Archive for October, 2010
Due to work-related time pressure, grinder and press development were limited this year, but a few important advances were made, primarily to the grinder. Readers will recall that in previous years, as the efficiency of the accompanying systems improved, the limited power output of the single rider powering the apple grinder became a limiting factor, both to output and to the quality of the experience. Accordingly, last year we borrowed a tandem bike and hooked it to the grinder. This made a dramatic difference in terms of grinding speed; the two pedalers working together could easily keep the system going at top speed no matter how fast the apples were fed. However, the user experience left something to be desired, as the mounting of the tandem bike was not perfectly rigid, leading to something of a precarious feeling. This was not helped by the fact that in a typical tandem setup the two cranks are locked exactly in phase by the timing chain, leading to significant surging, especially with platform pedals. At the close of the 2009 cidering it became obvious that the right way to do tandem power would be two single bikes, side by side.
The sixth annual Five Islands Orchard Cider Weekend was held this last weekend, with about 40 in attendance, including an increasingly large and energetic contingent of kids. Despite the poor apple harvest, the cider output and yield broke all previous records. Approximately three bins of apples were processed on Saturday into 155 gallons of cider in about six hours by entirely pedal-powered equipment, and the yield was an unprecedented 75% – not including cider consumed directly.
The weather was beautiful, the pot-luck grub was fantastic (among other things, Kelsey brought homemade croissants made from scratch), and the kids ran around like banshees. The side-by-side tandem drive was much more stable than the tandem bike, and Beth took her role as User Experience Officer seriously, suggesting a very effective plexiglass spray guard to protect the pedalers from flying apple bits. There were some minor technical glitches, but compared to previous years the hardware performance was very good – a more detailed report with proposed modifications for next year will follow. Here are some photos:
Trailer load of apples, infested with kids:
Apple procurement has been a bit different than usual this year. The biggest issue is that the weather was really strange this spring, with unusually warm conditions causing the apple trees to blossom 2-3 weeks ahead of schedule, just in time for a hard freeze that killed as much as 90% of the crop in places. The main orchard at Poverty Lane was especially hard hit. Kelsey and I made a field trip up there to get bittersweets for cider, and their awesome “two below the barn” orchard with its wonderful array of apple varieties was virtually barren. The trees looked great, with strong new growth compensating for the lack of fruit, but hardly an apple to be seen. Fortunately, their other plantings of bittersweets fared better, and we bought a 600lb bin of Dabinet drops for cider.
Many orchards even in central New England lost 80% of their crop, and the you-pick season was over basically before it started. Kelsey and Joshua have nonetheless secured 2 bins of apples from Brackett’s orchard, so we should be fine for cidering despite the crop failure:
This year’s experience points out the risks that climate change poses to agriculture. Obviously the hot weather this spring and this particular crop failure can’t be specifically blamed on greenhouse gases, but the rate of such incidents is bound to increase as the climate gets warmer and weirder. I am hopeful that the location of our orchard less than a mile from the moderating effect of the ocean will spare us from the worst of this sort of risk.
Holly and I spent this morning in the machine shop, fabricating parts to upgrade the pedal-powered apple grinder. We want the power of two cyclists to operate the grinder, but the technique we used last year was not satisfactory – coupling a tandem bike to the grinder by the fork led to dramatic vibrations, and the setup was marginally stable, leading to a precarious sensation for the pedalers. From an ergonomic and aesthetic standpoint, it would be much better if the two pedalers were side-by-side, and if they could each independently drive the mill. So that’s what we’re implementing.
In the basic pedal mill design, the main grinder drum runs on a 5/8″ shaft, and it’s driven by bike chain from a jackshaft with a ~4:1 increase in speed. The jackshaft had a crude adapter that we made by brazing a steel shaft collar onto the threaded bearing cup of a bottom bracket, which is the same thread as a standard freewheel. So we threaded a freewheel onto the adapter, and drove the freewheel (again with a ~3:1 increase in speed) from the large front chainring of a bike, which bolts on via the front fork. In the modified design, the jackshaft remains, but it is pulled back toward the pedalers and outside of the plywood grinder box, so it can be extended out to the left. We machined a heavy bar of aluminum to support the pillow block that carries the left end of the shaft, and machined a longer 5/8″ jackshaft from a ground stainless rod. Holly turned two aluminum freewheel adapters with a 1.375-24 thread on the OD for the freewheels, and a 5/8″ reamed bore on the ID. As soon as I can find somebody with a suitable 0.1875″ keyway broach I’m going to broach the freewheel adapters and the drive sprocket, so the whole thing can carry serious power without slipping and tearing up the shafts. I’ll post pics as soon as I get it provisionally assembled.
I suppose the timing may be pure coincidence, but I think Bill McKibben gets to declare victory: the White House is going to do solar.
Last year the cider equipment worked pretty well, but there were a few issues to be worked out for this year. The 37,000 lb bike-powered hydraulic press worked pretty well; the only issue was a lock ring that broke on the rear wheel, necessitating a quick swap from other bike equipment by Dorson & co. Sunday morning we incorporated the soft-seat check valve and the SCBA tank accumulator, which added significantly to ease of use and crushing power. When I was last in Five Islands, I went up to Woolwich and got a more robust lock ring from Davis “Bikeman” Carver at Bath Cycle and Ski, and my dad and I dusted off and reassembled the press. It demonstrated its power by crushing a couple of four-by-four scraps that were lying around.
The grinder also worked pretty well last year, but the inline tandem drive looked a bit dodgy, so this year I’m going for something more robust – I hope to implement a side-by-side parallel tandem drive off of two separate bikes, so both riders can watch the action, and each has his or her own freewheel for independence. I’ll post pics when I get it working…