Hi Nicklas,
I have a large Makino wire EDM with a working envelope of 1200x900x300mm with
UV axes for tapered cutting. I also am looking to update the machine but have
other projects in front of it. One neat feature of my wire machine is edge
finding and locating the center of a hole if re-po
For cost comparison purposes we have custom dies made in China for $900 and
anodized aluminum is about 2x the market price of bulk aluminum. Our
extrusions were anywhere from 2" - 7" wide and we generally had a pallet or two
made at a time.
Dennis
> ---Original Message---
> From
There isn't a need to exchange parts once they are in place. Board
manufacturers get by with flash gold plated connectors because they are lower
cost and the flash plating is only good for so many swipes before the connector
cannot meet its original spec of contact resistance, current capacity,
I second the point about not using a PC. Most of the CNC reliability issues I
see are with backplane card edge connectors for DC servo drives and connectors
subject to vibration/chafing of gold plating and oxidation of tin plating. A
consumer grade PC motherboard is not meant for machine vibra
Hi Andy,
I created a DDS algorithm for our stepper-based robots that would use digital
step rates of 1pps up to 300pps. This was the max speed using the battery,
Freescale driver and steppers we had.
The DDS interrupt algorithm ran on an Atmel 20MHz mega part with 1Hz
resolution. It allowed
Hi Dave,
That's funny. I am an engineer but opinions and others' expertise are always
welcome. That is how I learn. I found some inexpensive HPLC pumps on ebay but
most are sold as-is. You don't know if the seals are any good and if some
yahoo like me tried to push solder paste through it..
Thanks Dave. Thought I would throw it out there. I don't have any experience
with a HPLC pump. What if the geometry were larger and the check valves could
cope with a suspended solid? Think on the scale of a small hydraulic valve
body.
Dennis
> HPLC pumps are made to deliver precise flo
I found a high pressure pump (up to 40,000PSI) that may work with solder paste.
These are readily available on ebay as high pressure liquid chromatography
(HPLC) pumps. A description is here:
http://www.lcresources.com/resources/getstart/2b01.htm
Even if a standard Waters style pump has geom
Andy,
Do you know if the Accupin method is still patent protected? Within the last
year I looked up the ball-in-tube patent and those guys are pretty proud of
their round balls. To me, pins are just as viable. Thanks for the "Accupin"
reference.
Dennis
>
> I think that a multi-pole on
Hi Ralph,
Wow. I had not thought of using thin FR4 and milling it out for a stencil. I
do have some fairly thin PCB material used for multilayer stackup. I'll have
to investigate cutting my own. That may save some time if properly automated.
My only accurate machine is my Bridgeport CNC an
Hi Peter,
I agree with the auger-type metering as opposed to relying on the temperature
dependent viscosity of paste. I'm dwelling on an idea to put a small hole in a
stainless stencil strip and filling the hole under pressure. The small stencil
strip would move from "fill under pressure posi
I have tried laser cut plastic stencils but they are not a joy to use. The
raised cut edges are about 20% higher than the plastic material itself and the
squeegee and paste get caught up on them. It leaves a thin layer of paste on
top of the plastic between the cutouts. Using a $80 stainless
Hi Jon,
I use a manual stencil printer now and it does work pretty well. The issue is
banging out a stencil for all of the proto boards I make. There are about 30
proto designs created per year and since the boards change a bit before they
become final, so does the stencil. I don't see the M
Hi Andy,
What types of diesel injectors are you working with? Direct injection? I'm a
fan diesel direct injection. There are potential uses for piezoelectric
injectors other than just pushing oil. I am looking for a similar injector to
deposit solder paste onto circuit boards.
Mydata has
I'm interested in camera recognition of fiducial marks on printed circuit
boards as well as an upward looking camera to determine orientation of SMT
components when picked with a vacuum head. This can be applied to stencil
printers, solder paste printers, SMT pick-and-places, etc.
The SMT pick
This link is for a reprap SCARA: http://www.youtube.com/watch?v=Cquw7dvR80A
There was a conversation a while back about how many plastic Yoda heads and
other fast prototyped plastic waste would end up in land fills. I see the
above reprap SCARA being a positive and constructive engineering use
Hi Jeshua,
I spent a number of years feeding a Trumpf 4kW industrial laser. It has been a
while but I'll dump what I know.
1. The output of the laser beam changes width as it exits the laser tube. The
industrial machines use a patented fixed length beam delivery system. Think of
this as a
For that matter the build chamber could be sealed off and flooded with shield
gas to reduce waste. You would have the issue of getting rid of the heat but
coolant lines and a chiller work pretty well. There is another company in the
building I work in and they have a thin film vacuum depositio
Did John run it for an hour or longer to be able to repeat the "only one hour
run time situation"? I forgot what the capacity of the borrowed generator was
to compare it to a 15HP weak leg system. Even if the generator varied in speed
and voltage when loaded, one thing should be fairly certain
Hi John,
Too bad you can't connect your machine to a solid 3-ph line to see if the same
issue happens regardless of the power source. I had a handful of issues with
my '86 VMC like loose PC boards, oxidized connectors, etc. Now that it gets
more use it seems to be doing better. Keeping the c
I am making a batch of 1" diameter PC board wheels for use with the 75LPI
Avago AEDR-8300-1K1 quadrature encoder module. The module is a reflective
style and the PC boards are gold plated for reflective purposes. Plating
with gold makes for a very flat surface as opposed to HASL hot air leveled
s
Hi Dave,
I have not found that the rotary phase converter slows in RPM during high low
demands as it is still an asynchronous AC motor and is there is no torque
demand on the motor shaft. I don't think a flywheel would help here. If it
were physically connected to a 3-ph generator it would be
I also replaced my 15HP TEFC bearings with a pair from ebay. Been quiet ever
since. The fan-end bearing was frozen and the balls were gliding on a grease
film against the inner race. It was noisy so I finally swapped them out.
Dennis
> ---Original Message---
> From: John Thornton
Hi John,
Sorry for the delay - just got back from a meeting. I also updated my
email address so I can post again!! My ISP moved to Google services and
my
email address changed. The EMC list had blocked posts sent from my new
address.
I'm guessing your 2.5" facing mill may not be rated at
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