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Member postings for Zan

Here is a list of all the postings Zan has made in our forums. Click on a thread name to jump to the thread.

Thread: Condenser Cooling water flow
24/02/2021 10:37:02

Yes hopper. I did make gunpowder!

no Duncan the condenser is there to provide a vacuum to give a greater pressure difference, and to reduce the  sink temperature of the engine as much as possible

Regarding condensate temperature, thermal efficiency is all about temperature difference, the hotter the hot source (T1) and cold sink (T2) difference the greater the efficiency so a cold condensate means a bigger temp difference and therefore More efficiency.

Maximum theoretical efficiency = (T1-T2)\ T1. %. Measured in degrees Kelvin

if one considered only the engine efficiency itself and take the boiler heat source out of the equation, steam tables show that a tremendous increase in pressure is needed to increase temperature, and of course that brings lubrication problems associated with reciprocating engines. Remember all early steam engines were powered by the vacuum in the condenser, not the steam pressure

Stumpf in his treatise of the “Unaflow Engine” had a simple maxim “ Keep the hot end hot and the cold end cold” amazingly, his cylinders were cooled in the centre where the exhaust is, and that caused expansion problems resulting in the cylinder needing to be bored barrel shape. so the smaller dia hot ends expand more and result in a parallel bore. This was achieved by reversing the process, the normally water cooled centre jacket was fed with steam while the hot end steam jacket was water cooled thus reversing what is found when the engine is running. His other important aspect by the way was to keep piston end clearance very very small , just a few thou carefully calculated in relation to the overall expansion of cylinder and piston systems.

 

one of the many reasons aircraft fly so high is because of the air temp being lower results in a lower cold sink. This also enables greater cooling of the turbine blades which run an a higher temperature fluid than their melting point

Edited By Zan on 24/02/2021 10:41:11

Edited By Zan on 24/02/2021 10:44:09

23/02/2021 22:29:34

I found about this out as a 10 year old with a love of chemistry! The local chemist gave me a glass condenser, which was duly set up to make distilled water with the cold initially going in the top. Result, steam not distilled water flowed out the bottom. Very disappointed I cursed (sulk), then had a think, switched the water input to the bottom n bingo it worked. By the way I set my wooden retort  stand on fire, I used a mammon  burner for heating 

easy reasoning.  With  the cold water in at the top, it hit the hot steam at the top, it also got hot, therefore cannot cool at the bottom. If. It goes in at the bottom, it will rise being forced to the top getting hotter all the time, but will always be less than the steam. So the bottom where the steam is coolest, get the biggest temp drop with the cold water input. At the top, the cooling water although hot by now is still lower than the steam input

so in at the bottom, out at the top  very logical when you think about it 

 

Edited By Zan on 23/02/2021 22:33:17

edit.  Dont you hate auto type

Edited By Zan on 23/02/2021 22:34:38

Thread: Using a vfd for two machines
21/02/2021 00:03:40

V d f thin on the ground? There’s thousands for sale Google it. Not worth the risk of disconnecting whithout. Switching the mains off and destroying the vdf Get one for each machine. I have one on each of my 5 machines they all have different perimeters set to suit the individual requirements. They are cheap( ish) compared with the uncertainty of remembering to change the settings n plugeps. What happens when one machine is running very slowly and you want to run another at the same time?

20/02/2021 23:59:22

StrangeG double post without the edit! See below

Edited By Zan on 21/02/2021 00:04:32

Thread: Confusing t-slot dimensions
20/02/2021 23:53:31

Ps you need good clearance with t nuts, so decimal mm dimensions for them come with the fairies

20/02/2021 23:51:32

You got a machine, so mill t slot nuts to suit each one Using nuts in place of proper t nuts will give you grief in the long term. Make them, it would take less time than typing your post.....

all my 4 millers which I have had had different sizes. First task with each new machine was to mill sone new ones...

Edited By Zan on 20/02/2021 23:55:21

Thread: Should it be bent? Meddings Content
20/02/2021 23:48:24

Strange!

