So now the project is complete.
The mattress needs to be height adjustable. With this design there are 3 heights available. High, low and floor.
The frame is made of 3/4×3/4 ” 14 gauge steel tubing. It is sized to fit about 3/4″ inside of the wood frame.
The frame is supported at the corners, however the screw and nut locations would collide with the sides. So I used buried nuts welded into the end rail pieces prior to assembly. To do this the holes are drilled (#7) and tapped (1/4-20 ) 3/4″ from each end. A sacrificial bolt is inserted and a nut is placed on it finger tight. The nuts are then welded in place. I used a MIG welder. However the day was windy and my skills rusty after the long winter so they are not the prettiest of welds. (so feel free to pick on my weld quality)
I have often used this technique for buried fasteners when bolting through relatively thin stock like this or for beds where the nut plates are buried in the wood legs.
The holes for the webbing were then drilled in the sides. It is much easier to do this while the frame is still in pieces. I always make a list of the hole distances prior to marking and drilling. This is easy in a spreadsheet and minimizes the chances for an error half way through and the piece ending up looking like swiss cheese. I will use #8 x1/2″ hex head self tapping sheet metal screws. The holes are 9/64″ or #28 drill.
The frame was then welded up, welds ground flush, flap disk sanded (120 grit) primed and painted.
The webbing is 2″ light polypropylene webbing. I ordered a 150 foot roll and used most of it.
When securing the second end the triangle tip should hang over the side by about 1/2″. Now you start the screw through the webbing. Next you use a nut driver or impact driver and hex bit to lever the screw over after catching the tip in the hole. This adds just the right tension. Use hex head screws, I can’t imagine how frustrating this would be with just a straight screwdriver. The long straps are tighter than the sides and installed first as I did not want to bow in the sides
The frame is hung from these small pieces. They make the hole spacing forgiving and provide access to the screws that are otherwise hidden mostly by the frame. 1/4″ long spacers are placed between the straps and frame. These were made on the 3D printer, although you could also pay the price at the hardware store.
Now ready for delivery. Gap around the mattress is one finger thickness – just about perfect.
The curved end rails made for some interesting routing for the mortises. The slats were inserted into the bottom rail mortises and aligned behind each of the mortises. Then pieces of blue masking tape were used to mark the length to the bottom of the rail and the angle. An additional 1/2 inch was added to arrive at the final length.
The router was set up with a fence to guide the cuts and keep them centered. However the direction of the plunge for the mortise is perpendicular to the bottom edge at that point. The ends of the mortises are then not parallel with the slat edges. There are then 2 options:
Chisel the ends to be parallel with the slat ends. This is very hard with a small gouge in the Oak.
Bevel the edge of the slat to approximate the angle of the slot end. This is FAR easier.
Below you can see the end rail and one of the slats. The slot nearest the slat has some small burn marks, so you can see the direction of the plunge. The end of the slat has been trimmed to length and the right end beveled to roughly match the mortise end.
One final test fit with all of the slats in place.
Next step was rounding and beveling of the edges of the legs and rails.
Now on to the finishing.
Completing the rails
Today’s tasks included completing the front and back top rails and making the bottom plates that fasten the ends to the front and back .
The top rails needed to be transformed into the sleek shapes in the drawing. This meant making the under-hanging lip, adding it to the rail and the generating the sweeping curve of the rail top.
The underhanging lip is a 1/2″ thick semicircular segment which is then glued to the rest of the top rail. To safely and accurately make a shape like this you must start out with a larger piece, shape the edge and then rip it off. Below you can see the stock being run through on the router table with a 1/2″ radius round over bit. The fence is set flush with the front edge of the router bearing. The fence is needed as the bearing of the router bit will not be landing on un-cut stock and it provides the needed support for the cutting depth. The feather boards help to both guide the stock and keep my fingers clear of the spinning router bit.
This profile was the glued on to the top rail. You can see it as the bulge in the lower left of the rail as seen below. The drawing of the rail end was the printed out square with the end and with no perspective in Sketchup. This was then printed life size (which took several tries). The print out was the cut out and placed over the ends of the rails and the outline traced with a sharpie.
The corners and excess were then saw off on the bandsaw and table saw. At this point the goal is to have a rough approximation of the curve which is ready for hand shaping. The bandsaw with the table tilted offers a safer alternative to the table saw when there is a small land / support area under the base of the stock and the cut has no support directly underneath it. Be careful here, greater overhang under the cut can fling the stock or break the blade if you lose control. In retrospect a feather board behind the blade would have been a good idea here.
