Hi All, I am new to this site. I have a Craftex CT129 with an upgraded R8 spindle. I am very much still learning. I have a question about what others may have been experiencing in terms of table accuracy. I put a 0.01mm accuracy dial indicator on (I have done from the spindle and from the base to rule out some movement) and run the table full Y direction and the table is very good. Much less than 0.01mm deviation over the whole Y travel. When I do the X axis however I see 0.09mm to 0.1mm different from left to right. That is some 3.5-4 thousandths over the maximum travel over the 11 or so inches of travel. I checked the gibs and everything to make sure it was not looseness or something. It is a very consistent and gradual increase from 0.0 mm on the left (bed all the way to the right) to 0.09-0.10mm on the right (bed all the way to the left). I measured the bed to way thickness on each end of the table and the difference is pretty much what I measure with the indicator. So it seems the bed is not ground to all that accurate a tolerance. I suspect i pretty much have to live with it and have been working around it (shimming vice with a bit aluminum foil and shimming parts I put right on bed as required). I was just curious what others are seeing with their small mills. Is this within an expected tolerance or is it way the heck out. Thank you.
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- Joined
- Oct 11, 2016
- Messages
- 4,008
More than 15 years ago I bought a busy bee knee mill and it was very good. Just sold it for an upgrade to a bigger mill. The new Busy Bee mills and lathes seem to be bought from the lowest bidder. I hope you can make it good.
What model of knee mill may I ask. In a way already wish I had bought a larger mill. Although space might be a problem.
I did get the X issue sorted. See this thread:
http://www.hobby-machinist.com/threads/g0704-accuracy-question.60622/#post-500226
I did get the X issue sorted. See this thread:
http://www.hobby-machinist.com/threads/g0704-accuracy-question.60622/#post-500226
- Joined
- Oct 11, 2016
- Messages
- 4,008
I used to own a b048 8X30 knee mill with power feed. It had 7 X 23" of travel and used a 1.5HP motor.
I now have a 9X49 First (bridgeport clone) mill made in Taiwan in 1991, needing reconditioning. I paid less for the bigger used mill than I did for the B048 mill...
I'm a big fan of buy used and rebuild it. My lathe I bought in 1982 from Busy Bee, also made in Taiwan. Now their lathes are too poorly made and too expensive to buy.
...If I had to go new there are a few select models from Grizzly I'd consider, or one (but only one) of the offerings from Modern Tool. There's better value in a used machine, if you are very picky about what you buy and wait for the right one.
I now have a 9X49 First (bridgeport clone) mill made in Taiwan in 1991, needing reconditioning. I paid less for the bigger used mill than I did for the B048 mill...
I'm a big fan of buy used and rebuild it. My lathe I bought in 1982 from Busy Bee, also made in Taiwan. Now their lathes are too poorly made and too expensive to buy.
...If I had to go new there are a few select models from Grizzly I'd consider, or one (but only one) of the offerings from Modern Tool. There's better value in a used machine, if you are very picky about what you buy and wait for the right one.