RE: [CAD_CAM_EDM_DRO] Robotic Arm

Hi Jon

They say it's no problem to use it double sided. You put the parts on one
side first, flow the solder, then do the other side.

Apparently the back side doesn't get hot enough to melt the solder.

I quite understand the problem of parts getting jammed in the back side, but
normally they put all the flat parts on one side, the chips resistors etc,
then do the other side, so the flat bits are against the chain belt. You
could always just drop a silicon mat underneath like one of those used for
glue guns.



Dr. Mark Vaughan Ph'D. B.Eng. M0VAU

Managing Director

Vaughan Industries Ltd, reg in UK no 2561068

Water Care Technology Ltd, reg in UK no 4129351

Addr Unit3, Sydney House, Blackwater, Truro, Cornwall, TR4 8HH, UK.
Phone/Fax 44 1872 561288

RSGB DRM111(Cornwall)

_____

From: CAD_CAM_EDM_DRO@yahoogroups.com
[mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of Jon Elson
Sent: 28 March 2007 03:54
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: Re: [CAD_CAM_EDM_DRO] Robotic Arm



Mark Vaughan wrote:

> It's strange really that there are so many of us all been playing with

mills

> over the past few months, about to start PnP and reflow soldering.
> I was trying to remember the manufacturers name of my oven earlier and
> couldn't, it is a MADELL.
> The conveyer is just a link chain job formed out of 2mm stainless wire.

You

> could make a jig up to fold links and assemble to do your own.

I don't think I could use this type, as there are components on
both sides. I'd expect the links to bump components on the
bottom side.
The whole

> thing is about 18 inch wide, and the links are probably about 2.5 inch

wide,

> and half an inch apart. The belt travels on rollers and each end,

basically

> a metal rod with several bosses on it, smooth ones in the middle and
> notched, cog like ones at the side to tractor the belt along. A simple
> variable speed motor drives it.
> The heat elements are big bar heaters that generate a lot of heat, but do
> not glow. About 6KW in all. I have thought about building one and using
> fusion heater tubes from photocopiers, a photocopier also has a nice big
> servo or stepper that drives the paper path that would be ideal for the
> traction belt. The elements are mounted in three boxes that sit above the
> PCB, each one being a heat zone, with temperature probes about an inch

below

> them that feed into 3 PID temperature controllers, each driving PWM into
> solid state relays to drive the heaters. The inside of the boxes is all
> painted with a thick hi temperature paint, and the outside insulated with
> something like rockwool, tin foil, and then another rockwool and tin foil
> lined box over the top of that again with fan blown air circulated between
> it and the heater boxes, and out to a vent tube. Finally to standard fans
> blow over the PCB as it exits.
> It's so simple, and they sell for so much money over here, I might even

look

> at making some.

Yup, that's basically what I've been able to figure out from
looking at various pictures on the web.

Thanks,

Jon





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