42 replies to this topic

[cooperman435]

AND AGAIN Im replacing my current wooden racks with new metal ones.

If anyone is interested in any metal laser cut racks, either in kit form to weld youself (easy to do only 4 joints to do :-) ) or fully made up. Please PM me or post here and Ill put up the pictures and designs.

They will be CONSIDERABLY cheaper than any Ive come across before as Ive a friends workshop cutting and bending them for me at mates rates but the more I order at once the cheaper it will be.

Im making all sizes from 2" to 6" but onky curently in straight racks with 10x2", 8x2.5", 8x3", 6x4", 5x5" and 4x6" per rack.

If anyone desperatly wants anything diferent I can change the plans of them to suit easilly, and can make fan racks too if desired ive just not gotten round to it yet.

Bonus is they appear to be ending up lighter than my wooden racks are now due to the very well engineered design we have made.

Pictures etc if interest is shown.

Phill

[martyn]

Always interested to see peoples rack designs, especially an 'inventors'
Don't want to get your hopes up though, don't need any more so won't be buying.
Would be great to see pictures, I remember having a huge dose of rack envy when Digger posted pics of his stainless ones!

[digger]

And here is the gratuitous picture again, although a few more have sporned since this photo was taken.

[Spyrotechnics]

Digger - out of interest do you use anything to hold the racks together??

[barnsley-mark]

Nicely made, these will be so much easier to handle and stack in vans etc. well impressed

[cooperman435]

Hopefully on thursday but more likely friday/monday Ill have one to collect so Ill take pictures and then make it up for a show and tell :-)

[digger]

Digger - out of interest do you use anything to hold the racks together??

If I were to do them again, I would change the design a little.

When upright I just bang a few stakes (long metal spikes) through the uptright tubes at the ends of the racks, this seems to work fine. (Yes I know there are several schools of thought and some ratchet strap banks together, there is no reason why this can't be done). I guess U shaped stakes would also do the job

I do have some end plates made up for slotting the racks onto again through the end tubes for fans.

The sandwick construction of the base is so strong that even when angled with stakes through the end tubes there is no issue at the base of the mortar.

The main part of the design was to try and remove any structural part of the rack which could be in direct contact with a mortar rupture hence the low profile bottom sections (below the level of the plug in the mortar).

Nicely made, these will be so much easier to handle and stack in vans etc. well impressed

Thanks, That was one of my main design criteria, it also helps when combining different sizes in a fan.

[Spyrotechnics]

I guess U shaped stakes would also do the job

Yes thats what I was thinking of

We have looked at the liles of Pyroquip but weren't too sure and had looked at getting our own made but the cost of laser cutting seemed to make all but huge orders very expensive

Edited by Starsky72, 23 May 2012 - 09:33 AM.

[digger]

Yes thats what I was thinking of

We have looked at the liles of Pyroquip but weren't too sure and had looked at getting our own made but the cost of laser cutting seemed to make all but huge orders very expensive

I found laser cutting to be reasonable value. I admitedly had the plates (3 per rack) cut for 75 racks in one go. This cost £1400 this included the cost of the stainless steel (for 225 plates) including VAT. The cost of the tubular materials was on top of that. I work at a refinery that spends up to millions per year on stainless products so I get good prices on the tube. Maybe I got a good price on the cutting by association.

[cooperman435]

Well faster than I though I have a 2" prototype now.

Pretty much all there but for a few minor adjustments to make welding easier without having to grind anything first and one hole slightly off from where it was supposed to be.

Base is 3mm and the sides and top are 2mm thick, weight is actually less than my 2" racks were made in 25mm plywood which is suprising and nice too.

the small pairs of holes are for a loop of metal to be welded into to act as the tie down points for leaders or igniter wires btw

Tell me what you all think

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[martyn]

I like them, they look very strong.
A few thoughts, NOT criticisms.
I could not tell from the pictures what the tubes would be bearing on, presumably ply or something fixed inside the lip of the bottom channel. Is this replaceable with the uprights welded on, or does it need to be slid in from the end.
The deep channel looks as if it would present a large surface area in the event of a shell failure in the tube, this may or may not matter.
Is there plenty of room to get your hand around the upper channel to carry them when they are loaded with tubes, and you would not want that inside edge to be sharp. It's also often handy to have a grip of sorts along the ends to shiggle the rack into position, but that's a very minor point.
Are you going to galvanise them, it looks like a lot of surface area, but perhaps no more than conventional box section.
Out of interest, is the chanel a standard section, or have you had it bent for the job.
Would it be an option to punch up the tie points, it looks like that has been done on Diggers.
Overall they do look very professional, impressive.
Thanks for sharing.

