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Member postings for Ian P

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

Thread: What am i doing wrong
10/03/2020 22:33:32

My introduction to lathe tools with carbide inserts was about 15 years ago when I bought a toolholder with 10 tips at a local steam rally, I was instantly converted!

I then bought a set of five tools with inserts from a well know supplier. The tip were pure rubbish, if the purchase had been my first introduction to indexable tooling then without doubt I would have been put off for life.

Point of me mentioning this is that the tip in Steve's picture looks to be identical to the ones supplied in the set I mentioned, they have the same dull grey look and the same parallel 'gutter' around the perimeter.

Ian P

PS, I did not know much about tips when I made my steam rally purchase but I now know they were the fine grained polished type for machining aluminium and plastic. (which I now use for 90% of all my turning)

Thread: Best Cutter for HDPE.
04/03/2020 21:53:54

By coincidence I was sent a link today for some cutters that look to be ideal for your purpose.

You should be able to Google this

'ALU XP Europa Tool'

Ian P

Thread: AT1 inverter 3 wire control
27/02/2020 15:27:54

I dont know the VFD you have (a link to the manual would save people having to do their own research)

A 'standard 3 wire control' unit (two switches presumably) is only standard in respect of a non VFD motor control setup. Your VFD might need two N.O. switches.

Possibly your VFD might cater for one switch being N.C. but if not it may be that your switches have open and closed contacts so could be rewired (still should only need three wires).

You will probably need another three wires for the speed potentiometer too.

Ian P

Thread: Cable Gland
25/02/2020 14:52:21

I fully understand the workspace envelope required for woodworking and when I need to use my radial arm saw now only do so when I can wheel it outside. I'm not sure though whether your current plan is going to be as convenient to operate as you expect.

In normal parlance, 'Emergency Stop' switches are just for that purpose. Using four separate ones just to stop the machine without having an equally easy to operate 'On' switch is highly unusual (or at least I have never come across a setup like that).

Some general thoughts (on this particular) machine control.

Feeding the motor through a contactor (as you are planning) then gives the No-Volt release feature that nowadays seems to be mandatory so that good.

The contactor should have a low voltage coil so that all the control wiring (some of which we now know needs to be flexible and frequently moved) is isolated and would not cause a hazard if it got damaged, tripped over, fell iunto a bucket of water, or whatever.

Only three low voltage wires (which would not need an earth) are needed to connect to two pushbuttons that would be the On/Off controls for the motor. If the Stop button is the larger or more prominent button of the pair, then in effect it is your E-Stop. You can have as many two button pairs as you want from the same three wires if you want to control the motor from several locations.

The more switches and controls you have, especially if they are widely dispersed the less likely one would be to instinctively know which one to use in a genuine emergency.

If this machine has approximately a 'square' format like a large table, then just two E-Stop switches or control positions on diagonally opposite corners are just as reachable as your four will be.

Other options to consider could be, a keyfob type wireless control of the motor maybe on your hand or wrist whilst working, foot operated switches (that need to be kept depressed).

Ian P

24/02/2020 23:12:27

Its late and was just going to turn my PC off when I saw the lasts posts on this thread. The thought then came to me that most of the topic has been about emergency stops.

I know these are so the motor can be stopped from any side of the machine but I then wondered how the machine can be started from any side of the machine?

If these are purely 'emergency' stop buttons then how is the motor started and stopped in normal use?

The original machine has an on/off switch on the motor its itself, it looks like a simple mechanical switch so presumably you intend to leave it permanently in the ON position and control the motor from your DOL mounted on the wall. Does this mean that you might have to walk round to the other side of the machine after you have started the motor?

Sometimes (and I'm guilty of this too) its possible to get carried away on a particular route to solving a problem without really analysing what the problem is. In this case the more switches, wiring, terminals, circuitry and other components that seem to be increasingly involved, the more likely that faults and operational complications will be possible.

The keep it simple approach has a lot in its favour, why not have a length of string strung just overhead that pulls out the 13A plug (like the communication cord in a train carriage). OK thats crude and its not really a serious suggestion but the proposed system of emergency stop switches carrying mains voltage does seem a good idea either.

