400mm V band clamp, how to make?

I want to hold two large disks of plastic (acrylic and Delrin) one of which has an O-ring set into its mating face. Whilst its possible to have an array of fixings around the periphery my preferred method would be to use a custom V band clamp.

I say custom because I cannot find any supplier of a non rusting clamp about 400mm diameter. They only seem available up to about 150mm.

V band clamps usually have sloping internal faces to axially compress the two flanges together but in my application the O-ring is very soft and a ring rolled out of extruded 'U' shaped aluminium channel (say in four separate quadrants) would be perfect.

I can fine tune the thicknesses of the two disks to use a channel section about 20mm internal width and about 10mm deep but I'm looking for a method I could I use to 'roll' or bend into a circle?

Image shows a typical V band clamp (On mine if the joint faces are all parallel then there is no need for any great tension to hold it closed).

Sorry for the long description, I'm looking for ideas really

Ian P.

Ian - have a look at **LINK**  (Neophix.co.uk). They reckon they do up to 2000 (2m) dia, and a wide choice of fastening methods.

No connection - just found them with a search using Google.

Edited By Keith Long on 09/04/2022 21:53:12

These people claim to go up to 2 metres, but I'll bet they aint cheap Neophix

I used very similar on big vacuum systems, place in Bala North Wales was our go-to supplier, but it's a long time ago

Well spotted and thanks Keith.

I've had few Googling sessions over several days and completely missed that company. I will contact them on Monday and enquire what their minimum order value is as I only want two or three of these clamps.

Ian P

The type of clamp illustrated is similar to the type used to secure lids on metal drums, there seems to be several advertising, but unhelpfully sized by drum capacity. Might be worth a call?

Robert Butler

I have some blue plastic storage barrels that use these V band type clamps but nobody seems to make them in stainless steel. A pity, as they would otherwise be ideal.

Ian P

Take a piece of flat or square or rectangular bar. Roll to the correct OD. Secure to a rotary table or similar and mill out the inner part (woodruffe cutter, T-slot cutter, horizontal cutter held in vertical arbor) to form the channel. For aluminium, a wood router and suitable jig would do it if your mill cannot accommodate the 400mm dia.

Buy a Mikalor-type clamp and cut it half. Fix to the beginning and end of the fabricated channel (IME, the securing bolt or trunnion or both of a stainless Mikalor clamp is sometimes not stainless).

If you need sealed containers can you not buy the type with screw on lids that have a sealing ring fitted in the lid?

On the sailing boat we have them to hold all the items in case of a sinking in far waters. They are about 30" by 25" dia.

You're looking for "Vee clamps", used to make thousands at 'Smith & Johnson' taken over by 'Eminox'. These people may be able to help :- https://abbeyclamps.co.uk/products/bolt-clamps/v-band-clamps/.

Easy to make if you have a ring roller with shaped compression rolls.

Regards Ian.

I dont have any way of rolling my own rings (or any way of milling a 400mm diameter ring!) so will make enquiries at the two companies suggested.

Ian P

Greetings, would a string of sturdy cable ties do the jib?

Regards

Brian B