Got a question on my G0709 lathes guys. The saddle wheel has a lot of backlash in it. How do I get the backlash out. It looks like the carriage handwheel for the saddle engages the rack via a gear, I would think there is some way to take the slop out of it. Does anyone have any ideas??
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Grizzly G0709 Question
- Thread starter Mike8623
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There is more than one gear in the gear train from handle to rack. The play could be in any one of them or more likely due to a combination of play in all of them. The rack to output gear joint might be tightened by shimming the rack lower to reduce the backlash there if it is excessive, but making the other gears tight would require the major work of making new gears and/or changing the center distances between the gears. Does the backlash cause any specific problems? Using the hand wheel scale to move the carriage accurately is difficult due to each revolution of the hand wheel coming out to a weird number of distance traveled (at least on my Kent 13x40). I find it more useful to just use an indicator with a magnetic back placed on the ways and reading the carriage travel that way.
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Every manual machine has some backlash. The carriage is usually the worst. Machinists handle it by taking up the slack by feel before starting to count revolutions of the handle. Always approach each cut by turning the handle the same way, which eliminates the backlash.
If you can't live with that, then install a DRO, which will always show you the exact position of where the carriage is.
If you can't live with that, then install a DRO, which will always show you the exact position of where the carriage is.
Thanks for the response guys. There is about .060 play in it. I can see the gear move as I move the wheel. It looks like to me it is the engagement between the gear and the teeth of the rack. When I turn the wheel I can see the gear turn instantly and the slop is inbetween when the gear engages the teeth on the rack. I see no way to improve this without a new gear.
I can manually turn the handle and take the up the slack while machining before making the cut to cure it or I could use a magnetic based gauge to measure, I guess the long story is I can live with it, just thought I would fix it if I could.
I can manually turn the handle and take the up the slack while machining before making the cut to cure it or I could use a magnetic based gauge to measure, I guess the long story is I can live with it, just thought I would fix it if I could.
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I have a G0709 and have about the same back lash in the crank also. I never use the graduations on the carriage hand wheel so never had a concern. I used to use a 2" travel dial indicator on the lathe bed to control the depth of cut/boring in the Z-axis. I went with a 2-axis DRO from TPACtools.com this past summer.
Bruce
Bruce
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I am not at home now, but that sounds like about what I have.
If I need precision Z movement, I put a 1" travel indicator (with a magnetic back) on the ways, with the tip touching the cross slide. Then I can easily adjust carriage position by 0.001" if necessary. You can get magnetic backed dial indicator from MSC for $25. I also have a 2" like Bruce, but I don't use that one as often as I find it more cumbersome.
DRO is on my Christmas list.
If I need precision Z movement, I put a 1" travel indicator (with a magnetic back) on the ways, with the tip touching the cross slide. Then I can easily adjust carriage position by 0.001" if necessary. You can get magnetic backed dial indicator from MSC for $25. I also have a 2" like Bruce, but I don't use that one as often as I find it more cumbersome.
DRO is on my Christmas list.
If I understand correctly, your issue is with the carriage and not the crossfeed. Either requires taking up backlash before starting a cut so the dial indicator answers already given should be your easiest and most accurate remedy. To address how to reduce the carriage backlash...not really an easy fix I know of. Most lathes are not meant to be relatively free from backlash on this axis unless CNC driven.
Thanks guys, I guess my question has been answered. I don't do enough lathe stuff to justify a DRO and besides I don't know how to work one. I went to Gunsmith school years ago and they didn't have such items back then or at least the school didn't have them, Heck they wouldn't even let us use the power feed on the mills until our second year.
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Magnetic backed ones cost no more. You can attach it to the ways with the point touching the cross slide and accurately measure carriage travel.
I also use it for boring or internal threading. I run the carriage tip the tool is touching the end of the bore, and put the dial indicator so it shows about 90 degrees needle movement before you hit the end to give me warning of when to drop the half nut or release the carriage power feed. An easy way to avoid crashes.
Like this $16 one:
http://www.shars.com/magnetic-indicator-back-w-1-dial-indicator
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