# Lathe Spindle Brake



## PT. Johansen (Jul 23, 2015)

I just managed to complete another small project in my ongoing quest to add functionality to my lathe.
I hope this posting might inspire someone else to have a go, to improve or modify to their liking. Much in the same way this forum have inspired, or solved many of my own predicaments.
Let me first make clear that 10 months ago I had never used a lathe for anything, nor did I own one.
I have always been a builder/maker/tinker/woodworker, and have had a desire to delve into the machinist’s field, but I never got round to it.  10 months ago I decided to give myself an early birthday present in the form of a lathe. Here the story begins

*Motivation:*
I do not own a mill, and occasionally I use the lathe for indexing. To get around the issue of the workpiece rotating, I needed a reliable way of keeping the chuck locked. This is where a chuck brake would normally be used. However my lathe doesn’t have any, nor can I prevent the spindle rotation in any other way.  My late is a generic 10x22 Chinese import. It just happens to bear the Weiss brand name, but it’s nearly identical to various other brands (Grizzly, Warco and PM). The described brake design could be applied directly to any of these if anyone fancies.

*Design & considerations:*
The main aim is to ensure no spindle movement while performing other machining operations.  It is not meant to assist in stopping the chuck while rotating.

While researching and evaluating what had been done before, I came to the conclusion that I wanted to apply the braking power to the spindle itself.
With such an approach I could avoid any slack, slop or backlash in connected components. It was imperative not to put any load on the spindle bearings while braking was active.

I also wanted a system that should be fixed on the lathe at all times, and did not interfere with normal lathe work. Lastly it should be cheap and very functional, as I haven’t recently sold any valuable multibillion IT company.
As It is beyond my current skill level to machine an entire brake system, I needed to find usable components more or less off the shelf. I ended up adopting components from a bicycle diskbrake system.
If such a system can stop a 100kg gorilla going 40 km/h downhill on a bicycle, it should be able to hold a 5” chuck. Admittedly the use of bike parts was partly inspired by CrisB257 on youtube, but I did not want to copy the design completely.

*Solution*
With the specifications done, the remaining task was to find somewhere to place a brakedisk. This actually took quite some time to figure out, but now it seems simple enough.
On the back of the spindle after the drive pulley is a gear, (part of the leadscrew gearing) after this, a few spacer bushings. I figured that it would be possible to remake the largest spacer, to include brakedisk.


The new brakedisk spacer should look something like this


And this is how it assembles on the spindle.



Next picture show an overview of the complete design: Green designates parts that need fabrication.



Topic will continue in next post.


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## PT. Johansen (Jul 23, 2015)

*Non fabricated components.
*
Mechanical brake caliper BR-M375. ~20$




Brake wire with sleeve. End termination type is more or less irrelevant.  5-10$


Push/pull toggle clamp 5-10$



*Reality check.*
All together it ended up looking like this.
I decided to use a toggle clamp for activation of the brake as they are “selflocking” at end positions.







Small details are yet to be done, but it is working as intended.
The brake holds the chuck in place, even if I try to force the chuck with the chuckkey.


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## brino (Jul 23, 2015)

Welcome to the site!

Excellent write-up! Great use of photos and drawings.
Great descriptions. It's the whole package! 

I really appreciate the post, and the effort it took to organize it and share it.
I am now looking forward to more! 

-brino


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## Firestopper (Jul 23, 2015)

Nicely done PT, I don't always use the lathe brake, but when I do it's nice to have. One instance I recall was torquing the ring gear bolts on the carrier for a third member. Had no real way to secure the part otherwise.
Thanks for sharing.


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## PT. Johansen (Jul 23, 2015)

If anyone has even the slightest interest in this project, here is my design sketchup file. Feel free to use it in any way you like. 
Drawing dimensions will probably not apply to any other lathe than mine, or simmilar, but at least it is a place to start. It's also a way to take the design apart and consider improvements


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## PT. Johansen (Jul 23, 2015)

brino said:


> Welcome to the site!
> 
> I am now looking forward to more!
> 
> -brino





Thank you,I have been sneaking round for a while.
I suppose I should probably make something similar for my stepper motor spindle indexer, but dont hold your breath 
The rest of what I have done is only tiny improvements, especially when I see what people on this site are capable of.

I have actually posted another project, but not on this site http://madmodder.net/index.php/topic,10655.0.html
Even though I have made other, more complex projects, this lathe light is in use every time I’m in front of the lathe.
It's not always the stuff that takes the greatest effort that is the most useful.


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## janger (Jan 2, 2023)

What happens if you accidentally turn the lathe on while the brake is engaged? Good project. Thanks. -J


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## tq60 (Jan 3, 2023)

Easy to add an interlock.

If you have push button motor control then the control is low voltage, low current.

Simple adding a switch connected to the lever that opens when active.

Inside locate the wires from the STOP button, disconnect one and add new wires from there to brake interlock, brake switch in series with STOP switch should work.

Unplug lathe then Lift one wire and make sure it is not touching anything.

Plug lathe in and try to run it, if it starts then you need to lift wire from run switch.

Sent from my SM-G781V using Tapatalk


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## rwm (Jan 3, 2023)

Nice work. I am curious if that brake could also be used to stop the motor in an emergency? Is the bike brake strong enough? Would the motor pulley slip in that event? I was considering putting a bike brake or snowmobile brake on my lathe motor pulley as a safety.


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## great white (Jan 3, 2023)

rwm said:


> Nice work. I am curious if that brake could also be used to stop the motor in an emergency? Is the bike brake strong enough? Would the motor pulley slip in that event? I was considering putting a bike brake or snowmobile brake on my lathe motor pulley as a safety.


be cautious if you have a thread on chuck. I've had a spindle stop dead on it's own (electrical fault) and the chuck unscrewed itself and went flying!

Sudden stops with screw on chucks = bad!


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## rwm (Jan 3, 2023)

Good point. I have a D1-3 on my Southbend


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