You can choose the size of nickel silver bolster for mounting the BullAnt to your model. There are three types of bolster, a cross mounting and an end mounting, and you can order any type as swiveling or fixed. There are, in addition, three sizes for each bolster.
The plain bolsters on the left are the cross mounting versions and the 3 on the right are the end or cantilever mount versions. The cross bolsters have had the side fold removed to make it simpler to mount the BullAnt, but the end mounts retain the folds. The mounting holes are all 2.0mm diameter and the spacing between the two holes on the end mount versions is 3.5mm. The mounting hole centres for the 20, 26 and 32mm cross mounts are respectively 17, 23 and 29mm. The distance from the bogie mounting hole to the centre line of the end mounts for the 26, 32 and 38mm end mounts are respectively 22.9, 28.9 and 34.9mm.
The 26mm end mount is suitable for BullAnts with wheelbases up to 38mm, the 36mm mount suits wheelbases up to 46mm and the 38mm suits wheelbases up to 50mm. The next photo shows how this mount might be used.
You also have the option of having the bolster swivelling, which would be the normal case, so the bogie can rotate in the model, or fixed. The fixed option has the bolster attached (soldered) to the spine section so it does not rotate. This option is quite often used where the unit is fitted to a fixed wheelbase model. Note that each bolster option has the choice of swivelling or fixed.
Some modellers will prefer to have extra fixed bolsters to make the attachment to their model easier. If this is the case, please leave us a note in the comments section of the order.
Bat Wing mounts have a wider spread at the ends, with 2mm diameter holes placed 11.5mm apart. They are otherwise the same length as the standard 20, 26 and 32mm mounts, and the hole centres are the same, at 17mm for the 20mm mount, 23 for the 26 and 29 for the 32.
The total width of the widened section is 15.5mm. The Bat Wings will restrict rotation of the bogie slightly, but should not affect the rotation for all but the most extreme angles.