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dkerrivan
07-06-2014, 11:44 AM
looking for thoughts here from the community.

I knew re-reading the plans was a good idea after regretfully putting everything on hold last fall.

As I drifted off last night, my hind brain kicked out a reminder to look at the axle tabs in the plans. If I read them right, and I did draw this out, using the center point Brad suggests, based on 14 mm axle leaves about 3 mm maybe a bit more depending on your welds on the bottom edge of the tab.

I went with 20 mm through hubs, and the corresponding size bolt. If I use the suggested center point, I will have zero to a hair of metal at the bottom.

What have others done? Moved the center up an 1/8th to a 1/4 in. Towards the eventual weld to head tube or made the tab a bit longer to ensure enough metal on the bottom of the tab? I am not worried about the weight, but the mechanical strength and potential impact to the geometry in the end, and emphasis is on the strength, as I figure the geometry can be sorted out.

Let the comments begin!

DK



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darnthedog
07-06-2014, 12:12 PM
As I built my tab to the Warrior plans with the 20mm through axle per plans I can say you enlarge the tabs to fit the Axles and center point as you mentioned. There has to be enough meat of metal to hold those axles.
As they cannot just be forked like a regular bicycle. They will collapses if the nuts ever come loose.
So mark a center point using your axle nut rather than using the measurements from the plans. Set the nut on your tab so the nut is completely over the tab. Put a centered dot and drill there instead of the point on the plans.
I cheated and did not weld 2 pieces of metal together- I found some scrap 1/4 material to make my tabs. The hole will only need to be large enough to fit the axle bolt through.
Hope that helps.

dkerrivan
07-06-2014, 01:08 PM
I am using 1/2 inch plate rather than welding 2 pieces of 1/4 - local metal supplier had a chunk I can get a few out of for $10 cdn. So I can build one for swmbo if she wants... :-).

Thanks for the input DTD.

I am sort of leaning to mark Brad's center point and then as you suggest center the nut, and extend the bottom (rounded part) down to ensure enough metal to support. This will ensure the space needed for brake arm mounts to weld against. Might take a few pots of coffee and tea to sort this out...and that is half the fun isn't it?

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Twinkle
07-06-2014, 02:40 PM
I am using 1/2 inch plate rather than welding 2 pieces of 1/4 - local metal supplier had a chunk I can get a few out of for $10 cdn. So I can build one for swmbo if she wants... :-).



I used 12mm bar stock as it was drilled and donated to me by the 4 Ducks ( Thanks ) I welded the brake arms to it and angled the bottom of the fork tubes , I found this quicker and easier to jig up and weld together ( together with pre-drilling the holes in the cross boom) .

regards emma

John Lewis
07-07-2014, 04:08 AM
On one of my tadpoles I used drilled and tapped bar stock.
This to my mind was the best but difficult if you don't have the equipment.

On this most recent one I used the tabs. two pieces of 1/4" welded together as didn't have any 1/2".

You definitely need to allow sufficient meat around the axle hole. At least half the thickness of the axle is good.
I just used the TLAR principle. (That Looks About Right).

If you follow Darnthedog's recommendation I don't think you will go far wrong.

John

Neil B
07-07-2014, 06:40 AM
I used two of these

http://www.toolstation.com/shop/Ironmongery/Heavy+Gate+Fittings/Metal+Gate+Weld+On+Fittings+Eye/d170/sd2947/p85824

Saved me a load of work, and the holes were 20mm ish
I just had to delay fixing my gate till onother two arrived

Neil

DannyC
07-07-2014, 07:12 AM
My existing bike has 10mm bar stock as the tabs and it is perfectly ok.
My brother is a fabricator and his view was that if he could use this material as the hinge-pin mounts for wide metal gates weighing over a ton then I was unlikely to have a problem.
I bought a 1M length of 10mm x 50mm bar and now have enough to make many pairs.

I didn't like the idea of trying to drill it in 1 hit so I drilled the 15mm holes in 3 stages (3mm pilot - 8mm - 15mm) with the last being a TCT bit.
All seems good to me.

darnthedog
07-07-2014, 10:26 AM
I used two of these

http://www.toolstation.com/shop/Ironmongery/Heavy+Gate+Fittings/Metal+Gate+Weld+On+Fittings+Eye/d170/sd2947/p85824

Neil
That appears to be Cast metal on that page. How did it weld up? It would have save me from drilling issue I had.

Neil B
07-07-2014, 10:42 AM
It looks cast, but that was a coating on the metal.
They were difficult to weld, as my welder is crap, and does not like welding anything over 3mm. A good welder with lots of amps, would do it easily.

Neil

FrankCrank
07-07-2014, 11:33 AM
...hey Neil, like the idea of using gate mounts, not easy to drill a 20mm hole. On my mk1 I used tabs, but mk2 will have tubes instead :

http://s28.postimg.org/bx58ft3nt/Wheel_mount.jpg (http://postimg.org/image/bx58ft3nt/)

It's a 'work in progress, but think they should do the job. Note, the centre point angle is slightly different for these two methods......

Neil B
07-07-2014, 01:51 PM
Hi Frank
I'd made some tabs,and drilled them 13mm. I was just starting to file the hole, a job I was not looking forward to.
I glanced over to the pack of gate hinge tabs, and had a brainwave. I tried a 20mm bolt, and the rest is history.
One benefit of not having a tidy workbench.

Neil

HHJJ
07-07-2014, 03:18 PM
Mmmmmmm, 2 ideas that resolve the 'I want to build a StreetFox but those tabs look hard to do' issue.
....I do have the plan and the rear end and the tubing....

dkerrivan
07-07-2014, 09:38 PM
Neil, interesting. I gather they are galvanized i.e.: zinc coated?

For a country that is purportedly on the metric system, metric drill bits are exceptionally expensive in Canada. So I will be trying to get as close as I can with the easier to obtain, and less costly imperial stuff. hopefully titanium coated HS bits. As long as the plate I snagged isn't hardened, I should be good.

DK

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