10 K metric conversion

I am looking at a 10K lathe. It has a quick change box and inch gearing. I am told there is an aftermarket set of gears to convert this to metric threading. Any one hear of this?
thanks,
-armen

"I am told there is an aftermarket set of gears to convert this to metric threading."

Any English machine with a banjo can be converted to metric.

A 100/127 transposer (50/127 for SB; 60/127 for Monarch) is needed, plus a few miscellaneous stud gears. In most implementations, this transposer will be used as a compound gear, along with others on the banjo.

Since there are precisely 2.54 centimeters per inch 25.4 millimeters per inch; 254 decimeters per inch), and 127 is the smallest number of teeth which 254 can be divided into, a 127 teeth gear will always be in the gear train driving the leadscrew or box.

If you work out the lead, in inches for every setting of your box, and then apply the 25.4:1 ratio to those leads, you will determine what metric leads are available, using the 50/127 transposer alone.

Additional stud gears will be required in order to obtain the more esoteric metric pitches.

For the Monarch, the 60/127 transposer plus a 45 teeth stud gives many metric pitches using the box, but it takes 50, 55, 60, 65, 70, 75 and 80 teeth stud gears to cover every possible metric pitch.

In order to cover the ISO standard metric pitches, fewer stud gears are required.

Your SB and my Logan are no different, with a 50/127 (100/127 for the Logan) and a handfull of studs being required.

Boston Gear Works makes 16 DP 14-1/2 PA change gears, from under 20 to 128 teeth, including the all-important 127 teeth. Sadly, the bore is 3/8", and most small lathes take 5/8" more change gears.

Logan makes 3/8" face change gears with 5/8" bore.

SB made the set, and they go on ebay "sort of often" though I haven't watched for maybe a year or so. Low price seemed to be around $200 for the 100/127 set, up to around $400 (IIRC) for a NOS set with some other gears.

I ended up getting a metric set for one of my hardinges instead.

One of the tough issues with metric threading on an inch leadscrew lathe, is the lack of a threading dial. SB made them for metric, but they tend to need a specific drive gear for each metric pitch. Have to add quickly, I have not tried this, only read the descriptions. Another way is to leave the half nuts engaged, withdraw the tool, and reverse the spindle to start over for each pass. HB products, of course, are optimized to do this automatically as a matter of course even for regular threading ops, so it is not an issue.

smt


smt

"HB products, of course, are optimized to do this automatically as a matter of course even for regular threading ops, so it is not an issue."

HB lathes have a quick-acting feature.

Such a feature is available as a kit for other lathes.

See This or That for two alternatives.

I have a 10k that was made as a metric lathe, made in 1984. It had a threading dial with4 or 5 gears on it and adjusted via a slot on the mounting bolt.

The leadscrew, crossfeed screw and dial, compound screw and dial, the quickchange gearbox and the gears mounted on the banjo were all special metric parts, as well as the halfnuts, everything else is standard 10k parts.

I have personally seen three of these lathes, all made metric and all now converted to inch lathes. They were all school lathes bought when Canada suposedly went metric, starting in the lathe 70's.I am told the federal government had a program to pay for a percentage of new machine tools as long as they were metric.

I don't think they still have that program, if they do maybe I can afford a new metric 10ee.

Hello, I am interested in the metric South Bend , and how the four pinion thread chaser worked. Can you tell me what the lead-screw thread was on the metric 10K, and/or on the SB 9, also ? . Thank You.

I can't tell you what the leadscrew thread was on my 10k, I refited the metric parts off of my 10 k to a 9" model a that I got my conversion parts off of.I remember it was very close to the normal 3/4 8 tpi , I had one interested buyer insist it was 3/4 8 until a caliper was produced and the leadscrew measured.

As far as the threading dial is concerned, it had 4 or 5 gears on it and the mounting point that on a normal thereading dial is just a hole for the bolt to go thru, is in this case a slot that was wide enough to enable loosening and sliding the whole dial up or down to engage the gear that was used for the thread needed.

The dial had a huge amount of metric threads and the gear needed for each listed on a plate mounted on the dial.

I hope this helps you.

Yesterday I found a page at Tony Griffiths site <www.lathes.co.uk/southbend9-inch/page6.html> which I had somehow missed previously. It says there were lathes for export with 6mm leadscrews; also model A lathes with 3mm leadscrews and full metric gearchange boxes,and some with only change wheels. But what years ? . At any rate, a 3mm thread would look similar to the 8 thread/inch at arms length. (Actually 8.46667, or 8 and seven fifteenths, per inch); so the 10K possibly followed the same pattern of gearing.

"I have a 10k that was made as a metric lathe, made in 1984. It had a threading dial with 4 or 5 gears on it and adjusted via a slot on the mounting bolt."

Hardinge and Monarch toolroom lathes with metric leadscrews are also known.

The threading dial is always a problem as the fine metric pitches come in multiples of 5 ... 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.6mm etcetera, with 0.05mm increments ... whereas coarse metric pitches come in multiples of 4 ... 0.5, 0.75, 1, 1.25, 1.5, 1.75, 2mm, etcetera, with 0.25mm increments.

