Member postings for not done it yet

Hello Cheryl,

You will have a PM shortly.

I have a broken T slot which needs repairing. Question is: What would be the best way?

My first thought is to mill the bottom to remove the sideways slot and back to make space for a bolt hole through the casting. Then mill backwards (up on this pic) at an angle. A shaped steel "bolt", to replace the parts lost and removed, would be fitted through the hole and secured underneath and either welded or brazed to the cast.

The idea is that steel would give strength on the corner of the two slots and support the cast on the angled join. The intention is for a working repair, not just a 'decorative' one.

I'm open to suggestions as the casting is likely around 100 years old and is not replaceable. There are another couple of angles in an album.

Slots are 1/2" and their base width is 1"

Cheap tooling - go for the shaper.

Drilling or boring - forget the shaper!

I have just put out feelers for a shaper, even though I have picked up a really basic manumatic one.

The Eng, tech, at the college I worked at twenty years ago, rather coloured my view of shapers - a jaundiced one - and until I watched Emma in her spareroom machineshop making T nuts I had little interest in shapers. It has changed. She inspired me to try one. But a manumatic shaper is entirely different than running a powered version.

However, a mill will do far more than a shaper - curves and straight lines, as opposed to straight lines (normally)- so a vertical mill has to take precedence. Every time. A shaper set up can be left to chunter along, doing its thing - slow and reliable - while you get on with other faster jobs which must be watched. A bit like a mechanical hacksaw.

Just list the manipulations of each and cross off the common ones. Then decide if you can do without one or the other. It will be the shaper that is crossed off. But if you want to knacker your quill (or long travel) on your small hobby mill (or lathe) go ahead - but a shaper would do those jobs all day long with no detriment to the machine. Horses for courses!

Bayzle, if your arbor is 7/8", you could always take off that extra 0.225mm so that these cutters would fit .... but if you did that, it might mean your Imperal cutters would be a bit wobbly as well.

RING BOB ON 07598 792352? That is what it says on the auction site.

Then tell us all?

I bet that uneathed wire got a bit warm!

How many 100W bulbs did you run on your lighting circuit, before the days of fluorescent or led lamps?. Four at a time would be more than running a 1/2hp motor. Modern UK lighting circuits are 5A rated. Earth is for safety, and would not normally carry any current or be at any other potential than earth!

So, not so outlandish in days before conductor sizes were minimalised - and they only gave a 120V belt if the frame went live, not like our far more lethal 240V.

SB5 started correctly, refering to it as a mass, but sadly regressed to calling it a 'weight' further into his post. Weight is mg where m is the mass (which should not change) and g refers to the gravitational field which most certainly changes, dependent on location and a few other small but important factors (of which us mere mortals need not bother about).

IF you might get a vertical head sometime, you will need a change-over switch as the motor needs to turn the other way for both the Mkll and lll heads (have to think about the Mkl).

88mm of Y travel seems a tad small, an X1 has 145mm.

It'a horizontal, so comparing with a vertical mill is not too fair. You can only drill by 88mm, but you can flat (really flat!) a workpiece with a 150mm wide slab cutter in one go, which you cannot do so easily with a flycutter on the vertical (or this one either) without very careful tramming. Cross travel on the vertical is the vertical travel on the horizontal.

Vertical mills became more popular because they are easier for more manipulations, but you can't put six different cutters on a vertical mill at the same time, like you could on a horizontal.

It looks robust and could be driven by a VFD for extra speed control. Motor will likely outlast quite a few on the chinese offering.

Does the table feed work? An extra, if available, on an X1.

If those cutters are sharp, you have done very well. It will last longer than an X1. Centecs have the option of fitting a vertical head, so a bit of a leap ahead - but the downside would be finding a good vertical head for what you paid for the job lot.

An awful lot of negativity in this thread. And exaggeration, too.

1 billion miles per day would only require a further 8 Gigawatts of electricity generation. 2 GW could easily be saved by proper insulation of housing stock. We currently import/export as much as 3GW via international connectors. That will increase considerably in the interim period.

T

hat 8GW assumes 200Wh/mile, the typical current usage for smallish EVs. (Tesla S uses a little over 300). That efficiency will doubtless increase as regenerative technologies are improved or introduced, battery energy density is enhanced, etc. There was one example of a discharged EV battery being almost fully charged at the bottom of a long hill (talking here of an alpine crossing, I believe!).

Fuel cells are readily available in ~1kW modules. Think here, that is 5 times the average power required by a typical EV. It may not meet peak power requirements but in twenty year's time the heavy right-footed drivers may be in the minority. Hydrogen will be generated more cheaply (better catalysts per eg).

