Member postings for old mart

At the moment there are a number of accessories for Smart & Brown on ebay UK, at the hugely inflated prices wanted, it is no wonder that most of that stuff is just sitting there month after month unsold.

Sad to say, that the very good Vertex vises have increased in price in the last few years and are well above the op's budget.

At the museum we have the ARC 125 versatile with the rotary base, and a pair of Bison 100mm, one of which came with the drill mill and the other which I bought new with a rotary base for much less than the list price, 1/5 in fact. They do suffer with the jaw lift problem by design, although it is possible to tighten them up to reduce the problem. We also inherited an apprentice made vise which although beautifully made, has the design shortcoming leading to jaw lift. 

As Clive Foster says, the advantage of a bigger vise is also the wider jaw opening, I bought the ARC 125 when confronted by the need for more than the 75mm opening of the Bisons and the extra size coupled by a different design doubled the opening.

Edited By old mart on 12/01/2020 16:52:50

I needed a bigger vise a year or two ago and got one of ARC's 5" with the swivel base. It opens a lot wider than the 100mm Bisons normally used and it works fine without the swivel base, which can come in handy occasionally. ARC also do a line of higher quality SG iron vises.

I would look at the 150mm / 6" sizes bearing in mind the capacity, and the weight, which rises quickly with size. 

Looking at your budget, the ARC 125mm vise which opens to 150mm is slightly above, but you might be able to stretch that far, it is the same as mine, the jaw lift is less than most, a lead hammer would probably not be needed, I have never regretted buying mine.

Edited By old mart on 11/01/2020 21:26:23

I see Lewis Hamilton has just donated a large amount of money to help with the problems the bush fires are causing.

Good for him!

Not today, but yesterday, I wanted to produce a female thread for a microphone stand.

That sounds straightforward enough, but microphone stands have the obscure thread of 5/8" X 27. At the museum we have hundreds of taps accumulated over the years from toolboxes donated to us. No luck there, I would have to singlepoint it on the lathe.

Of course the lathe did 26 or 28 tpi, and I was unlikely to be able to get the 27 with the limited number of changewheels available. Also, with the 16 size of threading inserts, the hole starting size of 0.588" was looking difficult. I got out a 12mm shank left hand holder and set it up in a four jaw chuck eccentrically and took off metal opposite the insert tip position. With a 1mm iso insert in the holder, I sacrificed part of the carbide with a diamond wheel until the tool would pass into the bore. Roger and I discussed the relative merits of going for 26 or 28 and jointly chose 26. I went for a sloppy fit of about 0.004" over the nominal size and the male part screwed in about 3/8" before starting to bind. The thread does not carry much over a pound of weight so it was a good result. I hope I remember to set forward on the lathe tomorrow before using it, although the chuck lock is fitted.

I think I will look at getting some size 11 inserts, the Chinese holders on ebay are less than £5 each.

Not today, but yesterday, I wanted to produce a female thread for a microphone stand.

That sounds straightforward enough, but microphone stands have the obscure thread of 5/8" X 27. At the museum we have hundreds of taps accumulated over the years from toolboxes donated to us. No luck there, I would have to singlepoint it on the lathe.

Of course the lathe did 26 or 28 tpi, and I was unlikely to be able to get the 27 with the limited number of changewheels available. Also, with the 16 size of threading inserts, the hole starting size of 0.588" was looking difficult. I got out a 12mm shank left hand holder and set it up in a four jaw chuck eccentrically and took off metal opposite the insert tip position. With a 1mm iso insert in the holder, I sacrificed part of the carbide with a diamond wheel until the tool would pass into the bore. Roger and I discussed the relative merits of going for 26 or 28 and jointly chose 26. I went for a sloppy fit of about 0.004" over the nominal size and the male part screwed in about 3/8" before starting to bind. The thread does not carry much over a pound of weight so it was a good result. I hope I remember to set forward on the lathe tomorrow before using it, although the chuck lock is fitted.

I think I will look at getting some size 11 inserts, the Chinese holders on ebay are less than £5 each.

I remember occasionally starting up the compressor at the plating works back in the 60's. It was manual start, and it had a lever which you pulled up to get the thing rotating at about 200 rpm and then down quickly before it stalled. It would run normally after that. I was told that it started in star, then went to delta.

I have noticed that the little box with "stay logged in" or something like that, occurs at random. I try to stay logged in by minimising the active page and opening a new page, it works most of the time. When I have finished with the computer, it gets fully closed down and the power switched off, so I am used to logging on to all forums and the like.

The little hole is a mystery. I had not thought of the possibility of a flat sided piece fitted in the bore. Certainly not brazed or silver soldered as that would show up after you polished the end. I recon that we will never know the full story unless a NOS one turns up for close study.

I would appreciate advice as to whether this gasless wire supplied welder is worth buying. Reels of the wire will also be on sale at the same time.

**LINK**

This is the motor I bought for the Tom Senior light vertical R8 conversion, it is run in delta and through a Schneider VFD from the domestic mains. The spec gives the expected speeds, torques at different frequencies. The machine runs between 25 and 75 Hz.

**LINK**

Edited By old mart on 10/01/2020 17:02:37

In my book, an engineer is someone who has completed at least to university degree level.

Time to buy a metal bottle brush to clean the chuck threads before mounting, and having your own airline is useful if used carefully.

I don't think I'd ever have the nerve to try a magnetic chuck on a lathe, even surface grinders normally have a positive stop to rest the work against to prevent the wheel firing projectiles across the workshop. Grinding forces are much less then turning ones, good luck.

For collets, you have a choice of MT2 using a home made drawbar, er 25 or 32 with exactly the same drawbar, or a screwed on backplate with an er 25 or 32 plate bolted on. The er 25 is generally limited to 16mm maximum collets, which may be enough for your requirements. The backplate method has no need for a drawbar allowing long stock right through the spindle, and also if the plate/collet register is left loose, you can fine adjust for zero radial runout on any critical work. 5C collet chucks are nice if the budget allows.

New ones are available at a staggeringly high price, second hand very difficult.

**LINK**

The good thing about the humble impact driver that you hit with a hammer is more than just the instant high torque, as you hit it the axial pressure is also instantly high, which stops the bit slipping out of engagement.

I would tend towards screwing the adaptor out in the opposite direction from the original assembly. That is clockwise viewing from the head with the screwdriver slot. There must have been a bit of swarf trapped as it was screwed together.

I would start by giving the 3/8" end a sharp rap with a copper hammer, and the slotted end likewise with a soft drift.

I am using a VFD with a 1hp motor taking advantage of the speed control. I have set the frequency to vary between 25 and 75 Hz. I feel that going lower than 25 Hz is not suitable for my requirements, because at that frequency, the motor speed is halved from the standard 50 Hz, but the power is also halved. Below 25 Hz the drop off of power is rapid.

You will have trouble getting a hole like that drilled using a drill press, there is too much slop in most of them. I would have difficulty using a mill and a stub length solid carbide drill. A short carbide end mill would be a viable alternative with a very slow feed. I don't think a cobalt drill would stand a chance.

The weight of the indicator is a factor when you are working in microns. 

You can eliminate errors with the brake disc by rotating it 180 degrees. It might work better if the main diameter was down instead of the boss. The faces could be checked with a micrometer for any thickness deviations.

Edited By old mart on 07/01/2020 22:06:56