I've tried not to be long winded here just wanted to describe what was going on before I asked the next best remedy, any and all suggestions will be gladly accepted.thanks for bearing with this. I am interested in adding some new business to my shop doing small engine cylinder boring and honeing as there are a lot of cycle and lawn shops waiting up to two weeks to have them done since the local machine shop only does small cylinders when they have enough to fill a days worth of work. I am familiar with the engine related aspects of clearances and measuring. I don't have experience machining cast iron liners though and know not to bother with nikasil ones. I have an enco13" gap bed lathe and enco mill with 5" quill plunge with r8 shank 10x54 on the table. Chatter marks and varying spirals are what I get with either machine. I have used an offset boring head in the mill with both brazed carbides and hss tool inserted and locked through type bar. On the lathe I have bolted to faceplate and bored with hss through bar type boring bar with about the same results. Even taking a light cut at 1 thou on the radius per cut still had light patterns requiring about 6 thou on the diameter worh of honing to make marks realy dissapear. Both of these though are with bars atleast 5 inches long on the junk cylinder I was test cutting and only supported on the tool holding end. I am guessing this springing is what is giving the patterns? It was suggested I use the lathe and make a bar supported at both ends with the cutter passing through the cylinder mounted to the crossslide. This seemed like a better idea being supported at both ends, but would need to be about 18 to 24" long since it would need to be twice the overall height/length of the workpiece for the cutter to pass through. Had thought of using an angle plate with a hole bored through the center would make it easy to hold the work and easy to get perpindicular to the ways and only slightly difficult to center them once the faceplate was squared. Would this give me enough support using say a 1.25 bar since some of the cylinders I would do are as small as 1.5 in maybe less? Is overall machine rigidiy a problem ? I have been told the asain machines and r8 shank just arent sturdy enough. True? I have also had my eye out for a 16 " southbend since another job I have been doing tapers on would go much nicer on it... if the supported boring bar is a better option just needing a sturdier tool. Or should I just come off the change and get a van norman or kwik way bar and be done with it? This also becomes a prob b/c van norman 944 doesn't go small enough, kwik way bars look like I would need both a fws2 and an fr model to cover the range I guess to see.
20 years ago