A Bit More Welding

Today I tack welded the piece that extends from the back of the main tube. Took a little bit of re-doing to get it straight but I was rewarded because it is bang on now. This piece will be trimmed to length once I establish how high the rear wheel needs to be, and thus how the rear triangle lines up. This was a most satisfying task.

When visiting my sister and family on the weekend, I still haven't hinted strong enough for them to let me build a chopper bike for my nephew. One project at a time I guess ;) p.s. Thanks to Lara and Aidan for the bikes you gave us.

More Bushing pics

Just a few more pics of the bushings after I notched them.

Trike Riding

This weekend I met Tina in the little town of Bentley, Alberta to shop at one of Western Canada's best recumbent bike stores. Bentley Cycle and Trading Post has an amazing selection, especially in a town of 1000. For the first time in my life I got to ride a couple of recumbent tadpole trikes. I fell in love. Here is a pic of the one I liked the most: the TerraTrike Zoomer. Compact, light (30 lbs) and narrow enough to fit through a doorway without tipping. I must say it is a fun ride. Completely stable, very comfortable, combining the coolness of propelling yourself with the ride and handling of a go-cart. Really a shame they are $2200. Sigh.

Cutting the Inside Hole in the Bottom Bracket Tube Bushings

Last night I cut out the "Inside Hole in the Bottom Bracket Tube Bushings"

The first pic shows what didn't work: using a ground off wood bit and lathing it out with my drill press and cross slide. Cut not bad, but no way to measure.

2nd pic shows the was that worked. Put an end mill in the drill and rotate the bushing stock on a bolt bolted to a clamped piece of wood.

One bushing is PREFECT, the other is a hair loose, I may redo it, cause it is fun to make!




One bushing installed, one on the bench.

More Than One Way to Skin a Bushing

Yes, that is a chisel clamped in the cross-slide and yes, I was wearing safety glasses. I started making the bushings for the bottom bracket tube tonight out of UHMW. I had been disappointed in the quality of the "cut" made by my hole saws, and they would have been a little to small anyhow. I came up with this solution: rough cut the bushing bigger than the final size, mount it in the drill press to spin it and then use my cross slide to clamp a chisel and turn it to final size like on a lathe. I was having a lot of chatter, but the I angled the chisel so that it was cutting with the corner only and it works great. With the cross slide you have excellent control and from the last pic you can see the fit is excellent! Now I will make one more and try to figure out how to accurately drill the hole in the centre.

Bottom Bracket (That goes on the Front!)

The bottom bracket on a bike is the part that holds the bearing for the crankset (the gears your pedals are connected to). I was all set to start building the bottom bracket assembly for the trike when I discovered that the pipe I got didn't fit inside the main frame tube like it was supposed to. Close but not comfortably close. I thought, and discussed with Grant, my options like extending the slot that is needed to clamp this tube in place or using a pipe expander ($15 at princess auto). For fun I thought I would try just using the existing frame of the donor bike with some UHMW bushings, since if it didn't work, I could still switch to plan b, c or d. I was a bit surprised that it worked out better than I thought. I might just keep it. If you are wondering why there is the piece sticking up at a 60 degree angle, that is to mount the front derailer to and will be trimmed to be about 6 inches long. I can also use it to mount my water bottle (threaded holes already there) and my bike speedometer, head light, tow hitch, coat hook or snow plow attachment. You get the idea.

In the above and below pictures you can see other mounting holes that I could potentially use to adjust the length of the "boom" instead of a clamping system.

One thing I discovered is that although UHMW is great to cut, drill or machine, it isn't the greatest to cut with a hole saw. The saw gums up when it starts to melt. I will makes some better bushings if I decide to keep this design.

I like this picture because you can see the corner of that blueprint. Makes me looked organized or that I am going from a set of plans or something.

Any volunteers to draw some pedals and gears for the Progress-O-Meter?

Cutting the Rear Triangle Extention Tube

Ok, you gotta realize I am just making up part names now... But then again if you can come up with a better one.. it is the tube that is an extension of the main tube to connect to the bottom of the rear triangle. The rear triangle holds the rear wheel, and as Aidan is fond of saying, "the triangle is the strongest shape", or something like that. Ok here is what I did:

I had to cut a 2" grove at a 40 degree angle, so I drilled 2 guide holes in the 2" pipe at a measured 40 degree angle. I then cut with a hole saw using a guide made of a piece of a rod I salvaged out of a printer (that's a plug for gleaning if you didn't notice!). You can see I have started cutting from both ends as the hole saw only goes so deep.

Gack! you say, that's not lining up, how is it possible that the cut lines aren't going to meet properly??? Turns out it is an illusion. If you look at how the hole saw will intersect the tube, all will be ok. Trust me.

Here is the finished joint after a fair bit of trimming/fitting/cleaning up with a grinder.

Here is how it fits. Looks pretty nice I recon... Like I said, fair bit of fitting to get to this point. Notice my signature jiffy marker lines. If I want a precise mark I colour an area with jiffy then use a fine scribe, it works great!

A overall shot to show where this piece goes: