Andrew Hutchinson
Pizza Cutters IMG_4558
This set was made with the Proto:160 form tool shown elsewhere . Doing them to P:160 with the P:120 form tool meant a lot of extra moves and hand work. Since I 've no intention of using the Kato drive ( Kato based designs use 1mm axles where as I'm using .0625" O-1) I decided to cheap out on the wheels I make for my test mules. They're made out of a stringy hot-rolled steel and neither face is trepanned to form. The treads are .250" and on my machine they really need a lower surface speed than I turned this material at. To get around this the lathe was shut off while the form tool finished up its travel. On this set I didn't even sink the bore with a D bit, just drilled it .037 from my "A" chuck without any efforts to offset it back onto the lathe's centreline. Pecking helped. In the end it seemed to work well enough - at least as well as the gear muffs would allow and in practice it traverses my hand-laid work. Atlas code 55 was another story. The pieces I had were over gauge (that's safe from a production standpoint) but where the track went over a scale inch out the flanges became hyper sensitive to vertical deflections. Running at full speed and reversing over these spots would jump the rails as would accelerating from a standing start without launch control. It was funny - the lights would go out, the wheels would spin then grip and then drive right over the rails before spinning some more having cleared only a quarter inch or so. Clearly a software problem! In the quest for increased road-holding one of the two pins that retain the phosphor-bronze pickup beams was shaved off giving the axles the ability to rotate a little bit relative to one another. They travel in an arc which can lead to excessive steering at the extremes of travel but that's the price you pay with fixed point rigid beams. The bigger problem is the lack of secondary suspension. I have no answer for that where the Kato is concerned and it is the reason I'm doing what I can to go a different route. The upside is that I get to learn new and exciting things and I get to keep more of my own modelling in-house. Vimeo videos of the unit running can be seen on my channel here: vimeo.com/91331482
Pizza Cutters IMG_4558
This set was made with the Proto:160 form tool shown elsewhere . Doing them to P:160 with the P:120 form tool meant a lot of extra moves and hand work. Since I 've no intention of using the Kato drive ( Kato based designs use 1mm axles where as I'm using .0625" O-1) I decided to cheap out on the wheels I make for my test mules. They're made out of a stringy hot-rolled steel and neither face is trepanned to form. The treads are .250" and on my machine they really need a lower surface speed than I turned this material at. To get around this the lathe was shut off while the form tool finished up its travel. On this set I didn't even sink the bore with a D bit, just drilled it .037 from my "A" chuck without any efforts to offset it back onto the lathe's centreline. Pecking helped. In the end it seemed to work well enough - at least as well as the gear muffs would allow and in practice it traverses my hand-laid work. Atlas code 55 was another story. The pieces I had were over gauge (that's safe from a production standpoint) but where the track went over a scale inch out the flanges became hyper sensitive to vertical deflections. Running at full speed and reversing over these spots would jump the rails as would accelerating from a standing start without launch control. It was funny - the lights would go out, the wheels would spin then grip and then drive right over the rails before spinning some more having cleared only a quarter inch or so. Clearly a software problem! In the quest for increased road-holding one of the two pins that retain the phosphor-bronze pickup beams was shaved off giving the axles the ability to rotate a little bit relative to one another. They travel in an arc which can lead to excessive steering at the extremes of travel but that's the price you pay with fixed point rigid beams. The bigger problem is the lack of secondary suspension. I have no answer for that where the Kato is concerned and it is the reason I'm doing what I can to go a different route. The upside is that I get to learn new and exciting things and I get to keep more of my own modelling in-house. Vimeo videos of the unit running can be seen on my channel here: vimeo.com/91331482