Hewlett Packard 'scope black rubber feet

[qu1j0t3]

It seems these things are frequently found broken off.

I think one of my scopes has intact feet to measure, so I was wondering about the possibility of 3D printing replacements.
Maybe this material would work? https://www.shapeways.com/materials/elasto-plastic

Of course, there might be other avenues to get replacements. If so, let me know!

[bjcuizon]

Maybe before printing the feet, first check on the local hardware store as they might have these "feet" already with the matching screws for it. 

[edpalmer42]

I have an HP 1744A scope with feet like that.  I don't know if they're supposed to be a bit rubbery or if they're hard plastic that gets brittle and a bit rubbery with age.  Two of mine broke so I just took them off.

The function of the feet is to prevent anything on the back from touching the floor if the scope is set down vertically.  Electro-plastic doesn't look like it's stiff enough for that.  The feet are also designed so you can wrap the power cord around them.  That wouldn't work either.  Maybe 'Strong & Flexible' would be okay, but I don't really know.  Have you got a quote from Shapeways?  I suspect that the price would not be attractive for an exact replacement.  Maybe better with a lot of simplification.

There's a guy on ebay that sells replacement feet for Tek 465 & 475 scopes.  He has also made feet for other scopes.

If I was going to replace mine, I'd probably just use a steel rod with a rubber foot on the end.

Ed

[qu1j0t3]

Good points both. Yeah, probably a silly idea to 3D print. I think I still have the screws, only the rubber has broken off. I'll sleep on it, thanks for the suggestions.

[bjcuizon]

Oh, so you're talking about the feet at the back of the scope. All the while I was thinking about the feet at the bottom. 

[edpalmer42]

Oh, so you're talking about the feet at the back of the scope. All the while I was thinking about the feet at the bottom. 

I'm not much better.  I just assumed he was talking about the ones on the back.  I forgot that there were feet on the bottom until I looked.    

Ed

[bjcuizon]

Oh, so you're talking about the feet at the back of the scope. All the while I was thinking about the feet at the bottom. 

I'm not much better.  I just assumed he was talking about the ones on the back.  I forgot that there were feet on the bottom until I looked.    

Ed

Hehehe   

[qu1j0t3]

Yes, indeed, the long feet at the back. Stands or stand-offs, I guess.

I'm tempted to find a low-tech answer here pretty much along the lines edpalmer42 was thinking.

[texaspyro]

Search Ebay for HP feet in the test equipment section.   There are people selling clone feet for the bottom of the instrument (without tilt bails) and the back corner feet.   Also people selling real HP feet often with bails).  The clone bottom feet seem to run around $2.50 each in small quantities.  I just bought a couple of sets of 4 real HP feet with bails for $16 each.

The screws for the back feet can be a bit hard to find.  They are  long-ish (42 mm?) with, I seem to remember,  a funky metric thread.   I ordered a bunch from HP years ago.  For the quantity that I ordered (a couple dozen) it had to get management approval...  apparently they don't want outside repair shops competing with their own service department and get antsy about selling "large" quantities of spare parts.

[edpalmer42]

Pyro, you're just teasing, aren't you?  Things are already confused enough, thank you very much!      

No, these are a different type of foot.  I've attached a picture that shows the feet we're talking about.  The closest thing I've found on ebay is for Tektronix scopes.

http://www.ebay.com/itm/Tektronix-465-475-a-b-Custom-Machined-Replacement-Cordwrap-Feet-Set-4-pieces-/182698356817

I just noticed that one of the pictures he posted in that auction shows a set of feet for an HP 1741 scope!  qu1j0t3, you didn't mention what model you've got.  Is it one of the 1700 series?

Ed

[texaspyro]

Shapeways, etc will 3D print in metal for what turns out to be not too insane of a price.   I saw an video where some guy had them print some reverse engineered high security keys for around $20... I don't think that they well print keys anymore...

[qu1j0t3]

edpalmer42, wow. Thanks for the ebay link. I've contacted that seller already about HP feet. We seem to have some kind of telepathic connection because the feet are for 1741A and 1746A.

(I have a 1703A with—unbelievably—intact feet, just a few smashed knobs, including Volt/Div, sadly.)

So, about knobs... These are the ones I need:

[edpalmer42]

Shapeways, etc will 3D print in metal for what turns out to be not too insane of a price.   I saw an video where some guy had them print some reverse engineered high security keys for around $20... I don't think that they well print keys anymore...

If I'm interpreting their pricing correctly, making these feet out of 'Strong & Flexible' (nylon) will cost $7.24 each.  Steel is $56 each.  Aluminum is $101.22 each.  Other metals are more expensive.  That's based on a volume of 10 cm3 as measured by water displacement, 14 cm3 'bounding box' volume and an approximate surface area of 40 cm2.  I'm not sure I believe those prices.  Anyone care to check my calculations?

Ed

[texaspyro]

So, about knobs... These are the ones I need:

I have made replacement knobs and buttons by casting a mold in silicone rubber or even clay and then filling the mold with epoxy.  The tricky part can be working out how to mount them to the shaft.  Knobs with set screws are usually not to bad..  drill a hold and tap it.  Also coloring the knob  to match.  A grey epoxy like JB Weld is OK for most uses.

This all assumes you have a similar knob to make a casting from.   Knobs with clear, labeled skirts are also a pain to do...

[qu1j0t3]

Just ordered two sets from seller "fredusack" as recommended by edpalmer42.

Fred's drawings for HP stands match my measurements and the finished product looks great; this is the current store listing http://www.ebay.com/itm/Tektronix-465-475-a-b-Custom-Machined-Replacement-Cordwrap-Feet-Set-4-pieces/182779038576