Paul at http://www.pae2k.com makes them...Bob

But, those are 18 DP, and are intended for the SB 9" machines.

IIRC, the others take 16 DP change gears, as do most 10" and larger American lathes.

Peter, I believe that both the 9" and 10K lathes use 18DP gears, though Paul advertises his metric change gears as fitting the 9"B/C lathes only. Not sure why.

I spoke via email with Paul, the gears will fit a SB 10K as well as the SB 9", they share those items. They will not fit the heavy 10...Bob
http://www.groups.yahoo.com/group/southbend10k/

"Not sure why."

Nor am I.

My Logan uses 16 DP for everything except the backgear, which, understandably, uses 14 DP.

18 DP is a real space-saver for the smaller 9" SBs (but Hardinge uses 20 DP for its 9x18 TL, its later 9x HLV-B, and is current 10x HLV-H, which are actually much larger lathes).

Quote: " I believe that both the 9" and 10K lathes use 18DP gears, though Paul advertises his metric change gears as fitting the 9"B/C lathes only. Not sure why."

I bought a set of these gears from Paul for my 10K, and posted pictures of them a couple months ago. They are beautifully made, the system is well thought out, and the documentation is extensive.

However, I hope my making note of them on this forum did not give him extra headaches. He clearly explains on his website the reason they are advertised only for the B & C models. The reason is that with the normal complement of change gears that come with the B & C lathes, he has worked out the combinations (gear charts), often several options of combinations, to give almost any metric pitch that will likely be commonly necessary for standard metric or model makers work.

Now the problem with the A models: These come with only 3 change gears on the banjo, which are not much applicable to more than a few metric pitchs. The gear ratios in the gearbox, unfortunately, do not correspond to much in the way of further useful metric pitches. The practical way to use Paul's gears on an A Model is to set the gear box to a multiple of 8 tpi (leadscrew pitch), and then make the metric set up on the banjos using the metric transposition set in combination with the correct set of SB change gears, accrodign to his supplied charts. Therefore, to use the transposition gear set and arbors with an A model 9 or 10K SB, quite a few additional regular change gears need to be purchased, to get the same wide range of metric threads.

I bought my set knowing this, and planning to make any necessary change gears myself as a shaper project, to practice up for further gear making for my TL lathe. Unfortunately all theortical due to serious lack of time at this point in my life . But at least both sets of 127T transposition gears are on my shelf for the 2 lathes when a supply of round-tuits comes in .

smt

"I bought my set knowing this, and planning to make any necessary change gears myself as a shaper project, to practice up for further gear making for my TL lathe."

But, this set is 18 DP, while HB's is a special version of 20 DP.

Please refer to my posts on the TL metric issue, in the BP/HB Forum.

Use of one of "Exactus's" lathe spindle indexers will facilitate making a 127 T and a 100 T gear using any DP 127 T and 100 T change gears as a reference.

However, a 37/47 transposer is only 0.020 percent error over all 23 metric pitches, and 37 and 47 teeth, as well as all others which are required, are available from Boston Gear Works' distributor stock. (Boston doesn't make a 127 T gear in 20 DP).

Hi Stephen,

He clearly explains on his website the reason they are advertised only for the B & C models.

Click to expand...

I wasn't questioning why he advertises his system only for the B and C lathes (that's clear enough to me), but why he doesn't include the 10K. I suspect that it is because there are so few B and C model 10K's. I can't even recall ever having seen one, though I know that South Bend made them.

Anyone here have a 10K without a QC box?

Ooops, I take that back.

Just pulled this photo of a 10K "B" from the archives:



I've forgotten who this one belongs to, but it is a rather fine looking machine.

Peter5322,

you misunderstood, or more probably in the interest of brevity I did not explain fully.

I got the HB metric transposition gearset several years ago. And continue to acquire gears for it (it=one of my TL's) here and there. IME, the hardinge metric stuff and spare gears are cheaper at auctions and on ebay than the SB stuff. Or perhaps they _were_. (as a hint, it cost less than 1/2 the price of Paul's very fairly priced kit for the SB, and came with a few more gears).

Always figured that by the time I got around to the project, there would be duplicates by then in the spares pile just from normal accumulation. Otherwise, it would provide an interesting project to make the Hardinge modified/stub 20DP cutters using a diaform, and then making the gears on a shaper.

In the meantime, Paul's metric set for the SB came up on Ebay a couple months ago, and I bought it as an additional accessory for my SB 10K. In a pinch, 18DP involute gearcutters are available off the shelf (unlike the hardinge pitch) reasonably priced. That is to say, if a metric thread becomes essential, and the set up needs approached as a job rather than a hobby, there is quick recourse to a reasonable solution, at least for me. (keep in mind, the way I used to single point metric stuff was with a set up in a mill-drill).

IOW, the 2 different transposition gearsets are for 2 different lathes, you need not worry!

Paula,

Thanks for the info on SB lathes. I never knew the 10K was made without a QC box (Thought all 10K's were A models) 'Course that should not be surprising....If you ever saw my post back when it "accidently" followed me home (might have been on the old Chaski or early PM), I thought it was a 9A when bought I just see way more hardinge and cataract, which also has more appeal for me. SB stuff "in the wild" is a bit rarer around here.

smt