Wanted - Folding press for G3 Coach construction

[keith Bristol]

Morning All,

I am working through the production of some coaches, Having built a prototype it has been demonstrated that i need a home workshop size press to fold 90 degree turns in up to 2mm steel aluminimum.

Does anyone have one they wish to dispose of / know of one / suggest a source. I dont really want a new one as the budget does not allow it and I am trying to keep costs down for the batch.

Keith

[IanT]

Interesting question Keith - as I assume you want to fold a complete full length carriage side - and not segments.

In this case (dependent upon prototype) you are going to need something nearly 3' long. This is a bit longer than most machines in the "home" marketplace. I have a 3-in-1 machine that will "fold" 18" - but I would not recommend this type of tool for what you need. It is effectively a press - with movable 'teeth' pushing the metal down into a 'V'. I'd suggest that you need the type where the metal is pre-clamped between two edges - and then an arm moving through 90-110 degrees actually folds the edge up.

I've had a look around and Warco do a 48" folder that looks as if it works on this principle - but at 1600 pnds - it clearly fits into the unaffordable category.

I think your best bet would be to call the larger used machinery dealers - they advertise in Model Engineer (I can provide details if you need them) and see if you can get a commercial tool for a reasonable price. I'd guess most ME's don't want to fold this size of sheet - so they may not be too expensive.

Otherwise there are several DIY designs out there that would work at 3' width. If you can weld (or know someone who can?) - then this design looks pretty simple, being made mainly from angle. There is an exploded diagram you can download in PDF format and then you just decide the overall dimensions required.

http://www.millerwelds.com/interests/projects/bending-brake/

Regards,

Ian T

   

[AllWight]

Hi Keith

Just a thought when I have built my 00 coaches I used a pair of bending bars admittedly they are not as long but could you not rig up some lengths of 50mm steel angle and attach the rig to a vice or alternately you could try popping down to your local preserved railway. They usually have a plethora of machines for forming metal to shape particularly in carriage workshops. Ask them nicely and in my experience a box of biscuits works well as bribery/incentive, but you never heard that from me.

Mark   

[IanT]

Actually Keith, I'm being daft - Mark's suggestion of 'borrowing' some machine time is the cheap/easy solution.

This is the sort of thing that any 'Poly' that teaches sheet metal work will have. In my experience the Instuctors will normally be very open to someone with a specifc 'hobby' job to do - provided you keep it reasonable. I know metal work has gone out of fashion somewhat - but I certainly saw this kind of tool at Bracknell Tech when I was there doing my welding course a year or so ago - well worth a try.

Regards,

Ian T

[midnight miller]

Hello Keith

Try asking round the vintage car lads , There ought to be an old time sheet metal shop still about .


                                                        John

[keith Bristol]

Thanks all.... You are right there are four folds the full length of the coach which for the Mark 1 is 860mm long! The two long edges on the chassis I have folded but in future I will get the laser cutter to do. The issue is with the long folds on what forms the base of the coach sides and attached them to the chassis.

I had found the warco folder and I too immdeiatley moved on. They shut the tech college workshop here and I did know a few of the tutors. maybe i can get my son in law to ask around the Bristol Model Engineering society?

The latest progress on these is that the 8 chassis are folded and built and I am about to order some bogie sides and buffers that were seen in the latest magazine.

Cheers Keith

[Ted Sadler]

I was talking to Alan Marsden today, who has built several Mk. 1 carriages. He said that he cuts small slots in the fold-under base and turns them individually on a standard fly-press.

Regards, Ted

[andrewfoster]

I've found that the simple manual folding presses are hopeless for long folds, even if you add a finishing press in the brake, especially in that kind of thickness. The problem is that the folding press is never stiff enough, and will bow in the middle, with horrible results. I added stiffeners to one: it was better, but still wasn't good enough. There are larger and better presses available, but at a considerable cost. I now have anything on the Gnome bridges over 12 inches done on the huge press that the laser cutter has, and the modest cost is worth every penny. If you have a friendly sheet metal fabricator in the neighbourhood it would certainly be worth asking if they'll take in a relatively small job like this.

Andrew

[keith Bristol]

Ted

That sounds a good option, I will build it into the design...... I am about to have a batch of coach bodies water jet cut so simples!

Andrew...

Thanks

I will try teds on the pre production run but I was planning to ask the cutter to do it long term anyway on the chassis as this is on view.

Cheers

All

[IanT]

I think Ted's suggestion is a good one too - but you do of course need an 'open-ended' press or folder, so that the carriage side can be slid sideways to do the incremental folding. It wouldn't work on my 3-in-1 for instance, as the press 'sits' inside the machine frame - and this is true of most folders too.

I'd guess Alan M uses a simple V-block under his fly-press and so there is no side 'frame' with this set-up to obstruct the movement of the carriage body.

Regards,

Ian T