Scratch Built Tiger 1 1/8 scale

[Hobbyman]

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[tankme]

Finally have all the wheels turning!..At the moment It's 25KG...Every axle bushed and idler gear on one motor for clearance.Test drive on 18volts but variable speed via drill triggers is now not working ....flat out or nothing . Had the triggers apart to adapt to servo control so suspect something in there I did as both triggers have same fault .Have petrol motor ready to set up generator ..Think It's 25cc and runs sweet . 5 amps draw on battery at full speed .If triggers are dead I might just use switches on/off for steering and engine throttle for speed .when gas motor is in .Is their a speed controller out there for tracked vehicles that can handle 18volts and about 12 amps that is available for home builders ? AmourTech have one for their kits but not listed as a separate part.

There are actually quite a few ESCs out there now that can do 18V and 12A. The Dimension Engineering make good ones (https://www.dimensionengineering.com/).

I'm trying a set of these in my 1/6th Sherman build, but haven't installed them yet: https://www.ebay.com/itm/164800318690?_ ... CC8P0PYVYR

Instead of searching on 18V ESCs, search on 24V ESCs. They typically work on anything between like 9V to 24V.

And if you are looking for ideas on scratch built large scale tanks, check out https://www.rctankcombat.com/order-of-battle/tanks/. My Sturmtiger is listed on that site as T065. That site is what got me into tanks again.

[Meter rat]

I have just read this thread, and realised I had not welcomed you to the forum. How very remiss of me.
Welcome from Argyll and Bute in Scotland. That is a very impressive beast (even if it is yet another tiger) you are building.

[Hobbyman]

Thanks everybody......much appreciated ......

[Hobbyman]

Had a test drive today but problems ....drill trigger electronics cut out when I rev up the motor, suspect voltage to high , motor overheating , may have to water cool......carburetor adj range poor ,but may be the over heat causing this ......Need to have motor/generators easily removed/replaced as one unit...as with the top deck and turrent.....this beast is heavy and It's not finished yet! I have 4 mtres steps up to my basement/workshop......accident waiting to happen here !

[tankme]

Had a test drive today but problems ....drill trigger electronics cut out when I rev up the motor, suspect voltage to high , motor overheating , may have to water cool......carburetor adj range poor ,but may be the over heat causing this ......Need to have motor/generators easily removed/replaced as one unit...as with the top deck and turrent.....this beast is heavy and It's not finished yet! I have 4 mtres steps up to my basement/workshop......accident waiting to happen here !

Could be trying to draw too much current from the battery. Drill batteries typically have some overcurrent protection to keep the battery from starting fire.

[Herr Dr. Professor]

I am still trying to comprehend a "build" as sophisticated as yours, Hobbyman. I think I now see that you are using drill motors with a petrol-powered generator of some sort, just like train engines as I mentioned earlier. But maybe I am wrong. I also noticed now a comment I missed earlier in October, that you "now have Win 11 and struggling with-it." I have had Windows 11 since it was released, and I struggle with it daily. With each new download, new "improvement" (mostly necessary for security), something else funky happens. Wait! Did I just describe Windows 11 or all electronics?

[Hobbyman]

Thanks for that encouraging reply re Win 11 Her Dr Professor I thought It was just me !The generators are BMW window winder permanent magnet 12volt brushed motors .When spun they become generators .I am using two in series ....ie pos to neg to pos to neg . I mounted the drill triggers on a common alloy plate to help as a heat sink for the voltage regulators and after that the variable speed wouldn't work on either of them.......So suspect that their might be some sort of voltage overload protection here .Tank went fine on low revs but stopped when I reved up ...throttled back to braking and open up and away It would go .

[Herr Dr. Professor]

Ah, BMW window winder motors as generators...! So my new electric Mini Countryman (actually a BMW-built car) would likely have the same window motors. And since charging stations here in the US are w-a-ay far apart, if I run out of juice, I can just keep pushing down on the windows to generate electricity.

Somewhat more seriously: in railroad diesel/electrics, there is something called a "transition" point. It's nowadays done automatically, but at one time the engineer had to make some kind of change as the engine built up speed and momentum. Might a similar "transition" be needed as the petrol engine revs up generating more and more electricity?

Now you know how much I understand about these matters.

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[Hobbyman]

Have striped /welded and ground the hull and painted It .Made new rotary switches using retract sw for forward and reverse...rudder for left/right and throttle for engine speed . Test drive just before todays photos , rec battery voltage dropped just a as I opened the throttle and the beast took off through the flowers and tried to climb the ivy fence before I caught up to It. Heaps of power at just off idle speed .Thoughts ....maybe one generator might be sufficient ......changing carb to a twin needle chainsaw carb and adding flywheel to crankshaft , missing some weight here as not using the clutch....rough idling and unreliable with only one adj for fuel .