Member postings for Andrew Moyes 1

The confusion may have arisen because there are two versions of the ML7. The earlier version has a bull wheel with 65 teeth as Michael says. Myford rationalised production and replaced it by the ML7R which used the same headstock as the Super 7 with a 60 tooth bull wheel.

There is a whole chapter on 'Modifications to "M.E." Drilling Machine' in the book 'In the Workshop' volume 1 by Duplex. Mine is the first edition published in 1949. It seems to be the Ned design as identified by others. The article runs to 24 pages.

The method I use is...

Put a stub of steel in the 3 jaw chuck and turn it to the required diameter.Slide the steady up up the headstock end of the bed. Clamp it to the bed. Adjust the fingers to the turned diameter. Free the steady from the bed. Slide it to the required position on the right of the bed and reclamp it.

Andrew

Joe Pieczynski recently posted this video **LINK** which shows how to pick up an internal thread. With the half nuts engaged, he inserts an internal threading tool tip part way into the thread, slides the tool back and forth between the flanks and finds the mid point using a dial indicator against the back end of the tool. He then locks the tool in its specially made holder.

I liked the basic idea and it got me wondering if it could be done quickly, without the need for a special holder, using a DRO. Indeed, it can. What is more, using a DRO enables it to work equally well with external or internal threading tools of any form. Here’s how…

1. Set the compound slide parallel to the lathe bed. Set the gear train to cut the appropriate thread.

2. Retract the tool to clear the thread. Engage the half nuts, observing the correct thread dial indicator position as per normal practice. Run the lathe under power and stop the motor, with the half nuts still engaged, part way along the thread. At this point I give the chuck an extra turn by hand to ensure that all the backlash in the gears and half nuts is taken up in the correct direction.

3. From this point on, do not turn the chuck. Set the DRO X-axis to zero. This memorises the carriage position relative to the leadscrew. The half nuts can now be disengaged.

4. Move the tool slightly to the left using the carriage handwheel and enter the tool tip part way into the thread. Bump the tool right and left against the flanks of the thread using the carriage handwheel, leaving sufficient sideways movement for the following step.

5. Advance the compound slide (turning the handle clockwise) while moving the carriage back and forth until the DRO X-axis reads equal amounts either side of zero. In other words the + and – numbers are equal. I work to the nearest thou and ignore tenths of a thou. The tool is now centred. Lock the compound slide in that position.

6. Advance the tool fully into the thread and set the Y-axis to zero.

You can now proceed to recut the thread by dropping the half nuts onto the leadscrew in any position permitted by the thread dial indicator.

The method also works with metric threads on an imperial lathe (and vice versa) BUT in this case the carriage must be returned to X=0.0000” to engage the half nuts and they must remain closed until screwcutting is finished, again as per normal practice.

Try searching online for 'alternative ivory'.

Andrew, the original flange mounting on my machine has a 110mm spigot, bolts on a 130mm PCD and motor flange OD of 160mm The motor I fitted is 0.55kW at 50Hz and 0.66kW at 60Hz with a frame size IEC71. I believe the flange mounting is described as B5 with frame size 71. (Note B5 flanges are different for other frame sizes.) Bearing Boys sell a TEC motor of this specification.

I fitted a three phase 0.55kW flange mounted TEC motor to my 1976 light vertical and it fitted perfectly without any alteration.

Expanding on Graham's suggestion of using a ball, that's the method I used to size the new Oilite bushes I fitted to the pulley of my Tom Senior mill. They were 1.1/8" bore and were too small after being pressed in.

It didn't take an inordinate force to press the ball through and was well within the capability of my 1/2" drill press. I used a steel rod in the chuck with a 60 centre drilled end to locate on the ball. It's not difficult to compress the sintered structure. There was a certain amount of 'spring back" of the bush after the ball was forced through so I heated the ball for a few minutes in boiling water and that enlarged it to give the running clearance I wanted. The result was a perfectly round highly polished bore that was still porous and exactly the size I wanted. I think this method is less risky than reaming.

I have a DW mk1 mill that I made from the kit circa 1980. The spindle blank was supplied pre-drilled through at 11/32" for a 5/16" drawbar. Neither 3/8" nor M10 will fit. The tail of the spindle is 5/8" diameter with two opposed keyways cut into it 3/32" deep. There isn't enough metal left to drill it out for the larger drawbars. The OP might have the mk2 version of course and that might have a larger spindle - I can't help if so.

Andrew

+1 to what Alan says. I kept forgetting to shut off the oil drip after each use. Instead I put two drops at the start of each session and maybe another drop if I was turning for more than an hour at a time. After 40 years use, the measured play in the white metal bearings was still 0.0005" as when new.

Andrew

Hello Tom. It's certainly possible to raise the knee singlehanded with the handwheel, but I wouldn't describe it as 'easy' when going up. Coming down is easy by comparison.

