Reply with QuoteThis is a great thread on modifying an 8x lathe. He changed the bearings, bored the head and made a new spindle among other things.
http://www.cnczone.com/forums/mini_l..._slow_mod.html
bob
8X12 spindle bore
Have gotten to the point that the 3/4" through spindle bore on the 8x12 is not working for me anymore.
What is the largest that anyone has safely reamed their spindle bore, or is there a way to mod the machine up to a 1" through spindle without spending more than the cost of the machine to do it?
For what I use the lathe for, everything is fine, just need to be able to feed 1" stock/work pieces through the spindle or it time to find another machine.
Similar Threads:
This is a great thread on modifying an 8x lathe. He changed the bearings, bored the head and made a new spindle among other things.
http://www.cnczone.com/forums/mini_l..._slow_mod.html
bob
Hi Dano523,Originally Posted by Dano523
I found myself in the same situation as you describe with your 8X12 several years ago. After much searching and pondering (they weren't as many 8x12's in use then ... (the 7X series were the hot, well documented lathe) ... there weren't as many alternative, affordable bench top lathe choices as today.
I took it upon myself to put a new spindle in the 8X12 ... I was fortunate in finding a retired Master Machinist who found my " little guy" lathe project
interesting ... he did not charge me as he should have and I got the completed and oversize spindle for approx. what the lathe original cost.
Bottom line ... for approx. $800.00 - I had an 8x12 lathe with a 1.375" dia. thru hole and in the process I lost my ability to do threading due to the loss of banjo / gearing interface. Do I regret doing it ... No! ... Would I do it again ... No!
I'd buy a bigger lathe for starters ...
If you decide to do a larger spindle and I can help ... just give a shout ..
Regards,
Bill S
See, that is the rub,
I only want to get the spindle through bore to 1".
The HF 5" bolt on 4 jaw chuck covers me on the chuck for a 1" though I already have (plus the 3 jaw chuck as the same bolt pattern so no need for an adapter plate), and would just need to spin a new spindle , bore the head for new bearing journals , new bearing, and even try to save the spindle end gear to use the stock gearing with a new spindle nut/spider combo.
The huge part of the price will be stock for the new spindle, and since I run the lathe in both spindle rotations, going with a thread on end plate is less than idea, so it would mean turn down a huge chuck of stock with a lot of waste for a one piece spindle.
So the question really comes down to if I do need to make new spindle, how do we attack this in a one piece unit without paying $150 for a piece of 4" 12L14 round stock to turn down for it (and have a lot of waste). The bearing, journals, and end nut spider are the cheap part of the math, and it all boils down to a piece of stock for the spindle to keep the project under a $100 range. Push comes to shove, would even consider going to a sand cast for the spindle stock to save a huge chunk of money, and just pressing on bearing raceways (turned after pressing) for the bearings to the spindle.
_____________________________________
Now on the other hand, since we do have a photo of the stock spindle (is around .800 ID roughed reamed), lets go back to reaming the stock spindle instead to 1". The problem that I first see is that reaming it to 1" through is going to be that the end nut threads is going to be a problem. But what If we lathe off the thread, and make a male threaded end nut/spider with lock sleeve to tighten it instead; with the spindle rear internal threaded for that. Both the bearing areas of the spindle shaft will have plenty of metal there, and it just comes down to the back end of spindle holding up to end nut tension and machine torque. Really, if you crash the machine, your going to strip the teeth off the motor gear belt long before you kill the thinned spindle rear end (so this mod is out for someone running a VLD with more horsepower being put through the spindle).
Of the two, you have over $200 in materials for the new spindle/parts (and a lot of work), verse a few dollars to just ream the stock spindle to 1", removing the end thread section, internal threading, and making a new spider/end nut with tightening sleeve to tighten it back up (less than a hours work).
I guess since I do need to attack this in the next few months once I get back home, will do the stock spindle ream and end nut/spider/sleeve mod. Worst case, the spindle cracks as some point down the road and I just change out the spindle with a new factory one to take it back to stock, and start shopping for a larger machine then.
See, that is the rub,
I only want to get the spindle through bore to 1".
The HF 5" bolt on 4 jaw chuck covers me on the chuck for a 1" though I already have (plus the 3 jaw chuck as the same bolt pattern so no need for an adapter plate), and would just need to spin a new spindle , bore the head for new bearing journals , new bearing, and even try to save the spindle end gear to use the stock gearing with a new spindle nut/spider combo.
The huge part of the price will be stock for the new spindle, and since I run the lathe in both spindle rotations, going with a thread on end plate is less than idea, so it would mean turn down a huge chuck of stock with a lot of waste for a one piece spindle.
So the question really comes down to if I do need to make new spindle, how do we attack this in a one piece unit without paying $150 for a piece of 4" 12L14 round stock to turn down for it (and have a lot of waste). The bearing, journals, and end nut spider are the cheap part of the math, and it all boils down to a piece of stock for the spindle to keep the project under a $100 range.
_____________________________________
Now on the other hand, since we do have a photo of the stock spindle, lets go back to reaming the stock spindle instead to 1"(ID is .800 rough reamed to begin with). The problem that I first see is that reaming it to 1" through is going to be that the end nut threads is going to be a problem. But what If we lathe off the thread, and make a male threaded end nut with spider to tighten it instead; with the spindle rear internal threaded for that. Both the bearing areas of the spindle shaft will have plenty of metal there, and it just comes down to the back end of spindle holding up to end nut tension and machine torque. Really, if you crash the machine, your going to strip the teeth off the motor gear belt long before you kill the thinned spindle.
Of the two, you have over $200 in materials for the new spindle/parts (and a lot of work), verse a few dollars to just ream the stock spindle to 1", removing the end thread section, internal threading, and making a new spider/end nut to tighten it back up.
I guess since I do need to attack this in the next few months once I get back home, will do the stock spindle ream and end nut/spider mod. Worst case, the spindle cracks as some point down the road and I just change out the spindle with a new factory one to take it back to stock, and start shopping for a larger machine then.
You may want to look at the thread. Yahoo! Groups
It is noted that the original spindle is made of 3 pieces. I bet you could make a rough spindle shrink fit it together then finish machine it.
I wonder if someone could use the spindle from a spin indexer as a part of a shrink fit spindle..... Could order a replacement headstock from Harbor Freight, and put away the original headstock and spindle for use as a 4th axis later.
I forgot to mention little machine shop lists 8x12 replacement spindles. LittleMachineShop.com - Spindle, 8x12, 8x14 Lathe
Could also look at the Sieg C6 spindle they have been swapped into the 8x12/14, I do not know if they are made from 3 pieces like the other one was noted to have been.
Maybe it would be simpler to just get a G0602:
G0602 10" x 22" Bench Top Metal Lathe
It already HAS a 1 1/6 inch spindle bore, and I'm sure you would find uses for the extra capacity.
CR.
http://crevicereamer.com
Too many PMs. Email me to my name plus At A O L dot com.
In this thread it was mentioned in passing about boring out the headstock and adding a G0602 spindle. Yahoo! Groups
Later in that same thread it is mentioned that the stock spindle was bored .815" or so and was quite thin at the back. Yahoo! Groups