Meddings would not paint their motors a different colour to the drill, and it’s mounting is strange. The pulleys should align and not be so far out vertically which will cause wear and noise levels

I think this is a bigger problem than the bent arms, which can be corrected with “ washers” under the motor mounting bolts

Thread: Skynet is Coming
20/02/2021 09:56:11

too many devices are becoming so called smart

why would you want a phone app to control a toilet flush.. not nice later handling a contaminated device.....

do what you can to disable the wifi, the pw  protection on them is usually poor and it gives opportunities for hackers to get into your systems

My dishwasher annoys me, we only use one program but it has to be selected with three button ( extreme left, centre then extreme right ) presses not one if you hit the wrong button in the centre the so called eco program runs for 3.5 hours not our normal 29 min......

my camper van control unit had only three buttons one to cycle through then select with another then back to the first to cycle through the changes you need. So frustrating when you miss the thing u want. It failed, repaired, failed replacement costs £300 . So I , ripped it out n replaced it with switches

Edited By Zan on 20/02/2021 09:59:00

Thread: Newton Tesla Electric Drives
19/02/2021 13:36:42

Perhaps off topic, but regarding single phase noise and problems.

Interesting! But it all depends on the s phase motor. When I got my new s7 in 82 I had to get a motor, and as I had already broken the bank I opted for a cheaper foot mount roped motor. It was TERRIBLE! The chatter and vibration marks made the new machine a real pug. I took it back n got a Brook Crompton redial the mount. Oh what joy! Super smooth, and used until I managed to get a cheap vdf in about 98


Thread: Machining a kurt clone vice
19/02/2021 13:22:02

Well done, a good solution

Thread: ml10 or some other?
19/02/2021 13:12:58

I have been very happy with my s7 new in 82, but then I had to add a gearbox and even then a motor!

looking at the specs for the Warco, it looks a better machine with a better bed guide system, full gearbox and screwcutting, enabling a range of sliding feeds as well . What is good is the spindle bore, the 9/16 on my Myford was a constant annoyance until I got a cheap Colchester student 15 years ago( not much used!)Buying the Warco would give you about £300 to spend on other stuff.

the speed 10 looks a good machine with its stand and the tool range is ok but not brilliant the vertical slide is shop built and looks as if it lacks rigidity in the mounting   You won’t get a lot of use from the studies. The cutting tools could be good or v poor, some stuff I looked at when considering the Myford were to say the least a bit sad.

Edited By Zan on 19/02/2021 13:14:08

Edited By Zan on 19/02/2021 13:15:34

Thread: You think you have trouble starting your car on a cold morning?
16/02/2021 19:23:40

Gee you can’t get decent coal these days I wonder where it came from?👻

Thread: Further Adventures with the Sieg KX3 & KX1
14/02/2021 10:16:28

Interesting stuff Jason, always fascinating to see your efforts , you are teaching us all so much with your experience. Keep it coming!

how exactly did you align each side of the flywheel when flipping it over? I’m intending to do something similar, and considered a pin in the central bore then another removable one to mate with one face of the 1” dia holes you produced

did you use the “ tool stay down” feature ( can’t remember the exact wording} when doing the initial adaptive clearance?

Thread: Bridgeport power feed
26/01/2021 23:02:32

My Bridgeport was converted 10 years ago

ill post the circuit diagram in the morning, but

1 rip out all the fuses and anything between vdf and motor

2 wire the vdf directly to the motor use the reverse switch to control only the digital inputs to the vdf or you could inadvertently reverse while motor is running Don’t ask........... I did this while testing after fitting a new drive shaft and forgot.... new vdf a month later......

3 my transformer has a 220 v input and a 440 so former used to give power to the control contractors and the power feed the 12 v is great for led lighting

4 a single 240 contractor was wired up for main power on with a new pair of push buttons on the control panel  I don’t like 240 v going here, but there was no choice  all 240 v power is fed from here to vdf, DRO and an external drive socket 

5 the motor control contractor now just triggers the vdf enable digital . I like this because it enables a satisfying clone when turning on ans enables using my knee to turn off

6 (edit) both the micro switches in my power feed failed by age cracking. So replace these while you are at it!

