[sagreen]

I'm having problems on my G0602 lathe (cnc conversion) where during a parting operation, as the parting tool gets closer to the center, the entire carriage dips and the tool tip goes under the part. I noticed that I could grab the carriage and by hand force a .010" measured deflection of the tool tip at rest. I thought, ok lets adjust the saddle plates so there is less play. It seems that Grizzly chose to not create any saddle plate adjustment setscrews, similar to other benchtop lathes, on this lathe.

Anyone else encountered and solved this problem? The lathe is almost unusable with this level of slop in the saddle.

Scott...

[Azalin]

I have the very same problem. My lathe is not the same but similar. A Siege C6.

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[atomarc]

Scott,

I don't know your machine..have never seen or worked on a small lathe like that, but find it hard to believe the manufacturing process didn't allow for some way to attach the saddle to the ways, which would be bolts, which would probably mean a way to adjust the setup. I could be wrong, but I've included a link that may or may not shed some light on your problem. Good luck.

https://www.youtube.com/watch?v=spgGXLR3gs4

Stuart

[sagreen]

Scott,

I don't know your machine..have never seen or worked on a small lathe like that, but find it hard to believe the manufacturing process didn't allow for some way to attach the saddle to the ways, which would be bolts, which would probably mean a way to adjust the setup. I could be wrong, but I've included a link that may or may not shed some light on your problem. Good luck.

https://www.youtube.com/watch?v=spgGXLR3gs4

Stuart

Thanks, yeah I've watched this video. If you fast forward this video to 1:38, Mine has the exact same plates as he has, just doesnt have the gib screws. The plate that I have looks like the one in the attached picture. It relies on that ledge to provide the offset. Its at least .01" below the bottom edge that its supposed to ride on.

Scott...

[atomarc]

I'm not 100% sure I understand what you have, and I certainly don't want to insult you, but do you not have the equipment/machinery/ability to add screws or whatever to the 'plates' you have to make them fully adjustable?

This is a HUGE stretch, but if you don't have the resources to modify the plate, which appears to be quite simple, there is a method to use a cutoff tool upside down while running the spindle backwards. This method pull the saddle upward and could help solve your problem. If your chuck is a screw on item..which it probably is, then this wouldn't work.

If you have a milling machine, modifying those plates would be very simple and would give you super-adjustability of the preload on the saddle.

Stuart

[sagreen]

I'm not 100% sure I understand what you have, and I certainly don't want to insult you, but do you not have the equipment/machinery/ability to add screws or whatever to the 'plates' you have to make them fully adjustable?

Stuart

Yeah, I have the gear required to machine the plates. The reason I made that model in fusion was to machine a new set. I just didn't want to trash the ones that I have until I understood how others have resolved this problem. Seems like a crazy design to me.

If I want to machine the existing plates, I will need to create a bit of relief on the lower side of this plate so that the ledge will bind against the under side of the way. Then add set screws to move that face off of the bottom of the way. Thats the way the ones work in the video. The stock ones dont seem to be hardened at all so milling the existing ones shouldn't be a big deal.

Scott...

[atomarc]

[QUOTE=sagreen;2501042]Yeah, I have the gear required to machine the plates. The reason I made that model in fusion was to machine a new set. I just didn't want to trash the ones that I have until I understood how others have resolved this problem. Seems like a crazy design to me.

If I want to machine the existing plates, I will need to create a bit of relief on the lower side of this plate so that the ledge will bind against the under side of the way. Then add set screws to move that face off of the bottom of the way. Thats the way the ones work in the video. The stock ones dont seem to be hardened at all so milling the existing ones shouldn't be a big deal.


Scott,

Yes...that's the drill, and it's really quite easy. Give a go and let us know how it works.

Stuart

[Turbo442]

Back when I was messing quite a bit with my G0602 (when you could buy a new G0602 for under $1000) I had some issues like you are describing. In my case I could see banding when I turned a part that matched the pitch of the lead screw. After a bit of troubleshooting I found that I could lift the back of the saddle and that ‘play’ or ‘slop’ could be seen in the finish. Like you describe I had probably .005”~.010” gap on the non adjustable gibs. If I recall the gib is bolted to the saddle with a spacer. Basically I lapped the spacer until I removed enough material to bring the gap down to .001”~.002” something like that.


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[sagreen]

Back when I was messing quite a bit with my G0602 (when you could buy a new G0602 for under $1000) I had some issues like you are describing. In my case I could see banding when I turned a part that matched the pitch of the lead screw. After a bit of troubleshooting I found that I could lift the back of the saddle and that ‘play’ or ‘slop’ could be seen in the finish. Like you describe I had probably .005”~.010” gap on the non adjustable gibs. If I recall the gib is bolted to the saddle with a spacer. Basically I lapped the spacer until I removed enough material to bring the gap down to .001”~.002” something like that.


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Thank you. Yeah, I was thinking about using an endmill in my mill and milling off that part of the plate until I get it closer to .001"~.002". If I go too far, then I just have to implement the set screws.

Scott...

[sagreen]

Ok, problem solved...

Turns out the entire problem was because there was a loose bolt holding the front plate to the saddle. You have to remove the entire top side of the carriage to get to it as it screws down from the top, under the cross slide. I was taking it all apart to mill those plates and found this bolt loose. It was less than finger tight. Effectively no plate on that side. Glad I found the problem without having to mill and add the grub screws.

Scott...

[Turbo442]

Once everything is tightened back up still try and rock the saddle around during a test cut just to be sure.


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