you
in this presentation we look how we can put an internal 90 degree bend in steel cable tray we
know from talking in the classroom that we can use a cable tray bending machine and we know
also that we can buy them from the manufacturers and just bolt them into place so first we're going
to look at how simple it is to put a 90 degree bend in using the cable tray bender and then
we're going to look at how we can overcome it if for instance you're on a building site late in
the day we haven't bought a internal 90 degree bend and the cable tray bending machine isn't
available can we manufacture one ourselves so this presentation is all about trying to manufacture an
internal 90 degree bend in cable tray in order to use this cable tray bending machine we must
use the straight flange variety of cable tray we cannot use the return flange style because
it doesn't fit into the slots in the machine and allow you to pull an internal external bend
on its it has to be the straight flange variety of cable tray in order to use the machine let's
set it up and see that bend so our cable tray bending machine has two supports for the cable
tray itself these slide backwards and forwards depending on the width of the cable tray and
the actual flange is sitting to a groove within the actual side supports we slide it in like so
there is also a bar at the top here to stop the cable tray from flicking up or remove the pin
on the side here you can see that obviously it needs to be prevented from moving away and with
a conduit bending machine as well exactly the same we have an arm in order to pull down for
the bend itself so we lift up the arm we insert the cable tray so we make sure the pin is in place
to prevent the bar from moving up and we pull ourselves on a 90 degree bend it is difficult
for me because I can't step away so I'm going to see an approximate 90 degree internal bend
as I pull down what will happen however as you go to pull it out you tend to pull out slightly
the 90 degree bend or the bend that you require so you must be careful of that as you pull the
tray free from its position like so and you can see I've got approximately a 90 degree bend it
may be that I have to put it back in just to work it or I can just maybe flex into position so I've
created myself a 90 degree internal bend using cable tray bending machine however in this video
I want to show us if we've forgotten to perhaps buy a manufactured 90 degree internal bend or
there is no access to a cable tray bending machine on site can I produce quite simply
an internal 90 degree bend let's have a look at in the next part of the presentation so we saw
in the first by the presentation how we can put an internal 90 degree bend in straight flange cable
tray using a cable tray bending machine we also said in the first by the presentation that you
can buy internal 90 degree bends from electrical wholesalers which can be bolted into place however
we're going to now look at a technique where we have neither options we haven't got a cable tray
bending machine and we haven't bought from the wholesalers and internal 90 degree bend so can
we produce and make one we're going to use a bar this is just a piece of metal I've got from my
engineering workshop so a piece of bar it could be a large screwdriver and there is a slot in
one end so all I've done is used a hacksaw and put a groove slot in one end we're going to use
this in order to make an internal 90 degree bend in our straight flange cable tray so see that
in the next part of the presentation so I'm gonna take my homemade bar so I've got a piece of metal
with a sort cut in it I said it could be a large screwdriver you no longer needed and you've you
put a groove in one end of the shaft of the actual screwdriver itself so either way I've got a groove
in a piece of metal to use as a lever in order to put the crimp section similar to this here of the
internal 90 degree bend in the cable tray the advantage of doing it yourself is that you can
make the bend considerably slower so in other word you could have a more gradual bend than one formed
by the tray bending machine or we could make quite a severe or tight bend it does depend on
the bending radius of the cables that are going to be laid on the tray so see how we're gonna do it
then so taking our bar we've got a point here at the top it doesn't matter where I start I'm going
to do it somewhere in this section here so I've got no marks on the tray at the moment I'm just
going to improvise this internal 90 degree bend position like so so I've got my slotted section
of my bar down on to the actual flange itself and I'm just going to pull it inwards first so
I went in and already you can see that my trays just fractionally kicked up and I've got a kink
in the side of the flange so I went in first I go to the end of the kink section and I'll
bring it out the opposite way so I'm going to pull it towards myself kink again and repeat
the process once more go to the end of the part that's kinked and kink once again so we've now
got several kinks in position on the actual flange itself starting going in first out and then back
in again we'll do one more so we go to the end of the kink section and we pull now back in so
I've done about three in out in out turn it round now and repeat the process parallel with where you
started the last one remembering I went in first lining it approximately up and we went in first
back out and then back in looking from the side on you can already see my tray is started to raise
up we've gone in out in out as we've got a kink section similar to the kinking that was produced
by the cable tray bending machine itself it's going to take me a few moments now to work this
down in order to bring it up to 90 degrees so let's see that in the next part of presentation
so using just a bar with a groove that I'd cut in with a hacksaw and that crimping technique
of managed to produce an internal 90 degree bend in cable tray without the need for a
cable tray bending machine or to buy one from the manufacturer Friday afternoon on
a construction site need an internal bend no cable tray bending machine no wholesaler is
going to deliver you one in time can you produce one simply bar with a groove in it simple in and
out technique on each side and produce me a 90 degree internal bend very similar to the one
that was produced using the cable tray bending machine but I have control over how slow this
internal bend is so if I put less force on my motions in and out I make a more gradual bend
if I needed to increase the bending radius I can put more force on the in-and-out crimps
in order to make a tighter internal bending radius so simple technique in order to put an
internal bend in only using simply modify piece of metal bar I hope this video has been some help
you