[cooperman435]

I like them, they look very strong.
A few thoughts, NOT criticisms.

I could not tell from the pictures what the tubes would be bearing on, presumably ply or something fixed inside the lip of the bottom channel. Is this replaceable with the uprights welded on, or does it need to be slid in from the end.

The deep channel looks as if it would present a large surface area in the event of a shell failure in the tube, this may or may not matter.

Is there plenty of room to get your hand around the upper channel to carry them when they are loaded with tubes, and you would not want that inside edge to be sharp. It's also often handy to have a grip of sorts along the ends to shiggle the rack into position, but that's a very minor point.

Are you going to galvanise them, it looks like a lot of surface area, but perhaps no more than conventional box section.

Out of interest, is the chanel a standard section, or have you had it bent for the job.

Would it be an option to punch up the tie points, it looks like that has been done on Diggers.

Overall they do look very professional, impressive.
Thanks for sharing.

Indeed yes the tubes are sat on 1"ply, which we have now incorperated a cutout on the side panel to allow insertion after welding, this it to allow replacing of it later in life and the ability to galvanise, electroplate or powdercoat them as 100% metal parts, painting could be done with the wood there if wanted.

the dep chanel was one thing I picked up on too but after looking online at NUMEROUS tube failures they ALL filaed some distance up the tube, never that I saw directly at the base, this said dont forget theres a 1" stand off from the bottom of it to allow the wood so a 80mm deep section has just 55mm length of tube inside and then theres the plug of around 1.5" for the 2" tubes in question. This leaves just 17.5mm of "tube" inside the bottom section. larger tubes have an increase in depth to take the extra forces but are made to take the plug depth into acount too.

Also with the new side entry point for the wooden base there is a venting place fro gasses rather than the sealed box we have on this one.

Laser cutting doesnt leave burrs, the edge is not "sharp" but if you ran your hand down it at full pressure you could cut yourself, Im planning on running a sanding disk down the edges we will grab with my anglegrinder before construction starts to make sure there safe though. yep there easy to grab from the sides.

galv, electro plating, powder coating or painting, its up to whever wants them I can get the lot done easily, cost could be prohibative but if loads done at once then cheaper. Powder coating is my favourite option as colours are nice :-)

the whole thing is made from 1 peice of laser cut 3mm (for the base) and 3 peices 2mm (sides and top) sheet steel then bent into place.

Im putting 4mm bent wire loops into the two holes to act as tiedowns, if pressed up from the sheet its self we considered it a loss of structural strenth and would have added quite a bit of cost too. this way you can use them as is or put the wire loops in as I will do as such a prominent loop is a lot easier to use I find.

Ill do destructive testing once a full set is delivered as we were ironing out the bugs in this one first, I think I already spotted most of the issues you found but if anyone sees more PLEASE say now or ill go into full production with an easilly trectified fault :-(

Phill

[Spyrotechnics]

Very nice job! What method are you using to link the racks together ?

[Spyrotechnics]

also, do you plan on making 50mm, 65mm, 75mm & 100mm all the same height/width?


cheers

Stuart

[cooperman435]

links can be made if I later decide by putting a single hole in the side of the rack and welding a nut behind it which will allow a both to be screwed in through a rod with holes. If when Ive tried a few I decide to do this then I can get it added to subsiquent cutout orders free.

They are all differing heights as the tubes will protrude the same given height above the rack top, this is mainly to make the largest side opening possible to allow escaping gasses from a CATO. Ill be able to fasten together same sized racks but not diferent as they will alter in length.

ALL my old racks are the same length but its impractical to now have them the same height or length really and would add a lot of weight/cost to these ones