Hacking the Rigol DHO800/900 Scope

[Jajaho]

Hi

I'm here with a quick update on the front cover.
I have attached a quick and dirty render of the first version.
After a test print I will post the cad files on my grabcad page, https://grabcad.com/jakob.holz-1

Please share your thoughts and suggestions.


Have a nice day, bye!

[mwb1100]

I see it has "e2fsck" in the system. Who's brave enough to try to use it?

“e2fsck  -n” will run the command in readonly mode and will not make any changes to the file system so you can get an idea what the corruption is.

[ebastler]

I'm here with a quick update on the front cover.
I have attached a quick and dirty render of the first version.
After a test print I will post the cad files on my grabcad page, https://grabcad.com/jakob.holz-1

Please share your thoughts and suggestions.

Will there be a bit of extra room for adhesive padding strips (felt or similar)? Might be a good idea to avoid scratch marks on the scope, and also gives a bit more tolerance on the dimensions.

Is the Rigol logo on the front raised? How would you 3D-print this -- doesn't the lid get printed lying face-down?

[Fungus]

Is the Rigol logo on the front raised? How would you 3D-print this -- doesn't the lid get printed lying face-down?

You fill it with support material then pull it out afterwards.

[ebastler]

Is the Rigol logo on the front raised? How would you 3D-print this -- doesn't the lid get printed lying face-down?

You fill it with support material then pull it out afterwards.

Not sure how you are envisioning that. Do you propose to print the whole lid face-up, with mountains of support material on the inside and below most of the edges?

Or print if face-down, with a 0.5 mm layer of support material everywhere except where the letters are? How would you remove that material and get a reasonably unmarred surface? (Maybe if you have a multi-material printer and can load a dedicated support material which does not bond strongly with the main layer. But even then it seems a challenging geometry.)

I would rather go with a smooth front without any logo, which you can print face-down and get a nice texture from your printer's bed surface. Or maybe an embossed logo can work, if the recessed areas of the letters are not too wide.

[Jajaho]

Hello and thank you very much for your suggestions.

First I should clarify a couple of things:
1. This design should be printable without any support material.
2. By printing the cover standing up on the bottom of the cover I can angle the top of the cover such that the overhang can be printable.

I have chosen to print it standing up due to two concerns:

1. The latch.
The latch has to be printed such that the layer lines flow parallel to the bending force (please look at figure1 for this).
The latch could be printed this way with the cover laying on its front face but than the latch would have less material supporting it without making it bulkier.

2. The front surface.
It would look very nice with a textured build plate. But with a flat (glass top) which are still very popular this would give it an "ironed" look which I do not like. So the entire esthetic would depend on your build plate, and the goal of a good design is to avoid that.
(although I have to admit thinking about it, a textured look would be very nice  )

3. Round edges.
Round edges with a big radius like here can not be printed lying flat because at the bottom this results in unprintable overhangs.
You could say: "Don't use round angles then." -No, it looks nice. The Rigol design esthetic is very pointy with lots of sharp edges and pointy corners, a slight round over would defuse this a bit imo. (but I'm en engineer and not a designer, so what do I know...).

4. Embossing
The embossing can stick out (like it currently does) or cut in to the front face.
Both have the same problem when printing it attached to a side wall eg. the first line is unsupported (please look at figure2).
But with the logo sticking out only 0.4mm this is less than one layer line width so it will actually be supported.
The problem comes when the wall is printed at an angle (like here) the solution is to add a taper at the bottom so the overhang is 90 degrees.

Note: I will have to ad a steeper bootom taper than it is the case currently to make the model printable.

So those are my thoughts.
I will try the design on an ultimaker 5.
If it works, great. If not, I will try a simpler front geometry and print it flat like you suggested.

Again thank you very much for your suggestions and have a great day.
Bye.

[enson72]

Hi. What about the HDO802? Can it be upgraded? And to which model, if possible?

[Fungus]

Hi. What about the HDO802? Can it be upgraded? And to which model, if possible?

You can upgrade it to a HDO812 with 50Mpts memory. Measured bandwidth is about 200Mhz.

