DIY Murphy Bed

[Paul Marion]

Hi all,
I'm new to the forum. I'm not a professional woodworker by any means. I do some woodworking on weekends for my household needs.
Just wanted to post a few pictures of a murphy bed I made for our spare bedroom. This bed will be used about once every two months, so didn't want to spend too much on it. It's a full queen size.
I didn't buy a kit or follow any online plans.
There's a garage door spring placed horizontally at the bottom under the bed to help with lifting/pulling down.
I used large 1-1/2" cam follower roller bearings for a pivot mechanism (ordered from Aliexpress - $20 for 2 - shipped to my door). Super smooth operation!
The bed is held in place vertically in the unit with two neodymium magnets. I also installed a plunge lock on the side for extra security.
The legs do not fold; they're bolted in place with a simple bolt and handle mechanism.
Cheers
Paul
PS: Sorry. Can't figure out how to rotate the second photo.

[Warren Lake]

dont know about Murphy beds but kinda an expert on Murphys law


M bed 1A.jpg

[Jamie Buxton]

Wow. Want to explain that garage door spring thing with a little more detail?

[Rick Potter]

Welcome to the creek Paul.

I agree with Jamie, would love to see pics of how you did the spring arrangement. A Murphy bed is on my extended list.

[Paul Marion]

I used this spring force calculator to figure out the right size: http://www.acxesspring.com/extension...culations.html
Ended up using what's considered a 180lb garage door spring.
In my first attempt, the spring was cut in half which gave about 250lbs of force at 12" of travel. That was a perfect counter-balance. After a few test runs, I wasn't comfortable with that much force so I just reattached the two halves with a ring. That gave about 120ish lbs with 12" of travel. Even though it's not a perfect counter-balance, it still helps alot.
The big drawback with my system is that, when pulling the bed down, the spring only starts to help when the bed is at about a 60 degree angle (90 degree = fully vertical; 0 degree = fully horizontal). That didn't really bother me because there isn't much weight to push/pull between 60 and 90 degrees. You could probably re-design the system and make the spring assist you all the way.
Also, I probably could have simplified the mechanism in the corners by using a pulley block. However, I had already ordered the bearings that you see (from Aliexpress - not expensive) so I just went with that.

Spring 1.jpgSpring 2.jpgSpring 3.jpg

[Paul Marion]

A few pics of the leg system. Very sturdy.
Top corners are removable and are held in place with a magnet when the bed is not in use.
The legs attach with a bolt in the middle. I glued a piece of wood to the bolt to make a handle.

Legs 1.jpgLegs 2.jpgLegs 3.jpg

[Paul Marion]

Pivot mechanism is a cam follower roller bearing. I had never heard of this type of bearing before this project.
The bearing goes through 3/4" plywood. The plywood is sandwiched by two steel washers epoxy glued to the plywood.

Cam roller bearing.jpgBearing.jpg

[Jamie Buxton]

That's a fine engineering job. Simple and effective.

[Lee DeRaud]

The big drawback with my system is that, when pulling the bed down, the spring only starts to help when the bed is at about a 60 degree angle (90 degree = fully vertical; 0 degree = fully horizontal). That didn't really bother me because there isn't much weight to push/pull between 60 and 90 degrees. You could probably re-design the system and make the spring assist you all the way.

That's not a bug, it's a feature...wish mine worked that way.

I built one back in 2000 with a kit from Rockler using pneumatic cylinders that, as you phrase it, assist all the way. When pulling it open, getting enough leverage to compress the cylinders is a bear until it gets out to 60 degrees or so and the platform's weight starts to kick in.

[Dan Rude]

I have to say a great design. Though you may never have it break, I would still put a safety cable through the springs. When used on a garage door, the bar that runs through it provides this if it breaks to the springs. These are much safer than the side springs. Otherwise, I may steel your ingenious design for my Son's bedroom, when he goes off to college. Dan