Capt.Canuck

I received my first HL tanks yesterday - a Panther and KV-1.

After some initial problems and minor surgery, both seem fully functional and are working well.

The only significant current issue is that the foremost wheel on the right front side is virtually without suspension. The spring is very weak, and the tank is consequently sagging on the front end when at rest, and it will no doubt effect performance when in use.

How do I go about fixing this?

TIA for the advice.

Cheers,

Stephen

Buckeye36

My Feedback: (3)

You could try to swap the spring with a spring from one of the middle road wheel suspension armsif it doesn't work you could buy some new springs.

Buckeye36

My Feedback: (3)

An additional option is to clock the spring, explained in this post:
http://www.rcuniverse.com/forum/m_78...tm.htm#7833221

fsciorelli

I've experienced the same issues with my KV-1 and am also checking outt options, including clocking of springs.

I've been checking out upgrade springs and was wondering are the Tiger 1 springs the same as the KV-1? From what I can tell they are both torsional/swing arm types. The other thing is that in the case of the KV-1 the tang that engages on the hull side is not 180 degrees from the side that engages the swing arm.Its proabably 210/150 degrees off depending on how you measure. That means that the right side springs are a mirror of the left side springs. It appears that the PZIII and Panther/Jadgepanther springs have the two tangs 180 degrees apart. I tried an upgraded set that are in the 180 degree config on the KV-1 and they did not seem to provide any improvement.

1sgt

It might be easier for some of us to understand better if you used clock positions to explain the spring locations, ie: 12 O clock is the center top, 3 O clock is the center right side etc. That's why they call it clocking the springs.

Jim

fsciorelli

I'll take some photos of the springs side by side and post them

Panther G

The KV is known to have this issue right from the beginning. Mine would not even sit level on level ground. It sagged too the right front. This is a glaring oversight on HL's part as it is noticeable right out of the box. I am surprised it has not been addressed at the factory yet as these have been out over a year now. there is no call for this type of issue to continue this long. It just fuels the Brand X Vs Brand Y fight and HL just brings it on itself by not making such a minor fix. No excuse IMO.

cheap tank

This is a panther but its the same idea.You can see the differance from the first to second wheels.

Panther G

Are those springs both from the same set initially? maybe somebody just gets them in the wrong order during assembly. I have not heard this complaint from everyone who has a KV, makes me wonder if thats the issue.

vano12

Mine looks absolutely fine and level or I don't know where to look for the weak suspension

cheap tank

I did not explaine that very well sorry. What i ment to say was thats the differance after i drilled another hole for the spring to go in.

Ex_Pat_Tanker

I used a set of the upgraded springs intended for the JagdPanther (I think they were from Welshdragon). No more sag

tgr6669

My Feedback: (1)

 The hl jagdpanther/ panther sping are what you need (the upgraded ones ) I have those and reclocked the springs . Works great .

Panther G

If you push down on the top of the tank, does it rebound? If it does not do it within reason you will need the new springs,especiallywith metal tracks.

Panther G

The reason i say that is your KV is riding low. Tanks that have return rollers actually carry part of the weight of the track. This is called sprung weight. tanks like the Tiger and Panther that the tracks return on the road wheels have what is called unsprung weight. the tanks suspension is not carrying part of the weight of the tracks. With metal tracks the stock springs may not be able to support the tank properly of a long period of time.

tankmaster5001

Strange I have heard people talk about this problem with their KV-1 but I never had this problem with mine...actually if anything the springs are alittle to stiff.

vano12

Pushed all the way down and it went back all the way up. This tank is solid. I was thinking about getting the Pz III as my first but I am actually very happy about the KV - 1. I wanted a wide track tank.

Ex_Pat_Tanker

Well I guess somebody had to get lucky ! After a coat of paint and a set of mato gears in the back of mine, it acted like a dog with a bad case of worms [&:] - at that was before I dropped on the resin KV2 turret I had bought for it [:@]!!

