Monday, July 11, 2011

Kyosho Blizzard Restoration (part 3)

Another small update.  After receiving the servo conversion wiring (J to G) I did some bench testing of the Futaba Conquest 4 channel radio with the Robot Logic IMX-1 mixer and the M.troniks Viper 25 Marine ESCs.  The IMX-1 mixer has a simple procedure to configure the transmitter trims so the neutral stick setting can be configured to match the neutral pulse width expected by the IMX-1.  However, with the old Conquest, the neutral setting was beyond the limits of the trims.  There was no getting around that, unfortunately, so I bought a new 4 channel radio: a Futaba 4YF FM system.


The box says it is for airplanes, and the transmitter has the profile of an airplane on it, but this set is actually for ground-based models.  I chose channel 70, the same as my old Conquest system.

After making sure it was in working order and verifying that it was going to work with the IMX-1 mixer and ESCs (it did), I opened up the transmitter to move the racheting adjustment from the left stick to the right stick for control of the front blade.  I want to use the right stick for steering (left-right) and blade height (up-down).  It was simple to do.  The racheting mechanism is a flat piece of metal held by a screw, and it gets swapped with a single spring on the other stick.  Voila, now the right stick is ratcheted and un-sprung and the left stick is sprung!

The color of the transmitter isn't my favorite.  It's supposed to look like metal, but I'd rather have black.  When I was looking for a new 4 channel system, I looked at the 4GWD system from Futaba, but it had a few negative points:
  • It's AM.   I like FM, PCM, and 2.4G for the improved interference resistance.
  • It doesn't come with rechargable batteries.  I don't like using dry cells.
  • It only comes with 2 servos.  Not that I need any more, but...
For the same price, the 4YF seemed like the better deal.  Of course I am overlooking the fact that the 4GWD system was more computerized with an LCD display, digital trims and 3 model memory. But I didn't need those features, and felt that an FM system was a better long-term choice.

I made some simple foam battery holders.  The ESC radio wires were routed through the front foam block and the motor wires were soldered to the ESCs and heat-shrinked.

After trimming and ESC setup I did some driving around the house and gave the electronic drive system a workout.   It works well, but with some small drawbacks.  The first one is that when driving in reverse, the direction of the sticks is reversed from what you'd consider "normal".   So, pulling back on the throttle makes both tracks go backward, but then steering left makes the right track slow down and the Blizzard moves back and to the right.   You can get used to it with practice, but it wasn't something I expected.  The second minor drawback is that the sensitivity of the IMX-1 is not adjustable, and it does not take much steering stick movement to alter the direction of the vehicle.  If the transmitter had steering exponential, I think it would help mitigate this, but the T4YF is fairly low-end and doesn't have such functionality.  Both of these things are just annoyances.  Having the drive system be totally electronic is a major improvement over the stock MSC system.  Am I ruining the vintage spirit by doing this?  I don't think so.

Here are some pictures of the blade, muffler and blinking light circuitry from the accessory pack that were bought at the same time as the kit in December 1985:




Finally, I started to clean the original polycarbonate body this past weekend and it actually cleaned up very well.  Just a final wash and rinse and it should be ready for masking and painting.

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