Here is a list of all the postings IanH has made in our forums. Click on a thread name to jump to the thread.
|Thread: 3 Jaw Chuck Internal jaws - looking for a home|
I purchased a “new old stock” Pratt Burnerd 200mm 3 jaw chuck a few months ago, it came with both external and internal jaws. Unfortunately when I put it on the machine I found that the internal jaws were wrong.
Just to be clear here, the internal jaws are what I consider the “normal” chuck jaws.
The jaws look right and are the right “scale” for the chuck, but somehow they are not quite right being very stiff....I think the scroll form is different, the jaws perhaps being for a slightly larger or smaller chuck.
I set off to find replacement jaws, and to cut a long story short...eventually sourced a new old stock set from the US that are perfect - this leaves the jaws that came with the chuck redundant.
The jaws are unused as far as I can tell and look a quality job...if they would suit you, then let me know and they are yours for the cost of the postage or just come to Cheshire and pick them up. They are marked R148.
|Thread: Steering Wheel - how was it made?|
I think these were sourced from Bluemels and not the factory...
Looking for a steering wheel for my 1929 Morgan I was gifted the mortal remains of an original steering wheel rim that looked like it had been in a car that had rolled at some point!
The celluloid covered rim is made from thin steel tube with a seam around the inside that has been left open - i.e. it has not been welded closed for example. The finger grips are small steel pressings that have been pinned on just to one side of the open seam.
Where the spokes of the steering wheel centre attach to the rim, there are slugs of wood inside and there is a pin either side which I assume is to locate the wood. The tube either side of the hole for the wood screw has clearly been hot - presumably part of the manufacturing process.
On the outside of the rim there is a neat line which looks like a seam maybe... but could just be a tooling mark?
How did they make that originally I wonder?
One of the holes for the wood screws that attach the rim to the spokes - there is the remains of a wooden slug in here, and you can see evidence of heating either side
The inside showing the open seam and finger grips pinned on to one side of the seam.
|Thread: Crankshaft repairs|
|I have redone the bottom end of a JAP 60 degree twin and used what is now I believe a very well established approach. New shafts are made out of EN36B and then carburised, you leave additional material on where you don't want the shafts hardened e.g where it is threaded. Then turn these details and send the shafts for hardening, finally the hard surfaces are ground to size. Tapers are abandoned being replaced by press fits.|
|Thread: Ball Turning attachment for a Cowells?|
I use a small/miniature commercial boring head bought at an exhibition mounted horizontally in a tool holder.
Another approach that might appeal if you are making a number of balls to the same diameter is to bore a piece of silver steel bar to a diameter 0.7 times the diameter of the ball you are aiming for. Then turn a chamfer on the outside to give a sharp edge. Harden and temper.
Rough turn the ball, then use the tool you have just made by hand to finish the ball. There must be something on the web that shows this if you have a root around...
Edited By IanH on 01/08/2018 21:52:30
|Thread: Saving a toolholder|
Apologies if this is old hat, but I use a couple of lovely Carmex miniature tool holders for internal screw threading. Fantastic things but rather expensive. I came to change the tip on one and found the M2 Torx screw to be stuck and immune to all my normal tricks to get it out. As the methods used got more and more desperate, the tiny T6 Torx socket got more and more mangled.
I resorted to a method I have used in the past with jammed stuff (including the odd tap) at much larger scales and was successful, saving the tool holder.
I took a nut and ran a countersink into the thread from one side, then I sat it on the head of the torx screw, and with the mig welder set to minimum, welded it on to the countersunk head of the screw. The M2 screw then came out easily with the aid of a spanner. The thing I was pleased about (apart from saving a chunk of money) was carrying this off at this small scale. A replacement screw came from Protool the next day...fantastic service!
|Thread: 3D Printing for Lost Wax Casting|
Apologies for the messy post....
By coincidence I have just finished a batch of similar levers for Morgan Three Wheelers. These are reproductions of the Amal originals. I am 3D modelling them, then making alloy tooling (CNC and conventional milling and turning) which goes to the foundry for wax injection. There is one tool for the levers, it produces either the long or short lever. There is a second tool for the bodies - this tool is designed to produce single or double levers, left or right handed. I add the Amal logo on with the CNC miller.
|Thread: Which Type of Hyraulic Press?|
I have a Sealey 30T press based around a conventional looking jack mounted upside down. I bought this, used, some years ago and it has done good service. The problem with this press, and it may be a problem for all presses of this type, is that the jack has a coarse square threaded element allowing you to adjust the reach of the ram when setting up, and this is very imprecise. When I am pressing anything requiring any precision, I use a bolster to keep things aligned.
I don’t think I would attempt to broach anything with this press unless I had something else involved to keep everything lined up. The presses that feature a conventional looking hydraulic cylinder do not have this issue as far as I am aware.
|Thread: Crich trams|
Here is my Morgan parked up at the Museum -a good day out!
|Thread: Colchester Student/Master Replacement???|
I am building a new workshop and have the opportunity to upgrade my machines. I have an elderly round head Colchester Student and would love to find a more recent gap bed Student or Master in outstanding original condition but this is proving to be hard to find at any price.
