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21st Jun 2018, 10:32 AM #31Senior Member
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- Jan 2016
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- Gosford
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- 63
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- 173
The conversation here is an interesting one and I need to be careful because I was quite a passionate and vocal detractor regarding the merits of D&T, or lack thereof. What I will say is that there is a lot of truth to the old saying, "You reap what you sow" and as a country we now see the result of de-skilling.
Back to the topic. I inspected the Advance lathe yesterday and bought it for a fair price. It is a dinky little thing, smaller than I'd expected but still a very nice little machine that will certainly perform some work adequately. It's condition is pleasantly quite good and it doesn't appear to have been knocked about or neglected. I can see that it does have the precision shortcomings I expected and as spoken of here in the comments. I can live with this. I'll learn how far to move the feeds to advance the tool point by 1/1000" and go from there. A problem appears to be the setting of the top slide to perform taper turning. I haven't had a good look at this yet.
It will need to have the chunky segmented belts replaced with appropriate V-belts since they are too big to be moved into the slowest spindle speed position. The motor position will need to be shifted in my setup as it presently interferes with the change gear assembly. It needs to be re-setup for complete functionality but the general condition certainly leads me to believe that I have a good base with which to proceed.
My main concern here now is that I'm on a slippery slope of the failings in this machine leading me to wanting a better one.
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21st Jun 2018, 11:14 AM #32Most Valued Member
- Join Date
- Jun 2011
- Location
- Australia east coast
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- 71
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- 2,713
Why should you be immune to the affliction that most of us have suffered from? I'm still looking to upgrade from my Monarch CY lathe with taper attachment to a DS&G with taper attachment...... I want the bigger spindle bore, you see......
OTOH I'm very happy with the Chipmaster lathe & Kearns S type HBM, there's no possible way I could upgrade from the Kearns.
PDW
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22nd Jun 2018, 08:52 PM #33Senior Member
- Join Date
- Jan 2016
- Location
- Gosford
- Age
- 63
- Posts
- 173
As should be expected with anything new in my shed, I immediately pulled it apart. There were 2 reasons. Not only did I want to inspect it in more detail but it was much easier to get off the back of the ute in bits. Even though it's small the cast iron is a bit heavy and with the motor it's a 2 man lift.
All seems good but I couldn't simply slide the countershaft out of the support frame to get the reduction belt out. The actual lathe components all appear to be in very good condition.
The countershaft might need a little gentle persuasion with a knockometer but I'll be doing a thorough inspection first. I removed the drive pulley and the grub screws on the stepped cone pulleys. It is all free but it wouldn't move in either direction by hand pressure. I'll need to free it all up and have it disassembled if I wish to replace the old belt, which I do. Otherwise I have to split the headstock and remove the main spindle. At this point I'd rather not but it may be required. Alternatively I need to find a smaller profile segmented belt that can be fed through before joining the links.
Sent from my SGP521 using Tapatalk
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26th Jun 2018, 08:30 AM #34Senior Member
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- Jan 2016
- Location
- Gosford
- Age
- 63
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- 173
I have stripped nearly everything apart (photos will come later) and it is now possible to see that there is some slop in the full nut / lead screw mechanism. Quite odd that I couldn't really see or feel it when it was all together. Nevertheless, I now know it's there and it will create issues with precision.
I will move the carriage from the middle to either end today to assess if it is the screw or nut that is worn, or both. My assumption here is that if it is the screw that is worn, the free play will be worse in the high use section and nearly gone at the tailstock end where the nut doesn't usually reach. If it is the nut (which I expect is the case) the free play will be more constant throughout the length of the screw.
Either way, there is the dilemma now of what to do about it, if anything. I'm wondering if a new nut can be made because I doubt I'll get a replacement OEM part for it. Any advice would be most welcome.
Of course it also begs the question of how much free play was in the screw / nut combination when it come out of the factory.