Now comes the exercise part. There was a LOT of hand planing required to get to the final profile. Remember this is Oak. It took just over an hour to plane the rails and another 1/2 hour of sanding and touch up planing. I started with a #6 plane set for a fairly aggressive cut. The shavings piled up quickly and my heart rate rose as well. I think I was excused from skipping my usual workout on the elliptical (the shirt did not stay on long after this photo).
When planing a curve like this, you start out with the facets cut on the saws approximating the curve. With the plane, you basically bisect each facet, adding new ones and incrementally going from a rough set of angular faces to an ever better approximation of the curve. The sound of the plane and touch of your fingers guides where to make each cut, angling each one differently than the prior one. After planing, then the sanding starts with 80 grit cloth backed paper on a long stick.
The next step was to start cutting the brackets which hold the end pieces to the legs. I wanted to minimize the visible hardware on the final bed, sacrificing a bit on having more hardware showing on the crib. The ends are held on with 12 gauge steel plate brackets (about 0.1″ thick) . The brackets are cut out with the plasma cutter (much more fun than a saw).
The brackets are then drilled to 1/4″ for the screws and then the locations are marked with a transfer punch. The holes are drilled and brass threaded inserts are screwed into the wood. Below you can see the frame with the bottom bakets in place and ready to start making the top end brackets.
What will become the headboard of the bed is the tall / wall side of the crib. This week we have sanded all of the legs and rails and spindles.
The headboard has three flat panels. They are glued up from two 5mm (not quite 1/4″) thick sheets of oak veneer plywood. The front facing side has the same quarter sawn white oak veneer as the dressers and the back side is rotary cut white oak . I did change form 2 panels to 3 to accommodate the size of the plywood off cuts from the dressers and in the end, I do think it looks better with 3 than with 2.
The panels were glued together with TiteBond Cold Press veneer glue and placed in the vacuum press to cure. Vacuum time was 1.5 hours. They were then left in the bag for another 3 hours and then removed and placed on stickers to dry further. This is critical. If you simply take the pieces out and lay them on a flat surface they will cup badly due to the moisture leaving faster via the uncovered top.
The top rail assembly for the back was similar to the front with the dado (facing right) cut prior to assembly.
The Workmate is the handiest way to hold an assembly like this. The top and bottom rails are placed first and the gap measured (at least twice) and then the length including depth of the dadoes is added prior to cutting all of the pieces to length. The dividers have tenons on the end and dadoes on the sides, so the panels are retained all around. The end gaps are 2″ to conform to safety standards.
Next comes test assembly of the footboard and shaping of the top rails
Return to the shop
The last few weeks were taken up with vacation and conferences. So there has been no progress on the crib. Teal and I had brought in the last of the wood from the shed, but it was not thick enough for this project and has to wait for another project. This was the last of the Wisconsin Woodworker’s Guild Logfest hauls that I had set up to air dry. At its peak, it was over 1300 board foot of lumber, which has now been reconstituted into many pieces of furniture for the family and friends.
So yesterday we set off for Kettle Moraine Hardwoods which is our local lumber mill. They had a nice selection of thick Red Oak (5/4 and 8/4 – 1.25-2″ thick) and we picked up some Hard Maple and an Elm slab for future projects, as well.
Once home, it was time to surface the boards on the jointer and planer and then cut them to rough length in preparation for sending them to the CNC router. At this point, there was a minor design change as the thick stock for the legs was completely cleaned up at 1.86″ vs the 1.5″ I had in the design. So we decided to go with thicker legs. However, this leads to more work as I did not have a router bit that would cut deep enough, which will be detailed later below.
I fired up the computer for the CNC router and some problems arose. I had not used it for ~2 months and only had the windows 10 logo showing for 45 min. At this point, I rebooted again and it came up in a few minutes. However, Mach 4 which is the CNC controller software for the router had a whole series of errors when starting, and was unusable. Most of the plugins would not work. So I restored it from the backup copy, restarted the PC again and it started to work. However, in testing, many of the configuration parameters were missing including “little things” like the home switches and control for the spindle. Digging through my notes for the configuration values, I got it running again. Now, thoroughly annoyed, it was time for a reward of our home brew Imperial Stout which is now ready for consumption.
After re-zeroing the CNC router it was time to set up the first part and make a test run. The crib end top rails were chosen as they are the smallest parts and least costly in case of problems. The 8/4 stock for the leg pieces was over $150. Making wach leg approximately $35-50, so I was not going to try those first.
So the stock is clamped on the CNC router and you can see my “cheat sheet” where I have printed out the outline and marked the distances from the near end for the various clamps.
Next you can see the cut under way. At this point I have left off the dust shoe, so there are chips EVERYWHERE.
