Member postings for Peter Cook 6

Interesting discussion, but simply adding a fixture plate doesn't give any Z-axis control. I would have thought for any realistic milling use you would be far better off with a vertical slide (with T-slots?) to which you can afix the workpiece or a small milling vice.

Almost certainly started life as a rifle bullet . 0.375" is the calibre for a Winchester or several other hunting rifles.

Why the groove - to hang from a cord as a trophy?

No problems with Dyson here. The new one is a replacement for a DC01 I (alright we!) bought in 1994. Still works, but is heavy and the power cord is becoming more of a pain.

Not sure if people can't be bothered, or if they have no idea how to! The number of people who use technology that not only do they have no idea how to fix, but worse they have no idea how it works either worries me. I wonder how most of them survive.

I just purchased a new vacuum cleaner ( A Dyson). Opened the box to be greeted with a label that said they were not supplying a printed manual in the interest of saving the environment - I should download one from the internet.

However there is an outer cardboard shipping sleeve, an inner cardboard display box and then every separate component of the machine is wrapped in an origami exercise of corrugated cardboard together with extra pieces to fill the spare space.

So they save one five page booklet, but still supply about 40 separate pieces of card - most quite large when unfolded!

The environment or their costs?

Suspect you will not get anything - only your credit card details harvested.

Sandals?

Probably two different groups of forums.

One group ( call them HOW) covering the techniques and issues associated with actually printing. As John said in the second post, most of these forums are printer specific although there are some more general ones.

The other group (the WHAT) are associated with creating or acquiring the things that you want to print. The biggest in this latter group is probably Thingiverse - Digital Designs for Physical Objects although there are others e.g. 3D Models for Free - Free3D.com

Beyond these "libraries" you get into the forums dedicated to software that allows you to create your own 3D designs and again these will depend on the software you use to create the things you plan to print. That opens up the whole "which 3D design package" religious wars can of worms.

My experience - get a printer, use YouTube (if required) to help you put it together, set it up and get started by grabbing things from Thingverse, then graduate to designing your own. Use forums to help solve particular problems.

Doing the math on Tax, Insurance, Maintenance, MOT, Tyres and Fuel divided by the miles (not many these days) - simply using a Taxi is starting to look very attractive!

Depends what you are planning to do with it.

I frequently use 4000rpm plus on my SX1LP when drilling tapping and clearance holes for M3 and M4 fastenings, particularly in aluminium. If M3 & M4 seem very small to you - it's probably of little value, and the odd hole at lower speed will work just as well.

I also use 1 & 2mm mills in aluminium to cut small 3-4mm wide slots. Again the high speed is useful.

I do feel pangs in the wallet when I look at the SX3.5ZP!!

Edited By Peter Cook 6 on 02/02/2022 17:52:22

Wikipedia Coining (mint) - Wikipedia has some basic information about the making of coin dies in medieval and ancient times.

There are people I know who hire "a man" to put pictures up - not sure they would know what a "thread" was let alone a left hand one!

In case anyone is interested!. It has been a bit cold in the workshop for progress on the "other projects", so I have amused myself by developing the design for the church clock model. Rather than the original idea of having the chime triggered twice (rather than the four times of the original), I did some spread sheeting to develop an alternative time train that gives a once per hour minute shaft, and for which the wheels are fairly close to scale - I chose 6mm = 1" as I prefer to work in metric, but the clock is clearly imperial dimensions. So far only the time train is close to a finished design, the chime & strike trains will be closer to the original as the gear ratios can be retained.

The model so far is

Time Train
                         Church Clock Model
Great wheel Teeth 120             150
Rotates Every      3 Hours     3 Hours
Ratchet Teeth         20                 20
1st Pinion Pins       10                   8
2nd Wheel Teeth     90               116
Rotates Every min  15                   9.60
2nd Pinion Pins         8                  8
Escape Wheel Pins 35                35
Rotates Seconds     80                39.7
Pendulum Period secs 2.29         1.13
BPH                       3150             6343
Minute Wheel Teeth 40                 50
Rotates            Once per hour Once per hour
Bevel Gear Teeth    76                   60

Dimensions 1" = 6mm
                              inches          mm       Scale
Great Wheel           11.75           76        1.08
2nd Wheel                8.5             59         1.16
Escape Wheel          5.5             32         0.97
Minute Wheel           4.0              26         1.08
Bevel Gears             7.5              28          0.62
Drum                        6.0              36          1.00
Pendulum Length   51.20          320          1.04

Using MOD 0.5 for the gears, the second wheel is a fair bit (16%) bigger than scale which required the escape arbour to move to one side, at which point it clashed with the minute arbour drive wheel, so the bearing mounts needed lengthening to raise it up to maintain depthing. The output bevel gears also needed to be made a bit smaller to avoid a clash with the second wheel, but otherwise things are fairly close to scale.

