Thanks guys. My plan is to build another trail scooter using many of the ideas from last years build off bike but with some refinements in the bike itself as well as the techniques of construction.
Things I want to keep from the original: speed range (0 to 12 mph) and pulling power; one piece removable motor pod containing engine and jackshaft; floorboards; dzus fastened screens; and rear cargo area.
Things I would like to change: would like the bike to be about 3 inches lower and about a foot shorter; a more pleasing look to the front end, upper front frame bar, and the cargo area; better design for mounting the wheels and axles to the frame to make removing the wheels easier; and a trailer hitch.
As far as improved construction techniques, I would like to use my new to me CNC milling machine to make some of the parts. This of course will add considerable time to the project because first, I have to get my son to write the programs and second, it will require fixtures to be made to hold the parts.
Should be a fun project no matter what.
Things I want to keep from the original: speed range (0 to 12 mph) and pulling power; one piece removable motor pod containing engine and jackshaft; floorboards; dzus fastened screens; and rear cargo area.
Things I would like to change: would like the bike to be about 3 inches lower and about a foot shorter; a more pleasing look to the front end, upper front frame bar, and the cargo area; better design for mounting the wheels and axles to the frame to make removing the wheels easier; and a trailer hitch.
As far as improved construction techniques, I would like to use my new to me CNC milling machine to make some of the parts. This of course will add considerable time to the project because first, I have to get my son to write the programs and second, it will require fixtures to be made to hold the parts.
Should be a fun project no matter what.
Thanks fm71. I was just going to let it get DQ'd and then post on the Project Logs section because I have no idea how to change it. I did read the instructions and was hoping I lucked into doing it right. Maybe before the next required post I can get my son to show me how to do it right.
That's my wife's cat. She calls him Tip but I call him Mr Vicious. He likes to stalk and attack my hand when I lay it on the arm of the chair. The game started when he was a kitten and has been a regular activity for the last six years.
That's my wife's cat. She calls him Tip but I call him Mr Vicious. He likes to stalk and attack my hand when I lay it on the arm of the chair. The game started when he was a kitten and has been a regular activity for the last six years.
The old dog learned a new trick---the photo came out the right size without my son's help.
The part in the photo did require my son's help. He had to program the machine. That is the first test piece from our CNC mill. If made in 1/4 inch thick steel that would be a wheel flange for a hub. We made the first one out of plexiglass to experiment with the machine. It started as a 7 inch square clamped in a Kurt vice. The inner diameter and the four bolt holes were machined first with a finish cut after rough cutting. The outer diameter is rough because it was made in one circular cut with the piece falling out at the end of the cut. When the part is made from steel the outer diameter will be made in 4 arcs leaving about 1/4 inch between arcs to provide stability and the ability to do a finish cut on all but the four 1/4 inch sections. We can then either bandsaw the four 1/4 inch sections to get the part out of the square and hit it with a belt sander or make a fixture to hold the piece from the center hole and do a finish cut all the way around. Since the outer diameter is not critical we will probably just cut the four small sections on the bandsaw and sand those small areas smooth.
Next time we will experiment with making two different flanges to hold sprockets. One with a 1 3/4 inch center as the wheel flange above and one with a 3/4 inch center to be used on a jackshaft.
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The old dog learned a new trick---the photo came out the right size without my son's help.
The part in the photo did require my son's help. He had to program the machine. That is the first test piece from our CNC mill. If made in 1/4 inch thick steel that would be a wheel flange for a hub. We made the first one out of plexiglass to experiment with the machine. It started as a 7 inch square clamped in a Kurt vice. The inner diameter and the four bolt holes were machined first with a finish cut after rough cutting. The outer diameter is rough because it was made in one circular cut with the piece falling out at the end of the cut. When the part is made from steel the outer diameter will be made in 4 arcs leaving about 1/4 inch between arcs to provide stability and the ability to do a finish cut on all but the four 1/4 inch sections. We can then either bandsaw the four 1/4 inch sections to get the part out of the square and hit it with a belt sander or make a fixture to hold the piece from the center hole and do a finish cut all the way around. Since the outer diameter is not critical we will probably just cut the four small sections on the bandsaw and sand those small areas smooth.
Next time we will experiment with making two different flanges to hold sprockets. One with a 1 3/4 inch center as the wheel flange above and one with a 3/4 inch center to be used on a jackshaft.[/QUOTE]
very cool!!!
The part in the photo did require my son's help. He had to program the machine. That is the first test piece from our CNC mill. If made in 1/4 inch thick steel that would be a wheel flange for a hub. We made the first one out of plexiglass to experiment with the machine. It started as a 7 inch square clamped in a Kurt vice. The inner diameter and the four bolt holes were machined first with a finish cut after rough cutting. The outer diameter is rough because it was made in one circular cut with the piece falling out at the end of the cut. When the part is made from steel the outer diameter will be made in 4 arcs leaving about 1/4 inch between arcs to provide stability and the ability to do a finish cut on all but the four 1/4 inch sections. We can then either bandsaw the four 1/4 inch sections to get the part out of the square and hit it with a belt sander or make a fixture to hold the piece from the center hole and do a finish cut all the way around. Since the outer diameter is not critical we will probably just cut the four small sections on the bandsaw and sand those small areas smooth.
