Homemade Parts!

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Homemade Parts!
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Posted: Sep 27, 2019 at 12:40 Quote
przecinak wrote:
Will a 12mm thick 5745 aluminium plate be strong enough for a direct mount stem?

You're probably good. Since I'm guessing you're not going to be good with maximum weight savings with it. 6061 is usually what gets used for stems/ milled bike parts. But like with anything metal the heat treatment of it can change a lot of the properties.

Posted: Sep 27, 2019 at 13:00 Quote
NorCalNomad wrote:
przecinak wrote:
Will a 12mm thick 5745 aluminium plate be strong enough for a direct mount stem?

You're probably good. Since I'm guessing you're not going to be good with maximum weight savings with it. 6061 is usually what gets used for stems/ milled bike parts. But like with anything metal the heat treatment of it can change a lot of the properties.
Yup, really depends on what heat treatment it has. 5745 H111 for example can be as weak as about a quarter of 6061 T6, but other heat treat variants can be fairly close. If all you can get is 5745 I'd make sure to get something like H24 or H26, but better would be 6061 T6, 6082 T6, 2014 T6 or 7075 T6, roughly in ascending order.

All that being said any of those can work as long as you get the design right. You'll need a bit less material for a 7075 T6 stem than 6061 T6, and more material still for 5745. If you can only find 5745 H114 which seems to be the commonly available variant I'd avoid it. It's only about a third as strong as 6061 T6 and much less still than 2014 or 7075 so you'll wind up with a pretty heavy stem.

Posted: Sep 27, 2019 at 14:18 Quote
przecinak wrote:
Will a 12mm thick 5745 aluminium plate be strong enough for a direct mount stem?

I'm guessing you have access to a chunk of half-inch plate and you're looking for a fun project with it. Great idea and I'm sure you'll have fun with it!

Design is always more important than material. A flawed design could fail if it was made of pure carbon nanotubes.

Yes, your material should be strong enough if the you leave plenty of excess material in all vulnerable areas, use smooth radii, put washers under all fasteners, etc., but think of the time and effort you're going to put into this stem project. That's worth many times the price of a small chunk of 7075 plate. Maybe it's worth getting the 7075.

Posted: Sep 27, 2019 at 17:01 Quote
Kustomango wrote:

Out of interest how are you preloading or tensioning these? Just pushing the crowns together or a through bolt from below?

Very well made- all of your parts A+ ... Something to keep in mind though- most of the parts that bike manufacturers make go through rigorous testing time and time again, sometimes years before they release them to the public. I would err on the side of caution making stems, mounts and cranks...

Posted: Sep 28, 2019 at 1:53 Quote
therevfryslim wrote:
ktm87 wrote:
therevfryslim wrote:
thats some lovely machining. the chili is a nice touch.

Do crowns of this type usually use needle bearings, or is this unusual (hence 'let me'?).

Thanks mate. no ive never seen these bearings use on a mtb before. they are what all motos use tho which was why i had the idea to try them out. first time i put the crowns on without even putting the bolt in for preload there was zero play or slop in it at all

Fair play. Another bit of moto tech migrating to mtb! they look hard as nails though. We use this type of bearing all over the place at the sawmill I work in (scaled up, of course).

FYI Other pinkbike users, please could you snip out pictures when quoting posts unless referencing one specifically...so much scrolling...

These thrust bearings have been used in bicycles before, have been tried several times. Don’t tend to be the more durable things in the world for bikes and have been phased in and out a couple of times over the years. Not a lot of linear loads on an MTB single crown. Haven’t seen them really used much in the double crown world, curious to see what the longevity is like.

Posted: Oct 4, 2019 at 5:13 Quote
Remedial lathe-work from "Turning 101"...

Posted: Oct 11, 2019 at 5:20 Quote
Hi,
My anodized ISCG bash guard...



Posted: Oct 11, 2019 at 9:12 Quote
Yes ! But...I don't really control the final tint Cry

Posted: Oct 15, 2019 at 4:23 Quote
Here is the process of new prototype.

It will be 70 mm wide, and roughly 150 grams with titanium hardware.

Finishing up and lab and field testing.

Stay tuned

Production process of Shovel Components Ultra Wide stem
Production process of Shovel Components Ultra Wide stem
Production process of Shovel Components Ultra Wide stem
Production process of Shovel Components Ultra Wide stem
Production process of Shovel Components Ultra Wide stem
Production process of Shovel Components Ultra Wide stem
Production process of Shovel Components Ultra Wide stem
Production process of Shovel Components Ultra Wide stem
Production process of Shovel Components Ultra Wide stem
Production process of Shovel Components Ultra Wide stem
Production process of Shovel Components Ultra Wide stem
Production process of Shovel Components Ultra Wide stem

Posted: Oct 15, 2019 at 10:36 Quote
That looks superb! tup

Posted: Oct 16, 2019 at 21:21 Quote
Looks good! You do that on a 3+1 machine?

Posted: Oct 17, 2019 at 12:59 Quote
Thanks fellas.

I found in the storage an old but unused rotary head with chuck mounted. After examining it, I found out that rotation can be divided from 90 deg to 7.5 deg, but only manually.

When I was designing this one, I was thinking of making it all on 3 axis machine with 6 different positions, but this helps a lot.

I always love to make prototypes, and it always thrills me while doing it.

Glad you like it. This is how it's supposed to look.

New prototype on the way

Posted: Oct 18, 2019 at 6:39 Quote
Hope also make some fantastic home made stuff : )


 
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