Doesn't exist? -- 8 TPI threaded chuck to fit an 80mm HF faceplate (w/ picture)

[Firebrick43]

For example, are these crap?

https://www.amazon.com/dp/B083JWGSYZ

No, the holders are not. As others have said, there are different grades/geometery of inserts that give a better surface finish on light weight lathes such as yours.

You can even get HSS inserts for those tool holders.

warner hss insert

 

[bcrimmins]

for the HF mini, is it necessary to use 1/4" holders? Or can I get away with 3/8"? What are the implications of that extra 1/8" of height causing a different contact angle/position?

 

[ttabbal]

for the HF mini, is it necessary to use 1/4" holders? Or can I get away with 3/8"? What are the implications of that extra 1/8" of height causing a different contact angle/position?

It can make it difficult to get the cutting edge on center. HSS can just be ground differently to make up for it.

 

[bcrimmins]

It can make it difficult to get the cutting edge on center. HSS can just be ground differently to make up for it.

Good point, RE grinding down the HHS

 

[bcrimmins]

Just want to say... WOW... thank you all so much for the masterclass!! Just what I needed to get my lathe journey started!

 

[homebrewed]

1/4" sized HSS blanks won't take as long to grind to shape compared to 3/8" ones. They won't be quite as strong as 3/8" cutters but I don't think an un-modified mini lathe has enough power to break one, unless you crash the tool into a rapidly spinning chuck. I've used both sizes with no mishap.

The 4 way toolholder that comes with these machines is designed for 5/16" sized cutters so that is something to consider. To use 1/4" cutters in it you will need either a spacer under the toolholder to elevate it, or spacers underneath the individual cutters. A QCTP makes it a lot easier to swap in different-sized cutters and get them on-center.

 

[bcrimmins]

UPDATE

Hey gang, been traveling and slammed, but managed to actually fabricate a functional ring chuck out acrylic on my laser cutter. Made my first ring ever on it and it worked great! But I can tell it's pretty fragile and so I'd only get two or three rigns out of it before having to make a new one. Which is easy. But I'm going to redesign it to be more robust... maybe get 10 rings out of one.

Thanks again for all of the advice!!

 

[rwm]

That is awesome! Nice work. What is your plan to upgrade this?

 

[bcrimmins]

That is awesome! Nice work. What is your plan to upgrade this?

• Double the base thickness so that the 'fins' can be inserted deeper for a stronger hold.
• Increase the thickness of the fins from 3mm to 4 or 5mm, for strength and stability.
• Increase the over all length by about an inch to reduce the angle of the fins. This will increase the contact surface area between the ring and the fins and lessen the tendency of the ring edge to mar the fins' edges.