There is currently about 50GW electricity generation capacity. That is only just sufficient for current peak usage (with power curtailment by some heavy power consumers). Night rates (economy 7) are ideal for EV owners, reducing the cost of recharging by near to 50% Think here - that is more than adequate for the 50% of drivers doing less than the average of 20 miles each day. But, agreed, it does not take into account of those that do no miles for six days and 150 miles on the other day of the week - but they are not the average, and there are better alternatives for this type of motorist! (rent a vehicle when required, rather than ownership, per eg)

Electric motor cycles are already available as options. 100 miles range and quicker than many current commuter motorcycles.

The 8GW assumes no home generation. Home PV systems are currently limited to 4kW peak per phase if connected to the grid. With battery storage opportunities improving, most EVs could be charged from home systems for at least part of the year at zero grid usage. Especially if home systems were extended to cover the roof (10kW or more?)

No, look ahead with some modicum of positivity. It can be done with the will to do it. And stop being so negative!

a ban on Diesel and Petrol car sales from 2040!

They did not say that. You missed out the word 'new'! My car is 15 years old and still going.

IanT,

You will have a PM shortly. Nowt to do with m2 taps (but a means of catching your attention if you miss the flashing message icon! ).

All yahoo fora are a nightmare to navigate as far as I am concerned. The Centec one is compounded by the current site owner only putting up posts if and when it suits - sometimes days after the post was keyed in. Maybe that will change as the owner wants to abdicate. Non-appearance of posts leaves one wondering if they were lost in space, deleted or just several days late (by which time the posts show up the topic might be already covered by another member).

First question might be "How hard is the metal?" If relatively soft, a morse taper with strips of fine abrasive carefully glued on, could be used to remove any high spots. If hardened, a reamer may not be an option - and if reamed it would need an absolute minimum of material removed while retaining concentricity. All morse tapers would fit that much deeper into the cone and it may have been reamed previously....

It would appear, from the yahoo forum site, that possibly some 2A machines were fitted with 5/16" drawbars. Not totally clear as there is often some doubt as to what the machine may have been originally (I believe some 2Amachines may have the nameplate but converted to a belt driven spindle -probably at a time of gearbox failure).

It appears, at present, that Centec and Centec 2 machines were all originally 5/16" and all 2B machines were 3/8".

As vertical heads were supplied for Centec 2 onwards, the Mkl vertical heads were likely all 5/16". All 2B machines would have been supplied with Mklll vertical heads, so 3/8". Anybody's guess as to the drawbar size(s) on the Mkll heads, but I'm sure Centec would have changed both horizontal and vertical drawbars to 3/8" at the same time. I would have thought that the change was made at the 2A, but whether at the introduction or mid-stream is not yet determined. I believe the 2B gearbox was uprated c/f the 2A. Motor power was increased for the 2B and that may be related to the changeover (both machines being built at the same time for a number of years).

There appears to be no definitive change-over date (from 5/16 to 3/8) at the present time. Boring a shaft to oversize may, or may not, be a good move. The shaft was likely well over-engineered in its day, so easily bored with no detriment. It does not need to be taken out to 3/8", even, if studding is used as a drawbar. The drawbar would need to be separable (or a blank taper fitted or collet could left in situ) should the machine be used in vertical mode if David's perfectly adequate solution is applied.

Most of this is currently a topic on the yahoo forum, of which you are a member. Perhaps Gary Wooding will chip in with some clarification - as he appears to be a very reliable and likely the best informed Centec owner.

At that price it is clearly no good at all. They are asking not much more than scrap value! If it is in the Ottawa, ring my sister in law and get her to collect it. She can repatriate it to Blighty, as excess baggage, next time she flies over.

Better listing it in the 'for sale' ads? Lost on here unles continually 'bumped'.

Remove nail heads and drill down two sides (at about right angles?), close to the nail, and prise off timber? Should be enough to loosen the grip of the nails.

Hope that they have been nailed straight and not 'on the tosh'.

Edited By not done it yet on 22/07/2017 15:46:34

What other gases could be produced?

Like natural gas, propane will contain small amounts of sulpur ethers (or other sulphur compounds) to give it a recognisable smell (to allow leak detection before an explosion occurs!). Even with complete combustion SO2 will be produced in small amounts. All high temperature combustionncan also give rise tomoxides of nitrogen. Both of these are irritants and form the appropriate acids when dissolved in water.

The bottles state they contain 110L, the 600g must be the total weight.

Nope. Can't see it. They do sell 390g ones, too, slightly cheaper. Other cannisters state volumes but the CO2 doesn't. At least not on their advert/catalogue. Please show me where it is stated and I will be very surprised. Ideal gas laws are only applicable to ideal gases (are there any?) but PV = nRT is a good approximation in most cases.