GW Instek MDO-2000E

[SWR]

I'll give it a shot and post the results when I have received the generator.

[SWR]

I received the Leo Bodner pulse generator tonight ... What a handy little device!

It was measured at 32ps rise time and 27ps fall time.
Well below the specified 40ps.
Well done!

I measured a rise and fall time of 1,22ns on the MDO-2204EX with a low end 50 terminater on a BNC T-adapter.
All my RF terminators are N or SMA and I don't have a BNC through terminator, so that will have to do for now.
It should compare to an analog bandwidth of 287MHz which is above the specified 200MHz.
It would propably be a little bit higher with a proper termination so I'm quite satisfied with that.

It doesn't get warm so I'm going to print a small housing for it to protect the SMD components.

Thank you Leo for a well designed and useful calibrator.

[SWR]

I made a small protective shell for the LB generator and attached the STL file in case some of you want it and can't be bothered designing one.

It clicks together and is held in place by a moderately tight fit between the tiny layer ripples.
It was sliced for and printed on a Prusa I3mk3, so adjustments might be needed if you have a different printer.

[rhb]

Please post a link in the thread Leo started so other people see it.  While not as elegant, the heatshrink should serve me fine.

BTW I was playing with mine and one of the 60dBm.com reflection bridges.  Vary educational.  I discovered that most of my BNC cables were NG and my DEC thinwire 50 ohm terminators were not as good as cheap Chinese stuff from eBay. Most of the BNC cables came out of an aircraft harness.  Most likely replaced for cause rather than retirement of airplane.

[HighVoltage]

I made a small protective shell for the LB generator and attached the STL file in case some of you want it and can't be bothered designing one.

It clicks together and is held in place by a moderately tight fit between the tiny layer ripples.
It was sliced for and printed on a Prusa I3mk3, so adjustments might be needed if you have a different printer.

Nice!
Could you please save the two shell pieces in separate STL files or even better in two IGS or STEP files.
Thanks

[SWR]

I have included the Design Spark files, but unfortunately Design Spark can't make STEP or IGS files.
The program can be downloaded for free from RS-components if you want to make changes.

If your CAD program support many import formats, you can also rename the .RSDOC files to .ZIP and check if you can find something that is compatible with your system.

[HighVoltage]

I have included the Design Spark files, but unfortunately Design Spark can't make STEP or IGS files.
The program can be downloaded for free from RS-components if you want to make changes.

If your CAD program support many import formats, you can also rename the .RSDOC files to .ZIP and check if you can find something that is compatible with your system.

It worked, I figured out a way to use the STL files and make them in to CAD files.
Thanks

[SWR]

Cool.
Then you can post a pair of STEP files.

[grizewald]

I made a small protective shell for the LB generator and attached the STL file in case some of you want it and can't be bothered designing one.

It clicks together and is held in place by a moderately tight fit between the tiny layer ripples.
It was sliced for and printed on a Prusa I3mk3, so adjustments might be needed if you have a different printer.

Many thanks for this, it printed perfectly on my printer (custom CoreXY). I made a small modification to the design and added the specs as embossed text so that I could fill them with black marker and gently sand the surface afterwards to remove the overspill from filling the text.



The effect looks better in the flesh than it does in the picture!

I've attached a ZIP of the revised .STL.

[rhb]

I want three!  1 MHz, 10 MHz and 100 ps pulse.  Unfortunately, I don't have a 3D printer.  If someone reading this can print 3 of these for me I'd be very grateful with payment by PayPal. Or direct me to someplace that will print them to order.

It would be *really* nice if Leo offered these.  I've got heatshrink on mine, but the case would be much better.

Reg

[grizewald]

I want three!  1 MHz, 10 MHz and 100 ps pulse.  Unfortunately, I don't have a 3D printer.  If someone reading this can print 3 of these for me I'd be very grateful with payment by PayPal. Or direct me to someplace that will print them to order.

It would be *really* nice if Leo offered these.  I've got heatshrink on mine, but the case would be much better.

Reg

I'd be happy to print three for you if you want at no cost other than the postage, you could even have three different colours. Then again, if you get hit for import charges, it might turn out to be a stupidly expensive way to get three plastic cases printed, what with you being in the USA and me being in Sweden!

I used Tinkercad (free, web based) to add the lettering to SWR's original .STL files. You should be able to find someone local to you via 3dhubs or you could get Shapeways to print some for you.

Alternatively, you can get perfectly acceptable prints from a $200 Creality 3D printer and once you start, you'll discover no end of useful housings, jigs and accessories that you'll never know how you lived without.

[rhb]

My mother grew up in Stockholm before coming the the US with the Swedish diplomatic service in 1944, so it might be worth any tariff (unlikely) just to say they came from Sweden.  "Made in Sweden" is a big deal to me and my two sisters.  I never had the opportunity to stay in Sweden long enough to  learn Swedish, but both my sisters did.  However, I think you are correct, I should buy a small 3D printer.

I didn't realize that 3D printers had become cheap and good enough to be worth having.  The Monoprice Mini Delta looks as if it would serve my needs very well.  I have a well equipped 150 sq m shop with a full range of tools and tooling for wood and metal.

The Creality reviews I read indicated that they have some issues with ABS in the cheaper models and bed leveling is a hassle.  While they offer greater build volume, I don't expect to be making large prints.  Small custom enclosures or brackets are my most likely build.  And the print times are so long that even if I got a bigger printer, I'd keep the Mini Delta for small prints.

