RC Tank Warfare community hobby forum

'Morning All,

My Sherman Firefly Mk Ic (Hybrid) build is progressing with the successful mating of Mato VVSS Suspension, Idlers (with adjustable mountings), Tracks, and Drive Sprockets to the metal lower hull of the Tamiya kit.

I've modified the stock kit gearbox final-drive shafts to accept the Mato Drive Sprockets by carefully machining one of the "flats" just a little more to accept the Mato Sprockets, and then trimmed the shaft length to bring the tracks into line with the VVSS units, but there is a slight difference between the outside diameter of the sprocket-end of the Drive Shaft, and the inside diameter of the Mato Drive Sprockets - enough to cause the sprockets to wobble as they rotate (and Yes - the mounting bolts have been tightened! ).

Does anyone make an aftermarket final-drive set to adapt the Mato Sprockets to a Tamiya Sherman Gearbox? The machining is beyond my abilities.

Pictures to follow as soon as I resolve some camera-computer interface issues.

Cheers,

Chris Preston,
Victoria, BC
Canada

The only suggestion I can offer is to modify Tamiya Sherman drive sprockets by narrowing them so that they will fit the Mato track. To do this, I use the really old Tamiya sprockets - those produced from 1974 to (maybe) the mid-80's or so. After that, the drive sprockets had the elongated teeth of the current ones that don't mesh well with the Mato track. The early ones had much shorter teeth.

I cut the width of the sprocket halves narrower, and use a thin aluminum or brass sleeve to fit in between the two sprockets and hide the joint; and use JB Weld inside the sleeve to hold everything together. It works because you're still using Tamiya parts, and the only really critical issue is to get the width right. And I know that it works because I have had to do this 4 or 5 times. Nowadays, the biggest problem is in finding a Tamiya Sherman that's old enough to have the early sprockets.

Having said all that, I am SURE that someone out there has a better (and simpler) idea!

I read the first paragraph properly this time and realised you are using a Tamiya chassis.

Good luck and look forward to photos.

'Morning All,

I've had a good look at the Tamiya sprockets in the hope that I could modify them to fit the Mato tracks, but I don't think that's possible. So far, what I've done is this: on the sprocket-end of the shaft, there are two flats machined onto the end to receive the stock Tamiya sprockets - which are too wide for the Mato track. I machined one of the "flats" making it slightly longer so the Mato Sprocket would fit, which it now does. In order to get the correct distance between the hull and inboard sprocket, and get the drive sprockets to line up with the rest of the suspension and have a straight run for the tracks, I also had to shorten the outboard end of the drive shaft by several mm, so now everything lines up properly and the tracks have a straight run. The only remaining issue is that the diameter of the outboard end of the drive shafts (that the sprockets sit on) is slightly narrower than the inside diameter of the Mato sprockets, resulting in a loose fit onto the drive shafts for the sprockets. Someone over on the DAK site had modified the Tamiya drive shafts to properly accept the Mato Sprockets, but I didn't see any contact info there, and I was hoping someone here might be able to help. I'm going to see if I can resolve it myself.

So - apart from my outstanding issue with the loose-fitting Mato sprockets on the modified Tamiya shafts, I've successfully mated the Mato VVSS units and Idlers to the Tamiya lower hull...........and it looks like a Sherman lower hull with VVSS. Life is good! Pictures to fSollow, as soon as I resolve a camera/computer interface issue (and I don't have a 13 year old I.T. specialist at home to help me.

Cheers,

Chris

Good Day All,

First post in a couple of years (other modelling projects and a house move). Someone on this board recommended modifying the MATO VVSS road-wheels by adding sealed bearings to each wheel (and modifying the mounting arms for each for each suspension unit). Right after reading that post, the road-wheels started to jam up and not rotate, affecting how the model moved (or didn't move)!! I finally got around to purchasing the recommended sealed bearings and just a couple of weeks ago, modified all six VVSS units accordingly. Performance is now much smoother, with the model running with jamming up. Now.....on to finishing this build!

On a related note, I'd like to replace the stock Tamiya motors with a slower RPM/smoother running set of motors - drop in replacement. Has anyone else done this and could you recommend what type of motor and a source for same?

Cheers,

Chris Preston
Victoria, BC

Hi, check out my build below for slower rpm high torque motors.
Cheers Martin

viewtopic.php?p=301375#p301375

We all get busy at times...

Keep up the work, and keep us posted of the work you have finished.

Chris Preston: I am glad you will be back at this build. So it was last mentioned in 2018; hey, my FAMO build might just take me that long, too.
I, too, am curious about slow RPM motors for a tank. I'm all for "low and slow, mean and clean." The link for the seller from which Martin bought the engines came up as a 404, but the motors to which Martin is referring and which are in photos he provides are Igarashi N2738-51. Time to consult "Dr. Google."

'Evening All,

Many Thanks for your replies to my recent post, and your words of encouragement - it helps!

I'm looking at my turret - a Nick Aguilar cast resin Firefly turret, and trying to work out how to mount the recoil unit to Nick's parts, and use Tamiya's turned aluminum 17 Pdr Barrell...........which is designed to slide into the mantle, but without provision made for recoil! My recoil unit is a stock Tamiya unit from a decommissioned Pershing I acquired from a friend, and there's room in the turret for that and the Elevation unit. I'm just tring to figure a simple way to have recoil using Nick's turret, and Tamiya's 17 Pdr Barrel and Recoil unit.

Any thoughts?

Cheers,

Chris Preston
Victoria, BC, Canada