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Novel tyre rack design

Posted: Sat Jun 01, 2019 8:55 am
by Fred
Looking at the steel racks at the local workshop all banana shaped from load and impact over the years and insufficiently strong construction using light angle iron for the supports.

The issue with angle iron is that it is at its weakest 45 degrees between the faces, exactly where a tyre in one of those racks exerts its force.

I was pondering that and realised that what we call Warratah stakes or Y-posts, used for wire fences on farms, are ideal. They are higher tensile than normal steel, and with two edges against a tyre have a backbone in the perfect perpendicular direction to remain stiff. Mint.

So I bought 4 the other day, 1.8m galvanised variants. The tar variants are sticky and messy, plain/raw not available. Undrilled also not available, but likely not a big stiffness hit anyway.

Tonight I measured, cut to length, and ground the zinc off the ends ready for welding.

Vertical straps will be 50x3 mild steel flat bar screwed extensively into the floor joists. These have front-rear stiffness, but no side stiffness, so sideways will need some bracing/triangulation.

Tyres I need to store are:

1) 635-650mm diameter ute/nissan/mazda
2) 550mm suzuki/starlet
3) 410mm+ (15") wheels

Figured out I want about 300-350mm spacing between the inner edges of the Y-posts and the angle matched for 650mm tyres, with centre-to-wall spacing at half of 660mm for worst case.

Joists have 150mm from bottom to 50mm insulation now embedded between them. Tyres need to be able to pass over the Y-posts without binding on the insulation.

So the straps should be 700mm which gives a little clearance rolling each into place once complete.

37mm across the smaller dimension of the Y-posts.

The closer together I have them, the less the tyres will hang down below them once placed on the rack, and the more space for stuff below to share the room. Also the less wedging effect, another design flaw in the workshop racks which have the tyres way down in there for max stability at the expense of reliability of the rack longer term.

Math time:

650 / 2 = 325 = distance between centre of Y on once side and the other.

30 degrees from vertical / 60 degrees from horizontal = angle for Y-posts to be welded

Bottoms of 50x3 flat bar should be radiused for safety.

Pieces of flat bar broken down for car fitment are 2175, 2190, 1660 and pieces to cut out are 700mm +/- a little.

Looks like I should take 3 from the 2175 piece, and one from the 1660 piece and keep the 2190, 65, and 955 mm offcuts for the future. I'll do that on the chop saw tomorrow.

Then welding the Y-posts on at the right angles and 30/60 degrees, cleaning up the sharp bits, drilling holes for screws, holes for bolts for front-rear ties, cutting front/rear ties, bolting it together, testing with a tyre/wheel, and screwing it into the building.

Will also need at least one stay to the side, but I can add that later if required. Maybe it'll be okay without it - we'll see.

Pics of steel and ground Y-posts:

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Re: Novel tyre rack design

Posted: Sat Jun 01, 2019 11:02 am
by Fred
Tyre rack is going here, with the 50x3mm vertical straps hanging on the outside of the two most extreme joists between the speakers.

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The Y-posts are 1745 long, minus 5x45 joists and wasted space caused by them.

Re: Novel tyre rack design

Posted: Mon Jun 03, 2019 11:20 am
by Fred
Yesterday, came suddenly: https://www.youtube.com/watch?v=NrgmdOz227I

Straps cut and cleaned:

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Tacked, welded, etc:

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Marked, punched, drilled, chamfered:

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Brace holes drilled:

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Nearly done:

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Hung and braced:

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Done and filled up already:

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9 wheels and tyres in there! 4 large, 5 small. All but one of the large ones were floor space takers, now sky high and out of the way. Win.

But what about today, I hear you asking? (I jest, no one reads this except me) Next post.

Re: Novel tyre rack design

Posted: Mon Jun 03, 2019 12:44 pm
by Fred
Shelf for below the rack:

Procurement:

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Bracing:

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Installation, legs:

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Not fully utilised yet, but already making a positive difference. With the trans off the KL-ZE I can now nose the KP60 up to the BMW front-cut and close the doors behind it without manoeuvring around. Win.

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