[neptunier]

hello all,

shortly i machined a gang block for turning on the lathe. i want to machine motocycle handles in aluminium, 150mm long, 40mm diameter. unfortunately i get a lot of instability in the part when getting aaway from the spindle since the part is not supported with a tailstock. the first 50mm are fine, then it starts with bad surface and chatter. i was going very slow with the feedrates.

i was thinking of making a kind of tailstock that could be clamped to the z axis and would support the part with an m8 screw from the bottom. i dont need best precision, but it should machine smoothely.

i sketched a tailstock in fusion. since i am not so experienced with this stuff i wanted to ask whether this could be a solution? would this prevent chatter? i would machine this part out of steel, 15mm thick. the total length would be like 300mm.
sorry the first 3 pictures are turned 90° to the left. linux behaves sometimes strange ,-)

thanks for any help,

have a good new year 2017,
michael

[neptunier]

i would really appreciate some help on this topic. i added more detail to the model, maybe it is now clearer. there would be no need to adjust the lenght of the tailstock, an the stock would be 150mm ( about 5") long, 40mm (1,75") diameter.

thanks for your input,
michael

[InMesh]

Unsupported work will almost always chatter to a certain degree ,you could use a kind of sacrificial cup at the end ,in the past I have made a few different shapes that have a small bearing in the opposite end then turned a shape to fit the work piece .Made out of nylon delrin usually even hard wood I remember good luck .

[neptunier]

hello,
i just finished the tailsock for millturn, and it works :banana: it is made from steel, with a bearing in which the center tip is. there is a little chatter because the tool is sticking out too much. if i press my finger on it it is more quiet. if you like to see, here is a little video: https://www.dropbox.com/s/038o29h1td...turn1.mp4?dl=0

i am using msm millturn, the tool change also works.
here are some photos, sorry for the wrong direction, my linux does not want as i want it to.

michael