Another small project biopsy simulator grabber

implmex · Mar 20, 2020

Hi All:
Here's another project I was given to make recently.
It is part of a prototype grabber mechanism for a surgical simulator.
Milled on a Minimill with a 6K spindle and then cut off on the wire EDM.
( A faster spindle sure would be nice!)

Apparently I'm the only shop in Vancouver of all the ones contacted by the customer who was willing to take it on.
17-4 PH in condition H900 and I now have to polish it and build the housing for it.
The compression spring that goes in it has an OD of 0.89 mm and is 2 mm long.
Don't breathe too hard or it'll blow away!

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

CAMasochism · Mar 20, 2020

Impressive for sure. Also, get a more powerful macro camera lens please.

trevj · Mar 20, 2020

Egads man, you do some really cool stuff!

Thanks for posting that!

henrya · Mar 21, 2020

Damn!
Only way I could make that is to buy one from you.

GregSY · Mar 21, 2020

My first step in making that would be trying to see it.

TeachMePlease · Mar 21, 2020

Neat! I can't believe everyone else no quoted... Is there no medical stuff there?

implmex · Mar 21, 2020

Hi TeachMePlease:
There are a couple of factors that make the situation in our town what it is.

First, I have no idea how many shops the customer actually contacted but I do know there are not that many around these days.

Second there are no drawings, only crude Solidworks models and I have built versions one and two of this project so they have a history with me.

Third, I'm only making one prototype; most reasonably equipped shops are totally uninterested in taking on such a small project...they want to make hundreds or thousands, so they quote very high or not at all, and they have lead times measured in multiples of months.
I am a semi-retired old fart who likes this kind of challenge, so I play in my man cave full of obsolescent toys and make some pin money to keep my Lovely Wife in milk and cookies.

So I mine the opportunity this presents; I know I cannot hope to compete on production except under special circumstances; I'm way too fucking cheap to modernize my physical plant (my newest toy is vintage 2011), and I'm no longer too eager to kill myself to get a hot job out...I've been doing this for over 40 years and I figure it's time to mellow a bit.

Since I like to solve challenges, this kind of work is perfect for me, and there is enough to keep me plenty busy.
I doubt a REAL shop could make enough money to survive at it though...the couple of bigger prototype shops that once existed here all seem to have gone the way of the dodo, and most small players are lucky if they have even the basic gear, so I don't have much in the way of competition.
Besides, most machinists in this corner of the world freak out if the drill is under 1/2 inch diameter...they typically make bigger chips than many of the parts I make.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

Tyrone Shoelaces · Mar 21, 2020

The one that went up my ass to take a sample of my prostate was a fair bit bigger than that one.

Regards Tyrone.

Dieseldoc · Mar 21, 2020

And had bristles and a hand crank attached. :cryin:

Tyrone Shoelaces · Mar 21, 2020

Dieseldoc said:
And had bristles and a hand crank attached.

It certainly felt like it.

Regards Tyrone.

rcoope · Mar 21, 2020

As another customer of Marcus's as well as running a research shop that does a lot of weird parts, I can attest to the fact that when your parts get tricky and you need them in onesie twosies, it's hard to get anyone to quote, even in the US. Once you go to production and are ready to write $100K PO, it's possible to get into development work with ISO medical device shops, but those first few parts are hard to get. Having said that there are definitely not a lot of EDM shops here, so that's one of Marcus's unique capabilities.

TeachMePlease · Mar 21, 2020

implmex said:
Hi TeachMePlease:
There are a couple of factors that make the situation in our town what it is.

First, I have no idea how many shops the customer actually contacted but I do know there are not that many around these days.

Second there are no drawings, only crude Solidworks models and I have built versions one and two of this project so they have a history with me.

Third, I'm only making one prototype; most reasonably equipped shops are totally uninterested in taking on such a small project...they want to make hundreds or thousands, so they quote very high or not at all, and they have lead times measured in multiples of months.
I am a semi-retired old fart who likes this kind of challenge, so I play in my man cave full of obsolescent toys and make some pin money to keep my Lovely Wife in milk and cookies.

So I mine the opportunity this presents; I know I cannot hope to compete on production except under special circumstances; I'm way too fucking cheap to modernize my physical plant (my newest toy is vintage 2011), and I'm no longer too eager to kill myself to get a hot job out...I've been doing this for over 40 years and I figure it's time to mellow a bit.

