brarmanini

Hello All,

Over the last few weeks I have been tinkering with an Asiatam recoil/ elevation unit install into my HL Panzer IV with converting a short barrel model to a long barrel. For the recoil / elevation installation I relied on the follow Asiatam Recoil / Elevation Unit installation thread found here.
[link]http://www.rcuniverse.com/forum/m_10033386/anchors_10102909/mpage_1/key_/anchor/tm.htm#10102909[/link]

The install took me a little longer than I wanted because of the new mantel machining and also trying to fit Tamiya electronics into the hull with all the required components; just last week I finally found a supplier that carries the crimps that go into the wire from the recoil unit to the tamiya pcb header. Got everything installed and was off testing the recoil in action.

When I tested the recoil, I got no action. I verified the tamiya electronics were hooked up properly. I checked the voltages coming from the tamiya electronics, 3.3v on positive, 3.3v on trigger with a transient to 0V when triggered and of course the ground. I verified I was getting these voltages at the recoil motor. With no action with the recoil connected to barrel, I disassembled the recoil to just running the motor. Again no action on the recoil motor with no spring or gears connected to the recoil motor.

I disconnected the recoil wiring from the mfu and connecting the wires directly to a 6v battery, the recoil worked perfectly. I added in some resistors inline with the motor to get the voltage drop down on the motor to 3v to replicate the nonworking recoil. Well with any extra resistance the recoil would not work.

One other note is that the barrel slides extremely easily in the mantel.

So has anybody gotten the tamiya electronics to work the the Asiatam recoil? If so, how did you overcome the power issue to drive the recoil motor.

I figure my only options here are to use a direct connection to the battery with the trigger coming off the tamiya electronics with an optically isolated relay, or some form of darlington transistor (opto is preferred to protect the tamiya electronics).

Thanks for all your help in advance.

Bret

heavyaslead

Could be the trigger needs a high/low signal to start the motor recoil (not getting correct signal for starting perhaps).

The actual Tamiya recoil has some capacitors across the terminals that may make a difference in motor noise for the signal trigger.

As a note: I have damaged the tigger sense on the MF unit by incorrectly wiring the recoil so be careful.

brarmanini

Thanks for the response Heavyaslead

I can clearly see the trigger circuit go form a high state to a low state when measured with a multimeter. I wish I had my oscope back....
I did install caps to between terminals and the motor case before testing.

So what happened to your mfu?

heavyaslead

Well the MFU sense circuit got damaged, not really by me, but the Motor assembly was wired incorrectly.

This was a brand new Tamiya kit, must have sneaked through QC when boxed. Really unusual considering the great quality of Tamiya kits.

Anyhow, it did not sense the switch on the motor assembly and continued to 'recoil' until the reload algorithm was conplete (9 seconds for a heavy tank)

Once I rewired the motor assembly correctly, it worked as it supossed to, unfortunately I had to get another MF unit to see the correction work.

tomhugill

Send it back to tamiya they will sort it for you under the warranty!