As regards lubrication, there are two ball oilers on the left hand side of the knee. One is for the horizontal shaft that carries the handwheel and small bevel gear. The other is for the thrust bearing of the Z axis feed screw that takes all the weight. In theory surplus oil from that might find its way onto the large bevel gear teeth but mine, when I just felt them, were quite dry. I've treated the teeth to some grease and that has made the gear operation smoother.

Like Steve, I have a light vertical and believe the arrangement is the same. The three large hex headed bolts that face the rear of the machine should be tightened fully in use as they clamp the gib firmly to the knee. The three grub screw with locknuts on the side are the ones that adjust the gib. The procedure is to slacken the three large bolts just sufficiently to allow the gib to move but no more. The adjustment is carried out by slackening the locknuts and turning the grub screws and relocking. The three large bolts are then retightened fully.

I have found the adjustment is a bit tricky. Unlike the X and Y adjustment, gravity is involved and the parts are heavy. When carrying out the adjustment, it's important to centralise the table using the X and Y handles so that the centre of gravity is as directly as possible over the Z feed screw.

Even when properly adjusted, I get the jerky operation you describe if the table is extended fully to the right or left and especially if there is a heavy vice off centre in the same direction as the table. As Steve says, it can be a reminder too that you've forgotten to release the table lock.

As for the lumpy gear movement, it sounds like they could benefit from some lubrication. If you wind the knee up to the top, you can get at them from below.

Andrew

My chuck looks identical with purpose-made screws you'd need to turn yourself.

The screws are 3/8" BSF, thread length 1.7/8" and the head is 0.556" diameter by 0.278" high.

Andrew

From memory of when I rebuilt mine a few years ago - you are just left with the two bearings (items 4) which are a tight interference fit and the bearing spacer tube (item 7) which is a clearance fit. They should press out from either end as the bore of the quill is parallel throughout.

Andrew

I have exactly the same three phase suds pump on my Tom Senior mill and wanted to convert it to single phase, too. I played around with different values of capacitor and found 2.5 microfarads gave the nearest to a balanced 230 volts across all three phases.

A standard M4.5 x 0.75mm tap fits the tube on mine nicely.

This follows on from the interest shown in my Kennedy hacksaw restoration in the 'Hoover motor lubrication' thread. I hit a snag with replacement of the main bearing and the following is the method I used.

The shaft is ¾” diameter and the bronze bearing is 2” long. I purchase two 7/8”OD Oilite bushes x 1” long, thinking it would be a straightforward job to press the old bush out and new ones in. I then found that Kennedy didn’t follow normal engineering practice by reaming the hole. The hole is left as-cast with a pronounced taper. Their solution was a bush stepped on the outside and driven in from the wide end. The bush fitted the bore with line contact only around two rings, at the narrow end and in the centre.

I reamed the bore 7/8” but only half of the bore cleaned up. I pressed in the first bush and retained the loose bush with Loctite. I cleaned the outside of the loose bush with acetone and used an oil-tolerant grade of Loctite. I also machined a mandrel to align the two bushes, making sure no Loctite came into contact with the mandrel!

For the shaft, I used ground silver steel that was 0.5 thou under nominal size. The two Oilite bushes were also 0.5 thou undersize as supplied. The pressed-in bush contracted a further 1.5 thou.

Reaming an Oilite bush to size is not recommended because it smears the porous bronze and destroys its self-lubricating properties. Instead, I used a technique recommended in an old booklet by a bearing manufacturer. That was to press through a precision ground hardened steel ball. Mine was spot-on 0.750” diameter but due to spring-back of the bush, the shaft still did not enter the bushes. I heated the ball in stages with a blowtorch and used the drill press to force the ball through. It eventually enabled me to get exactly the fit I wanted with a highly polished, truly circular and porous bore.

Hi Leslie and Chris. I haven’t made the progress I intended on the Kennedy hacksaw restoration. Partly because I hit some snags but I have also been diverted to help my son restore his new flat. However your requests will encourage me to get it finished and take photos.
Leslie - I renovated the Hoover motor first and didn’t take any photos while it was apart. If you have any specific questions I will try to answer them. One thing to note is that there are only three wires in total emerging from the start and run windings. One end of each winding is commoned within the windings and that wire goes to the neutral terminal. The other end of the run winding goes to line terminal and the other end of the start winding goes to line via the centrifugal switch. It’s therefore not possible to reverse this motor – not that you would want to anyway in this hacksaw application.
I'll open a new thread on the issue I had with the main bronze bearing.

If I recall correctly, when I studied the photos posted by Roy Milner on eBay, it was apparent that he used his own casting for the headstock, confirming what Michael quoted here. The shape of the casting around the pulley and in front of the backgears was different to standard. Also, the enlarged gear on the back end of the spindle (38T on my Beeston big bore machine) means the fourth gear (after the two tumbler gears) has to be enlarged to 38T too in order to preserve the 1:1 gear ratio for screwcutting. That changes the tumbler lever geometry too. So a conversion will not be easy.

Andrew M

Edited By Andrew Moyes 1 on 29/06/2021 08:36:18

Jeremy - I've a spare set of unused jaws that I don't now need. Send me a PM.

Andrew M