Panther G

This is what i don't understand about the KV. It is so inconsistent from one to the next. One persons works perfectly, others are impossibly flawed. i just don't get it. Mine was so unstable the tank would literally hop when you tried to drive i and darn near jumped off the ground when you fired the gun. This is really why i never tried to get it back from my nephew. i had plans to correct everything but he seems to be happy with it. Actually he would be better off with one of my T-34's as he likes faster tanks. I have one I am going to do up for him as a surprise.

Perry S.

Maybe they bought springs from a couple of different vendors. Mine were a little weak and I installed the upgrade springs. Much better now.

Perry

fsciorelli

Perry,

Where did you get your upgrade springs? Did you also clock the alignmnent hole in the hull?

Frank

Perry S.

I got them from Phil at RCtankwars.

snakestretcher52

No suspension issues at all with my KV.

fsciorelli

Perry,

I got some from Phil also. I did not clock mine though, and it didn't seem to be an improvement.

Frank

fsciorelli

All,

I've put a few photos together of the various suspension springs I'm aware of. My goal is to find a fix for my sagging KV-1 suspension

The first attached photo shows the KV-1 with two different springs installed. The spring on the right is the original spring that came with the Kv-1. The spring on the left shows the upgraded spring from my Impact Pz III suspension set

The second attached photo is similar to the first, except now with the upgraded spring I received from RCTankWars that is advertised for the KV-1 on the left.

The third photo shows several springs removed from the tank side by side. This is maybe the most interesting photo. From the left the springs are as follows a: upgrades spring from RCtank wars, b and c: right and left Pz III springs from Impact, d: original KV-1 spring (left)

Observations on each:

a: Upgrades springs from RCTankwars
1) All coils wound the same direction (counterclockwise (CCW) as shown in photo)
2) Tang that engages hull is 180 degrees from tang that engages swing arm. If you assume the tang that engages the hull is 12 oclock, the tang that engages the swing arm is at 6 oclock.
3) Wire diameter is 0.038"

b and c: right and left Pz III springs from Impact
1) Half coils are wound CCW and other half clockwise (CW) for right and left side
2) Tang that engages hull is 180 degrees from tang that engages swing arm. If you assume the tang that engages the hull is 12 oclock, the tang that engages the swing arm is at 6 oclock.
3) Wire diameter is 0.038"

d: original KV-1 spring
1) Half coils are wound CCW and other half clockwise (CW) for right and left side
2) Tang that engages hull is about 150 degrees from tang that engages swing arm. If you assume the tang that engages the hull is 12 oclock, the tang that engages the swing arm is at 5 oclock.
3) Wire diameter is 0.035"

OK so relative comparison.
a) The Pz III Impact upgrade and RCtankwars upgrade springs should have the same spring rate (same wire diameter) and the same results when installed in a given tank
b) KV-1 springs should have a lower spring rate (0.035" vs 0.038" wire) but the 150 deg angle between the hull tang and the swing arm tang will result in a greater spring force than the 180 degree configuration when the swing arm is at a given position. With the tangs at 150 degrees you achieve the same effect of what others have done by "clocking" the hole in the hull 30 degrees.

I just checked out on line the equation for spring rate of a metal rod. If the helical spring in the RC tank suspension is equivalent, then the spring rate is proportional to the wire diameter to the 4th power. That would make the spring rate of the 0.038" coil about 39% greater than the 0.035" coil. If I'm incorrect please let us know what the correct formula for spring rate is. Thanks

Last thing to contemplate. The last photo is of the Mato Tiger 1 upgrade springs. Notice that the angle between the two tangs is less than 180 degrees. If the wire diameter is at least 0.038" then it should be similiar to the original KV-1, but with a higher spring rate.

My go forward plan is to either use the RCtankwars or Impact springs on my KV-1 and clock the hole in the hull at least 30 degrees, or purchase the Mato Tiger 1 springs and give them a try. I'm not in a big rush right now, so I might just order the Mato springs.


Frank