Shaft Extension for Door Latch

[Don52]

My customer made a custom door, which was considerably thicker than a standard door. This meant that standard door knob hardware would be too short to reach through the door. Door knob extension kits are available, but these were also too short. To solve the problem my customer purchased a second door knob assembly so that he could scavenge the two shaft parts that were required. The task was to weld an extension to the outer piece that looked like half of a pipe. The inner piece appeared to be made of pot metal and I was reluctant to attempt to weld it. I know that Muggy Weld makes a Super Alloy 1 product that can weld pot metal, but a kit costs $105. My customer and I decided to machine a sleeve to extend the shaft, which would be glued on using Loctite 680. The first picture shows the drawing and the parts that my customer provided.

1. Drawing and parts


I was concerned that the sleeve would interfere with the numbs on the ID of the shaft so I ground them off.

2. Grinding off nubs


I like to remove the plating before I machine plated metal to avoid smearing the plating on the area to be welded, because the plating will cause porosity in the welds.

3. Etch off plating in HCL


4. Plating removed


The first machining task was to remove the radius on the end of the shaft in preparation for welding.

5. Squaring off one end

[Don52]

Next, I trimmed the end of the outer extension shaft.

6. Trimming off the other end


Below are the machining tasks that were performed on the inner shaft.

7. Facing end


8. Center drilling


9. Turning OD


10. Nice coil chip

[Don52]

Here are some additional tasks for the inner shaft.

11. Parting shaft


12. Drilling shaft


13. Reaming shaft


Next, I sanded off the mill scale in preparation for welding.

14. Grinding off mill scale


Now I was finally ready for welding.

15. Setup for welding

[Don52]

Now the welding steps:

16. Ready to tack weld corner


17. Welded out


18. Close up of weld


I didn’t want to penetrate on the inside, because it would interfere with the inner shaft.

19. Inside of weld



The next step was assembling the inner shaft with 680 Loctite.

20. Sleeve Loctited

[Don52]

Here is the painted shaft.

21. All done and painted


And here is the whole latch assembled.

22. All done and painted


-Don

[walker]

I just use Schlage locks, they can do up to 2” without doing anything. Extension kits are about 15 bucks.

[Don52]

I just use Schlage locks, they can do up to 2” without doing anything. Extension kits are about 15 bucks.

The door is about 4” thick, I couldn’t find any extension kits that would accommodate this.
The extension kits that I could find only extend only the center shaft not the outer one.
Normally this is ok assuming that you want the door strike on the outside of the jam, which would be lined up with the outside of the door.
In this case the door has 1 x 4 trim on the outside so the latch needs to be installed deeper in the door.
As a result the outer shaft needs to be lengthened as well, so that the latch can engage with the outer shaft.
I do agree with you that an extension kit would have been a good solution, if it would work in this application.
Thanks for mentioning this solution.

-Don

[VaughnT]

Beautiful work!

[farmersammm]

If you weld the key in, you'll never lose it

[Capt B]

Well done!

[John T]

Nice work Don

good thing you are retired....

[Redlands Okie]

Darn nice work. Just keep in mind a good locksmith shop or door hardware supply vender can provide knobs for such problems. Got to pass up the box store stuff. Being to provide it in the style the customer wanted? On time ? Probably not, and thats when skills such as yours become so handy. Once again impressive work.

[albrightree]

Nice job, and a really good job on the documentation. I really like that third hand you have there. Ground clamp, ground strap, adjustable, and bronze feet. Where did you buy that ? I could certainly use one in my shop.

Thanks for sharing

[Don52]

Nice job, and a really good job on the documentation. I really like that third hand you have there. Ground clamp, ground strap, adjustable, and bronze feet. Where did you buy that ? I could certainly use one in my shop.

Thanks for sharing

This one is from Strong Hand Tool. I liked it because as you noticed it has the ground strap (work lead) on it.

https://www.amazon.com/Stronghand-To.../dp/B01DL9Y7ZU

-Don

[Mikel_24]

If I ever need to make a living on my welding skills... I want every random customer to provide parts and drawings like yours! Beautiful work!

[geezer]

You obviously have the patience of Job and great attention to detail. Nice work

[smithdoor]

Looks great.
I had do that a few times myself.

Dave

My customer made a custom door, which was considerably thicker than a standard door. This meant that standard door knob hardware would be too short to reach through the door. Door knob extension kits are available, but these were also too short. To solve the problem my customer purchased a second door knob assembly so that he could scavenge the two shaft parts that were required. The task was to weld an extension to the outer piece that looked like half of a pipe. The inner piece appeared to be made of pot metal and I was reluctant to attempt to weld it. I know that Muggy Weld makes a Super Alloy 1 product that can weld pot metal, but a kit costs $105. My customer and I decided to machine a sleeve to extend the shaft, which would be glued on using Loctite 680. The first picture shows the drawing and the parts that my customer provided.

1. Drawing and parts


I was concerned that the sleeve would interfere with the numbs on the ID of the shaft so I ground them off.

2. Grinding off nubs


I like to remove the plating before I machine plated metal to avoid smearing the plating on the area to be welded, because the plating will cause porosity in the welds.

3. Etch off plating in HCL


4. Plating removed


The first machining task was to remove the radius on the end of the shaft in preparation for welding.

5. Squaring off one end

[Lis2323]

Nice work, Don! . Not that any of us are surprised lol.


Sent from my iPad using Tapatalk

[Bob]

Very nice work but your buddy bought the wrong lock set. I too built my own outside doors and had to do the same exact thing. Some locksets use a square rod instead of that rounded one. I used key way stock the same size as the square rod in my lockset. I just had to thread each end. My door was about 3" thick. Oh, don't forget that you will also have to make a new strike plate with the little square hole in it.

[Don52]

Very nice work but your buddy bought the wrong lock set. I too built my own outside doors and had to do the same exact thing. Some locksets use a square rod instead of that rounded one. I used key way stock the same size as the square rod in my lockset. I just had to thread each end. My door was about 3" thick. Oh, don't forget that you will also have to make a new strike plate with the little square hole in it.

Nice looking door and hardware.

-Don

[NotaVegetarian]

Wow very nice. That’s a great idea and write up.

[farmersammm]

wrong thread