Member postings for John Hinkley

After deciding to down-size and having sold all my workshop machinery, I purchased a 3D printer to stop the grey matter from atrophying and have started off my adventure with it by printing off some parts of a vehicle differential and rear axle downloaded from thingiverse.com. Mostly because I couldn't find a suitable file of the hypoid bevel gears I needed for my own design. It's been a long-held ambition of mine to construct a scratch-built racing car chassis and this seemed as good a place to start as any. Having reduced the size of the prints to 70% of their published size to suit my requirements, I soon found the need to enlarge various holes to suit the fasteners I intended to use. Problem - no drill stand and now no milling machine! So, thought I, why not print one? So that's what I'm going to do. But first, I had to design one which will fit within the printer's envelope (254x254x254mm). This is the render of my design, produced in Alibre Atom.

For scale, it is about 250mm high. Power comes from a 12-24V motor left over from my die-filer project, fed by a 0-12V variable power supply. Should be good for up to about 3500 rpm or so. As I will only be drilling into plastic and mostly just enlarging holes already in the prints, torque shouldn't be a problem, I hope. Further progress will be documented in my album "3D printed drill stand", appropriately enough and I'll probably add the odd video to my YouTube channel, too, from time to time.

John

Link to my YouTube channel

Link to thingiverse file source

Edited By John Hinkley on 12/07/2023 20:15:17

Some while ago in "Reader's Tips" in MEW, a contributor (sorry, I can't find the reference) suggested a simple solution to this problem. Basically, dig out those old Lidl or Aldi callipers you picked up for a fiver each and cut the scales into two halves and voilà, two thin parallels of the thickness you require. Of course, if you have more than one calliper you can have longer ones. I always found the cut up ones sufficient for use with my 100mm Arc versatile vice.

John

No longer being the owner of the book to which I referred in my earlier post, I found a couple of snippets through a search of one available to buy. It may, or may not, interest you to see that "the teeth were cut using end mills on specially constructed machines".

I wish I hadn't given the book away, now!

John

Coming in a bit late on this subject and with zero experience with either horology or high speed milling, I offer the following:

It seems to me that it might be feasible to use a larger cutter, as suggested by Jason earlier, and "sandwich" the workpiece between two sacrificial pieces of, for example, brass, milling away all three pieces of material at the same time. No need to go completely through the lower slice. Use the hole to secure the slices together and/or secure to the work table, with or without superglue assistance.

John

Jason's link appeared while I was typing!

Edited By John Hinkley on 10/07/2023 13:06:53

I once had a book published in the 1930s about "modern engineering practices" and that had a photo of a chap in the Citroen factory standing next to a very similar herringbone gear. It was inferred that the Citroen double chevron logo was derived from their specialisation in producing these gears.

John

Chris,

The very fact that the sender of the email has spelt "scutinize" that way, would suggest to me that it's a U.S.-originated scam. Don't touch it with your, or anyone else's, bargepole.

John

Michael,

Have you considered hiring one from somewhere like HSS?

John

After a successful bout of machine and accessory selling, I parted company with my lathe today. My goodness, the garage/workshop sure looks empty. I shan't be totally idle, though, I intend to concentrate my attention on CAD/CAM design and 3D printing the results.  I have a few ideas bouncing around inside my head. I only hope I can get them out.

Another batch of goodies coming up for sale in the not-too-distant future.

Just got to decide which side to place the 3D printer when it arrives.

John

Edited By John Hinkley on 22/06/2023 16:34:59

Maurits,

How much does the tool protrude from the toolholder? Too much and the tool will waggle about like a waggly thing and dig-ins will follow. As you are using a 250-000 QCTP tool holder, you could invest in an HSS cut-off blade such as This one from ArcEuroTrade. It has the top relief already ground into it and will presumably fit straight into your toolholder. As has been said, use lubrication, slowish speed and steady infeed.

