Lift Assist - Redesigned!

michaeltoc · Post by **michaeltoc** » Wed Feb 17, 2010 7:51 pm

I just got my lift assist today, and it's been redesigned. The upper tie bar has been eliminated and the main lift arm bracket has been extended to bear on both upper way tubes. I assume this is to eliminate the twisting problems that many have experienced. In fact, there is a supplemental instruction sheet that tells you to loosen the tubes and make sure they are fully seated, and then tighten the set screws. No mention of Nick's tip to rotate the tubes for optimal alignment.

In anticipation of the lift assist, I rotated the tubes so that the welds were both on the bottom (one was on the bottom, one was about 2:00). I didn't notice any better or worse movement of the headstock. However, I did notice that when the headstock was locked, as the carriage is moved toward the headstock there would be some resistance (not binding, just resistance). If I unlock the headstock, the carriage would move smoothly. I rotated the tubes back to the "factory" position, and the carriage moves smoothly whether or not the headstock is locked. (The tubes have been in this position for 25 years, so I guess they didn't like being moved).

I then installed the lift assist, and all is well with no twisting or racking of the tubes.

Michael

fjimp · Post by **fjimp** » Wed Feb 17, 2010 8:32 pm

michaeltoc wrote:I just got my lift assist today, and it's been redesigned. The upper tie bar has been eliminated and the main lift arm bracket has been extended to bear on both upper way tubes. I assume this is to eliminate the twisting problems that many have experienced. In fact, there is a supplemental instruction sheet that tells you to loosen the tubes and make sure they are fully seated, and then tighten the set screws. No mention of Nick's tip to rotate the tubes for optimal alignment.

In anticipation of the lift assist, I rotated the tubes so that the welds were both on the bottom (one was on the bottom, one was about 2:00). I didn't notice any better or worse movement of the headstock. However, I did notice that when the headstock was locked, as the carriage is moved toward the headstock there would be some resistance (not binding, just resistance). If I unlock the headstock, the carriage would move smoothly. I rotated the tubes back to the "factory" position, and the carriage moves smoothly whether or not the headstock is locked. (The tubes have been in this position for 25 years, so I guess they didn't like being moved).

I then installed the lift assist, and all is well with no twisting or racking of the tubes.

Michael

How about a picture of the redesigned lift? Jim

michaeltoc · Post by **michaeltoc** » Thu Feb 18, 2010 6:44 am

Pictures of the new lift assist.

dusty · Post by **dusty** » Thu Feb 18, 2010 8:07 am

Thanks Michael for those two pictures. Could I impose on you for the same at the other end.

This may mean a rebuild if I can do it. It looks like two pieces of metal, properly drilled to bring the tie points to midway between the tubes, would constitute an upgrade kit.

Mine works though so maybe this is one of those cases where "If it works, DON'T FIX IT!".

wa2crk · Post by **wa2crk** » Thu Feb 18, 2010 9:08 am

Hi Guys;
What does the original look like? The one in the pictures looks exactly like mine which is maybe why I never had the twisting problem. Is there a picture of the original design available?
Bill V

dusty · Post by **dusty** » Thu Feb 18, 2010 9:39 am

[quote="wa2crk"]Hi Guys]There are a couple photos in post #29 of the Push me Pull me Drill Press thread that shows the original lift assist.

friscomike · Post by **friscomike** » Thu Feb 18, 2010 9:55 am

Howdy,

Thanks Michael. The redesign looks good. I like it.

Are the lift assist arm and upper brace made of aluminum or steel? I'm up at the house and don't fancy a walk down to the shop to check, yet... I'm wondering if I couldn't improve the old design by simply adding a steel/aluminum strap across the way tubes and connecting the free side of the brace to the strap. I could weld it or bolt it in place.

Best,
mike

fjimp · Post by **fjimp** » Thu Feb 18, 2010 10:18 am

Thank you Michael I appreciate the pictures. I do like the heft in the redesigned version. Yet as well as both of mine work I seriously doubt I will make any changes. Jim

michaeltoc · Post by **michaeltoc** » Thu Feb 18, 2010 11:38 am

dusty wrote:Thanks Michael for those two pictures. Could I impose on you for the same at the other end.

By "the other end", I assume you mean the lower bench tube end? If so, it is identical to the original.

All parts are exactly the same, except that the main lift bar has been extended to stretch across both upper way tubes, and longer bolts are used to attach the front brackets. The lift arm is not centered between the tubes, but offset towards the back as in the original design. The upper tie bar has been eliminated, as it is no longer needed. The lower assembly has not changed from the original design.

dusty · Post by **dusty** » Thu Feb 18, 2010 12:05 pm

michaeltoc wrote:By "the other end", I assume you mean the lower bench tube end? If so, it is identical to the original.

All parts are exactly the same, except that the main lift bar has been extended to stretch across both upper way tubes, and longer bolts are used to attach the front brackets. The lift arm is not centered between the tubes, but offset towards the back as in the original design. The upper tie bar has been eliminated, as it is no longer needed. The lower assembly has not changed from the original design.

Thank you again, Michael. Your final explanation changes my vision of the redesign completely. It appears that all that has been done is the stress that originally was applied to only the rear way tube is now distributed by that bar which goes between the way tubes.

I thought that what was being done was a centering of the lift bar between the ways.

The same effect could be accomplished by simply adding a bar beneath the existing 'half bar'. Longer bolts would probably be required.

As said before, no value in doing this unless ones lift is not working correctly.

Wonder why they didn't center the lift bar as long as they were making this change. One will never know without seeing the stress analysis.

This sorta indicates to me that rotating the tubes was a theory.

[ATTACH]7943[/ATTACH]

The piece that is shaded darker would be an addon and a matching piece would have to be installed at the other end of the lift tube to maintain relationship.