Edited By Zan on 26/01/2021 23:06:27

ps I run the motor at a fixed speed using the vari speed unit, but it’s noisy and I’m thinking about changing to a direct drive as indicated above. Just worried about cooling the motor at low speeds. The fan at the moment draws a lot of air through the head to cool everything 

Edited By Zan on 26/01/2021 23:17:14

Thread: Electronic Lead Screw Project
21/12/2020 23:34:54

Long reply. Won’t work.. hit code of conduct not post and lost it

Thread: Problem slot milling in lathe
30/11/2020 18:55:04

What moved? The vice? Vertical slide?
I suspect though as already said the slides should be very securely locked.
i think this is mainly a backlash issue. I bet you fed in towards the centre to position the slot. I.e pushing the slide in. The normal cutting tool in turning will be forcing the slide out against the thrust bearing on the screw. Your cutter does the opposite and will pull it in away from the thrust bearing. So you are effectively suddenly giving a setup with little intrinsic rigidity a climb milling situation , and all the backlash will be taken up, thus once any inevitable snatch starts it will rapidly increase

perhaps a way forward is to make it a slightly elliptical slot by starting a cut at the back and feed in FPS out from the lathe centre a trace then go back, increase the depth and repeat . You will still be climb milling but the cut will be of a significantly reduced length rather than the full periphery of the cutter. Best to experiment on an unimportant bit of stock

Edited By Zan on 30/11/2020 18:56:47

Thread: What collet chuck dimentions for s Sieg SX2?
21/11/2020 23:33:16

For my sx2 p cnc conversion I used the R8 spindle this was used with a 3/4 collet and the cutters are mounted in 3/4” silver steel chullets. They are very very carefully clocked in the 4 jaw then drilled, bored and reamed for the cutters held in place with 2x2 ba grubs. Height location is with a 5/32 silver steel bar registering against a machined ring ( in situ) on the end of the spindle. Photo 2, offsets are set off machine in a dedicated setting device seen in photo 1 . It’s highly accurate and the silver steel cost little from a specialist supplier near Harrogate

The advantage of this system is it is ridiculously cheap and has a very very small extension unlike many er chucks , and as Ketamine says, the sx2 is a mini mill and thus the more we can help it the better

The height is set with the dti device in photo 3 it has a length of 115 mm when the clock reads zero when in contact with the work

8e04841c-83dc-4002-86ab-7bcde086b530.jpeg

2369b6496-7ffe-4a43-a93c-2917dab55034.jpeg30771fc09-5631-489a-b841-0813b391ca05.jpeg

 Sorry about the aspect ratio!
once the cutters are fixed in their holders the size is recorded from the setting jig in the Mach 3 tool table, and in addition into Fusion 360 which I ciponstantly use for 3D cad and cam code production.

The machine is very well used.   Pm me for more info

Edited By Zan on 21/11/2020 23:34:13

Edited By Zan on 21/11/2020 23:38:57

Thread: Calibrating Micrometers
12/11/2020 19:44:35

Andrew. He said......“ I have bought some second hand 2", 3" and 4" micrometers. Is there any way to check that they "zero" correctly without using a block of known size?”

The only way to zero a 2” micrometer is with a 1” standard you refer to a 1” micrometer 

 

Edited By Zan on 12/11/2020 19:45:27

Thread: Myford ML7 Chucks - Which one?
10/11/2020 23:19:48

If you get a new Chuck go for a 4 jaw self cantering. They give a very solid grip on material are incredibly accurate and contrary to popular belief they still grip hex material on centre. Despite the warnings above, my 125 mm has been on my well used S7 for 20 years with no ill effects

Thread: Moving a Myford VMC advice needed thanks!
10/11/2020 23:13:14

Looks a nice machine glad it worked out, but two points. Dump the swivel base, I have used mine twice in 20 years so converted it into a horizontal spin fixture.
More important, the vdf is very vulnerable to swarf which will fly far and wide, esp when fly cutting aluminium. it needs a decent ventilated enclosure with mesh to keep the grout out. The one on my Bridgeport is in perforated box mounted on the back of the column

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