Since I like to solve challenges, this kind of work is perfect for me, and there is enough to keep me plenty busy.
I doubt a REAL shop could make enough money to survive at it though...the couple of bigger prototype shops that once existed here all seem to have gone the way of the dodo, and most small players are lucky if they have even the basic gear, so I don't have much in the way of competition.
Besides, most machinists in this corner of the world freak out if the drill is under 1/2 inch diameter...they typically make bigger chips than many of the parts I make.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

I totally get what you're saying.

I was tasked with making something very, very similar in appearance and size...

Only, I need to make a LOT more of them

Making the first one is fun. Making the next 9,999 is less so. I wouldn't mind being in your position in about another 30 years. We'll see what life brings.

GregSY · Mar 21, 2020

It's because we've been taught that only losers would take on work that doesn't lead to them making millions, and profit margins of more than 200%. In fact, it's become a haven for the incapable. For example, I happen to be the world's best machinist and could easily make a small, handheld device that would allow anyone to fly to the moon and back home in a day- but I don't get interested unless I can take an order for at least 65 trillion of them. The issue is not my competence - it's the piddling market.

implmex · Mar 21, 2020

Hi again All:
So today I made a housing for these little grabber parts and I thought I'd walk everyone who is interested through the process, just to get all our minds off that damned coronavirus we're all wringing our hands over.
So there will be some pictures.
When you see how rough everything looks, remember it is TINY...those EDM pits and cutter marks are almost imperceptible to the naked eye.

So here are the pictures in three posts:
The order of the pictures got a bit screwed up and I can't seem to fix it...sorry about that.

Cheers

Marcus
www.implant-mechanix.com
www.vancouverwireedm.com

implmex · Mar 21, 2020

Here's the next set:

implmex · Mar 21, 2020

And here's the last set:

So I made two turned parts, then cut them up on the wire.
Next I made a sleeve to hold the halves together and tacked them with the laser welder after aligning the split in a vee block.
Next I drilled the cross holes and laser welded a 0.035" pin into one side, then cut it to length
Next I fiddled the guts together (Yeah, I sproinged one spring with the tweezers and it's gone forever, but I had 6 so it's OK)
Next I put the lid on, sleeved it again to align it, and laser welded the lid. (I just freehanded the weld...I was too lazy to set it up on the orbital table)
Then I clocked it into a vee block again and drilled the end holes.
Last I set it up on the wire again and bucked it off to length, and Voila...there it is sitting on my finger.

Some of you may be asking why I built the housing out of pieces this way instead of just cutting a U shaped slot out of a turned part.
The reason is that the little grabber jaws and the spring are so damned tiny it's impossible to put them together into a one piece housing (at least for me!)
This way I could fiddle the bits together under the scope and then just put the lid on.

Cool project...hope the customer will be happy (well maybe not about the price

!)

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

.

implmex · Mar 23, 2020

And here's the last of the parts; simple turning and wire EDM.

Cheers

Marcus
www.implant-mechanix.com
www.vancouverwireedm.com

D Dubeau · Mar 23, 2020

Nicely done as always Marcus. I've always like the finicky problem solving jobs that nobody else want to touch too. Way more rewarding than seeing if I can beat yesterdays part count.

sfriedberg · Mar 24, 2020

Very nice, Marcus, but I have to ask a question about something other than the teeny tiny part... Is the clamp for that V block actually porous enough to be letting light through, or is that a visual illusion from a reflection or maybe a streak of oxidation?

implmex · Mar 24, 2020

Good morning sfriedberg:
That is an illusion.
I made a bunch of Vee blocks ages ago when I had a big block of hardened A-2 left over from an abandoned project.
I took the chunk and just wire cut little mini Vee blocks until the whole plate was used up.

Since I hate the more common style of Vee block with the strap clamp on the outside, I came up with this design so I can just lay the block over on its side if I want to, or squeeze it in a vise without the clamp always getting in the way.
When I wire cut the vee blocks, I also wire cut a bunch of clamps...they're just remnants of a plate of 4140 I had laying around so they get stained and rusty after a while, and that's what you're seeing.
Had I been a bit more strategic I would have used 440C for the Vee blocks and 316 for the clamps because they get used a lot on the wire EDM, but I was lazy and in a hurry, so now I just wire brush off the rust when it annoys me.

Cheers

Marcus
Implant Mechanix • Design & Innovation > HOME
Vancouver Wire EDM -- Wire EDM Machining

Another small project biopsy simulator grabber

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