Machining fun

[Stuart Samuel]

Since I don’t seem to have any time for hobby stuff lately, and a bit of a challenging part came across my bench at work, I thought I’d share.

Making two for now, 48 once the design is finalized. End caps for coloured glass tubes, with lit acrylic (EndLighten, spreads light down the length) inside, for a youth community centre.

(I realize my work address is at the bottom of the drawings, but having already been mentioned by name in the media in connection with the Centre Block rehabilitation, that ship has sailed, as far as I’m concerned)

 

[Stuart Samuel]

The youngest guy in our shop had an excellent idea for producing these, and made it in two pieces, pressing them together afterwards, which let him avoid trepanning that 1 1/4” deep seat for the glass tube. I’m going to try grinding a tool to cut it, but I’m also going to call Castellar and ask for a quote on regrinding an annular cutter.

 

[Susquatch]

which let him avoid trepanning that 1 1/4” deep seat for the glass tube. I’m going to try grinding a tool to cut it, but I’m also going to call Castellar and ask for a quote on regrinding an annular cutter.

Ya, grinding a trepanning tool to cut 1-1/4" deep would be a challenge.

An annular cutter would be WAAAAY easier. Not only that, but trepanning afterward to get it to size would probably be easier too. I take it no off-the-shelf annular cutter would work that way?

 

[Stuart Samuel]

The initial design (in house) would have been fine with a 1 1/2” annular cutter (we already have one!), but it’s since changed in OD, ID, and depth. Checking the glass tube I can see why the OD changed, the tube’s nominally 38mm, but is very slightly oval (a few thou), and is just over 1.5 in spots. I don’t think press fits work on glass.

I’ll bet the depth change was down to the tube manufacturer not wanting to drill holes any closer to the end than 1/2”.

The designer will be in later, and we can talk about reducing the ID, so at least the bulk of the work could be done with a 1 1/2” cutter, and then the OD could be bored out. Maybe I can even talk her out of using 6-40 screws to retain the glass! (Yes, you read that right)

 

[Susquatch]

I don’t think press fits work on glass.

Sure they do! That's how they make crushed glass......

The designer will be in later, and we can talk about reducing the ID, so at least the bulk of the work could be done with a 1 1/2” cutter, and then the OD could be bored out.

Be a lot easier to bore the ID.

Maybe I can even talk her out of using 6-40 screws to retain the glass! (Yes, you read that right)

It's more common to use screws on glass than one might expect. But I don't like it either.

 

[Shoprat]

Hopefully you have a good pillow picker ( designer) . After 20 years of working with them, I have become very jaded. The good ones understand manufacturing has its challenges, and are receptive to changes or ideas. The others are hell bent on seeing their design the way they envision, regardless of failure. Once it fails, love the change order!

 

[Stuart Samuel]

Hopefully you have a good pillow picker ( designer) . After 20 years of working with them, I have become very jaded. The good ones understand manufacturing has its challenges, and are receptive to changes or ideas. The others are hell bent on seeing their design the way they envision, regardless of failure. Once it fails, love the change order!

In this case the designer is another employee here. She’s very bright, but tends to design very complex solutions, having no manufacturing experience. I suspect the client (an interior design firm) only cares about the exterior appearance, so hopefully we can simplify this a little.

It’s unfortunate, we’d talked about the part a month ago, and I showed her the annular cutter. As I said, I suspect I know why she changed the dimensions, I just wish she’d given me a heads up.

 

[Dan Dubeau]

Looking forward to seeing the finished product. I love when the functional/practical side of machining meets the artistic side. I don't get to do enough of that.

I can see making that out of 2 pieces being MUCH easier to machine, and assemble. A few different ways to go about it, but depends if you have the creative freedom to decide how you get there in the end vs having to stick with the design. Spirit/intent of the design, vs letter of the design.

