Nothing to lose really.
- Thread starter DannyC
- Start date
In a departure from our advertised program today saw the universe flipped by 90-degrees.
Well, OK just a Sturmey Archer 8-Speed flipped by 90 Degrees.
I found that if I turned the proposed dropout tabs to face the rear of the trike then the 8-Spd could sit inside the rear triangle.
It does create an issue in that the power-side of the chain will want to saw its way through the cross-rails of the seat (unless either the seat is raised, or a diverter pulley is employed).
thinking ?
do we really need a triple on the front ? looks as though with the 2 smaller rings there would be no seat interference ?
also could the BB go below the frame ?
paul
DannyC
0
No triple really required it is just conveniently on a bolt-up mount for testing purposes. BB could go below the frame but then any option for having a double/triple up front is taken away completely.
It may be that I chain it up for testing with it under the frame and only on one chainring(no front-mech) to see how it all works and then alter it later.
The dropouts are now fully welded on where you see them here. I need to get a seat mount (with backrest stays) sorted so that I can determine the BB position and the front forks.
This is a long journey it seems.
DannyC
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Another little diversion....
I bought some acetal/Delrin slugs on evil-bay and I am trying to make a diverter pulley (or two).
Now, I admit I have got my order of operations all wrong and have boxed myself in a bit, but I think I will be able to recover.
Here is what it looks like so far. Gosh the Delrin swarf/flakes go everywhere. It is nice to work with though.
This will go on the drive side of the chain and will have dual-bearings and a 12mm axle.
Aluminium side-plates may be required.
I bought some acetal/Delrin slugs on evil-bay and I am trying to make a diverter pulley (or two).
Now, I admit I have got my order of operations all wrong and have boxed myself in a bit, but I think I will be able to recover.
Here is what it looks like so far. Gosh the Delrin swarf/flakes go everywhere. It is nice to work with though.
This will go on the drive side of the chain and will have dual-bearings and a 12mm axle.
Aluminium side-plates may be required.
DannyC
0
Yes indeed. The available/affordable delrin blanks I got are only 60mm diameter so a little on the small side (76-100mm would be better).
I am hoping to provide a wide-enough valley for a chain to run on and to accommodate any lateral movement (e.g. a dual/triple chainring up front).
The walls of the pulley are mainly there to encourage the chain to keep clear of the side-plates which will be the ultimate/final defence.
Danny, is the bore a through hole or is it shouldered in the middle?
(Guess you have a middle spacer in there)
There are many ways to machine them.
With an end shoulder for one bearing, middle shoulder for 2 bearings.
You may need an undercut for a circlip to prevent the pulley walking off the bearings.
I've made 5 pulleys so far this year. Three different designs. Bought a 75mm dia black nylon bar 1 metre long, should keep me busy.
If making in 2's you can machine one gripping one end, turn round to machine other one. Then part off, with a long blade.
Use tailstock support.
Second load, bore operation for the other bearing.
Or if making singles cut the blank with a 10mm(ish) grip length.
Machine off excess.
Hope that helps.
I will making some with the centre sprocketed teeth next, such fun.
Martin.
(Guess you have a middle spacer in there)
There are many ways to machine them.
With an end shoulder for one bearing, middle shoulder for 2 bearings.
You may need an undercut for a circlip to prevent the pulley walking off the bearings.
I've made 5 pulleys so far this year. Three different designs. Bought a 75mm dia black nylon bar 1 metre long, should keep me busy.
If making in 2's you can machine one gripping one end, turn round to machine other one. Then part off, with a long blade.
Use tailstock support.
Second load, bore operation for the other bearing.
Or if making singles cut the blank with a 10mm(ish) grip length.
Machine off excess.
Hope that helps.
I will making some with the centre sprocketed teeth next, such fun.
Martin.
Popshot
Was this for drive side or return side ?
If drive side has it lasted ?
If so where did it come from ?
Paul
DannyC
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Hi Martin,
I am sure Nylon is fine but I had heard that over time is absorbs moisture and swells a bit, so I went with Delrin which doesn't.
I have made them so that there are 2 pockets (one on either side of the pulley) to hold the bearings in.
An 8..10mm central section is to act as a separator between the bearings. I guess this is your "middle-shoulder" option.
As there is a "nut" on either side of the pulley it cannot "walk" anywhere (inwards or outwards) I think/hope.
Popshot
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Both and yes no issues. The drive side was / is a very mild deflection of the chain path though and that is likely the biggest factor in any wear rate. Got them from ebay. They were U shaped for a rope initially and I spun them in a drill in a vice and used a wood chisel to turn them flat. This was before I got the lathe.
Popshot
0
I have had issues with nylon swelling in other applications.
Popshot
0
And here is another one, it came out a bit better, may not need any side-plates.
I tried it with a length of chain for "fit" and it seems good.
That looks like it could survive any worst case scenario yet is probably not overly heavy. Looks great.
DannyC
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Thanks, it is 60mm Dia by about 25mm overall width, with a 9mm channel in the middle and the bearings are standard 28x12x8 so it should be able to survive a bit of punishment.
