Back Spindle Spider

[Jinx-)]

Trickymissfit, I already started this project using plain 1020, so why would you say chrom-moly-nickel would be better choise? Also I did cut ID threads, it was exactly what I had measured and its perfect fit.
Minor Dia Pitch Dia Major Dia Tap Drill
Class min. max. min. max. min. max.
M39x1.5 6 H 37.376 37.676 38.026 38.226 39 39.417 37.5

Just hate to start allover when I'm almost done...

 

[Trickymissfit]

You need to invest in one or a couple Valenite or OSG indexable insert boring bars. Much better, more rigid and you can the insert after indexing it numerous times plus you can spec them with through the bar cooling that puts coolant and lubricant at the cutting point.

Those throw away brazed carbide bars are fine for small jobs, one time and the carbide grade is questionable because they are made...over there.

From the looks of the chatter, bet it was singing.....

But then. we don't know what kind of toolpost you have. The indexable tooling likes an extremely rigid and repeatable toolpost like an Aloris or Dorian wedge lock.

Always things to consider. You'll need an indexable bar to cut the internal threads anyway unless you are an expert grinder at grinding a throwaway bar to the correct
thread form.

another good source for quality boring bars is to find a machine tool reseller. They will often have tons of Warner Swasey bars just gathering dust in all sorts of sizes. Whatever kind of steel they use doesn't seem to have much if any harmonics
gary

 

[Jinx-)]

Here's what this machine is made of and why I can't simply replace spindle nut with spider? It seems its just to keep pulley in place

 

[SidecarFlip]

when did Hardingh quit building that great little lathe? The only lathe I ever saw that would hang with a Monarch EE. They picked that auto back off up from Monarch, and who knows who Monarch stole it from!

Half nuts; I hate them! But we gotta live with them. Leaving the nut engaged all the time will also give you a better thread form anyway, so go with it. By leaving the half nut engaged you will eliminate a lot of the lead error that is compounded by the dial alone. (I always use the same number everytime)
gary

Have no fear Gary, it's an oriental clone (checked the website)..lol

 

[Jinx-)]

Trickymissfit, they quit building them after Hardinge lost its sole ownership to the board of directors and shareholders, somehow they decided its no longer needed... The machines they produce now no longer made in USA, they moved their production lines to China... However they still make some workholding here in US.

 

[Jinx-)]

Here's what I have so far and I think it might work...

 

[shortgrass]

Here's what this machine is made of and why I can't simply replace spindle nut with spider? It seems its just to keep pulley in place

And 'loads' the spindle bearing and keeps the spindle from falling out, on to the ways.

 

[Jinx-)]

spider will do same thing what spindle nut does, it will firmley push up against pulley.

 

[Trickymissfit]

And 'loads' the spindle bearing and keeps the spindle from falling out, on to the ways.

if you put pressure on the nut, it increases the load on the bearing pack in the spindle line. This causes the bearings to develop an irregular wear pattern that can never be overcame again. Plus they run way too hot, and are gone in no time. I had a tool maker do something similar with an Okuma Kadet. Bearings were gone in three days. Pay me now, or pay me later<g>!
gary

 

[Jinx-)]

Gary, thanks for the warning Okuma Kadet you say, hmm I remember one nice little cnc lathe, I meant low profile no comparison to Daewoo Puma model 8 I deal once...

So Gary, why would you say 8620 steel, is that almost like inconel? To be honest I don't know what steel I'm using, its low carbon and probably leaded, it soft and cuts like butter Maybe oil hardening tool steel can make better choice?

Anyway after considering my options I made few changes to the spider and I added slots for spanner wrench and I'll be using one of the spindle nuts and the second one will be replaced by spider.

 

[shortgrass]

if you put pressure on the nut, it increases the load on the bearing pack in the spindle line. This causes the bearings to develop an irregular wear pattern that can never be overcame again. Plus they run way too hot, and are gone in no time. I had a tool maker do something similar with an Okuma Kadet. Bearings were gone in three days. Pay me now, or pay me later<g>!
gary

Ok,, so maybe 'load' wan't the correct word. My point being, the nut is there to do more than "hold the pully on". Any bearing, adjusted on the 'loose' side, will chatter like a swarm of bees,,,, too tightly and they' ll fry. Same result either way,,,, premature failure.

 

[Jinx-)]

It sounds no matter what I do the result would be imminent failure. Searching web I found this article about this guy with a same lathe and he build spider for it, I should of search web first, because he got all the plans and steps how to do it. My spider is much simpler but its same concept as his...

A Rear Spider-Nut for the Grizzly G0602 Lathe | Projects In Metal, LLC

 

[Trickymissfit]

Gary, thanks for the warning Okuma Kadet you say, hmm I remember one nice little cnc lathe, I meant low profile no comparison to Daewoo Puma model 8 I deal once...

So Gary, why would you say 8620 steel, is that almost like inconel? To be honest I don't know what steel I'm using, its low carbon and probably leaded, it soft and cuts like butter Maybe oil hardening tool steel can make better choice?

Anyway after considering my options I made few changes to the spider and I added slots for spanner wrench and I'll be using one of the spindle nuts and the second one will be replaced by spider.

8620 is a mild hot roll steel. Machines much better than CRS. If memory is right it has a little sulphur in it to aid in machining. Downside like cold roll steel is that it will not harden without carbon being injected into the surface of the metal. yet 8620 is not gummy to machine like CRS. 70% of my mild steel machine work was done with 8620, as it was just that good.
gary

 

[J E Custom]

It sounds no matter what I do the result would be imminent failure. Searching web I found this article about this guy with a same lathe and he build spider for it, I should of search web first, because he got all the plans and steps how to do it. My spider is much simpler but its same concept as his...

A Rear Spider-Nut for the Grizzly G0602 Lathe | Projects In Metal, LLC

Use what you have now. You can always modify it latter to suite your needs.

J E CUSTOM