Indexable Tip Tools: - Cost $0.50
I was given several indexable carbide tips and this inspired me to make my own tool-holders & boring bars for them. These complement my 3/16" H.S.S. tools ground from blanks & my small brazed carbide tip tools.
Since making my indexable tools, I have found them to be invaluable for machining. They work equally as well as my neighbours $189 set at a fraction of the price - My set cost me 50-cents.
I made a set of 4 tool-holders from scrap steel (salvage yard - I used 1/4 of a $2 piece) & Allen-head screws removed from hard discs. Together with the 'free' tips, total cost 50-cents & a few hours work.
To compliment the basic set of lathe tools I added a couple of small indexable-tip boring bars. These were made from round section steel shafts removed from old scrapped inkjet printers. Together with the 'free' tips, total cost 0-cents & a few hours work.
All tool-holders were milled in the lathe using an old 9/16" end mill once owned by my father (at least 35yr old) & a re-ground broken 1/8" drill, used as an end mill. I also used my home-made angle plate with a drilling vice (2-1/2"), though I could have held the steel in my toolpost for machining if I didn't have the angle plate.
The tip mounting surface was milled at an angle of 5-degree down from the horizontal towards the cutting edge. This down-slope enables the use of both positive & negative rake carbide tips.
The first thing to know in making a lathe tool is the vertical distance between where the tool will sit in the toolpost, and the lathes centre height. My lathe can handle a 19mm high tool, other lathes will be different - mine is exceptionally high for a lathe of this size. When you know this, you will know the maximum height of the tool from base to the top of the indexable tip. I made mine at much less than the maximum height, & use packing to bring up to centre.The manufacturing process for the index tip toolholders is to:
There you go, a home made index tip tool. All the tools I made have required a 1/8" drill, #6NC32 tap & been machined with an old end mill & a re-ground, broken 1/8" drill.
Indexable tip, Carbide & H.S.S. Boring Bars: - Cost $0
(The boring bar toolholder & the standard boring bar came with the lathe when purchased).
The reground masonry drill boring bars are just normal masonry drills, with the tips reground as a cutting tool by using a 'greenstone' grinding wheel.The indexable tip boring bars started out as shafts out of old inkjet printers.
The H.S.S. boring bar is simply a reground twist drill that the cutting edge had broken on.
I have found that both the H.S.S. & the masonry drill boring bars are very good for boring out holes for small shafts, especially when I need to bore out a small straight or tapered hole.