Now the top rail is completed and vacuumed off.
Another shot in progress, looking down with the dust shoe in place.
With the top rails successfully completed, now I move on to making the legs. One of the front legs being cut. In order to prevent the part moving I used not only the 5 clamps shown but also some small strips of double stick tape which help reduce the part sliding under load immensely. With this CNC router, the limitation on cutting speed is not the machine, but the ability to clamp the work and avoid it slipping under the cutting forces. Cutting speed was 100 inches per minute, 18,000 RPM at 1/4″ depth of cut with a 1/2″ 2 flute carbide end mill.
Set up for one of the rear legs – 43″, 110 cm long. Not your ordinary tabletop CNC router. . Note the beautiful curl figure in the stock. Later, you will see how I make this “pop” when finishing.
The other back leg ready to cut
This is why I use wooden clamps. Just a minor nick this time. These are shop made on the CNC router.
Another look at the scale of these cuts and the finish off the CNC router. This was without a reverse last pass as I don’t (yet) have a router bit long enough to do so and that would look even better.
Here are the legs off the CNC router. As you can see I was not able to cut all of the way through. The depth of cut was limited to 1.5″ based on my largest end mill / router bit. So now they need to be run through the band saws and then flush trim routed. The end curves are too tight for my big band saw (24″ with 1/2″ resaw blade ) and need to be run through my small one (12″ with 1/4″ skip tooth blade).
Bandsawing the excess off the legs on the 24″ band saw.
Flush trimming off the excess. The holdfast works great to clamp irregular stock like this. Teal also assisted in taming the work. The Oak is a bit unruly. I often had to reverse directions to minimize tear out. This means taking climb cuts which try to throw the work and router around.
First dry fit test. Not bad. The cross pieces will be flush with the upper / inside edges of the legs in the final assembly.
The CNC router made this work feasible in a few hours. Otherwise I would have had to make templates, band saw to size and flush trim through several steps. I had done a similar project with curved legs – Elyse’s Sleigh Bed. This is MUCH easier and with less chip out to fix.
Movies of the CNC router at work
The first part is without the dust shoe (chips Everywhere) and the second part is with the dust shoe in place (much neater) .
Now that we have a starting point for the design, it is time to start gathering dimensions from the photos. Traditionally, I have done this by printing photos at half or full sheet and then scaling it manually. My goal when borrowing from an existing design is not an exact replica but rather using the original as a model to start for overall proportions. I am not into doing reproductions. Additionally, in this case I am making improvements in the design.
First, I will note the major known dimensions. In this case it is overall height width and depth. This is done on each photo. Do not assume (or forget) that the scaling will be different in each image. Next the actual size in the photo for these is measured and the scaling amount calculated. I will normally do the actual measurements in mm to make the math easier (avoiding fractions). You can use a caliper or ruler – I like using a caliper.
I double check that the X&Y dimensions yield similar results. If all you have is an angled or isometric view then this gets more complicated. Now I take measurements of measured features and do the math in a spreadsheet so I have a listing of my measurements and can easily double check for errors in case of a conflict. I will also do the actual photo measurements in one color and the final scaled in another to avoid mix-ups
I will typically start on paper and make sure that the dimensions make some sense before transferring to Sketchup.
You can also import a photo into sketchup and then start drawing your components on top of it. For rectilinear pieces it is better to use it to set a few lines and then draw as you normally would. Trying to match the photo underneath will otherwise lead to errors and out of parallel edges.
Here I have started with the curved end pieces. With the rudimentary curve drawing tools in Sketchup (arcs, lines and bezier curves) it took a lot of tries to get something that looked decent. I wish I could have gotten the NURBS lines to work which offer much more control. At this point I will lay down a couple of lines to mark the lower rails and then hide the photo. So now I can move into 3D space. each of the parts show becomes a component so I can mirror them for the other end and all of the modifications transfer as I work back and forth.
The top and bottom rails are then fit to the end posts. Now I mirror the ends, and set them approximately the right distance apart. I am still not sure if the end top and bottom rails will fully or partially overlap the legs.
Next come the bottom rails and I then draw guide lines up the leg posts to show where the top rail should line up vertically and the offset for the spindles from the inside edge. The inside spacing is an important dimension as you are only allowed 28 +-5/8″ by CPSC guidelines so you don’t have too big a gap around a standard crib mattress.
Now with the the back rail placed, and the frame colorized you can see the shapes better. I think it looks better with the taller top rails, but lest see what the girls say tomorrow.