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26th Jun 2018, 09:06 AM #35Member: Blue and white apron brigade
- Join Date
- Feb 2006
- Location
- Perth
- Posts
- 7,189
The section in bold is not quite correct.
If the motor is a 3P 415V motor connected as a delta (∆) internally the motor cannot be used on a 240V 3P inverter and that motor will need to be replaced.
If the motor is a 3P 415V motor connected as a star (Y) internally some internal motor rewiring is needed - this is the most likely scenario for old lathe motors. If you are not comfortable working with mains V then this is s job for a motor rewinder.
The best case scenario is on more recent Y motors which often can be converted from Y to ∆ inside the motor connection box.
Despite the above I have yet to be defeated by a conversion so I agree that lack of 3P in a shed is not that big a problem - well at least for small motors anyway.
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26th Jun 2018, 09:21 AM #36Most Valued Member
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- Jul 2016
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- Melbourne
- Age
- 35
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- 1,522
In regards to the wear, how much backlash at its worst? What is the OD and TPI of the screw, someone here should be able to help you, at a minimum I can grind the grooving tool so you can make it yourself.
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26th Jun 2018, 10:11 AM #37Senior Member
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- Jan 2016
- Location
- Gosford
- Age
- 63
- Posts
- 173
The thread form is 5/8" OD X 8 TPI square.
I have moved the carriage to positions along the full length of the lead screw and as I suspected, the play is consistent, which indicates that the lead screw is as it should be and it is most likely slop in the nut. Either that or this is how it came from manufacture. By clamping a steel rule to the bed with magnets and pushing the carriage away I am able to measure 0.029" (0.030" no go, 0.028" go). Whether it will actually flop about that full amount when in use and subject to tool loading remains to be seen.
As the lead screw is steel and the nut is bronze, it would make sense that the nut wears sacrificially to the screw. It was possibly considered a wearing part. Without knowing the tolerance off the factory floor it is difficult to assess the degree of actual wear or if there is any at all. I'm not sure how fine a thread pitch would be affected by this and only cutting screw thread in one direction you could assume that the bearing surfaces of the screw and nut would be the same for each pass.
To be honest, I don't really know it this is a concern or not.
By the way, the numbers stamped into the bed and tailstock are 44. Probably a very early example of this model lathe.
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27th Jun 2018, 11:57 AM #38Senior Member
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- Jan 2016
- Location
- Gosford
- Age
- 63
- Posts
- 173
Restoration begun.
Here are a couple of pics of some of the lathe parts stripped down for inspection and ready for clean up and re-assembly. I'm deliberately not going to re-paint it all as it is in fair original condition and I prefer to leave it that way. I have painted the fabricated steel frame of the countershaft assembly as it was poorly painted and beginning to surface rust.
Worth noting is the stepped cone pulley on the countershaft which is a 4 speed driving only 3 speeds on the spindle. With the original 1/4 HP motor running at 1425 rpm, and using the larger end provides the factory spindle speeds of 900 (886), 600 (540) and 320 (332). The bracketed numbers are my calculations based on the drive cone pulleys being 4", 3 1/4" and 2 1/2" and the driven spindle pulleys being 2 1/4", 3" and 3 3/4" respectively. Using the 3 drive pulleys on the smaller end would provide spindle speeds of 720, 415 and 233. Engaging back gears reduces all these speeds to 1/6 so I could rig this up to run at 12 speeds from 900 down to 39 rpm. It would require a mechanism to shift both motor and countershaft assembly independently in relation to the lathe bed to facilitate belt tensions.
I am considering using a more modern motor I have here which is 1/3 HP and runs at 1500 rpm. This would provide 933 rpm down to 41 rpm. I've already purchased 2 new v-belts to replace the segmented originals. These were too chunky to allow speed changes as there simply wasn't enough room between the pulleys and the headstock casting.
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28th Jun 2018, 09:34 AM #39Senior Member
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- Jan 2016
- Location
- Gosford
- Age
- 63
- Posts
- 173
It works just fine for what it is. Indexing and accuracy will be a pain. There is absolutely no calibration markings whatsoever.
