Indexable tool bits for mini lathe

[zoltan]

There seem to be two different indexable tool bit sets common made for the mini lathe:
1. http://www.grizzly.com/products/T10436
2. http://www.littlemachineshop.com/products/product_view.php?ProductID=1669

The tool bit shanks are different between the two sets. Sooooooo, which one should I go with?

 

[chucketn]

Zoltan,
I just bought the 1669 set from LMS(got it yesterday), and tried them out for just a little bit today. I have the OXA QCTP on my 7x and thus chose the 3/8" shank set. With what little I've used them they seem great!. I chamfered the edges of a cap for a mandrel I'm working on. The real test will come over the next few weeks if we have some warm weather. My shop still isn't heated!
I'll let you know what I think of them.
I also purchased a holder for round inserts to use for profiling and with a fly cutter, but when I ordered the tool, I forgot to order the inserts, so I'm waiting on a slow boat from China at the moment!

Chuck

 

[MCRIPPPer]

i have the littlemachineshop set. i love it. bought 2 boxes of inserts on ebay for about $50 (20 inserts total) bought tcmt 21.51 and 21.52 for different nose rad. the minilathe likes the sharper tip because it generates less cutting force. the large nose tools make a nice radius on shoulders. i think you should get the LMS one. it has better shapes IMO. you have left and right turning, left and right 45 chamfering. the grizzly one has some neat tools, but doesnt seems to have the chamfering or turning tools (very useful) for left hand (or right hand whatever it is. the non conventional direction ).

 

[zoltan]

Thank you very much for the suggestions. I ended up going with the LMS set and have already gotten a lot of use out of them. Now I just need to by QCTP holders for all of them...

 

[Capt,n John]

I sure could use more tooling for my lathe.

 

[ShopShoe]

I have a set like this, but can't remember the source. I think the inexpensive sets like this are similar. It's the inserts that do the work. I have also experimented with different inserts and have had some good luck. I have also bought inserts and made holders from square stock with good results.

(BTW, I also have the OXA size QCTP on my 7x Minilathe and it is much more rigid than the stock 4-way toolpost was.)

I think you may find that the screws holding the inserts are poor and will need to be replaced. In my set the thread for them is M2 x 0.40. I ordered a box of 100 SHCS from MSC.

Some things that others have mentioned and my overall experiences also seem to confirm:

1. For MiniLathe size machines HSS is still hard to beat. I have a bunch of HSS 5/16 toolbits and I can grind them myself and if I take the time they work very well. Carbide seems to help when the material being turned is hard.

2. Carbide is brittle and will chip and break where HSS will be dulled. I have probably ruined some work because carbide has chipped and I didn't catch it in time.

3. Indexable tooling seems to really work well with larger, more rigid toolholding ("As others report." Until I get a larger lathe I won't know how much this would be true for me in my shop.)

If you are up to an in-depth discussion, I think this thread is very informative:

http://www.homemodelenginemachinist.com/showthread.php?t=10175&highlight=Insert

Best of Luck and keep us posted.

--ShopShoe

 

[zoltan]

I'm aware of the upsides to using HSS and grinding my own, and used to do so. However, I don't have a lot of free time and I'd rather spend it using the lathe than grinding tool bits for it. However, I think I will try one of the HSS inserts which are available for my new set.

 

[Brian Rupnow]

I checked the websites you gave links for. On both websites the shanks are the same---3/8" square. There is no difference in the shanks.

 

[zoltan]

I checked the websites you gave links for. On both websites the shanks are the same---3/8" square. There is no difference in the shanks.

They're both 3/8" but they hold the inserts in different orientations.

 

[Brian Rupnow]

Okay---I looked again. Either set will work fine.

 

[Swifty]

I use carbide inserts a lot, and a tip last a very long time, although I do have a 14 x 40 lathe which is pretty rigid. I won't have to buy any inserts for the rest of my life, as I have quite a few packets of different shapes that were left over when I retired from my business.
Having said that, I still use HSS as well for brass etc.

Paul.