Baby Crib Project
My daughters, Jessie and Elyse, are both due at the end of March 2018. Jessie still needs a crib. So the question of: “What is the next project?” has been decided, and I have a rather short timeline. However, if push comes to shove, she can use the same cradle that she slept in as a baby that my dad made, while I finish the crib. This is another project where I am following in my Father’s footsteps making things for the grandkids.
- Solid back – avoid little fingers finding outlets and easier cleanup after dinner gets launched. Flat panel rather than raised panel per Jessie’s preference.
- Adjustable mattress height
- Convertible to a bed. This will make it last, rather than be a 2 year item. Appearance as a bed will take precedence over appearance as a crib.
- Follow CPSC guidelines for safety. This includes no cut outs – so much for Mackintosh style slats I had wanted to do on the CNC router (besides Teal and Jessie are not fans).
- Design needs to complement the other furniture I have made for Jessie which is of a craftsman style and have the same finish
So we have been digging through many Google Images, Pinterest, LumberJocks and many other websites looking for ideas as a launch point. There are a lot of ugly cribs out there! Besides, many designs that look OK as a crib do not look very good as a bed. On top of it you have the predominance of MDF and particle board based junk that is on most of the web sites.
Given that Jessie is expecting a girl, I was hoping for a sleigh crib / bed sort of design. However, many “sleigh cribs” have weird lumps for curves that seem to have been tacked onto an otherwise square leg. I want something that will be smooth and flowing. Plus, this will give me another excuse to play with the CNC router. Although, a band saw and spokeshave or template and router would probably work well, too. For Elyse’s queen size bed, the curves were laid out on a template and then pattern cut with a band saw and router. Her bed (ca. 2009) is shown below.
Now, I want to do something that is more “organic and flowing” for the end posts rather than ending squarely at the floor. This is a tall order for an engineering mind.
Much has been said about the changes in safety standards for cribs. The slat spacing requirements have changed, no more drop fronts (yeah!). However I was still worried about safety and started more research. The primary resources I used are:
- CPSC website: Full-Size Baby Cribs Business Guidance & Small Entity Compliance Guide which provides the inside dimensions but is silent on spindle spacing.
- International Association on Child Safety: iafcs.org/docs/Docs_Head_Entrapment_Presentation_Revised_2013.pdf which does provide spindle spacing and other useful information.
- National Institutes of Health: Age, side height, and spindle shape of the crib in climbing over the side.
Where to start?
After several evenings of web searches and IM messages back and forth with Jessie, a leading candidate for the basis of the design emerged. It is the “Franklin and Ben Mayfair Crib”. For an example see: Mayfair Crib This was the first site that it popped up on. Others sites list it as discontinued.
This is just a starting point. As on many projects, I will look at multiple designs and then take the pieces I like and modify for more robust construction and the techniques that I prefer.
Things I like in the design:
- The outside sweep of the posts – especially the inward curving feet and no “lumps”
- Curved top rails (teething deterrent). These will end up looking more like Elyse’s sleigh bed
- Looks nice as a bed
- Nearly solid back
- Openings at the ends of the back panel
Things that must be improved:
- Flat panel in back looks like it was tacked on
- Lots of fasteners and holes showing
- Flat inside edges of the legs when viewed from the side
- Extra side and bottom parts hanging on when converted to a bed
- Front bottom rail – likely will be removed as this will not be a day bed but rather converted to a full size directly (pending approval)
So now I need to gather basic dimensions and start the new design.
Completion and Finishing Touches
Final Drawer Alignment
The drawers are inset by 1/8″. This is done by having them held in place with squares as shown or a wooden jig. It is important to have both front corners held in place at once as it is very easy to accidentally move the drawer while gluing and pinning the stop blocks in from the back. I prefer to use pins rather than brads to secure the blocks while the glue dries. The blocks are rather small and brads will often cause them to split. I also typically use thick superglue for this step.
When marking the drawers for the hardware you can either make dedicated jigs or mark each drawer. For this I use masking tape and a fine point Sharpie. The reason for the sharpie is that no pressure is required and there is not a chance of a line telegraphing through the tape into the finish as with a pencil, especially for softer woods. Also if there is an errant mark on the drawer from the Sharpie, it is easily removed with xylene and does not harm the finish.
Note that I have also placed marks on the square so I have a firm reference and avoid mistakes. For the vertical alignment I run the marker along with a square set tot the correct distance from the bottom of the drawer- direct transfer rather than more measuring.
Each of the kids wanted a different style of hardware. Jessie selected glass knobs. These have screws permanently attached which are too long. Rather than measuring and marking each one individually, I made the spacer block shown below. This made the cutting much easier and helped prevent them from turning while cutting on the bandsaw. I plan to use this trick when cutting other screws on the bandsaw in the future.
