Some StarWars Model Parts

[wildo]

A buddy of mine asked me if I could make three of these small little plastic parts out of metal. Seemed easy enough. Yeah- it's small, but so what?
God... I'm such a newb. Projects like this are a frustrating reminder of just how much I have yet to learn. And also a serious kick in the backside to get my new lathe operational. The more I use the old worn out SB, the more frustrated I get. That said, here's another 'getter done.' (Sorry- I don't have a clue what StarWars model he's working on.)


"Hey can you make me three of these plastic parts?"


Yeah, probably- send me some dimensions.
"Here you go."



...Hmmmm... Twelve attempts later I finally got three parts complete without breaking off the long stem. That was WAY harder than I think it should have been.

 

[dave_r_1]

Obviously, you should have been using a follower when making the shaft section :-O

 

[mikey]

One word ... Sherline.

 

[Choiliefan]

...and sharp HSS cutting tools.

 

[markba633csi]

There is where a tiny lathe like a Unimat would really shine-
M

 

[wildo]

So let's turn this into a learning thread...

1) I know that HSS would have been ideal for this. Unfortunately, I just don't have a good grinder setup yet and so it's not easy for me to grind HSS right now. I used a new CCMT060204 carbide insert and tried to take big, real cuts. It worked, but I had many failed attempts. HSS is absolutely the way to go and I really need to get a good grinding setup.

2) Why is a small lathe better suited for making parts like this? Is it because of the mass of the carriage? Do the smaller lathes have higher spindle speeds and finer control? It's unclear to me why a smaller lathe would make it easier to create this part over a hobby sized lathe like the SB9a. What am I missing??

 

[brino]

Good job. Sometimes the small ones are harder than the bigger jobs.
I bet a lot of effort went into the small bag of parts in your hand.
-brino

 

[ThinWoodsman]

1) I know that HSS would have been ideal for this. Unfortunately, I just don't have a good grinder setup yet and so it's not easy for me to grind HSS right now. I used a new CCMT060204 carbide insert and tried to take big, real cuts. It worked, but I had many failed attempts. HSS is absolutely the way to go and I really need to get a good grinding setup.

2) Why is a small lathe better suited for making parts like this? Is it because of the mass of the carriage? Do the smaller lathes have higher spindle speeds and finer control? It's unclear to me why a smaller lathe would make it easier to create this part over a hobby sized lathe like the SB9a. What am I missing??

Fair point on the HSS. You way want to try honing the carbide inserts a bit using a diamond stone. It might help, might not.

I don't buy the "small lathe" argument either. The controls are smaller, setup is more cramped. There may be some merit to an argument like "a larger spindle means a greater surface area over which an imperfection could induce runout", but really you can resolve this with a test indicator - so you know before you even start whether your particular lathe is accurate enough for the job. Some mention might also be made of small parts being more difficult to grip in an 8" chuck, but a) collets, and b) grip a smaller chuck in the large chuck. Hey, even c) centers - use much larger stock than you need turn down the middle, part the ends.

 

[Choiliefan]

An old-timey lathe hand would turn these out on a jewelers lathe with a couple gravers on a tool rest.

 

[wildo]

An old-timey lathe hand would turn these out on a jewelers lathe with a couple gravers on a tool rest.

Gravers are so cool!