I am looking at new machines and have come across Excel, Warco and Mach. Warco do the GH1440 which is almost there...The Excel D360 looks very similar and the Excel D 420 has a bit more capacity again - Mach have the L 1340.
I would much rather buy the original condition Colchester but unless anyone reading this has one for sale - what do we know about these new machines?
|Thread: BobCAM - ANy experience|
Thanks for this,
Just had a super quick look at DeskProto and I might be wrong but on the face of it, it falls into a class of programs (like Meshcam for example) that generate tool paths for a surface - perhaps one face of a model. Whilst great for some classes of work (softer materials or low profile sculpting say), the problem you run in to with this type of program is their inability to define efficient machining strategies able to move significant amounts of material in roughing tool paths prior to one or more finishing tool paths with your fine tools to impart the surface finish you are after.
Note that when I say efficient I am not talking about comercial production, I mean practical strategies - the pattern for the larger casting shown above still has a significant number of machine hours in it.
BobCAM by contrast alows me to identify areas of the model to be treated differently, rather than consider it as one complete surface. I can then define a roughing tool path using using a large tool to remove the bulk of the material quickly. I can follow up a really large tool with a smaller tool getting closer to the finished shape without machining "thin air". Then I can define my finishing tool paths with my 1/8" diameter ball end mill or whatever.
It is horses for courses as usual.
Just thought I would provide a bit of an update - I did invest in Bobcad and here are some results. The parts shown in the photo are all lost wax castings produced from aluminium patterns machined in "proper 3D" with tool paths generated by Bobcad.
I find the 2D drawing a bit querky, but there is always a way to do what I want - it just isn't always obvious. The same is probaby true for the 3D modelling capability as well, although I do drop back into Solid Edge which has a lot more "horsepower" behind it.
The CNCZone forum is outstanding for providing support if you do hit a problem.
|Thread: Problem making Universal Pillar Tool.|
I made the universal pillar tool and almost certainly slavishly followed the dimensions in the book so mine will be as drawn - works perfectly! Tomas was my (virtual) hero during my model engineering apprentiship and trained me well.
|Thread: Vectric 2DCut and Mach3|
I am a Cut2D Mach3 user - recently graduated to BobCad Cam for 3D work. How did you generate the .dxf file for the brass hub caps (or whatever they are)? Cut2D has very limited cad capability so I tend to bring .dxf files from Autocad into Cut2D then add the text in Cut2D but I wasn't aware you could fit text to a curve. Are you generating the text elsewhere?
|Thread: This months MEW are 3 CNC features two too many|
Can I add my support to the comment about bodging - I have been astonished in recent months at the quality of some of work publicised by the magazine both in terms of technical content and execution.
As well as encouraging new starts, I think the magazine should be publicising outstanding achievements and inspiring us to constantly push the boudaries of what is possible in the "Model Engineers Workshop".
First off let me say that I haven't read the issue in contention because I let my subscription run out by accident.........doh! but as keen CNC user at home I can see little point and hardly any interest (even for me as an enthusiast) in pages and pages of G Code if that is what these articles contain. If you get into CNC you will very quickly realise that you will rarely go near G Code, the computer will look after all of that for you - the interest and challenge is in the new opportunities that are now open to you and sorting out how to exploit them on a budget (real 3D CAD and CAM software is extremely expensive and most home machines will be home brewed conversions of one sort or another).
I think that if we had articles on what folk were doing with CNC that might be a whole lot more interesting for everyone. Articles giving print outs of G code in past issues have left me wondering whether some of the authors have realy "got" CNC, or just got lost in it?
Iam going to vote for CNC here. I produce patterns for lost wax casting vintage car and engine parts - the patterns are always one offs - no repition work here. I moved into CNC milling simply to extend the range of geometries I could handle. Making a pattern for the expansion link illustrated earlier in this thread for example would be easily handled by my CNC mill.
What I don't do is reproduce the original parts themselves with CNC - there are folk doing this and to my mind the finished articles, whilst serviceable, do not make adequate reproductions of original parts. They shout out "billet made CNC" some indeed even make a virtue of this.
My approach is to come via the casting route - it is more expensive overall but you get a more authentic product. I am off to the foundry this morning to pick up some prototype Rolls Royce Phantom III oil pump castings - whilst some aspects of this pattern could have been done by hand, there were a series of ribs that curved and sloped that would be beyond me without my CNC mill.
Also don't underestimate the tooling challenges of using CNC machines - it stretches everything I have learned in many years of manual machining.
|Thread: BobCAM - ANy experience|
I have a busy CNC mill with Mach 3 on board and have found that almost everything I need to do can be achieved with 2 1/2 D machining. I bought Vectric Cut 2D and can not recommend this highly enough.
Looking now at true 3D machining I spotted BobCAM.
I have been searching the Internet for user reviews and have found little to commend this product.
I can't decide whether this is because the program is truly awful or because people are comparing it with commercial products at far highr prices. At the end of the day it has to work of course - does anyone have any experience of BobCAM?
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