After I designed and built the hand cranked wood windmill or fan, I got the idea to operate a Ferris wheel instead of a fan. My thought concept is below.
I Googled and found a Ferris wheel made of steel that was hand-cranked............and I liked the people basket design.
I showed my son my initial design in Sketchup, and he thought it was not fancy enough, the picky kid!!
So, I made it a little fancier with rounded bottoms on the 2 main vertical legs, and other stuff.
The 2 main rings that make up the Ferris wheel, are a little tricky to build. The 3/8" radial dowels need to be installed to the hub and outer ring segment, at the same the outer rim segment of 6 pieces is being glued up.
For the hub, I wanted to drill the 3/8" dowel holes while the blank was 6 sided, for ease of putting in the vise on the drill press. So, I came up with this concept.
So my process for making the hubs was:
1. Print out full scale pattern on paper from Sketchup
2. White Elmer's glue pattern to red oak 5.5 inch wide board
3. Use miter saw to saw the angles and make it 6 sided
4. Use table saw to saw off the last side
5. Pilot drill the 3/8" center hole.
6. Drill a 1/4" dp from one side using the pilot hole, then flip over and finish the 3/8" center hole........for no punch-out of material.
7. Use vise and drill the 6 holes 3/8" deep
8. Scroll saw the outer shape (tried big band saw, but burned the red oak)
9. Rough sand OD and break edges on drill press (can not use round-over router bit because guide bearing falls into holes on outside)
10. 220 grit sand
11. Wash off paper and glue using scotch pad and hot water.
Here is finished hub before I wash off the paper pattern.
I came up with this pattern to use...........from Sketchup
Using 3/16" thick Luan scrap plywood, I made 2 patterns required to make each segment. I scroll sawed out the outline of the finished piece, and saved both pieces. To use these 2 patterns:
1. Saw out 9x3.5 piece of 3/4" thick red oak
2. Place both patterns on top of blank
3. Using pencil, trace where 3/8" hole needs to be drilled
4. Removed inner piece of pattern using dental pick
5. Trace outline of outer rim piece.
6. Also mark where 3/8" diameter spoke hole needs to be drilled
7. Take rectangular piece to drill press, and drill spoke hole 3/4" into finished outer time
8. Go to miter saw and saw 2 angled ends
9. Scroll saw out outer rim piece
10. Use router table to do 1/8" round-over of inner and outer surfaces, skip over where spoke hole is drilled so bit bearing won't fall into hole
11. Sand on drill press
This process worked very well. You can see the 2 pattern pieces and 1st finished rim piece in the photo below.....
At some point, I need to decided to use one 3/8" diameter dowel.........or two of the 1/4" dia dowels........to join each wheel segment. I should be able to put the pieces in the vise, and drill them on the drill press.
I decided to use just one 3/8" dowel at each joint. I used my old Sears set of aluminum center finders, in this case the 3/8" size. To drill them, I tried to get the top horizontal in the vise on the drill press, using the big vise.
For this project, I decided to get out my Merlin steel band clamp. I did a dry clamping of the assembly to make sure everything was ok, before gluing.
You need to work quick, before the Titebond II yellow glue starts to set up.
I first glued the 6 spokes into the hub, making sure to shove them in all the way.
Then I worked my way around the 6 segments, gluing the end dowels, and the spoke. It was a little tricky to get the last few segments installed, but I was able to do it. I used the wood hammer to tap on the ferris wheel rim, plus the Merlin clamp to draw everything together ok.
The mating edges on the dowel joints never line up perfectly, so I will have to so some belt sanding to make them all flush.
The OD of the wheel is a little bigger than the paper pattern, which probably means I should have cut the angled length a little shorter, but it should still work ok.
I also noticed I will have some side-to-side run-out in the finished outer rim. I don't know if it will impact later assembly or not.
I used the 1.5" diameter 60 grit sanding drum on the drill press, to sand any mismatch between the 6 segments on the OD and ID.
I used the belt sander with a 40 grit belt to sand out the 6 segments joint interference. The 40 grit made some deep scratches, that took a while to get out with the 180 grit sanding drum and orbital sander.
Then I sanded the whole wheel, except the 3/8" dia spokes with 220 grit to finish it.
I had a little trouble with the 1st rim, but more trouble with the second rim. I had to use a 24" inch bar clamp to pull in a couple of the joints, in addition to the Merlin clamp (I took the Merlin clamp off while using the bar clamp, otherwise it won't fit. I finally got the 2nd one assembled ok.
I normally only use this on table tops, or shelf tops, to give the red oak a mirror like finish. Since I had some small gaps between the 6 pieces that make up the outer rim, I decided to use it here.
I had a new can of Behlen's, but the liquid always rises to the top, and you need to mix it. I put the big paint stirrer in the drill press, but forgot to turn the speed down from max to min....and I bent the paint stirrer. I straightened it out ok, but it was still slopping the thin liquid out of the can. I made a small stirrer from bent wire, and put it in the cordless 3/8" drill..which worked fine.
The process for applying the Behlen's is:
-stain with Spanish Oak oil stain and let dry
-rub in Behlen's with your fingers
-wait 15 minutes and wipe off excess with plastic knife
-let dry overnight, rub off excess with burlap rag
-coat 1 of polyurethane
-sand to 220 grit
-coat 2 of polyurethane, 3rd round of 220 grit and poly is optional
I made the carriers from hard maple from Menards. I used a 25/64" drill bit to give some clearance for the 3/8" dowels they swing from. After they were built, I had to run the drill bit through both holes at the same time.......for the dowels to rotate smoothly.
On the first unit of a project like this, I like to make a mock-up to evaluate the design.
