is just to much for the parts.

[keilau]

My Abrams with all the metal upgrades including ball bearing gear boxes is the heaviest tank I have, lightest position was too soft, moved everything to the second and it's been fine. Unfortunely the post for one of the rear suspension arms cracked in half, looking for some suitable thin wall tubing I might use to reinforce the posts on the replacement hull I have, I assume all the added weight is just to much for the parts.

Will a replacement chassis work?

https://www.toucanhobby.com/products/hl-3918g-chassis-dzn1?pr_prod_strat=e5_desc&pr_rec_id=da533e77c&pr_rec_pid=7636313178362&pr_ref_pid=7636313309434&pr_seq=uniform

[keilau]

If you already moved the springs to the second hole position and it is still to soft and sagging then consider adding a third position hole. This will greatly increase the spring force.

I have added additional hole positions on several tanks with nearly perfect results. The draw back is the spring life is shortened by ~25% or slight more depending on how hard you drive the tank over rough terrain.

The HL 2 holes spring mounting design work very well for the 11 pounds Leo. (Thank you, Rubicon99) I moved all the coil springs to the second hole position. Now, the tank sits level and the whole chassis sits a few mm higher.


A personal commentary: This coil spring suspension is working fine for the medium weight plastic chassis, metal gearbox and solid metal track RC tanks. In direct comparison, the torsion bar suspension on the HL Merkava or even the Tongde M60 offers refinement that even a causal tanker like me can appreciate.

[Roaming Gnome]

Will a replacement chassis work?

https://www.toucanhobby.com/products/hl-3918g-chassis-dzn1?pr_prod_strat=e5_desc&pr_rec_id=da533e77c&pr_rec_pid=7636313178362&pr_ref_pid=7636313309434&pr_seq=uniform

well I already have the chassis from the first tank, but the holes for the axle screws show hairline cracks, and that tank was pretty much stock with a steel gearbox and red motors. I disassembled the thing last night, and found that both rear swing arm mounts were actually broken, so I'm wondering if it's just to much weight period at the root of things, had I been smart I'd looking for plastic accessories, have no idea why I went with metal

[keilau]

well I already have the chassis from the first tank, but the holes for the axle screws show hairline cracks, and that tank was pretty much stock with a steel gearbox and red motors. I disassembled the thing last night, and found that both rear swing arm mounts were actually broken, so I'm wondering if it's just to much weight period at the root of things, had I been smart I'd looking for plastic accessories, have no idea why I went with metal

It is highly unlikely that the metal parts are too much weight for the chassis. Heng Long use high quality APS plastic and mold substantial panel thickness. At about 10 pounds, the weight is far too small to do structural damage to the chassis. On the other hand, over tightened screw can surely crack the mounting holes, either during manufacturing or upgrading. If they are hairline cracks, it is possible to repair them using plastic welding glue and clamping.

For structural integrity, a replacement chassis is the preferred repair. Besides, the cost is very low.

[Roaming Gnome]

do you use any kind of thread locker? I have an ongoing issue with the screws actually loosening?

[keilau]

do you use any kind of thread locker? I have an ongoing issue with the screws actually loosening?

No, I never find it necessary. In the case of the suspension arms, I actually have to back off slightly to allow free movement of the arms. I did not have problem with the screw of the suspension arm getting loose on any HL RC tanks.

I must clarify that the Leopard 2A6 is the first coil spring suspension equiped tank that I loosen the arms to adjust the coil spring. The other tank that I mess with the suspension arm are the HL Merkava and Tongde M60A1 where I replace the nylon bushings with ball bearings. The arms are connected to a torsion bar instead of mounted to a plastic tube with screw. I have not run the Leopard 2A6 on rough terrain long enough to see if the screws come loose yet. I hope to hear from the more experienced members on this issue.

The metal upgraded Leopard 2A6, at 11 pounds, is the first HL I adjusted the coil spring. My other earlier era tanks, Sherman, T-34/85, Pershing are 7-8 pounds with full metal upgrade (less metal road wheels). The factory installed coil spring are good as is.

[sclui56]

keilau you could also get heavier coil springs from Toucan instead of adding a 3rd anchor hole. I swapped out the springs on the KV-2. For some reason, mine sat fairly compressed with stock springs at the time.

[keilau]

keilau you could also get heavier coil springs from Toucan instead of adding a 3rd anchor hole. I swapped out the springs on the KV-2. For some reason, mine sat fairly compressed with stock springs at the time.

I am very interested in trying out some stronger coil spring even though the HL one on second hole seems to work OK. I use the Tamiya hybrid tracks on the Leopard 2A6. The Tamiya track is about half the weight of similar all metal track from Mato. It may have helped.

I did not find any offer of coil spring at Toucan Hobby. I ended up ordered 2 set of 1.1mm coil spring for Challenger2 from RCtanklegion.com who is in Malysia. It may take awhile to get to US. They do not have set for Leopard so I have to get 2 sets to get enough pieces for the Leo.

