|
Post by ProQuest on Apr 3, 2013 10:22:58 GMT -6
Hey everyone,
This question is for any of the machinists in the group.
I'm starting to play with my lathe just a little. I noticed a lot of play in the compound slide. I adjusted the gib (sp?) but there is a problem. When I rotate the handle to move the compound slide away from the headstock, the movement is smooth and tight. But when I crank the handle to move the compound slide towards the headstock the slide does not move smoothly. If I loosen the gib to adjust so that the slide is smooth when moving towards the headstock, then it is too loose when moving the other direction. To put it another way, I can't seem to get the adjustment right so that the movement of the slide moves tightly and smoothly going in both the forward and back directions -- its one or the other. I took the gib strip out and checked for burrs. I sanded it lightly to remove what I thought might be the problem, but it did not do much good.
Any suggestions???
ProQuest
|
|
|
Post by CycRunner on Apr 3, 2013 18:43:45 GMT -6
Hey everyone, This question is for any of the machinists in the group. I'm starting to play with my lathe just a little. I noticed a lot of play in the compound slide. I adjusted the gib (sp?) but there is a problem. When I rotate the handle to move the compound slide away from the headstock, the movement is smooth and tight. But when I crank the handle to move the compound slide towards the headstock the slide does not move smoothly. If I loosen the gib to adjust so that the slide is smooth when moving towards the headstock, then it is too loose when moving the other direction. To put it another way, I can't seem to get the adjustment right so that the movement of the slide moves tightly and smoothly going in both the forward and back directions -- its one or the other. I took the gib strip out and checked for burrs. I sanded it lightly to remove what I thought might be the problem, but it did not do much good. Any suggestions??? ProQuest Do you have a Harbor Freight mini lathe or similar? I have a 7"X10" and am familiar with your problem. I have been able to adjust the gibs although it is a bit tricky. I think you just have to make very small changes to get it right. Maybe BSB, who I know is a machinist, can provide some help. Good luck!
|
|
|
Post by ProQuest on Apr 4, 2013 23:29:12 GMT -6
CycRunner,
I have a MicroLux 7 x 14, made by Seig. It is basically the same machine as the HF 7 x 10. So, you think I just need to keep making fine adjustments? I'll try. Thanks,
ProQuest
|
|
|
Post by Sporty on Apr 8, 2013 18:33:12 GMT -6
The gibbs are a pain, They need more, lol.
Ya same issue, I face too. Smaller movements help, but If I have to I adjust the gibs for that range, a full in and out does not work well. Depending where you are placing at. seems the middle is the best, to muc in and the back gibb wiggles, and if to far out, the front gibb. it wiggles. So i try and set it up, so I am in the middle and if not. I re adjust the gibbs.
|
|
|
Post by ProQuest on Apr 9, 2013 15:53:57 GMT -6
Thanks Cycrunner, Sporty,
I guess that what I'm experiencing is "normal" for these import machines. I found a range of about an inch and 1/2 in the compound slide movement where everything is smooth and tight in both directions. So, I guess the trick is to position the carriage so that I'm using the smooth section of the compound.
OK, I have another question:
Lets say I am turning wheels -- does it matter which direction I cut? In other words, if I start the cut closer to the headstock and move the cutter towards the tail-stock, or vice versa, does it make any difference? I'm really curious.
Thanks,
ProQuest
|
|
|
Post by B.S.B. Racing on Apr 9, 2013 15:56:56 GMT -6
Cut toward the headstock.
|
|
|
Post by ProQuest on Apr 9, 2013 15:59:39 GMT -6
BSB,
I was hoping you'd chime in. OK, towards the headstock it is. Unfortunately, that's the direction that is less smooth, but I'll keep fine tuning and adjusting til it smooths out. Thanks,
ProQuest
|
|
|
Post by Sporty on Apr 9, 2013 22:25:45 GMT -6
I still have a hard time, but the first few weeks. was a nightmare 4 me. Until I got it going good.
I use Stan popes tooling method.
I have shared this awhile ago with picture over there. But i'll give you a bit of into.
I make mandrell with the about 1/8th of a reduced nub the size of the bore. the only part that goes into the front face of the wheel bore (spoke area) this is facing the collet.
I use collets. Then I made a piece that has a whole that is slightly larger then the back hub and it fit on and over the back hub. the end is center, dead center and has a small recess dead center whole for the point.
I cut my wheels from right to left. going towards the collet (chuck).
This worked out best for me. once I got it down. I am able to turn wheels as good as .00015. Thats the best i can do.
On average tho. I see most often .0005.
I have to re cut / sharpen the bit about every 8 wheels to stay under .001
I take .001 for the first initial cut. then I go in .002 stages up until I am doing my last two cuts. then I go .0005 for the last two. Seems to work best for me.
I have about 3 custom mandrells to fit the typical differences I find in wheel bores.
.0960 , .0965, .0970.
Sometimes or often I find I need something inbetween. So I jsut use the smaller one of the size needed, goes on a little tight, does not seem to cause any issue when bore prepping or using on the cars.
I would just sort me wheels, in batches of the size of wheel bore. That way I didnt have to change the mandrell as much.
The mandrell, I used 1/4 inch drill rod. hard and a pain to cut the end for inserting into the wheel bore. but works well for me.
I'm sure theres a wide range fo ways. Hope this helps you some.
I myself would like to see what type of shape of cutter they use for trying to cut the inside and back of the inside for making light wheels.
I have tried to make about 4 different types of cutters and all seem to not work very well. n other words. im nto very good as doing inside work.
Sporty
|
|
|
Post by CycRunner on Apr 10, 2013 1:26:48 GMT -6
Sporty , How do you measure accurately to 0.00015"? I can see 0.0005 but not 0.00015"!
|
|
|
Post by B.S.B. Racing on Apr 10, 2013 18:48:47 GMT -6
Sporty , How do you measure accurately to 0.00015"? I can see 0.0005 but not 0.00015"! It's an easy thing to get messed up with decimal points especially if you don't use them everyday. I'm sure Sporty meant maybe .0001? I am really thinking .001?? I have indicators that read .0001, but I'm sure the runout in the headstock of his lathe is a lot more than that. He stated earlier about his gibs were worn. I would think if the gibs had that much wear the spindle has some runout as well. The turned diameter will only be as good as the runout in the spindle.
|
|
|
Post by ProQuest on Apr 12, 2013 19:08:00 GMT -6
Sporty, BSB, CycRunner,
I appreciate the help. Thanks,
ProQuest
|
|