|Project by Karson||posted 04-09-2007 12:09 AM||9800 views||16 times favorited||43 comments|
I just updated this project with larger pictures. The first posting had postage stamp sized pictures.
I have posted on the LumberJocks Web site the Cradle / Glider that I made for my wife, because Grandmothers need a baby cradle also.
But, I have never posted the original that I made for my daughter. My daughter was expecting twins and I asked her if she would like a cradle. Her response was yes. We then got down to finding out her requirements and then designing something that would fit her requirements.
Since she was expecting twins, her concern would be able to have both babies asleep, one in each arm, and then be able to get them over the edge and put them into a cradle without dropping them. We discussed a drop down side that would keep her from having to raise the babies up and to go over the edge.
Then her concern was the weight of the babies and having to bend over. Both arms are full and you can’t extend your arms and place the babies gently. So we discussed the height of the mattress. It was felt that a 27” height would be great. That was the height of my kitchen table and it seemed comfortable to bend over to that height and to gently place the babies down.
I had my requirements so I started the design. To build a hanging cradle would require the swing arm to be about 50 to 65” to the top. I felt that this would be unstable and frankly ugly.
So then I thought and proposed to her to make a glider. That way all of the swinging apparatus would be under the cradle and we wouldn’t have to go high.
I have also liked the gently swing you get from a glider (more back and forth) than a rolling motion from a cradle. A previous cradle that I made had long swing arms and the movement was gently but I felt that the glider would be even more so.
I spent the better part of 2 months trying to design the swing mechanism. I was able to get some ball cup bearings that are used sometimes in garage doors and definitely in the end of tubes for conveyer belts. I also got some shoulder bolts. They are used in lawnmower wheels where you have a ½” shaft with 3/8”x16 threads. And I purchased some 3/8” “TNuts”. My intension was to make something that didn’t require any tools to put together or take apart. No nuts to loose, special bolts that couldn’t be found etc.
Since I had a glider design, I thought that a completely removable front meant that it could be used as a glider for the children after they left the cradle stage. It now became a furniture piece that had a longer life than just the 4-6 months as a cradle. So I also wanted to make something that would hold up to some weight. It’s now not just 30lbs of babies it’s a couple of rambunctious children.
A glider is working in compression mode and not in a stretch mode. A swinging glider has the weight at the bottom and it’s trying to pull the glue joints apart. A glider on the other hand is trying to compress all of the parts together even more.
Since the front would be removed all of the structural strength had to be built within the two ends, the bottom and the back. The front could not be use to make it stable. The mattress bottom was made out of Baltic Birch with curly cherry veneer and with solid cherry glued with an edge bit that allowed the cherry to go into the plywood about 5/8”. Another support board was designed for the mattress bottom on the front to keep it from sagging with any weight that might be placed on it. A modified sliding dovetail was designed that would lock the bottom into the back and the front support. The reason that I call it modified was because the back was already at an 8 deg angle with the bottom and a regular sliding dovetail would not work. The bottom is fit into dado’s cut into the center style of the end panels.
The back is attached to the ends with biscuit joints. All of the style and rail cuts were made with cabinet router bits and I then put a loose tenons into each of the joints for additional holding strength. The support for the base has two legs with a brace between them. The brace has bed hardware to lock the support into the legs.
I made a full size pattern on a sheet of plywood for the end panel, and I designed it for an 8 deg slope off of 90 deg. I made jigs to hold all of the parts at the required angle when they were routed.
The wood was curly cherry that I got at a sawmill about 5 years ago. The sawmill owner had tried to plane it smooth and because it had a curl figure he chipped it terribly. Luckily it was cut oversize and I was able to get rid of all surface checks at ¾” thick. The end panels were made with what I call Satin maple. I’ve never seen a name given to it in maple but in Beech it’s called curly beech, but it’s design is not what I’d call curly maple.
The finish is 2 coats of Danish Oil, followed with 3 coats of amber shellac, followed with 5 coats of clear shellac. It was then wet sanded with mineral oil and 600 grit sandpaper. I then French Polished the surface with additional Shellac. It was then waxed and polished after allowing 30 days for the finish to cure.
When I made this cradle I took a lot of assembly pictures, when I made the one for my wife I didn’t. So these are the only assembly pictures that I took, so I thought I’d post some of them here. I took about 80 picture but I won’t bore you with them all.
The front pieces
The end panel
Dry fitting the end, bottom and back
The back is attached with a custom designed sliding dovetail
The bottom with the extension showing
The ends bottom and back being dry fitted
Gluing the front support, back and one end
Gluing the other end on
All glued up and starting to sand.
The bearings in the end panels
The front attached and in the up position
The front attached and in the down position
The latches to hold the lower front on the cradle
The latches for the upper and bottom
The first coat of Danish Oil
The other end panel
The cradle with the two length arms Short for cradle and long for glider
Sprayed with amber shellac
Hanging to dry
The cradle in cradle mode (note no support between the legs)
The cradle with glider swing arms (note support is between legs)
The glider mode
The walnut cradle with the end dados and biscuit slots shown
The Woodhaven horizontal router table I used to cut the loose tenons slots
What it was all for Zach and Hannah.
Checking out where it was built
Zachary and Hannah almost at their 6th birthday. Sitting in the Cradle/Glider that sits proudly in their living room.
I found some replacement bearings that could be used for the hangers in this cradle FR6-2RS Sealed Ball Bearings, or FR6-ZZ Shielded Ball Bearings
The cheapest that I found is at usabearingsandbelts.com
Additions 2-12-12 Coming up to the 6th birthday of the twins.
Here’s an addition of a picture of Zachary and Hannah sitting in the Cradle/Glider that sits proudly in their living room. They have grown up into a couple of beautiful and smart children. That’s not just their grandfather making that statement. Their parents also provide that information. I was given this picture on the eve of my 70Th birthday.
-- I've been blessed with a father who liked to tinker in wood, and a wife who lets me tinker in wood. Southern Delaware firstname.lastname@example.org †