Handwheel Driven Leadscrew

[jcrous]

I have a Quantum 210 x 400 mm Metric Lathe with a 2.0 mm leadscrew. This lathe is very similar than the Warco 180 lathe.

I recently visited the Warco 180 lathe web page and asked the owner a question or two. One of the questions was about backlash in the Handwheel that moves the saddle left and right. I found the answers on the page of the gadget builder as his lathe is similar as well.

Andy pointed out that I will have better results if I put a handwheel on the leadscrew. I have studied the mod on this page and I wholeheartedly agree that it will be a very good mod / improvement.

My leadscrew ends exactly flush with the end of the lathe bed and my leadscrew is of right hand thread. If I add the handwheel onto the leadscrew directly, it will have to be turned anti clockwise to move the saddle left, and not clockwise as all the other handwheels. I am thinking of adding a small gear onto the leadscrew onto a small axle that I will epoxy into the leadscrew. Onto that gear will run anothe gear that will turn the laedscrew in the opposite direction if I turn the handwheel clockwise, causing the saddle to move left (towards the spindle). This way will cause the handweel's centre to be not on the leadscrew's centre but about 20 mm towards the rear. I can mount it in a movable part that can slide away to disengage when I do screwcutting or anything where I don'st want this handwheel to turn.

Is there perhaps somewhere a mod of similar design? The mod that I have seen on mike's mod page is where the owner has extended his bed a few inches and added a longer leadscrew. The new handwheel have space left on this extended bed to be mounted and can move to disengage. I do not have this space, however I may be able to fix a type of an angle plate to do this mod, mut it will extended more to the right as the first mentioned idea and will still be working the othe way around.

I will appreciate any suggestions or references to other existing mods.

[Stilldrillin]

Johan.
I don't know if you've seen this.....    http://madmodder.net/index.php/topic,7643.0.html

The best mod, after roller bearings!

The handwheel handle moves towards me. Moving the tool towards the chuck.

It feels perfectly natural after a few minutes practice! 

David D

[andyf]

It's odd that your leadscrew has a righthand thread, Johan. My lathe which is its baby brother (or cousin) has an LH thread. I can understand that it might seem strange at first to turn a leadscrew handwheel anti-clockwise to send the tool away from your hand, when the feedscrews on your cross slide and top slide do the opposite, but David D seems to have got used to it pretty quickly.

One good thing is that if you are starting work on a piece of stock and turn the handle the wrong way, that will remind you which way you should be turning it, without doing any harm because you will be pulling the tool away from the stock.

I soon got used to my dial (which is geared 12:10 to the leadscrew so I could put 100 rather than 83.333, graduations representing 0.001" each on it) turning in the opposite direction to the handwheel.

Andy

 

[Meldonmech]

Hi Johan
                I fitted a leadscrew handle to my Chester DB8, the handle operates anticlockwise, I was going to fit a gear to change the direction, but was amazed how quickly I got used to it. I no longer feel it problem, so will leave well alone.

                                                                          Cheers    David

[DavidA]

The problem appears when you have two machines.  One where you turn the wheel in the normal direction,  and one where you don't.

It is very easy to make a mistake and ruin hours of work.

Best to have them both working the same way.

Dave.