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Post by loub on Nov 5, 2023 17:08:43 GMT 10
I thinking of drilling a 32 mm hole using a hole saw though the sides of my vans 6 inch chassis in the middle of the side.Towards the rear of the van.My chassis is a continuous 6 inch dural steel from the draw bar to the back.I read it here or on the old site as long as you dont touch the top or bottom of the rectangle steel rail you don't weaken it.Is this right.
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Post by jr on Nov 5, 2023 17:26:04 GMT 10
Hi loud, It would probably be OK if it is far enough distance from the suspension mounting location and close to the rear and you don’t have a big box or something heavy hanging on the back. I assume you are talking about DuraGal which has a light gal coating on the outside no gal inside. Why do you need a 32mm hole? JR  |
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Post by loub on Nov 5, 2023 19:32:05 GMT 10
I want to run a pipe though it.There will de no weight other than the pipe.
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Post by bazza44 on Nov 6, 2023 7:44:13 GMT 10
Peter I don't know what the pipe is for but have you thought of going under the chassis and back up again using elbows to form a sort of S trap. It is common for a shower outlet to be done this way.
Barry
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gerrym
Seasoned veteran
Posts: 404
Location: Brisbane
Tow/Motorhome: MUX
Caravan: Billabong Grove 16 ft
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Post by gerrym on Nov 7, 2023 7:31:57 GMT 10
Not sure about steel, but in timber and concrete, it must be no more than D/4 and in the middle 1/3
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Post by Old Techo on Nov 7, 2023 8:07:45 GMT 10
Peter,
You are referring to drilling within the neutral plane of a beam. That is the axis of a beam where there is no stress when the beam is flexed.
A beam under load is stressed with one side compressed and the other side stretched. The very centre of the beam is largely unaffected.
This is much easier to imagine with an I beam where the top and bottom are thick and heavy and the 2 kept apart by a thinner web.
A rule similar to Gerry's exists for steel beams but we are getting into engineer's territory.
I read JR's question more to be why '32mm' rather than why do you need it.
My question is do you want a hole through both sides of your chassis rail or just one side? Chassis makers do often drill holes in one side to permit wiring runs.
My other question in my mind is exactly where you want any holes in terms of loads i.e. suspension attaching points.
If any holes are drilled they should be in the neutral plane i.e. the vertical centre of a symmetrical beam's depth. Your beam is 6 inches so the mid-point is obviously 3 inches.
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Post by loub on Nov 7, 2023 22:00:14 GMT 10
Yes OT that is correct,in the middle of the neutral plane though both sides.The area is appof 3 ft from the rear of the van,way pass the suspension and the back water tank.I don't have any extra structures on the rear of the van to put much weight there.
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Post by Old Techo on Nov 8, 2023 7:05:45 GMT 10
Peter,
If yours looks anything like this Golf are you talking about a position roughly where I have shown here?
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Post by loub on Nov 8, 2023 8:29:15 GMT 10
Similar but behind the rear wheels by a foot or so.
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Post by Old Techo on Nov 8, 2023 8:37:30 GMT 10
Do you mean more like the green arrow position
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Post by jr on Nov 8, 2023 11:08:33 GMT 10
I expect what you require is similar to the attached photo, but your hole would be in the centre and through the main chassis rail. This 32mm hole is in my chassis cross member and has very little loading but I made the hole a little bigger and inserted a pipe with a 32mm plus inside diameter and welded the pipe all the way around to stop water getting in the chassis and also gives it a little more strength.  JR |
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Post by loub on Nov 9, 2023 6:34:50 GMT 10
I expect what you require is similar to the attached photo, but your hole would be in the centre and through the main chassis rail. This 32mm hole is in my chassis cross member and has very little loading but I made the hole a little bigger and inserted a pipe with a 32mm plus inside diameter and welded the pipe all the way around to stop water getting in the chassis and also gives it a little more strength. JR Yes about there out. |
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