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28th Jun 2018, 09:51 AM #40Most Valued Member
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- Jul 2016
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- Melbourne
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- 35
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- 1,522
So none of the dials have any graduations? Might have to invest in some dial indicators and magnets.
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28th Jun 2018, 11:07 AM #41Most Valued Member
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- Jun 2011
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- Australia east coast
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- 71
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28th Jun 2018, 03:23 PM #42Senior Member
- Join Date
- Feb 2014
- Location
- Werribee, Melbourne
- Posts
- 178
Glivo, my old Senneca Falls lathe (circa 1900) would fall into that category with no dials anywhere but as mentioned above you can use dial indicators with quite good results. The dial indicator is out of focus but you can see where I place it against the toolpost - very usable when threading.
IMG_2545.jpg
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28th Jun 2018, 06:19 PM #43Senior Member
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- Jan 2016
- Location
- Gosford
- Age
- 63
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- 173
As serial number 44, I'd say it is probably about as basic as it comes. There isn't a calibrated indication mark anywhere to be seen. It may make a good electric guitar pickup bobbin winder or could be useful for stripping old line off fishing reels.
I successfully turned a 5" length of 3/8" x 16 Whitworth thread between the 4 jaw chuck to a dead centre on it today by just using my knowledge of the process and watching where the grub screw on the cross-feed handle was sitting at each pass and counting the turns in or out. This was indexing by eye and feel and the fact that this also has free play doesn't help, but I pretty quickly taught myself to use it that way. So what this means is that either the cross-feed screw or the thread in the saddle casting is also worn. The thread is rough as I did it with a very hurried and crudely ground tool and didn't bother too much with cutting fluid. Nevertheless, it shows that threads can be cut without any indexation calibration. It is never going to cut zero tolerance threads.
The clutch for the lead screw can only engage in one position per rotation so the feed is already indexed in that direction. Being a permanently engaged full nut means this has to be done anyway. The only thing I had to worry about was returning to and then increasing to the correct depth of cut, which I was able to do without graduations or numbers. I made multiple shallow cuts and lined up to the existing thread each time without any problem. This maybe only because it was 16 TPI on an 8 TPI lead screw. I haven't put my head around an odd thread pitch yet but I think it will work that way no matter what pitch it is.
The gear wheel tables for this machine are obviously wrong because without a tumbler reverse when I followed the charts I get counter-rotation. I had to include an extra direction change pulley to provide the reversal required. On a non reversing lathe you can't have 2 idler wheels, so you can see in the 16 TPI train the 3rd counter-rotation idler. The chart for the lathe shows only 2 pairs to achieve 171.6 TPI (maximum for lathe with supplied gears) but it actually takes 3 pairs to achieve this both for the full reduction and directional change again. I parallel turned the bar down to 3/8" using this feed.
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28th Jun 2018, 09:09 PM #44Senior Member
- Join Date
- Jan 2016
- Location
- Gosford
- Age
- 63
- Posts
- 173
The lathe is only set up temporarily on a large work board. I'm considering different options to use the extra pulley on the countershaft to double the speed variation range. There are several possibilities to achieve this. The simplest is going to be running the pulleys 1/2 width out of line and using a tension adjusting idler pulley. It may create early belt wear but nothing too serious over the distance.
I'm going to start on a sheet metal lathe tray to collect the excess liquids required for this solid bearing lathe and I've noticed in some pictures that it actually came with a solid extra base mount plate. This allows swarf to fall through where at the moment is can't easily be cleaned out so I'll need to improvise on this as well.
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29th Jun 2018, 12:11 AM #45Most Valued Member
- Join Date
- May 2011
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- Murray Bridge S Aust.
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- 71
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- 5,959
In your pic of the tools, how long do you think they'll stay like that??
One thing I don't like is a show off, but in your case, I'll make an exception.
BEAUTIFUL work.
KrynTo grow old is mandatory, growing up is optional.
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