The escape wheel teeth on the original are flattened and about 1/8" thick. To scale they look rather fragile at 0.75mm, so I have used 1mm pins and modified the pallet spacings to suit (I hope!). The plan is to make the arbours from silver steel and harden the pivots. All bearings are brass. Several parts (the frame, the escape arbour, bevel wheel bearing supports and the pendulum support are clearly cast iron. They will be fabricated from steel ( silver soldering is a skill I will need to acquire). The winding ratchet also looks to be cast and that together with the similar parts for chime and strike, plus the strike cam have some complex curves that I will need to work out how to make. I might see if I can find a local laser cutting organisation willing to make small one-off parts for a reasonable cost (unless anyone has a cheap desktop laser cutter capable of cutting 4mm steel plate going spare).

As always, comments and suggestions gratefully received.

Edited to correct tabulation of table ( I hope) 

Edited By Peter Cook 6 on 20/01/2022 17:50:07

Edited By Peter Cook 6 on 20/01/2022 17:52:38

Damaged bearings are highly unlikely to cause the controller fuse to blow unless the motor is so stiff to turn by hand that it is overloading, and I think you would have noticed.

Dave got there before me!

Edited By Peter Cook 6 on 16/01/2022 11:28:22

Fan (possibly slightly loose) was acting as a sound board. The motor is knackered. Any further effort is a waste of your time.

What sort of noise does it make?

Was the motor new or used. If the latter(or even the former), you may have a bad motor. If one or more armature windings have shorted, you would get the symptoms you have seen.

If you have a meter, try measuring the resistance (with the motor disconnected) between the input wires as you turn the motor slowly. You will see some variation, but if the resistance goes very low at one or more positions, you could have a bad motor.

Did the motor company test the motor, or just look at the label?

Edited By Peter Cook 6 on 14/01/2022 22:10:58

sorry Nope - Not in my experience. Time and experience getting the mill and lathe to do what you want grows far faster than the creative thinking and planning - you are always thinking of new things - so over time mill and lathe time shrinks as a percentage of the project.

However on the bright side total project time shrinks so you get more projects done.

Just a random idea - It s a calculator/convertor for precious metals. One measurement system used is the pennyweight , which is one 240th of a Troy pound, one 20th of a troy ounce (hence the 20 holes in the outer ring and is subdivided into 24 grains (the holes in the inner ring?) possibly the 48ths are half grains.

The fractions round the edge are all the approximations to the 16th's with correction factors for 48ths or 240ths. So for example 9(/16) is 3/5 + 9(240ths) and 7/12 +1(48th).

The only place pennyweight is still used ( and was still used in 1908 - it lost it's official status in 1878) is in the precious metals trade.

What it does and how it works I don't know, but the involvement of 16th's suggest it might be for converting the archaic troy/pennyweight system to the avoirdupois (1 lb = 16 oz).

Just my two pennyweight's worth.

My experience is that "despatched" is the status shown once the seller has created the shipping label and obtained the tracking number. It doesn't mean the Post office have got it.

When they do get it it usually shows as "received at....".

If they are still showing as dispatched, it is probably the shipper to blame not the post office.

I would wholly agree. MC and I both have Taig lathes so would fall very firmly in the latter category which is why I suggested he needed to think about slowing the lathe down from its 400+ minimum to do what he was trying to do.

I have stepped the soft jaws on my three jaw very successfully

That is a 90mm lump of aluminium, but I have swapped the induction motor for a DC one, and machined the jaws the other way round ( as inside jaws clamped on a steel rod) with a final light skim when reversed.

As the person in question who suggested slower speeds (and I make no claims to be an expert) I was sharing the numbers I use on my Taig. I normally use numbers close to those suggested by Dave (SOD). At 100mm he suggests 10000/dia in mm for steel and twice that for Aluminium. For a 100mm Aluminium that would be 200rpm.

I find it interesting that Andrew's numbers agree with SOD for 100mm (4" ) dia steel (100rpm), but the multipliers for brass (3 vs 1.5) and aluminium (6 vs 2) are so different. I will try cutting a bit faster in aluminium, but the Taig's minimum speed of 400+ rpm limits cutting pieces of steel to around 1" diameter.

MC's original issue was exacerbated by the interrupted cut (20 - 22 impacts/sec ) on a 100mm diameter. I suggested reversing the jaws and cutting the step close to the centre as if they were inside Jaws then only taking a final skim with them back as outside jaws.

Edited to get rid of icons

Edited By Peter Cook 6 on 11/01/2022 22:51:52