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This is a HOW-TO from a newbie to a newbie, so all you
pro's out there bear this in mind :) |
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Gap construction:
In this instance I must admit to having no knowledge on
building one of these so I took the liberty of following
my very good friend Stefan. His instructions and concepts
certainly are worth bearing in mind and I find his webby
one of the most informative and concise pages on the net.
As in all things I tried to follow the instructions but
found that given sizes over here (UK) don't always agree
with the author's location so its time to improvise. Don't
you just love that word :) This is where you put into the
project a little bit of yourself.
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Now I am lucky in one respect in that the place I work as
available a wide range of talents and skills and always on
the look out, I made the most of these. However there is know
reason why one could not achieve the same success by doing
this alone..
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OK, start time. I visited a pipe engineer and asked him for a
off cut off 6" dia pipe. He handed me a 8ft length of 160mm saying
will this do.. I only want 5" I replied. Anyway orf
I toddle with me pipe. You don't half get some funny looks
round here. Next stop was the chippy, smiling sweetly I ask
if he can cut this pipe into 2 x 5" lengths and 1 4ft length
(always thinking ahead, MKII). Thankfully he obliges, so I return
the unused portion. Next port of call is the coil shop, in there
I ask for 15" of 2" diameter copper pipe, alas they only have 42mm,
(do wish they'd keep to english), Thanking them, I again head for
my next port. The tool maker, he's sweet, I ask him if he can
cut the copper pipe into 2" sections and also square the edges
on the PVC pipe, being a bit cheeky I also ask if he can drill
2 holes into each copper section 0.5" from each end..
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Following day I collect my machined parts :) all polished and
deburred. Cant wait to get home now :)
Looking at the PVC pipe I see no problem in fitting
the first tube section, this is to be positioned in the center of the
PVC pipe wall, however, positioning the 2nd and 3rd etc
proves to be difficult. Quick revise on Stefans page, h'mm they
have to be 0.028 apart, pipes 42mm dia, wall is approx 1mm, how
do you calculate the distance apart on a curve??? After many
hours I concede defeat on this one, so by girlspower I align
the 2nd tube up, mark the hole position and drill two obrounds
(there oval holes ) offering the 2nd tube in place along side
the first one I proceed to set the gap at 0.028. Now to save face
I use a compass to set the distance between each centre bolt then
rotate 180deg on a pre marked center line and it gives me the next
hole position and with the obrounds I have a little to play with....
Each copper pipe is secured by 2 M5 brass bolts with star washers
There the little serrated ones :) These effectively locks the nuts
in place (I hope). Isn't technology wonderful :)
Work to date
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So its back to Stefans page for more instructions, I will emphasise
you cant ever read to much, after all there is no point in re-inventing
the wheel. Now seeing I have 7 copper tubes fixed it seems I need
to separate No1 and 7 by some insulating material. At hand I have
mackrolon but I guess any perspex type would do.
This is secured in place with araldite (2 part epoxy resin). I seem
to remember reading about air flow, quick recap.....
Back to the pipe place and I again ask for a 50-60mm off cut.
this time I get a 6ft length. Not wanting to appear cheeky
I decide to cut this myself. Now the gap housing is 5" long and
according to instructions (Stefans page) I need at least 3-4" at
the bottom for air flow. So with this in mind I cut a 8" length.
Next I need a way of mounting the gap 4" of the table.. Back to work
there I find some Plexiglas rod (wooden dowel would do), armed with this
I head back to the tool man. There he cuts this down into 4x5" length
and taps a hole (M3) 0.5" from one end into each one.
These are then secured to the bottom part of the large PVC pipe 90deg
spacing and provide the required distance from the table, (they also
look kinda sexy as well). Next I place the 60mm pipe in the center and
araldite it to the mackrolon spacer.
Assembly so far
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This is where I deviate slightly from instructions, I intend to mount
my fan on the top, blowing down, and require as much air flow around
the copper tubes as possible. so with this in mind I make a
cone out
of some thin clear plastic. This is glued to the top of the 60mm pipe
and its apex is just under the center fan. I found that opening the
fixing holes on the fan to M5 and using M5 self tapping screws it
produces a tight secure fit on the 160mm pipe. Another rummage in the
kitchen produces some tupper ware containers and by carefully cutting
the lids along there edge in a curve shape produce a section that butts
against the fan and outside edge of the 160mm PVC pipe. These are held
in place by my trusty araldite. Only thing left is to tidy the mains/fan
lead and secure it with some adhesive cable tie bases,
wallooo job complete &
side view
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BellaDonna |
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