What one does in their own home workshop does not have to be to industrial standards (its for your own use and its not operating 24 hours a day) but where possible it should at least be based on sound practice.

Rantover

Ian P

Thread: tipped tooling
23/02/2020 13:52:23
Posted by Douglas Johnston on 23/02/2020 13:49:31:

The other thing that is also often mentioned is the need for high speed. While this can be true for a lot of carbide tooling it is not needed for the sharp polished inserts. I use this type of insert most of the time on a lightweight machine and they cut well at a wide range of speeds.

Doug

Plus 1 to that too.

Ian P

Thread: CNC machining assistance requested
23/02/2020 13:51:25

A waterjet company I used recently have a machine that can alter the angle of the cut and I'm sure they could cut thick perspex more than good enough for your project.

Purely out of interest, since you have machined all these gears and other beautiful, what motivated you to have these plastic parts made by A N Other?

Ian P

Thread: tipped tooling
23/02/2020 13:42:59
Posted by gerry madden on 23/02/2020 12:56:10:

".… carbide doesn't like light cuts..." I hear this often and its just not my experience, particularly with the sharp aluminium cutting types. You can make the finest cuts with these and get beautiful finishes. The chips are so fine they are just a dust on the top of the tip.

Am I missing something ?

Gerry

Plus 1

23/02/2020 11:04:18

There is obviously something amiss here. Coincidentally I have just machined some cast iron with a carbide tool and got a almost mirror finish so carbide and cast iron can get on with each other.

Its only really possible to make suggestions as to what would improve your results if we knew where you were starting from. Details of the actual boring bar, which insert it has, hole diameter etc?

Ian P

 

Edit after seeing your reply. Tip type still applies

Edited By Ian P on 23/02/2020 11:05:17

Thread: Cable Gland
21/02/2020 22:43:07

Based on what I can determine from your text and pictures I would say that the type of cable and its installation are unsuitable, (if this is some sort of machinery).

If the cable is carrying mains voltage then it should really be three core (with an earth wire)

If the purpose of the gland is just to stop movement between the cable and the hole then the ones you showed originally are overkill. They are good for sealing and clamping the cable but provide no bend/strain support if the cable is flex and being moved frequently (that type of PVC cable would not last long in an industrial environment)

Routing the cable through a hole in the steelwork seems pointless, Going over rather than through the obstruction would only add a few extra cm of cable.

If the reason for not going over the edge of the metal angle is to prevent the cable being damaged by accidental trapping or being impacted, then it should be protected by a rigid cover or trunking. If there is a possibility of the cable passing over the a metal rib being damaged then I would surmise that even the less projecting wiring is vulnerable too.

Most of the above is just speculation without having more information on the application but its something that might be worth bearing in mind.

Ian P

Thread: VFD to lathe motor connector
13/02/2020 11:48:58

Gene, if you mounted the VFD behind the tailstock it need not addthing to the lathe overall length, it probably would not increase the overall height either, because the motor already projects rearwards any extra rear projection of the VFD might still be within your shelf depth.

I've just looked at a picture of the MD65 and wonder whether finding a three phase motor the same size and mounting arrangement as the original might be a difficult task.

Regarding the GX20 connectors. They are absolutely, definitely, the wrong things to use anywhere near mains. In my opinion they are a rubbish connector!

Where the 'Aviation' tag came from I've no idea but they are a low quality and badly thought out product. In addition to the other faults others have pointed out, the cable grip (whilst it looks 'technical' and well engineered) only really works on a very small range of cable diameter.

Ian P

12/02/2020 21:15:16

My suggestion to the idea of separating the VFD and motor from each other is dont!

Why not mount the VFD close to the motor so that it just become part of the whole assembly that you lift of the shelf.?

I dont have first hand knowledge of the lathe in question but if its compact enough and light enough when complete with its motor, for you to lift it on and off a shelf, then the weight and bulk of a modern small VFD is not going to make much of a difference.

A small VFD could be mounted behind the lathe at the tailstock end or maybe in a plinth under the lathe (taking suitable swarf ingress precautions).

