Here is a list of all the postings Martin Connelly has made in our forums. Click on a thread name to jump to the thread.
|Thread: Coronavirus - How To Register as Vulnerable|
The register has been available on line for a while, long before letters were being sent out. I can't remember where I saw it reported with a link to it, it may have been Facebook or something similar. I think if you go to www.uk.gov there will be a link to it or a search function.
Edited By Martin Connelly on 08/04/2020 17:33:24
|Thread: Aircraft General Discussion|
After about two weeks of silent skies there are aircraft out and about again. Here are two Eurofighters out this afternoon, about a mile away by the time I got the camera zoomed in on them.
|Thread: Small skeletonised drill Press|
Oldvelo, part of my job when I worked was to purchase the tools for the shop floor including hand drills. We were constantly being asked why the drills we bought cost 5 to 6 times more than the B&D and their clones in DIY stores. Our reply was always "value for money" . The DIY drills would have had to be treated as consumables due to the short life they would have had.
|Thread: Dividing head problem with angles.|
If your table does 1 revolution for 90 handle turns then yes. One handle turn is 4 degrees, 3.6 degrees is 90% of this. Any set of holes that allow you to use 90% of them will work. 18 of 20, 27 of 30, 36 of 40. Use whatever is available to you, small numbers are less error prone, 9 of 10 being the easiest but it's an unlikely hole count in a set of dividing plates.
Things have changed a lot since the Sparey book was written. He lived before the Internet, online ordering and delivery within a few days of ready made tooling with relatively low price. You have to look at something like making your own hardened and tempered centre as a training exercise rather than a necessity you have to make for yourself. It is a balance you have to find for yourself between making something for your own personal entertainment or training and getting the current project done without too many sidetracking sub-projects. That though can be part of the fun of this hobby.
A grinder is probably high on the list of necessary tooling for most lathe operators.
|Thread: I once built a go cart|
I once started to build a flat bed pen plotter but printer technology caught up and passed me (and got cheaper) before I got very far into the build.
|Thread: Making Progress with TurboCAD|
Nigel, my comments about Turbocad were based on what was being said in earlier posts in the thread, sorry if they were incorrect. I have looked in YouTube and found the following tutorial on using layers, model space and paper space in Turbocad and think it may be of use to you if you want to use these features.
Elmer's VR75 metric model in AutoCad and part of one layout sheet in paper space as described earlier.
It sounds to me like Turbocad is trying to be AutoCad but doing a poor impression.
I have been spending some time over winter doing a metric version of Elmer's VR75 as a solid model in AutoCad. I have completed the assembled model in model space with each part on a different layer. I have started doing the drawings in paper space with multiple layouts with viewports. Each viewport can be set to only show the required layer(s) for the part being drawn, the line thickness and colour used for that layer in that viewport can be set, usually black. The scale in each viewport can be set to an exact value to suit the paper setup being used. Dimensioning is done in paper space so that things like dimension arrows are automatically sized.
There are plenty of tutorials online for AutoCad. These show how model space, paper space and viewports are used to make the best use of CAD. Not using these programs as they were designed to be used is probably making things harder for the user.
|Thread: Check my sums please|
The triangle is radius and run out. I think it should be diameter and run out. The wheel diameter is about 6 times the wheel thickness. The error on the shaft hole shown on your diagram of 0.002" should be 1/12 of the run out. I think you should add 1/6 of the runout to the hole diameter for the new hole diameter.
|Thread: Some help needed with my build|
I think what you need is like a DIN 609 fit bolt made to suit your requirement. Free machining steel may be best to get a good finish to the correct size.
|Thread: Meccano spring drive belt|
I've dug out and dusted off a small Meccano pulley (it says so on the side) for you to see their profile.
Added. The dimensions are 4.75mm across the flange faces (hub is a bit wider) and 15.33mm outside diameter.
Edited By Martin Connelly on 04/04/2020 11:30:20
|Thread: DTI base|
Mitutoyo Technical Sales Dept. Tel. 01264 353123
|Thread: Recent conversions of Warco WM18 to CNC?|
Jack M, Mach3 has manual data input (MDI), no programming required, so you can get started with a converted mill before you progress to programs and CAD/CAM. You just need to know a few gcode commands to make the mill do what you do manually such as move the x axis 20mm to the left (or right) or the y axis away or towards you. Read through this to get an idea of using MDI. A mini wireless usb keyboard is useful as well for jogging the machine around.
|Thread: A few Thou Under?|
When you die cut a thread the metal can deform plastically and so some will push out to fill the in the peaks of the thread if you start with a slightly undersize diameter. There is no definitive value of how much under as all metals, even with the same designation, vary due to tolerance in composition, heat treatment and storage. Some also work harden as well just to add another issue. It is sometimes easier to start a thread is the end of the bar is tapered slightly over about 5 pitches of the thread.
Forces TV (Freeview channel 96) is rebroadcasting the 13 part series called Toolbox. If you are interested in a bit of tool history it is on at 17:00 today. Episode 1 is about the history of hand drills.
|Thread: Model of an epicyclic gear made by apprentices|
RGT, EGT, GEC Alstom then Siemens. Bay 40, mainworks. This, below, is a special that we used in large numbers.
Edited By Martin Connelly on 02/04/2020 12:47:06
Where I worked we used a lot of Allen epicyclic gearboxes. The older ones were cast casings but they changed to fabricated at some point.
|Thread: DTI base|
Henry, the link is just for a set of dovetail stems, a set of 2 for £6.60 so you can use your existing indicator with any metric mag base unit.
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