First I clamped a 3/8" diameter aluminum rod to my lower workbench. I installed the 2 outer rims, then all 6 carriers with people. When I rotated the Ferris wheel by hand, some wood people fell out, because the carriers were not all rotating properly. I cleaned out the holes with the 25/64" drill bit, tested again, and everything worked fine.
I made 2 pine main vertical pieces, and I marked the hole location with an awl......using a paper template I printed from sketchup. I made the real gears from red oak on the scroll saw. I designed the gears in the GearDXF program I downloaded to my PC. I printed out full scale paper patterns and white Elmer glued them to the oak blank. After cutting on the scroll saw, I washed and scrubbed off the remaining paper and glue.
I decided to use a 3/4" versus 3/8" dowel on the main ferris wheel shaft. I had already drilled 3/8" holes in the rims. I used a plastic drafting template to mark the 3/4" holes, then cut them on the scroll saw. I could not drill on the drill press, because the outer rim was too big to fit my drill press. This method worked ok.
Everything fit up ok on the mock-up. I noticed the height of the whole assembly could be dramatically reduced by having the crank in the 2nd hole up on the vertical column. The dowel would still clear the bottom of the carriers if it was there.
I went into the Excel spreadsheet I used for gear design, and found out 3 gears would not work, because I would need a 10 inch diameter gear, and I thought it would look too big on this toy. I found that if I replaced the (2) 6 inch gears with 2 new 4" gears, it should work ok.
I updated Sketchup to my latest shorter design, then made a comparison between them.
I like the shorter and more compact design much better than the initial concept.
I did test work on the hand cranked windmill, and found an 1/8" worked better than 1/16". These gears had 3/8" axle shafts.
But when I made my pine test piece on the Ferris wheel, using the same 1/8", the gears slipped, especially the smaller 2" gears. So, I got a piece of scrap red oak, and drilled 3/4" holes holes, then used soft white dowels (the red oak dowels stuck in the holes). I had way to much slop and slippage using the 1/8" + theoretical center distances...........so I drilled a new set of holes using theoretical centerline + 1/16"........and it worked great!!
It must be the difference between using 3/8" axle shafts versus 3/4" axle shafts, since the gears are about the same size?
I guess the moral of the story is to always run a test on a new design.
The hand-cranked windmill was the 1st project, where I was able to figure out how to make a crank handle that stayed put in your hand as you rotated it. I did not draw it quite correctly on that project, so I redrew it in Sketchup correctly.
I forgot on the hand cranked windmill, I made washers from 3/16" thick Luan to space the gears away from their mounting bracket.
I also forgot that red oak reacts with steel, and turns the oak black over time.
I had the sketchup drawing done with 1/8" thick steel washers, so I planed a piece of scrap Luan down from 3/16" to 1/8" on the planer. I drilled the 3/4" ID and scroll saw cut the 1.5" OD's on the washers.
I made the base out of pine, just in case I needed to make a change on the spacing of the 2 vertical main support pieces. I started at the bottom crank, and worked my way up. I pinned the gears using 1/4" dowels as I went.
When I made some of the gears, I did not want break-out when drilling the 3/4" shaft bore, so I first drilled a through hole with 1/8" bit, then drilled part-way with the 3/4" bit, flipped the gear over, and drilled from the other side. Although this prevents splintering and break-out, on the small 2 inch gear, the shaft hole was not perpendicular to the gear.....because the bit wondered when I drilled the 2nd hole. On future projects, drill through holes on the shaft bore, put a solid piece of scrap wood under the gear and drill slowly on the feed down to minimize break-out.
I tried gluing a 3/4" oak dowel in the original gear and re-drilling, but I got thin shavings left that fell out..........so had to remake the gear.
I decided to attach the center spacer to each of the outer rims, using a 3/16" dowel. I had to use a Brad point nail to mark the mating holes, because my Sears dowel center kit only goes down to 1/4". You drive in the brad point, then nip it with the side cutters, then force the 2 pieces of wood together. This worked fine.
I also drilled a 1/4" hole through the center spacer, and the 3/4" drive dowel.
I did not want to glue the center hub to the 2 outer rims with the dowel in it..........because the glue squeeze out my glue the center spacer to the dowel.
I brushed it on, let it run off for 30 minutes, then wiped them off using a new dry rag.
To speed up the paint drying time, I often put wood parts in the oven at about 120F for 10 or 15 minutes. I did this on this project.
The water based paint came from Hobby Lobby. I used a fine pointed artist's brush to paint the hair and smiles. I dropped a small dab of paint for the eyes using a wood toothpick.
The gears hung up at one spot. I inspected and found 2 fat teeth on the lowest 4 inch gear. I was able to knock out the 1/4" dowel retaining pin, then scroll saw and file the fat gears down to size. Once I did this, it ran flawlessly!!
I made a YouTube video of the model in action.
This was a challenging project, more so than I originally thought!
It was really strange that for the gear spacing, the theoretical distance between gear centers + 1/8" worked fine on the hand cranked windmill, but was too loose........and I had to change to Theoretical + 1/16" on this project. The only explanation is the windmill had 3/8" gear shaft bores........and this one had 3/4" shaft bores.
I should have focused more in the design stage, on making the over-all height as short as possible. When I did my prototype assembly, I found out I could reduce the height by many inches by just moving the crankshaft up higher.
The mineral oil finish on the maple carriers worked great. It would have been tough to put on polyurethane, then try to sand inside the carriers between coats of poly.
Pinning the gears using a 3/4" shaft.......and a 1/4" diameter dowel as the pin......worked very well.
This should be a fun one for adults.........and the grandkids to play with!!