[enson72]

Please tell me, if I have a DHO802, what should I write in these lines?
"rem TESTED on DHO804: RLU BW7T10
rem For DHO914, probably: BODE BW15T25
set options=RLU BW7T10"

I'm sorry, this is my first time doing this

[ebastler]

The "set options=RLU BW7T10", which is already there, should be just what you want. RLU means the memory upgrade, BW7T0 the bandwidth upgrade from 70 to 100 MHz. The two "rem... " lines are just comments and you can leave them unchanged.

[Martin72]

Like this:



Everything else is not necessary/possible.

[Mechatrommer]

Hi. What about the HDO802? Can it be upgraded? And to which model, if possible?

You can upgrade it to a HDO812 with 50Mpts memory. Measured bandwidth is about 200Mhz.

iirc the 802 front end all populated for 4 channels, except no BNC input. am i correct and if its possible to upgrade to 4 channels? by boring 2 holes on the front?

[Fungus]

iirc the 802 front end all populated for 4 channels, except no BNC input. am i correct and if its possible to upgrade to 4 channels? by boring 2 holes on the front?

No idea but would you do it for 50 bucks difference in price?

You'd have to buy two more probes as well...

[Martin72]

Plus chances are high that you have to populate missing parts on the board for ch3 and ch4.

[Mechatrommer]

iirc the 802 front end all populated for 4 channels, except no BNC input. am i correct and if its possible to upgrade to 4 channels? by boring 2 holes on the front?

No idea but would you do it for 50 bucks difference in price?
You'd have to buy two more probes as well...

the damage has been done. he already bought it and seek to upgrade. which one is better? $50 hack? or $100 hack?

[enson72]

The first thing I did in mine was to put an external 92mm ventilator. Got rid of the noise. Attached to plastic ties.

[BlownUpCapacitor]

The first thing I did in mine was to put an external 92mm ventilator. Got rid of the noise. Attached to plastic ties.

Bravo! I like this because it's comical and seems like something I would do. I remember hot gluing an AC-powered soldering fume extractor fan to a DIY soldering iron power unit I built because the PWM control circuit I designed kept getting too toasty.

[enson72]

After the purchase, I monitored the periodic interference in the amplifier. And it was impossible to hear it in the speaker because of the DHO noise. And I get tired of the long noise.

[Fungus]

The first thing I did in mine was to put an external 92mm ventilator. Got rid of the noise. Attached to plastic ties.

Does it blow or suck? What's your system temperatures before/after?

[Fungus]

Bravo! I like this because it's comical and seems like something I would do.

That was my first thought, too, as soon as I saw the VESA screw holes.

(I don't think they'll line up with a standard size fan though)

I've got a couple of really silent 120mm fans left over from a PC build. I might give them a go. I'm not sure which way the air should go though. In or out?

[enson72]

The outer one blows inside the case. The temperature on the radiator in different places is about 38. The temperature of the processor in the DHO interface after warming up to 52 max.

[enson72]

120 will rest on the bottom. DHO stands with a tilt. Therefore, I stopped at 92.

[Mechatrommer]

Bravo! I like this because it's comical and seems like something I would do.

That was my first thought, too, as soon as I saw the VESA screw holes.

i also have a few that size of fans and it will be very easy to do. but since i have no problem with noise yet, i'll keep that for later. what i would like to do in case if i do it is automatic power cutoff when fan not rotating, got blocked or end of life. we can detect this from sense/pwm line in 3 or 4 wires fan. i got the idea from dave's video removing the built-in fan and dso got halted. i learnt this technique from my big printer that was not turning on, i figured its fan got blocked by disintegrating foam meant for sealing... removing those stucked foams, the fan rotating again and my printer is working. i guess its a safety feature, suitable when fan operation is critical. ymmv.

[ebastler]

The DHO800 fan is noisy, for sure, but for some reason I don't find it too annoying. Not sure why.
Also noteworthy is the complete lack of any discussion on fan replacement in the DHO800/DHO900 threads. Go figure.

That post did not age well. 

[enson72]

Updated my DHO802 using the method from #334. Now the frequency is 100MHz, the memory is 50. Tell me, 200MHz won't work?