Making a Thingamajiggy

[thestelster]

I have to make some doodads, dohickeys, and whatchamacallits, which all get assembled into a Thingamajiggy.

Here are the doodads. But I forgot to take pictures of splitting them and drill/tap for screws.

 

[DavidR8]

Nice knurling!

 

[thestelster]

These are the whatchamacallits. Stainless 17-4PH.

 

[Dan Dubeau]

Nice looking whatchamacallits. 17-4 is one of my favourite metals to machine.

 

[LenVW]

Are those Drop-In replacements for Brand parts ?
Prepare yourself for the on-coming orders.

 

[Susquatch]

Nice @thestelster. Always love your work.......

Wondering why you used a center drill instead of a spot drill in the third photo of post #3.

 

[thestelster]

Nice @thestelster. Always love your work.......

Wondering why you used a center drill instead of a spot drill in the third photo of post #3.

Well, the truth is that my 1/4" spotting drill got dull a while ago, so I attempted to sharpen it to include a split point, and, well, it ain't the sharpest bit in the tool box. In fact, its pretty dull. I'll get to it again sooner or later.

 

[thestelster]

Are those Drop-In replacements for Brand parts ?
Prepare yourself for the on-coming orders.

Yes, except the factory ones are aluminium, and I wanted something more robust.

No orders please, I'd go broke!!

 

[Susquatch]

Well, the truth is that my 1/4" spotting drill got dull a while ago, so I attempted to sharpen it to include a split point, and, well, it ain't the sharpest bit in the tool box. In fact, its pretty dull. I'll get to it again sooner or later.

Ya, that explains that. Just order a new one on Ali or Amazon or even MCarr. It isn't worth the work.

 

[LenVW]

The factory ones have a ‘design’ life.
Companies like to maintain a ‘revenue stream’ after-sales.

Your ’robust steel’ ones would never need replacements.

 

[PeterT]

Nice work whatever they are, LOL. Maybe I asked you this already but on your regular V thread inserts, are you modifying point to suit the larger sizes? I noticed when I was drawing them in CAD using Machineries Handbook root calculation, they are surprisingly wide. I know they categorize the inserts by pitch range which should ?be the average or the minimum? But I am guilty of using a generic sharpy for bigger threads & they would have quite a pointed root. I know you mentioned the other style of insert you like which terminates on the OD or something. Maybe that was the buttress thread project. My memory is great, just very short span haha

 

[thestelster]

Nice work whatever they are, LOL. Maybe I asked you this already but on your regular V thread inserts, are you modifying point to suit the larger sizes? I noticed when I was drawing them in CAD using Machineries Handbook root calculation, they are surprisingly wide. I know they categorize the inserts by pitch range which should ?be the average or the minimum? But I am guilty of using a generic sharpy for bigger threads & they would have quite a pointed root. I know you mentioned the other style of insert you like which terminates on the OD or something. Maybe that was the buttress thread project. My memory is great, just very short span haha

View attachment 49336

This thread is 1/2"-20 UNF. Therefore the depth of the thread is 0.027", and the root width is 1/4 x P = 0.0125".

The threading insert I used, shown above, has a tip width of approximately 0.004".

So I plunge thread the screw with the cross-slide until I get to the required depth of 0.027". But the root is only as wide as the threading insert tip width, in this case 0.004". So to get the proper root width of 0.0125", I make more passes at full depth, 0.027", but I advance the compound axially 0.001" or 0.002" with each successive pass until I've gone 0.009", (required root with: 0.0125"- threading insert tip width: 0.004") (I set the compound so that it is at 0°, its travel is parallel to the bed ways.)

 

[PeterT]

Gotcha, thanks

 

[thestelster]

Here's the dohickey that holds the whatchamacallits and the doodads for the Thingamajiggy.

Not finished yet! Quite a bit to go yet.

 

[140mower]

It's looking like one hell of a whatchmacallit.

 

[PeterT]

@thestelster just getting back to that threading technique, am I reading you correctly? You make the initial thread to a depth using sharp vee tool (1). Then you increment laterally in steps to position (2) which forms the proper root distance (orange line). I get that part. But at what point do you confirm pitch diameter with wires or mic? I assumed at step 1 & then basically freeze that DOC? But I've never really paid attention to this detail but even the thread calculators have a root flat embedded in the spec which I assume is therefore embedded in PD measurement. Maybe you are checking PD along the way through step 2 & stop when its achieved (and thus root flat ends up being whatever it is? As opposed to 'targeting' a root flat distance which is how I read your comment.

 

[jcdammeyer]

It's looking like one hell of a whatchmacallit.

I still can't figure out what the heck it is.

 

[PeterT]

Some kind of angle setter / translater?

 

[140mower]

I still can't figure out what the heck it is.

I think it is pretty obvious that it's becoming a doohickey for the thingamabob that holds the whatchmacallit...... Simple process of elimination, dear Watson.

 

[thestelster]

@thestelster just getting back to that threading technique, am I reading you correctly? You make the initial thread to a depth using sharp vee tool (1). Then you increment laterally in steps to position (2) which forms the proper root distance (orange line). I get that part. But at what point do you confirm pitch diameter with wires or mic? I assumed at step 1 & then basically freeze that DOC? But I've never really paid attention to this detail but even the thread calculators have a root flat embedded in the spec which I assume is therefore embedded in PD measurement. Maybe you are checking PD along the way through step 2 & stop when its achieved (and thus root flat ends up being whatever it is? As opposed to 'targeting' a root flat distance which is how I read your comment.

View attachment 49382

View attachment 49383

Hi Peter, yes. That's exactly what I do. I stop advancing the cross-slide once I've achieved the calculated thread depth (.54125 x P). I'll measure pitch diameter at that point with either wires or thread pitch micrometers, then start advancing the compound axially and measuring pitch diameter along the way until I've reached the correct PD, and that my nut threads on nicely.

In your picture you show two orange circles which I guess represents the wires, but you only use the one diameter wire throughout the whole process.