The 9x20 Mods Thread

[Bill Gruby]

Re: 9x20 tool post flex

Here it is. Thoughts please. All will be graciously accepted. One mistake, where it says Driver gear attached to Lead screw, it should say Driven Gear. The Drive Gear is at the hand wheel. Sorry for any confusion.

"Billy G"

 

[wrmiller]

Re: 9x20 tool post flex

Hey Bill,

If you don't mind, I may borrow/adapt this idea for my small lathe as it is of a similar design.

 

[Bill Gruby]

Re: 9x20 tool post flex

Use whatever you need. Mine is an adaption of one by George Thomas. It is in the "Model Engineers Workshop Manual". That one may work for you also.

"Billy G"

 

[Ulma Doctor]

Re: 9x20 tool post flex

Beautiful work,Savarin!!!
:thumbsup2:

 

[savarin]

Re: 9x20 tool post flex

Here it is. Thoughts please. All will be graciously accepted. One mistake, where it says Driver gear attached to Lead screw, it should say Driven Gear. The Drive Gear is at the hand wheel. Sorry for any confusion.

"Billy G"

Does not the gear train add to the backlash feel?

 

[chips&more]

Re: 9x20 tool post flex

Here it is. Thoughts please. All will be graciously accepted. One mistake, where it says Driver gear attached to Lead screw, it should say Driven Gear. The Drive Gear is at the hand wheel. Sorry for any confusion.

"Billy G"

Bill, the larger handwheel is to increase resolution I take it? IMHO I would entertain a planetary gear train arrangement. Not so big and awkwardly offset. It would be in line with the existing feed screw and you could design in any ratio you want, like 2:1 or maybe even 10:1…Good Luck, Dave.

 

[savarin]

Re: 9x20 tool post flex

Bill, the larger handwheel is to increase resolution I take it? IMHO I would entertain a planetary gear train arrangement. Not so big and awkwardly offset. It would be in line with the existing feed screw and you could design in any ratio you want, like 2:1 or maybe even 10:1…Good Luck, Dave.

Now thats a good idea, I'm actually playing with a dual speed focusser unit for my scope that uses that idea.
3 steel balls sitting against a smooth small dia shaft, the whole lot sitting inside a tapered hole. Turning the large shaft is a direct drive, turning the small dia shaft is the speed reduction.
I have some renderings I will try to upload if any interest.

 

[Bill Gruby]

Re: 9x20 tool post flex

Bill, the larger handwheel is to increase resolution I take it? IMHO I would entertain a planetary gear train arrangement. Not so big and awkwardly offset. It would be in line with the existing feed screw and you could design in any ratio you want, like 2:1 or maybe even 10:1…Good Luck, Dave.

The reason for the larger handle and the offset is for easier use. The resolution will not change. The gears keep it 1:1. The offset itself gets it out of the way of the cross Slide handle. The handle is way too small for my big hands. The unit is not as big as you would expect.

"Billy G"

 

[Bill Gruby]

Re: 9x20 tool post flex

Does not the gear train add to the backlash feel?

Won't know that till I try it Charles. I guess it depends on the depth of the gear mesh.

"Billy G"

 

[chips&more]

Re: 9x20 tool post flex

The reason for the larger handle and the offset is for easier use. The resolution will not change. The gears keep it 1:1. The offset itself gets it out of the way of the cross Slide handle. The handle is way too small for my big hands. The unit is not as big as you would expect.

"Billy G"

Yes the ratio would/can be 1:1, but the handwheel is much bigger making the spaces between the graduations larger. That is increasing the resolution. So you can now add another level of graduations, like tenths. That again, is increasing the resolution. Let me think more on the small handwheel with too big a hand.