M109 German Tracks
Friulmodel 1:35 Scale Track Set No. ATL-125
Review by Terry Ashley
The Diehl track uses a redesigned and larger drive sprocket than with the US T-136 track and the set gives you two replacement sprockets to use with the track. The set consists of 160 cast track links; a further 160 separate rubber pads (in metal), the four sprocket halves and two sprocket axle stubs plus the coil of 0.5mm wire for the track pins.
The links include the main link with guide tooth and the two end connectors cast in one piece with the separate lower rubber pad section that you glue together using cyanoacrylate, one notable feature of the links is most have the end connectors cast parallel with the link with about a dozen or so cast with the end connectors at an angle so they sit flat around the drive sprockets and idlers as they should. While this gives the correct ‘sit’ of the end connectors around the sprockets it means the tracks have to be assembled with the angled links in the appropriate position within the normal links and care is needed to assemble and align these correctly, more on this below.
Image showing the link with end connectors and separate rubber pad (in metal).
The assembled track links ready for assenbly.
Casting is good overall with just a few small burs needing to be trimmed from each link as well as from the drive sprockets and as the pin holes are only in the end connectors most were fully hollowed out with only about 20% needing to be drilled out. Assembly of the drive sprockets is straightforward but you must file the base of the axle stub flat or it will not glue properly inside the drive sprockets.
Use tweezers to 'feed' the wire pin into the links to avoid them bending if hitting an obstruction.
The assembled track run detail, note I have used a felt pen to mark the angled end connector links
for easier identification when fitting to the running gear.
The correct spacing of the angled end connector links for both the AFV Club and Kinetic M109A2 kits working down from the drive sprockets is 5 angled links for around the drive sprocket, 4 straight links, 1 angled link under the first road wheel, 24 straight links for the ground contact run, 1 angled link under the last road wheel, 3 straight links then 5 angled links around the idler wheels with the top run of 32 straight links. That makes a total of 75 links needed for each track run with the actual M109A2 using 76 links per track run so with only 1 link different for the metal links means they are pretty much on scale.
To fit the drive sprockets (DS) you need to cut off the moulded on axle stub and drill a 2.9mm hole for the sprocket axle stub, but the insides of the kit final drives is hollow on both kits and the DS just flops about as there is nothing to keep the axle stub aligned. You can’t just glue the DS in place as it needs to be movable to align properly with the angled end connector links, so I added an inner plastic tube to hold the axle stub in place.
I used a section of 3.5mm plastic tube with the inside diameter drilled out to 2.8mm (for a tight fit to hold the sprocket in place while still allowing it to rotate). I drilled the 3.5mm hole into the final drive housings ensuring it is perfectly centred, this will also need a small section cut out on the lower front hull plate to allow the axle stub to fit all the way, or you could shorten the metal axle stub a little? The cut-out is covered by the final drive housing so can’t be seen from the outside so isn’t a problem.
The axle stubs need to be removed and holes drilled for the metal axle stub.
With the holes drilled I glued the plastic tube in place using thicker cyanoacrylate for an instant and stronger bond than with plastic cement so I could proceed with fitting the drive sprockets without waiting for the glue to dry. Just make sure the tube is glued perfectly square with the final drive housing and inserting a smaller drill bit into the tube as you glue in place with allow you to align this correctly. The drive sprocket axle shaft then fitted very snugly holding it firmly in place with allowing the sprocket to rotate for track link alignment.
The metal drive sprockets attached to the kit final drives as per text.
The small notch needed to be cut into the lower hull plate on both the AFV Club and Kinetic kits
to fit the metal axle stub, or you could shorten the axle stub by cutting about 3mm off the end if you wished?
If you didn’t want to do this the sprockets could be glued in place with cyanoacrylate but at the same time you fit the assembled track runs to ensure the correct end connector alignment, but this does not allow any sprocket adjustment if needed?
As you will need to adjust the position of the idlers wheels on both kits I also added a 1.5mm plastic rod ‘axle’ to the idler and drilled a corresponding hole in the AFV Club idler mounting. The Kinetic idler mounting is in two halves so is hollow inside and I needed to add a larger 2.2mm plastic rod the same as for the drive sprocket axles to fit the Kinetic idler axle.
With the tracks assembled these can now be fitted to the kit suspension taking care to align the angled links properly around the drive sprockets, first and last road wheels and idlers, you will need to adjust to position of the drive sprocket to align with the end connectors and adjust the idler to get the right track tension for the proper ‘sit’ of the top track runs. One problem with using “dead” individual links to represent “live” track is they will behave (sag) like “dead’ track if not tensioned correctly, so it’s important to get the track tension right for the proper top track run sit.
Assembled tracks fitted to the Kinetic M109A2 kit.
Fitting of the drive sprockets to the target kit requires the most work as the drive sprockets must remain movable while fitting the tracks to ensure they align correctly with the track end connectors and this also means you can’t move the tracks once fitted to the running gear.
In many respects this is a much needed set of tracks for the M109A2 and later as most users other than the US Army use the German Diehl track on their vehicles.
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