PART 2: Drive testing
I think it is important to point out the Spectrum DX8 radio system used for the testing. Although this system allows for a fair amount of customization that would surely effect the handling feel of the Sheridan, I made sure it was set to the most basic and simple settings in order to get a good base line assessment of the overall stock Tamiya Sheridan electronics, motors and gearboxes.
Driving the Tamiya M551 Sheridan was a bit of a let down! YES a let down, but in a good way! Why.....well because it was just too DANG easy and simple. It attacked all the obstacles on my trials course like it was a 1/10 R/C rock crawler truck vs the small 1/16 scale tank that it is. The Sheridan simply put all my other Tamiya (or Tamiya electronic equipped tanks) to SHAME at the ease at which it was able to be driven over each obstacle. Now that's saying a lot given the high standards of performance I demand of my tanks for handling rough, hard and technical terrain driving I place on them, as those that know me personally or those that have seen my tanks perform some crazy stunts can attest too. I build tanks to be driven hard and expect to get every dollar paid into them back in performance and entertainment. The Tamiya Sheridan is starting out on a good foot in these areas. That is not to say it is perfect, it is NOT and has room for improvements.
The Tamiya M551 Sheridan is an exceptionally mechanically quiet running tank (tested with sound turned off) and drives very smoothly over flat hard or soft sand/dirt surfaces. Its suspension however is in my opinion ridiculously over sprung (stiff) for this extremely light weight tank. To give you an idea of the weight, the Sheridan is about half the weight of the similar size Tamiya M4 and about as light as an all plastic Heng Long T34. Why is this important? The unsprung tank weight vs suspension stiffness does not allow the road wheels to articulate easily up and down and thus does not conform the wheels and tracks to terrain contours well. At slow speeds on rough uneven terrain the suspension does not flex well and the Sheridan does not drive as smoothly and effortlessly as it could otherwise(this can be seen clearly in the test videos). At high scale speeds ~40 mph over slightly moderate uneven terrain the Sheridan becomes rather bouncy in its driving performance. Not as bad as the Tamiya Abrams, but because of the Sheridans small size it sadly looks more toylike. I will be addressing some this issue with the addition of more weight being added to the forward 2/3 of the hull. This will most likely make the Sheridan a little unbalanced in the front, but I have found weight forward is often better then weight in the rear on tanks for high speed performance and rough uneven terrain.
Discloser note: An comment I wrote last summer about the suspension being pleasantly soft in performance after a short driving session with another Sheridan was right yet wrong and I wanted to point that out. That assessment was made while driving in flat packed and soft silty sand in which the stiffness could not be clearly seen.
The new Tamiya Sheridan DMD T11 control unit is so far proving quite a solid improvement in my opinion over the older 'two piece" DMD/MFU systems used in Tamiya's "WWII tanks". Smoother power curves, turn performance and ease of use (once you read the manual). It has more option for customizing the tanks performance then the older "two piece" DMD/MFUs. One in particular is the choice between "standard power" and "high power" settings which provides increased power for turning, similar to the setting the Tamiya Abrams and Type 10 tanks have. I tested the "high power" setting during the review and found it did help somewhat, but overall was not needed even in fine silty sand/dirt, mostly because I am running an 8.4v battery that already delivers more power to the motors vs the recommended 7.2v batteries.
IN SUMMERY:
Negatives. I found the Tamiya M551 Sheridan to have only one real issue, being over sprung. With a little added weight this can be somewhat address and should improve overall off road smoothness and track to ground pressure for even better grip.
Positives. The Sheridan is a rather quick tank with a scale "top end" speed (on a hard flat surface) of ~40mph (at 8.4volts). It is proving easy to maneuver in tight rough terrain, throttle control is excellent and it can slowly creep forward/back or sprint to top speed with ease. I suspect given its small size and easy handling characteristics it will prove to be both a good IR battle tank and a fun tank to put on demonstrations with. The DMD T11 control system is a solid improvement over the older "two piece" DMD/MFUs and should make for a great upgrade replacement control system for non Tamiya tanks (~$250 complete system and all wires).
Below are photos from the testing. Short videos clips of the testing can be see on my
Instagram @fsttanks. This includes the video of the ROLL OVER....LoL
M551 Sheridan on "rock climb" obstacle...Yes it drove right up and over the rocks. See Instagram video.
Tamiya M551 Sheridan on ditch crossing obstacle. See Instagram video.
Tamiya M551 Sheridan on ditch crossing obstacle
Tamiya M551 Sheridan climbing out of trench.
Tamiya M551 Sheridan on "step climb break over" obstacle.
Tamiya M551 Sheridan on "step climb break over" obstacle.
Tamiya M551 Sheridan on "rock climb" obstacle.
Tamiya M551 Sheridan on "40 degree side slope" obstacle. Hard to see the angle in the photo.
Tamiya M551 Sheridan making neutral/pivot turn while on "40 degree side slope" obstacle. Hard to see the angle in the photo.
Tamiya M551 Sheridan on "off chamber" rock obstacle heading for a bad moment! See Instagram video.
Tamiya M551 Sheridan ROLLING OVER!!! See Instagram video.
Tamiya M551 Sheridan climbing dirt berm and heading down into "L trench" obstacle. Notice the lack of any suspension articulation cause by overly stiff springs.
Tamiya M551 Sheridan dropping down into "L trench" obstacle.
Nothing special in this photo I just liked it and wanted to share it.