Thread: Need advice re drilling from engineers

My camp'o'matic is less than 750 kg loaded with about 70 kg ball weight. I don' t think it will worry the hitch as it is for all intent a new hitch.

I made the hitch with less drop to minimize the length increase which will end up at about 60mm from the stock 220 mm. The 330 mm hitch I bought still has AFAIR 2250kg rating, so 280mm is a non issue. I am trying to minimize the length increase by raising the pivot point which brings the door away from the winch mount which is high, so every mm you can raise the hitch means a mm more clearance.

The other consideration is I can flip the small drop hitch if necessary but not the one I bought as the door fouls on the mc hitch. My research found that there is only one drop available in longer hitches. That is why I did it to try and minimize the length increase.

I would defy anyone to be able to be able to tell that the hitch is not as supplied by a hitch manufacturer. The new shape is even stronger than the one I bought as the weld is more in compression than the vertical weld ,as it is on a 45degree angle and also longer. The hitch at 220 mm had a 3500 kg rating.
I guess I am a bit of a perfectionist but I see enough value in being able to open the door fully with the camper trailer hitched say at lunchtime , without raising the lot with the jockey wheel to offset any loss of departure angle. It is all a balancing act as I couldn't mount the winch lower or further back as the handle has to clear the front tool box.
Regards Philip A

To Tombie. I don't see any need to check as the hitch is made of stock hitch components and welded by a trailer company who weld towball mounts to trailers every day. That is why I had them do it as there are few places around who have the BIG welder , experience, and qualified welder to do something like that.
Also, as above the camper weighs less than 750 kg with small ball weight .
In any case in a worst case scenario I have very beefy cross over chains with 1tonne rated shackles but I am very sure that it won't happen. I don't take chances.
I have to laugh about standards a bit as the long 330mm Chinese Supercheap receiver came in a nice box with specs on the outside, stating the pin hole is 16.5mm. Funny that my 17.2 mm 11/16 bit fitted straight through.

I have seen caravans with 200 kg ball weights and equalizer mounts on 330mm hitches, which makes me grimace.
Regards Philip A

Sounds to me like you have taken all precautions, particularly if you keep your extended hitch exclusively for use with the lightweight camper trailer. You didn't mention the wall thickness of the 50mm SHS, I would be using the heaviest available, which I think is 5mm.
The issue with extending the hitch insert is not so much in the strength of the insert itself, but the increased moment applied to the attachment points at the chassis. Safety chains are usually attached to the towbar assembly, so would be small comfort if the bolts mounting the towbar to the chassis failed due to increase in leverage acting on them.
The original owner of my 130 had fitted a hitch insert about 600mm long because of the big rear overhang, absolutely ridiculous. I'm in the process of extending the drawbar on my camper trailer as a much more sensible solution.

Originally Posted by lr110qld

Much better to use a rotabroach than twist drills for that kind of work.

A decent drilling machine and rigid set-up will drive a small drill like an 11/16" through mild steel in one pass without a pilot hole. 500 rpm is about the right speed. If your machine doesn't have a coolant system, use an oil can and some Dexron, or EP diff oil diluted with laundry detergent and a bit of water. If deep hole drilling ( 2 or 3 times diameter) you need to be able to flush chips out of the hole. The diff oil mixture is good for stainless machining.