I work with a lot of leader line engineering at work, so 95% of what I make at work, I "get" to design on the fly because the actual "designs" are unbuildable. Sometimes fun, sometimes frustrating.......I much prefer when I am the sole designer from start to finish, but that doesn't always happen with timing, and our "designer" can crank out garbage much faster than I can dig myself out from the last heaping pile, so it's rare that I ever get caught up lol.

 

[Stuart Samuel]

Sure they do! That's how they make crushed glass......



Be a lot easier to bore the ID.



It's more common to use screws on glass than one might expect. But I don't like it either.

I’m not bothered by the screws on glass aspect, it’s that 6-32 screws and taps are a stock part for us, and she’s gone with a 6-40 (I suspect to get more threads engaged, but it only gets you 0.75 more).

 

[Shoprat]

In this case the designer is another employee here. She’s very bright, but tends to design very complex solutions, having no manufacturing experience. I suspect the client (an interior design firm) only cares about the exterior appearance, so hopefully we can simplify this a little.

It’s unfortunate, we’d talked about the part a month ago, and I showed her the annular cutter. As I said, I suspect I know why she changed the dimensions, I just wish she’d given me a heads up.

Sounds like you have a good thing going there,I’m sure you will be fine. An annular stock cutter would have been a dream. I like your idea of getting one ground , or use the most worn out lathe in the shop and let the run out get you there. Lol.

 

[Dan Dubeau]

Petition for a T&C grinder and an induction forge so that you can easily braze carbide teeth, onto your own custom cutter stock, and grind your own annular cutters for various custom glass tube sizes...... Never turn down an opportunity to purchase another tool .

 

[Stuart Samuel]

Looking forward to seeing the finished product. I love when the functional/practical side of machining meets the artistic side. I don't get to do enough of that.

I can see making that out of 2 pieces being MUCH easier to machine, and assemble. A few different ways to go about it, but depends if you have the creative freedom to decide how you get there in the end vs having to stick with the design. Spirit/intent of the design, vs letter of the design.

I work with a lot of leader line engineering at work, so 95% of what I make at work, I "get" to design on the fly because the actual "designs" are unbuildable. Sometimes fun, sometimes frustrating.......I much prefer when I am the sole designer from start to finish, but that doesn't always happen with timing, and our "designer" can crank out garbage much faster than I can dig myself out from the last heaping pile, so it's rare that I ever get caught up lol.

One of the things I like about working here (coming up on 12 years now) is that we generally have a lot of autonomy in how we get things done. The client usually specifies the appearance, we produce a shop drawing, but to make it is completely up to the person who’s on that job. We’ll bounce ideas off each other (there are three of us in the metal shop right now), but we each approach things in our own way, based on our experience.

 

[Stuart Samuel]

Sure they do! That's how they make crushed glass......



Be a lot easier to bore the ID.



It's more common to use screws on glass than one might expect. But I don't like it either.

Oh, I meant to say, the issue with the stock annular cutter is that the ID on the cutter is substantially smaller (0.055”) than the part as drawn. I don’t see an issue with that, the inner wall would be a little thinner, but the glass tube would still be constrained by the OD.

 

[YotaBota]

The drawing shows the set screws going thru the glass, I hope they come pre-drilled.

Sounds like a great place to work - "here's your job, let us know when you're done"

 

[Stuart Samuel]

The drawing shows the set screws going thru the glass, I hope they come pre-drilled.

Sounds like a great place to work - "here's your job, let us know when you're done"

‘And let us know if you need material’.

I’ve taken over ordering consumables, which works well as long as people PUT IT ON THE DAMNED WHITEBOARD WHEN THEY BREAK TOOLS.

Ahem.

Oh, speaking (typing?) of, anyone have a recommendation for supplies (cutting tools, hand tools, etc.) other than KBC? I’ve tried a few smaller places, but because they don’t carry stock, the wait time is usually an issue.

 

[YotaBota]

Or you walk into the stock room and find three boxes of what someone says "we're out of xxxx" lol