Here is a list of all the postings Tony Jeffree has made in our forums. Click on a thread name to jump to the thread.
|Thread: John Stevenson|
I decided yesterday to fit a new chuck that had been sitting around for some while to a spare backplate, and reduced the backplate diameter and register to fit the recess in the back of the chuck. At this point, as this chuck is of the kind that has 3 blind threaded holes at the back for the mounting bolts, the question arose as to how to (quickly) mark out the backplate for the 3 holes. Marking out the first was easy enough, move a sharp lathe tool to 1/2 of the PCD, use it to lightly score a PCD circle on the backplate, centre pop and drill the first hole, easy peasy. But short of messing with a rotary table (still not sure which box to look in since the move!), what about the other 2? At this point, as has happened often over the years, I remembered a tip that came from one of my many phone conversations with John. Machine a sharp point on a short length of threaded rod (or a length cut from a spare matching bolt) and thread it into one of the threaded holes in the back of the chuck, leaving the point sticking out and enough thread to grab onto to remove it later. Offer up the backplate, sight through the first hole to one of the empty threaded holes in the chuck, give the backplate a light tap where it touches the pointy bit, rotate the backplate 1/3 of a turn to sight through to the other empty hole, another light tap. You now have a rather blunted pointy bit but enough of a mark on the backplate in the other 2 drilling positions so you can make decent pop marks and drill the last 2 holes.
Unfortunately, it is 3 years too late for John to make a recovery, speedy or otherwise.
Yes - a great loss. My ML7 was his workhorse for many years, so it reminds me of him whenever I use it.
|Thread: 3D CAD software - what do you use?|
I eventually went for Fusion 360 and am slowly getting to grips with the interface - not surprisingly, it needs a change of mindset from what I was familiar with (2D CAD in Autosketch), so it will take a while. Not fluent enough to do much in the way of drawing within Fusion, but I have discovered that if the model you are constructing breaks down into a small number of layers, a perfectly workable strategy is to draw each layer in 2D using Autosketch (been using it for ~20 years now so very quick to use) and export DXF; you can then use Fusion as what amounts to an "extrusion engine" - import the first layer DXF, extrude it to the right height, import the next DXF on the top face, extrude that...etc. Rather quicker than the nuclear option of getting fluent with enough of Fusion's complexity to do the same job directly in 3D! The latter can wait until the nights start to draw in again.
Many thanks for the comprehensive and helpful responses - I will have to do some studying, not to mention downloading!
Time to bite the bullet and learn how to draw stuff for printing. What (preferably free!) software do people use/recommend?
|Thread: Printing clock wheels...?|
Sounds a bit like the metalworking equivalent - 90% of the time making jigs, fixtures and special tools, 10% making the part you wanted to make in the first place...
Thanks for the tip - I will give that a go.
Unfortunately, I don't have any 1 module cycloidal metal gears to run it in with, but yes, if I did, that would be worth a go.
I have Cura but haven't yet got to grips with it - obviously now is the time to start! Thanks for the tip...
Anyone attempted this yet? I have a copy of Art Fenerty's Gearotic (**LINK**) that I have dusted off & updated to the latest version, and have tried printing a couple of test wheels at 1 Module using a fairly coarse setting (0.2mm layers) on my Ender 3. Successfully printed a 60T cycloidal wheel and a supposedly matching 12T pinion, but the tooth form leaves a lot to be desired. Just re-doing the large wheel using 0.1mm layers but it is taking a while - the teeth seem to be "spreading" a little, so the tooth spaces look on the small side. Anyone had any better success?
|Thread: 3D printer recommendations|
Thanks - will take a look.
Indeed...I put my one failure so far down to that - cleaned the bed down with Meths and it has been fine since. I am taking care not to touch the bed when removing parts now.
I've printed 9 today, no raft, direct onto the Ender's heated glass bed. I'm finding that mostly they stay stuck, but release by themselves as the bed cools at the end of the job. Only one failure - one of the arms came unstuck and there was no option but to abort the print. The first one I printed onto a raft but it took twice the material and twice the time, and parting it from the raft wasn't clean or easy.
This version is suitable for a standard UK 4-hole punch:
This version is suitable for use with a standard 2-hole punch set to "A6" - punch twice from either end of the long edge.
It's OK Howard - it had been through the laminator. The problem was with the registration of the punching holes, nothing more. Problem fixed now because I have been donated some OHP transparencies that do the job very well.
Just fine if you want to print in Australia
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