Thanks a lot.

Have Fun!
Reg

[grizewald]

My mother grew up in Stockholm before coming the the US with the Swedish diplomatic service in 1944, so it might be worth any tariff (unlikely) just to say they came from Sweden.  "Made in Sweden" is a big deal to me and my two sisters.  I never had the opportunity to stay in Sweden long enough to  learn Swedish, but both my sisters did.  However, I think you are correct, I should buy a small 3D printer.

I didn't realize that 3D printers had become cheap and good enough to be worth having.  The Monoprice Mini Delta looks as if it would serve my needs very well.  I have a well equipped 150 sq m shop with a full range of tools and tooling for wood and metal.

The Creality reviews I read indicated that they have some issues with ABS in the cheaper models and bed leveling is a hassle.  While they offer greater build volume, I don't expect to be making large prints.  Small custom enclosures or brackets are my most likely build.  And the print times are so long that even if I got a bigger printer, I'd keep the Mini Delta for small prints.

Thanks a lot.

Have Fun!
Reg

In addition to what I said in reply to your PM, I'd steer clear of a cheap delta as they're often more trouble than they are worth. I'd also steer clear of ABS. It's an absolute bugger to print, often requires a heated enclosure to prevent warping and emits foul smelling and toxic fumes while you are printing with it. There are far better plastics available - PLA for things which don't need to withstand more than 50°C during use and PET-G for up to 80°C. Neither of these two emit toxic fumes and neither is particularly difficult to print.

Bed levelling can be a hassle on many printers, particularly so when the designers insist in repeating the mistake of having four connections between the bed and its support. Levelling a plane by adjusting four corner points is nearly impossible. The correct way to do it is with three points in a triangle (which as I'm sure you know, is all you need to mathematically define a plane). First you adjust one of the three points to be your reference and then you use the other two points to adjust pitch and roll.

Given that the actual print surface on most printers isn't perfectly flat to start with, the best solution is to get the print surface as level as possible mechanically and then use a sensor to create a map of the actual bed surface at many points and use interpolation when printing to translate the grid of probe points into the correction needed at any point on the print surface.

[rhb]

I have always considered the delta design a cost compromise.   After your post I spent several hours looking at prices and reviews startng with the cheaper Creality models, some of which compared them to the Monoprice models..  The Monoprice Mini Delta got very high marks from several reviewers.  The small size and speed were a significant plus for my intended uses.  So I bought one on Amazon and a roll of black PLA.

I've been following 3D printing for a long time, but generally unimpressed.  However, I also have extensive knowledge of manufacturing processes of all types.  I'm much more interested in hydraulic (aka rubber) forming of aluminum sheet,  injection molding plastics and casting aluminum.  But for under $200 if it will make usable brackets and boxes that will justify it.

My sister does a *lot* of miniature stuff.  I suspect she will use it more than I.  However, if I start using it for making molds for investment casting or  injection molding plastic that might change.

In general I view 3D printing as a solution for one offs, prototypes and tooling.  Spending several hours of machine time to make a single item isn't really satisfactory if you need a couple dozen of something.  So I've always been amused by the idea of 3D printers for manufacturing.

Have Fun!
Reg

[nctnico]

In general I view 3D printing as a solution for one offs, prototypes and tooling.  Spending several hours of machine time to make a single item isn't really satisfactory if you need a couple dozen of something.  So I've always been amused by the idea of 3D printers for manufacturing.

You can use 3D printers for small batches but getting at that point requires a lot of effort and good 3D printers. The casings for my HF differential probe are 3D printed and they seem to have a nice repeatability. I have outsourced design & printing to an external company though and they went through a couple of test prints to see what works best.

I have always been amused by the idea that you can buy a $200 printer and expect it to print perfect plastic parts right out of the box. From what I've read it won't and even 3D printers which cost 10 times more can be outright finicky.

[grizewald]

It's true that all 3D printers can be fickle beasts. My main printer is a CoreXY design which I've built from aluminium extrusions. It's built like a tank and has the best control systems and parts that I can afford. Most of the time, it makes great prints. However, I can't control the climate and consistently get worse results in the winter from all my printers.

However, I don't think it's fair to sweep all the cheap Chinese printers into the same hat. Many of Creality's 1st generation printers are "nice try, but no cigar", but the revised versions where they have added things like levelling probes are actually superb value for money.

The also have the huge advantage of only needing two main assemblies bolting together and they're ready to go. My big printer took me a long time to build properly and even longer to tune it and get to know the unique characteristics which it has.

The main limitation of FDM printing is speed. There are fundamental limits on how quickly you can lay down a string of molten plastic with +/- 10 micron or better accuracy. Then again, speed is only a perceptual issue. If you did want to mass produce parts with an FDM printer, all you have to do is add more machines! Just look at Prusa printers - they now have 500 of their own printers in their printer farm pumping out parts for new printers 24/7.
For the hobbyist, the only problem caused by FDM printing speed is one of impatience. As my printer is close to silent in operation, if a print takes 72 hours then fine! It's not as if it keeps me awake at night and power cuts are very rare.

 

[grizewald]

My sister does a *lot* of miniature stuff.  I suspect she will use it more than I.  However, if I start using it for making molds for investment casting or  injection molding plastic that might change.

She won't be using an FDM printer for miniatures, the resolution is simply too low. An SLA printer on the other hand is the miniature maker's dream and these days, similarly priced compared to a good FDM printer.