Making your own pcb's.

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zmemw16
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Re: F405 & F411 versions of the BluePill

Post by zmemw16 » Sat Dec 02, 2017 7:00 pm

@Roger
Won’t the heat degamnetize ?
yes it seems so
do i need a magnet inside ? i'm thinking of labs with liquid in flasks being stirred by an external rotating magnet. would (a) steel blade(s) follow an external one ?
Also, it would still need a bearing.
Why, if you mean one with balls, races etc ?
loads are almost zero, steel on brass or copper shouldn't be a problem running dry.
it doesn't really need a high speed to move some air around.
if required high temperature greases do exist.

anyway, pop rivets, find a large one with tension rod of about the size of rod you have, nip it up until it just locks in the panel, might be better to add some washers - you only want to tighten until just begins to bulge, way, way before the snap point and before it fully balloons the end.(tends to bend and shrink the hole.)
release the gun. push the rod back and out.
find a suitable rod and assemble ... ...

stephen

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RogerClark
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Re: F405 & F411 versions of the BluePill

Post by RogerClark » Sun Dec 03, 2017 7:23 am

BTW.

I had a go at cutting a stencil again on my laser cutter, and the results were not that good.

As in the video that victor posted, I used the "scan" setting which rasterises the image into scan lines and sweeps the laser head back and forth across the target area.

I'm not sure if its the material I'm using, but both the white mylar sheet and also a transparent projector side, both get quite a lot of melting around the outside edges of each pad.

Looking at the vidoes on YouTube the silhouette cutters seem to give a better result as they don't melt the plastic and give rough edges around the pads.

victor_pv
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Re: F405 & F411 versions of the BluePill

Post by victor_pv » Sun Dec 03, 2017 4:49 pm

There is a video of someone cutting the stencils with a laser, that besides commenting on having to experiment to find the right power and speed, he eliminated the burns by placing the mylar sheet between 2 sheet of normal paper sprayed with water. The water helps keep the area around the cut cool, so there was no melting in the edges. I don't remember how I found that video though, I'll try to find it again.

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RogerClark
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Re: F405 & F411 versions of the BluePill

Post by RogerClark » Sun Dec 03, 2017 8:56 pm

Thanks Victor ,

Having to play around with the power levels is normal for any new material I put in the cutter.

I have a parameter library for things I normally cut or engrave, like different thicknesses of plywood, but for new things I have guess a power and speed and run a small test cut ( or scan ) and take a look at the results.

For my Mylar sheet, which is a sort of almost opaque white colour, the machine is probably a bit too powerful, as there is a minimum percentage power at which the CO2 laser will strike.

On my machine this is around 10% of maximum power.
The guy at LowPowerLabs has a much more expensive machine than I do. Most cheap machines do not have a setting where you enter the power in Watts, they just have a setting for percentage , which is just a control on the PWM duty cycle that the controller feeds to the Laser HT PSU.

And for most people, max power is they can run the laser is not the 100% setting in the control software, because the HT PSU can deliver more power than the tube can handle , by about a factor of 50%.

So most people have a settings range of between around 10% and 60% in the control software which relates to 0 to 100% power

I have gone to the trouble of putting an insulated screwdriver onto the trim pot in the laser PSU and adjusted it, so that 100% from my controller PWM is 100% sustained power on the laser.

So I get a better dynamic range in my control software.

Nevertheless, it’s still very hard to get the settings right, especially for things which only need a small amount of power, because the power curve on the laser is non linear with respect to drive current


I think you said you have a small LED laser for your 3D printer . If so, I think you could probably cut the white Mylar sheet, as it takes very little power.
However the transparent sheet used in the video seems to take loads of power, as I am using 30%

victor_pv
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Re: F405 & F411 versions of the BluePill

Post by victor_pv » Mon Dec 04, 2017 3:12 pm

RogerClark wrote:
Sun Dec 03, 2017 8:56 pm
I think you said you have a small LED laser for your 3D printer . If so, I think you could probably cut the white Mylar sheet, as it takes very little power.
However the transparent sheet used in the video seems to take loads of power, as I am using 30%
Mine is a 3.5W laser, and seems to turn on with really light duty cycles, so I have a good chance of modulating it just good enough. At 20-30% it can burn wood and leather. As soon as I get a chance at cutting a stencil, I'll post an update.

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RogerClark
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Re: Making your own pcb's.

Post by RogerClark » Sat Dec 09, 2017 9:22 pm

Guys

If anyone comes across the web page (or video etc ) where someone describes how they fitted an internal fan in the T-962 oven, could you let me know.

Searched the web a few times over the last couple of days and can't find that specific modification.
I can only find the firmware and electronics modifications, but not the modification where some makes a small fan and drills a hole in the top of the T-962's oven chamber for the drive spindle to go in from the top.

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