The backs are covered with 1/4″ plywood. The oak plywood shown was actually quite reasonable.
The notches in the back are hand holds. They line up with the bottom of the 2nd row of drawer supports. Each is about 1.5×5″. This makes moving the dressers much easier, especially up and down stairs.
The tops are screwed on from below with #10 1 1/4″ flat head screws run up through the front and back rails.
Front Leveling Feet
When placing dressers against the wall on carpeting, they will typically lean forward. This is due to the rear feet being on the perimeter tack strip under the carpet. Adding screw in leveling feet in the front corners allows you to then raise the front until the back is again parallel to the wall.
In this shot I am still waiting for the rest of the handles and next time I need to remember to dust before shooting photos.
This has been quite the project and it is nice to have it completed. Now I just have 2 more deliveries to do and then straighten up the shop for the next project.
Finishing for “pop”
With the quarter sawn oak, I want to enhance the grain figure while also making the mix of white and red oak piece blend together. Additionally the finish requests were for 2 different colors. David and Elyse wanted a traditional Mission Oak style color and Jessie wanted a “Cherry” finish. This matches the colors of the beds and dressers I had made for them previously. The technique borrows from one that I had learned from Jeff Jewitt of Homesteadfinishing.com at a Wisconsin Woodworking Guild class a number of years ago.
The finishing schedule uses a base coat of dye, a barrier coat that locks in and protects the dye which is then sanded, a gel stain and top coats. I prefer to spray the finishes as the dyes can be tricky to do by hand and it goes a whole lot quicker. However if you are heavy handed with the coats they will tend to mottle. Go lightly and build gently – more coats is better than 1 heavy one. RESIST the urge to touch up the dye. It WILL appear to be uneven when initially drying but trust that you have laid it on evenly ant it will turn out in the end.
For David and Eyse’s:
- Transtint medium brown dye in alcohol (1 oz to 1 qt) – 2 light coats
- Blond shellac 1.5 lb cut – Zinsner seal coat dewaxed diluted by 50% with alcohol. Apply 2 light coats.
- Sand 320 grit – full scratch – no glossy spots
- Minwax Bolivian Rosewood Gel stain. Wipe on, let sit 10 min and wipe off (hard)
After the shellac (this was a bit heavy, leading to some splotching prior to sanding)
After Sanding . 320 grit full scratch.
After gel stain
- Behlen Solarlux dye – Golden Fruitwood – 2 light coats
- Garnet shellac (hock or shellac.com) 1.5 lb cut – 2 light coats. Garnet shellacs vary in color a lot. I use a “red” garnet vs a “brown” garnet
- Sand 320 grit – full scratch – no glossy spots
- General Finishes gel stain – custom mix – 2 parts CandleLight to 1 part Georgian Cherry
Apply finish coats – typically 4 coats sanded after 2 coats and then final 2 – all sprayed
If spraying indoors in the winter I use General Finishes Endurovar Pre cat Urethane. With 2 coats gloss and 2 coats satin. If you do all satin it will appear cloudy. All gloss and it is too shiny and I have not had great success rubbing this one out to satin.
If spraying outdoors I use Sherwin Williams Pre-cat Lacquer Hand rubbed satin finish. This stuff is wonderful.
All of these have some level of toxicity or at least particulate damage to your lungs. Spraying indoors is hazardous. Any flammables (including alcohol) in the finish pose a fire and explosion hazard and lacquer certainly is a good way to make your house go “BOOM” which is why I only use it outdoors. Relying on open windows or doors is not enough and in our wisconsin winters it is a serious problem (low temps and high winds on my west facing shop door). For this project I was finishing while it was -5 to +8 F outside.
Wear a respirator and make sure the filter cartridges are fresh. I sometimes forget with shellac and end up with a headache and decreasing finish quality during the session – typically getting too heavy as the alcohol takes hold. Not recommended. Water based finishes still have solvents in them and the particles are nasty lung irritants. I also run a ceiling mounted air cleaner when finishing (box with a furnace blower and filters) which helps a lot.
With the dovetail ends, the question arises of: “Where do you end the stain?” Stopping at the edge of the top leaves light lines in what should be the shadows of the drawer edges and ruins the separation effect. Just swiping down the sides is ugly. Trying to stain all the individual dovetails is madness. So I mask off at the top of the dovetails and stop staining there. It makes for a nice transition.
All of the photos are without the final finish coats which will add yet more depth. However, I need to let the stain cure for at least 3 days and a few above zero days to apply the finish (to allow for reasonable ventilation).