RC Tank Warfare community hobby forum

...no vulgar suggestions please! Just checking all the components in my Tamiya KT box, before i begin the build project. It took me a while to discover that some bits (an extra plastic barrel for example) are not to be used, and then I discover this on off switch- (illustrated).
Given that the DMD/MF units already have a power switch hardwired in, I couldn't see what this was for. It's not listed on the parts sheets, and not mentioned in the build manual, nor is this mysterious unit mentioned anywhere on the net as a Tamiya product.
After further research, I found something identical listed as an 'RC receiver on/off battery power switch'. Being none the wiser, even though I'd noted that the switch had Futuba style male and female connectors on either end, I'd guessed that it was to connect a receiver to a battery supply, but why? There seems to be no need for it in the kit; but I always like to prepare properly before building something (snowmen not included) and hence the query.

That's for running a separate battery pack for your radio. Usually a 4 cell AA pack. This was mostly used before that came out with the battery eliminator circuit (BEC) in the newer radios. Maybe they still put them in with the radios to give you an option.

If your electronics do not have a radio priority circuit, you might think about using a separate pack. I remember an R/C car that took off as fast as it could go, with no control. The motor took all the current and the servo could not move!

I'm gonna guess that you won't be needing it.

Bill

I'm going to step out on a limb here and recommend something that most would probably balk at, but here it goes:

If you haven't started the build, I would seriously consider using the styrene barrel instead of the aluminum one. If there's one thing I wish Tamiya never did, it would be going with aluminum barrels. Yes it was a big addition to static kits as an aftermarket at first because people had trouble dealing with seams, etc. but in RC, the weight of the aluminum barrel causes that unrealistic bounce we all get while driving around. Not to mention that I never needed to change the elevation arm in my Tiger I since it's not stressed by the added weight swinging round and the original very old Vallejo paint is still completely intact while most of my aluminum barrels have exposed metal scratches.

Again, I'm just throwing that out there, not challenging anyone in anyway. I understand people prefer metal parts and it's your tank, to each his own.

ausf wrote:I'm going to step out on a limb here and recommend something that most would probably balk at, but here it goes:

If you haven't started the build, I would seriously consider using the styrene barrel instead of the aluminum one. If there's one thing I wish Tamiya never did, it would be going with aluminum barrels. Yes it was a big addition to static kits as an aftermarket at first because people had trouble dealing with seams, etc. but in RC, the weight of the aluminum barrel causes that unrealistic bounce we all get while driving around. Not to mention that I never needed to change the elevation arm in my Tiger I since it's not stressed by the added weight swinging round and the original very old Vallejo paint is still completely intact while most of my aluminum barrels have exposed metal scratches.

Again, I'm just throwing that out there, not challenging anyone in anyway. I understand people prefer metal parts and it's your tank, to each his own.

You know, that got me thinking. Couldn't a lot of that be solved by balancing the metal barrel?

Roboticus_Prime wrote:

ausf wrote:I'm going to step out on a limb here and recommend something that most would probably balk at, but here it goes:

If you haven't started the build, I would seriously consider using the styrene barrel instead of the aluminum one. If there's one thing I wish Tamiya never did, it would be going with aluminum barrels. Yes it was a big addition to static kits as an aftermarket at first because people had trouble dealing with seams, etc. but in RC, the weight of the aluminum barrel causes that unrealistic bounce we all get while driving around. Not to mention that I never needed to change the elevation arm in my Tiger I since it's not stressed by the added weight swinging round and the original very old Vallejo paint is still completely intact while most of my aluminum barrels have exposed metal scratches.

Again, I'm just throwing that out there, not challenging anyone in anyway. I understand people prefer metal parts and it's your tank, to each his own.

You know, that got me thinking. Couldn't a lot of that be solved by balancing the metal barrel?

None that I could think of. My JS-2 is a good example. That flippin' telephone pole of a barrel bounces like a bobble head when using the geared elevation unit. I counterbalanced the turret itself with steel shot so it runs smooth, but the barrel and recoil still have to be independent to be able to pivot. The spring is supposed to offset it, but you can't fight Newton. It's like having a fat kid on a 20 foot seesaw.

I would think the only way would be to get a serious steel geared servo in there and either use a rack and pinion type set or way over engineer the servo and arm to take the lever action. I went with a servo in mine just to increase the speed for battling and it did cut down a bit on bounce but what would really cut down on bounce would be to get rid of the weight. I think this is the only time in the history of armor modeling that I wished for an aftermarket company to produce a styrene upgrade.

ausf wrote:It's like having a fat kid on a 20 foot seesaw.

If there is enough weight on the other end to balance the seesaw, then it will still work. If you put more weight behind the barrel, more of the force will be put into the fulcrum and not the elevation gear. Real tanks do this.

Still, I agree that plastic barrels is a much easier solution lol.

Roboticus_Prime wrote:

ausf wrote:It's like having a fat kid on a 20 foot seesaw.

If there is enough weight on the other end to balance the seesaw, then it will still work. If you put more weight behind the barrel, more of the force will be put into the fulcrum and not the elevation gear. Real tanks do this.

Still, I agree that plastic barrels is a much easier solution lol.

No, I get it, that's why you'd need a servo that could move some weight, which would also require finding a place to put that weight that doesn't interfere with depression (turret roof), elevation (hull electronics) or TBU base, wiring, elevation unit and turret ring.

ausf wrote: No, I get it, that's why you'd need a servo that could move some weight, which would also require finding a place to put that weight that doesn't interfere with depression (turret roof), elevation (hull electronics) or TBU base, wiring, elevation unit and turret ring.

Oh yeah, for Tamiya IR battling, any extra weight is a liability. I was thinking of a cheap fix for a non-IR battling tank.

Some interesting tidbits of information there, guys. Thanks. The BEC is a new one on me. I had no background in RC whatsoever before getting hooked on Tanks, and missed the background 'education' in RC terms, tricks and tips and technical jargon, that many others bring to the Forum. But I'm learning fast
The BEC drops the battery voltage to a safe level for the receiver, so that the receiver doesn't need an independent power/battery source (and thus the on off switch..Tamiya include). I get that. In preparing for this build though (and No, Ausf, I haven't started yet..) I'm just assembling all the bits I need, from cements to cutting tools. Hence a brace of queries on those topics too. But I also bought a Futuba Attack 4 WD 2.6Gig TX/RX set up to go with it as I'd read in the online build manual that it compatible with the DMD/MF-O! without going though set-up calibration. More than that, it is powered directly by the DMD unit, which presumably includes the BE circuit. Incidentally, it's great that you can download the build manuals before buying the Tamiya of your dreams, so that you can see what you're letting yourself in for.. I'm glad that Taigentanks are facilitating that too with their products.
Now i have most things sorted, I can begin (famous last words ). There's matter of the Cromwell finishing touches first, though.