Eliminates a lot of wiring and connectors, what not to like./

Ian P

Thread: gauge plate
10/02/2020 13:19:54

Frank, is this something you are making to your own design or are there published drawings/details available anywhere?

We have a 15 year old granddaughter that somehow (along with all her other activities) is part of 4 different orchestras and the cost of reeds is mounting up so I want to see if I could make them.

Ian P

Thread: Metric V Imperial Measurement
07/02/2020 23:32:23

On Wednesday this week I had an X-ray scan at a local hospital where my weight and height were measured in cm and Kg, The radiographer then looked at the two conversion charts on the wall and entered in the imperial values on her paperwork!

I was somewhat surprised but she assured me that how it was always done (maybe she meant thats how she had always done it)

I bet whoever interprets the images and processes the paperwork has conversions charts at their desk to convert to metric units!

Ian P

Thread: Hello and a question to start with
05/02/2020 20:22:55

Before buying a reamer I think it would make sense to establish whether its the arbour or the socket that are causing the problem. The OP stated the socket has little sign of damage so it could be possible the arbour is manufactured badly.

Ian P

05/02/2020 19:40:18

Morse tapers would have to be badly scored or damaged for them not to lock together, it might be worth checking the spindle by bluing with another Morse arbour. If the existing chuck runs true anyway the simplest fix would be to use superglue (or a Loctite) to retain it.

Drill press chuck rarely need to be taken out and put back in so gluing it in place might be a good workaround. Sounds rough, but is practical.

Ian P

Thread: How to hand grind 55 degree cutter for 32TPI?
03/02/2020 16:27:17

Wow!

An awful lot of interesting and useful information if all those replies, thanks to all.

Although not at the PC (or in the workshop) I've made some theoretical progress. One of the things that I had forgotten I had bought is an internal screwcutting insert holder, the best bit is that an 11NR-A60 tip is already in it! which is perfect for both the threads I need, just waiting for the 60mm tube now.

Pete Rimmer suggested 'For a fine tip like that I'd use carbide to turn some round HSS using the compound at 27.5 degrees then grind the HSS round down to half thickness then stone the radius'

That sounded very tempting but then I realised that the cutter would be very weak near the tip because there would be very little metal.

Jason's idea of relieving the bottom of the 'V' in a gauge is blindingly obvious now someone has told me.

For info, these are camera related threads and I now know the C mount is 60 degree so the same tip will do both.

Thanks

IanP

02/02/2020 22:45:51

The 60mm threads are 60 degrees, but the few details I can find on the C-Mount lens thread seem to say it is 55 degrees.

I will get a better magnifying glass and have a go at making a HSS tool.

IanP

02/02/2020 22:28:30
Posted by Mick B1 on 02/02/2020 22:21:28:
Posted by old mart on 02/02/2020 21:59:35:

32tpi would be so close to a point that thinking of a tip radius of 0.0037" produced by hand is mind boggling.

I would get er11 carbide tooling for that job, especially as the diameter is so nice and big.

I'd grind it as close as I could to a 55 degree point set in a Vernier protractor or one of those digital angle gauges from Lidl, then stone the tip rad by hand with a medium/fine India oilstone. If it's 32 TPI on a 60mm diameter it's not gonna matter much if the tip rad is too small and the root's a thou or two deeper than it would be if the tip rad's crack -on size, unless the thread's on an extremely thin-walled tube. So my stoned rad would do little more than break the sharp edge.

Slight correction to make as I have actually have two different parts to make and I got mixed up. One is a female 1"x32TPI (C-Mount lens thread) and the other is a 60mm OD extension tube with 58x0.75mm male and female threads at the ends. My sample is made out of 1mm wall tube (although I will use 2mm wall).

Ian P

02/02/2020 22:22:11

I have just had a quick look for an insert but small sizes of 55 degree ones seem rather thin on the ground and I'm unclear about the what the tip radius is (or how fine a pitch it could cut).

I have internal and external holders and it looks like I could get away with just with an internal tip.

Ian P

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