Next time we will experiment with making two different flanges to hold sprockets. One with a 1 3/4 inch center as the wheel flange above and one with a 3/4 inch center to be used on a jackshaft.[/QUOTE]
very cool!!!
Thanks ratbike.
Didn't get to do much this weekend. Helped my friend run parts on his Okuma machining center and punched holes with his Ironworker while the Okuma was running. My son programmed and did a short run of parts for him on our mill but did get to turn out the first real minibike part---the wheel flange pictured above. He left it as machined so you could see how it was made. He will cut the four small areas from the hub and hit the areas on a belt sander. We plan to make 5 more hub flanges. Two will be used on my project and the other 4 will be used on the two Broncos we have.
Milling these wheel flanges out on the CNC mill makes a very accurate part once tool pushoff is compensated for but is somewhat inefficient. If we were going to make more than 20 we would have them lazer cut.
I did cut a piece while we were there for an adjustable fixture to hold the wheel flange to the axle tube while it is being welded.
Haven't made much progress due mostly to weather and other projects and problems, but did get a fixture made to hold the wheel flange as perpendicular to the hub as possible while it is welded. The top piece was welded to the tube and then chucked up in the lathe and trued and then the bottom piece was welded on. I sat it on a turn table I made eons ago to paint (not by me, that stuff had to look nice) karate equipment so it can be rotated as it is welded. By putting different length slugs in the tube it can be used as a gauge for making identical spaced flanges without measuring.
My son welded this up for me. I had lazer surgery in both eyes for glaucoma last week so won't be doing any welding for a while.
Thanks incogrhino.
Looks like I need to get a post in to avoid the axe. Haven't done a whole lot but did get the rear hub welded up and trued, both hubs bead blasted and primed and most of a front end welded up. Also worked on the drive pod. Just can't get the package shorter than 24 inches with those lay down cylinder engines. Wish I had the capability to produce a vertical cylinder OHV engine with ball bearing crank, cast iron bore, and full pressure lube.
Looks like I need to get a post in to avoid the axe. Haven't done a whole lot but did get the rear hub welded up and trued, both hubs bead blasted and primed and most of a front end welded up. Also worked on the drive pod. Just can't get the package shorter than 24 inches with those lay down cylinder engines. Wish I had the capability to produce a vertical cylinder OHV engine with ball bearing crank, cast iron bore, and full pressure lube.
I got both hubs painted, bearings installed, and wheel assemblies and a sprocket installed. Also have worked on the drive pod and the section of the frame that it mounts to. Could have that finished but I want to drill all the holes for mounting the two together on the CNC mill. The reason for this is I may--and this is a big may-- make three more of these trail scooters for friends and I would like the parts to be totally interchangeable as well as faster to make. I have been documenting every piece I make so I can saw all the pieces at once.
The front end is finished except for fork stops which I won't weld on until I complete the frame. Will post pictures soon.
This is the front end that I came up with. Seems to work well with the wheel on the axle but without the wheel it will definitely bind up if loaded on just one leg. I'll do some more testing before deciding if it will be used or tossed in the trash. It definitely requires some care when welding up. The legs have to be parallel after everything cools.
One reason I came up with this design was that the shock could be as simple or as high tech as I want. If I use it I will probably replace the shock in the picture with a QA! coil over with the spring rate optimized for my weight. Fortunately there is a QA1 dealer in Gasoline Ally that is friendly and easy to work with.
This is the front end that I came up with. Seems to work well with the wheel on the axle but without the wheel it will definitely bind up if loaded on just one leg. I'll do some more testing before deciding if it will be used or tossed in the trash. It definitely requires some care when welding up. The legs have to be parallel after everything cools.
One reason I came up with this design was that the shock could be as simple or as high tech as I want. If I use it I will probably replace the shock in the picture with a QA! coil over with the spring rate optimized for my weight. Fortunately there is a QA1 dealer in Gasoline Ally that is friendly and easy to work with.
Thanks fistfullabar.
My son and I tested the forks thoroughly and they will be used. I will add a couple of gussets and the fork stops once I have the frame welded up.
We wrote out all the coordinates for the holes in the drive pod and frame section that holds it and will drill them all on our CNC mill. Having to keep our mill at our friend's shop slows things down since we only go there on weekends when his workers are off.
Just two months to go. It's not looking good for getting this thing done on time.
My son and I tested the forks thoroughly and they will be used. I will add a couple of gussets and the fork stops once I have the frame welded up.
We wrote out all the coordinates for the holes in the drive pod and frame section that holds it and will drill them all on our CNC mill. Having to keep our mill at our friend's shop slows things down since we only go there on weekends when his workers are off.
Just two months to go. It's not looking good for getting this thing done on time.
Nice fork design WLB :thumbsup:. If you ever want to make another set in the future, you could try 2 shocks/springs and move them closer to the tubes which might minimize the binding. The neck could be positioned in the center. I would like to borrow this idea, seems like a much simpler approach than trying to add springs on the tube plus it allows for dampening with the shock.