14-11-2014 14:33

audietron

Re: pic: 2169 'not so summer' off-season project teaser

This looks really nice! I do have a couples questions.
1. Do you have more bearing blocks then needed for one complete drive?
2. Are the slimmer blocks for 3/8 axle?
3. What is the hole in the side of the blocks (tensioning?)

Just a couple things I've been curious about. Thanks

14-11-2014 15:01

notmattlythgoe

Re: pic: 2169 'not so summer' off-season project teaser

I'm assuming the slimmer blocks are for the ends of the rails and the hole is for a tension bolt.

14-11-2014 15:23

Boe

Re: pic: 2169 'not so summer' off-season project teaser

I'm fairly certain this is right, KING TeC has done this type of tensioner in the past if I recall correctly.

14-11-2014 15:26

AdamHeard

Re: pic: 2169 'not so summer' off-season project teaser

It works well, and is easy to do/adjust.

The bummer (and one of the reasons we don't do it), is it limits frame mounting options in those corners.

15-11-2014 00:09

75vs1885

Re: pic: 2169 'not so summer' off-season project teaser

looks like your using the West Coast gearboxes, I milled myself the same pieces. Unfortunate, the chain we ordered hasn't come in yet, a mentor ordered it awhile ago. However, On Thursday we ran it and I had SOOO much fun using only the two wheels that are direct drives to the CIM/ Gearbox. It is quick as heck!

17-11-2014 08:32

llamadon

Re: pic: 2169 'not so summer' off-season project teaser

Thanks!
1. Nope, there are enough blocks for 4 axles, the bearing blocks are the ones with the bigger holes.
2. As previously mentioned those are actually for a 1/2 #20 bolt to be held for a tensioner.
3. It is a tapped hole for 1/4 #20 thread. This coupled with the bolt and bolt holder create linear motion with the bearing blocks, allowing for tensioning.

17-11-2014 09:41

Monochron

Re: pic: 2169 'not so summer' off-season project teaser

Having only really looked into COTS options for WCD, I would appreciate if you posted pictures of the final product, or even in progress product, so that I could see where and how all those parts are being used.
Looks crazy schnazy, but also confusing to the uninitiated

17-11-2014 10:47

Arpan

Re: pic: 2169 'not so summer' off-season project teaser

Semantics, I know, but the notation is 1/4-20

Also, one thing that I might worry about here is galling on the aluminum threads in the blocks. It's rare with aluminum, but it sucks to say the least.

Galling is cold-welding between your screw and your nut material (in this case the aluminum) because the oxide layer of the aluminum wears away (this is why stainless steel fasteners can be a bad idea, the oxide layer wears away and they gall even worse than aluminum) .

I've only had it happen to me once before, but it makes the screw pretty much impossible to remove save with a drill.

Some ways that you can prevent this:


1. drill and tap your hole for a larger size and use key-locking inserts to put in a nice steel thread. This solves all problems and is my preferred solution.

2. Apply a PFTE-based compound onto the threads (or powdercoat / alodize/ anodize the material). Also solves most of your problems

3. use coarse threads with a loose fit (not really practical here)

Failing making any changes to the part:

4. Don't over tighten! Use a torquewrench and tighten to a low torque.

5. Tighten the bolt really really slowly. This keeps heat from building up too much.

19-11-2014 18:45

llamadon

Re: pic: 2169 'not so summer' off-season project teaser

I will definitely do that for ya! It was confusing for me at first too.

19-11-2014 19:43

Ginger Power

Re: pic: 2169 'not so summer' off-season project teaser

The real question is will it be ready for Minne-Mini? If so it'll be really fun to watch.