Member postings for Howard Lewis

If any of this helps anyone, I offer the following details of my shop; (sorry to be SO wordy).

The one thing that I got wrong was to mount the workshop on slabs on sand/cement.

With 20/20 hindsight I would have had a concrete base, probably with steel reinforcing mesh.

1) CONSTRUCTION.

After very protracted negotiations with the Head Chef/Gardener etc, the maximum allowable size was 10'9" x 6'9" (NO WAY could the Bay Tree be re located, nor the Patio Wall!).

To provide headroom above the Mill Drill, the external height was 8 feet, sloping down to 7'6" at the rear. (Guttering takes the rain into a butt which helps cheer the Head Chef/Gardener etc a little).

For security, it has no windows, (I would only have covered them with shelves anyway).

The door is a fire door, the weight of which required 100mm x 50mm framing at that end, with a 6 lever lock, and three home made hinge bolts (see later). This is set, slightly off centre, (to align one edge of the frame with the front edge of the Fitting Bench,) in the 6'9" wall nearest to the back door of the house.

All wood construction, the framework is 50mm sq, with 19mm external cladding, and fibreglass insulation covered by 12mm ply internal cladding.

The roof is similar construction coverd by underfelt and good quality top felt , bitumen bonded to the timber. Nails only used to secure the capping strip around the edges.

The external walls are painted every two or three years with two or three coats of a water based preservative

2) Flooring.

The basic floor is 18mm ply, supported by 5 off 8" x 2" bearers, running the length of the shop. The centre two were spaced so as to admit the legs of a folding crane for machine entry.

I was lucky enough to be given some ex industry plastic mats with which to cover the "central" area of the floor.

These sit on top of some 15mm chipboard.

Similar, but in rubber was available from Toys r Us, at £18 for a 1 metre square. (MUCH cheaper than buying Industrial matting from folk like Cromwell Tools).

3) Electrics

Not REALLY the best!

Fed from a RCD in the Utility Room via flat 2 core and earth cable (What I would call 14/029).

There are eleven metal clad double sockets (One of which contains a filter, to prevent anything nasty from the thyristor invertor for the lathe from upsetting our house, or anyone else in the locality connected to the same phase) connected on a ring main.

It is MOST unlikely that I would use two machines at the same time, as well as a Fan Heater, so no problems anticipated, or seen, with current draw.

(A Brennenstuhl monitor, never shows the invertor for the 1.5 hp motor on the lathe drawing much more than a couple of amps. On a heavy cut, or a very rare dig in; the belts will slip).

Lighting

All fed, quite incorrectly, from sockets!

Two 5 foot fluorescents on the ceiling (the second, switch fed off the first when needed).

A worklight over the Fitting Bench and Bench Grinder, now with an LED lamp.

Two worklights, one each side of the Mill Drill, fitted with LED lamps.

(The worklights came, as you might guess, from the scrapyard at work, and merely needed cleaning up)

The 24 volt Halogen supplied with the lathe. (Modified by filing two 5/16" slots on the outer edge of the "reflector" to improve ventilation. Since then, the appetite for 24V 50W lamps - which are seen as frequently as hens teeth, has ceased).

Benches

Lathe Bench - Actually some ex supermarket wharehouse staging, standing on heavy angle iron to spread the load. Originally was supposed to be levelled by M10 setscrews, but so rigid that the rear leg at one end lifted in unison with the front one. This necessitated a rethink on the lathe mountings! The lathe now rests on three heavy angle iron cross bearers, which are supported by welded on angle irons resting on the 3 x1.5 inch lateral beams of the staging.

Fitting Bench, Steel topped, box section frame, bought from the scrapyard at work, 60 x 30 inches, but cut down to 18 inches wide and rewelded.

Mill/Drill is on 60 x 30 inch deep steel topped angle iron bench, (again ex works scrapyard) but cut and spliced to fit between the wall and the chip tray of the lathe (which slightly overlaps the end). Beneath are wooden drawers containing, in a jumble, tools like hacksaws, and automotive items that may come in handy one day. The drawers are supported on heavy angle "ladders" , welded to the bench at one end and bolted at the other.

High above the Mill/Drill, on the end wall, is a security light, which will illuminate if the mains supply fails, to allow switching off all electrical items, prior to exit.