[Rubicon99]

I am very interested in trying out some stronger coil spring even though the HL one on second hole seems to work OK. I use the Tamiya hybrid tracks on the Leopard 2A6. The Tamiya track is about half the weight of similar all metal track from Mato. It may have helped.

I did not find any offer of coil spring at Toucan Hobby. I ended up ordered 2 set of 1.1mm coil spring for Challenger2 from RCtanklegion.com who is in Malysia. It may take awhile to get to US. They do not have set for Leopard so I have to get 2 sets to get enough pieces for the Leo.

They tend to make the "plastic" hull Leopards, Abrams and others pretty bouncy unless you really add a a lot of extra ballast weight.

Best only used on the rear #6 and #7 road wheel sets to offset added rear sagging. This keep the bouncing to a minimum.

[sclui56]

I am very interested in trying out some stronger coil spring even though the HL one on second hole seems to work OK. I use the Tamiya hybrid tracks on the Leopard 2A6. The Tamiya track is about half the weight of similar all metal track from Mato. It may have helped.

I did not find any offer of coil spring at Toucan Hobby. I ended up ordered 2 set of 1.1mm coil spring for Challenger2 from RCtanklegion.com who is in Malysia. It may take awhile to get to US. They do not have set for Leopard so I have to get 2 sets to get enough pieces for the Leo.

You would need to reach out to Toucan via email, they are not painted.

[keilau]

They tend to make the "plastic" hull Leopards, Abrams and others pretty bouncy unless you really add a a lot of extra ballast weight.

Best only used on the rear #6 and #7 road wheel sets to offset added rear sagging. This keep the bouncing to a minimum.

I totally agree. In designing a suspension system, it is utterly important to tailor the total vehicle weight and spring stiffness.

[Meter Rat]

If I may add to this? I have fitted these springs to my Challenger, Abram, and T72. On the Challenger, and Abrams, installed these springs on the first wheel station, at the front, this was in position two (the harder setting), and the last two wheel stations. Wheel station 6, had the spring installed in the soft setting, and wheel station 7 the spring set in the hard position. I found installing stiffer springs at all the wheel stations, that there was no wheel travel, and the tank just shoogled over the terrain, even though both weight in at about 8.5kg (16lbs) The T72 only required stronger springs at the first and last wheel station, on the soft setting, as it is considerably lighter. By doing this, one set of springs cover all, three tanks.

[keilau]

If I may add to this? I have fitted these springs to my Challenger, Abram, and T72. On the Challenger, and Abrams, installed these springs on the first wheel station, at the front, this was in position two (the harder setting), and the last two wheel stations. Wheel station 6, had the spring installed in the soft setting, and wheel station 7 the spring set in the hard position. I found installing stiffer springs at all the wheel stations, that there was no wheel travel, and the tank just shoogled over the terrain, even though both weight in at about 8.5kg (16lbs) The T72 only required stronger springs at the first and last wheel station, on the soft setting, as it is considerably lighter. By doing this, one set of springs cover all, three tanks.

These are invaluable information from firsthand experience. Thank you for sharing. What are the weights of your Abrams and Challenger2? How are they being configured?

My tanks are much lighter, none above 12 pounds. It is from the fact that I use Tamiya hybrid tracks or Torro nylon tracks with metal wheels. I use ball bearing plastic wheels with solid metal tracks.

[Meter Rat]

These are invaluable information from firsthand experience. Thank you for sharing. What are the weights of your Abrams and Challenger2? How are they being configured?

My tanks are much lighter, none above 12 pounds. It is from the fact that I use Tamiya hybrid tracks or Torro nylpon tracks with metal wheels. I use ball bearing plastic wheels with solid metal tracks.

Both the Abrams, and Challenger weigh between 8.5kg and 9Kg, roughly 16lbs, and 17lbs respectively. Both have all metal wheels, sprockets and tracks (not sure of the make) with pads. 390 motors, ultimate gearboxes. All wheels have ball bearing, as do the gear box. Configuring the springs in the way I have done, leads the seventh wheel station over any obstacles, and acts as a duel spring. This also helps with track retention. With your tanks being lighter you may not have to set springs as hard.

[keilau]

Both the Abrams, and Challenger weigh between 8.5kg and 9Kg, roughly 16lbs, and 17lbs respectively. Both have all metal wheels, sprockets and tracks (not sure of the make) with pads. 390 motors, ultimate gearboxes. All wheels have ball bearing, as do the gear box. Configuring the springs in the way I have done, leads the seventh wheel station over any obstacles, and acts as a duel spring. This also helps with track retention. With your tanks being lighter you may not have to set springs as hard.

You are right. If I set the coil springs too hard, my tank will be a bouncing buggy car.