Ventilation is by an ex equipment 6" fan fitted high up, between the cladding, and with fixed vents at floor level. Externally, there is a duct over the fan opening, to prevent rain ingress.

Heating, when required is by a thermostatically controlled 2 Kw fan heater,. which only runs for a small percentage of the time, given the insulation. A lot of time, I work with the door open unless it is raining.

Rust is almost unknown, VERY little seen in the ten year life of the shop. Last winter was the first time that any, even very light, was noticed.

Edited By Howard Lewis on 14/09/2013 13:04:53

The risk is that a Series Wound Motor, off load will run faster and faster until it self destructs, as postulated in the original post.

Usually, what prevents this are the friction in the bearings and the windage on the rotor, which provide sufficient load to keep the speed below that where the centirfugal forces cause rotor windings to fly off.

Having said that, better not to find out the hard way that your motor is low friction and/or internall very aerodynamic!

Howard

Like many others, I have found parting off works better using a back toolpost (which is what is always used on Capstan lathes).

Various explanations have been offered for this, (pressure on dovetails. etc)

This carries a 3/32 blade in a holder which allows a little flexibility. This blade is ground at angle, so that the workpiece should have no central pip, (left on the base stock).

Theoretically, this is bad because the swarf is wider than the slot, but it works OK virtually all the time, maybe the flex in the holder helps

In the Front toolpost, I sometimes use a 2mm replaceable tip tool, and very rarely does it dig in.

In my case, the Mill/Drill came with MT3 after I was horrified by what the way that the Rodney milling attachment did to my Myford 7. Shook it like a terrier with a rat. maybe I was a bit heavy handed, but 0.020" cuts don't seem heavy to me!

The replacement lathe has a MT5 mandrel and came with MT5/MT3 sleeve, so I use MT3 for virtually everything, (even ex Myford days MT2 with a MT2/MT3 sleeve.

So standardisation/rationalisation was almost a no brainer.

Occasionally, I need to separate the ER25 chuck for use on the HV6 Rotary Table, so I made up a simple extractor.

If anything sticks in the Mill Drill, I also modded the top nut on the quill to allow me to use a screw extractor, rather than beating the bearings to death with a mallet. But if takes anything more than a light tap to release, you've overtightened things!

Ultimately, "you makes your choice and pays your money!" for what you believe will suit, and work best for, you.

When I changed lathes, ten years ago, PXF was a MUST.

The Myford Super 7 Sigma was my choice until I found the cost AND that PXF could not be fitted.

I use it pretty much all the time.

Whether you CAN have PXF will depend on how big a lathe you can accomodate.

My lathe is an Engineers Tool Room BL12/24, very similar to the WARCO BH600, or the Chester Craftsman.

Warco offer the BH600 in Imperial or Metric form. I think that Chester only offer the Craftsman in Metric form. The BL12/24 is basically Metric but is dual dialled, and so suits me as an Imperial Luddite who infrequently uses Metric.

I have never been brave enough to part off with PXF, despite having madeand fitted a Backtoolpost, so can't comment.

But for Facing, my view is that PXF is a must.

A personal slant is that I am extremely happy that the lathes listed above have a separate feed shaft, as I was used to as an Apprentice, and do not use the leadscrew to power either sliding or facing feeds.

As another aside, I made a 80T 1.25Mod gear for the Norton Box on the BL12/24to halve the feedrate, which meant repositioning the closure for the backgear cover. It is a worthwhile modification, allowing, using slow speeds and sharp tools, with lubrication, superb finish.

Hope that this helps a little.

Howard

Many Thanks to all who have replied.

I have now solved the problem, after a fashion.

The method was use a 3mm hard drill (ie TC tipped like a masonry drill, but ground for metal) run at the max speed of the mill/drill, with plenty of pressure, as recommended.

This drilled out the grubscrew, so the brass flywheel is now secured with an M4 grubscrew.

Again, Many Thanks for all the advice.

Buying some Stellite drills may be a good idea, against future mishaps, (which are QUITE likely in my case!

Regards

Howard

I have made a horrible boo boo and need to remove a 6BA grubscrew, which is thoroughly jammed in a part that I cannot scrap and replace..

The only thing that has made any progress was a left handed drill, and even that seems to have run out of steam at the bottom of the socket.

Any ideas Please?