John

Until 2pm today, I had a Warco VMC mill. It was permanently fitted with an ER25 collet chuck which I used for milling cutters and drills, making use of the compressibility of the collets for odd size drills within the range of the individual collets. Purists will frown on that method but the I deliberately chose whole number sized fasteners in my designs, which helps. Tapping sizes are different, of course. I had a drill chuck on an R8 arbor, but rarely used it for the very reason stated by the OP.

John

There's no denying he was right, though. At the time of writing this there were 894 people who wasted their time reading the thread and 7 who responded. Oh, and add me to that list, as well, now.

John

I suppose the copper and tin ages preceded the bronze age since the latter is an alloy of the former two.

John

I, too, am sorry to hear about your health problems, Iain. I am in a slightly different position, in that while not in the best of health, I have reluctantly decided to sell off the majority of my workshop contents to relieve my executors of the burden of getting rid of a multitude of stuff they know little about. I'm in the middle of amassing photos of what is going to be for sale and grouping tools into "lots". The main difficulty that I foresee is the not inconsiderable problem of transportation of sold machines, unless the purchaser is local.

Good luck with your disposal. i hope that the equipment all goes to deserving new homes.

I intend to buy a 3D printer just to "keep my hand in" because I know that my nephew will happily take that on when I've had my half-day out with the undertaker.
John

And if anyone fancies building a full-size one, here's some info/dimensions from which to build it. Might even be of use once scaled down:

John

Well, I suppose the expensive solution is to buy a printer with two nozzles! However, more cheaply, is it possible to print the "base" article with the text, say 2mm deep and then extract the text only from your original design from Fusion, Alibre or whatever as a separate STEP file? Print the text to a thickness of 2mm in the contrasting colour and glue the resulting text into the cut-outs in the base material. Can you tell that I don't have a 3D printer (yet)?

Google "two-colour 3D printing" and it throws up several YT videos to watch.

John

Edited By John Hinkley on 30/05/2023 17:19:49

As will become clear, I have little knowledge of and even less interest in, Steam engines, though I can and do appreciate the engineering that goes into them, full size and scale.

My late father was presented with a copy of D. A. Law's "Pocket-Book for Mechanical Engineers" in 1933 when he won first prize in the H.M. Dockyard School, Hong Kong as a 4th year fitter apprentice Christmas Examinations.

It is to this publication that I reach when a question such as this is posed. Often, I garner little from it, but on this occasion, I think there might be a bit of interesting reading within its hallowed pages. I present, for your delectation, a scan of two pages which may or may not be relevant.

If nothing else, it gives me pleasure to know my father read and hopefully absorbed some of its contents.

John

(In contemplative mood)

Nigel,

There will come a time when you will want to include in your designs a proprietary part such as a flanged nut or similar. Rather than draw it from scratch, it is much quicker to import a ready-made part from an outside source. Atom has a link to Traceparts Library in the add-ons section of the Utilities tab. I have used this facility, but it requires registering an account which I know you would be reluctant to do. However, I watched a video on YouTube the other evening by James Clough (Clough42) in which he designed a grinding wheel balancing device (2 actually) and he downloaded the ceramic bearing CAD files for one design from McMaster-Carr. I tried a few downloads myself from there and was pleasantly surprised by the sheer amount, quality and variety of examples available. It doesn't support Alibre files directly, so I chose to download them as STEP files which Atom handles and displays correctly.

Apologies if you already know about this but I'd not come across it myself, so thought I'd share it.

John

Edited By John Hinkley on 18/05/2023 19:56:32

I recently had my Warco grinder up for sale on this site but the two replies I got came to nothing so I decided to keep it. I could be persuaded to part with it if you can arrange pick up. It is as new and I don't want to make money from it, so it's competitively priced (you'll be surprised). You have no profile so I don't know where you are. I'm near Doncaster, South Yorkshire. PM me if you could be interested.

John

P.S. I need to downsize my workshop while I'm still above ground and breathing.

Well done, Nigel. Keep up the good work.

John

Lee,

I suppose it all depends on what you are trying to achieve. For example two crossing tubes:

Clearly, they "block" each other off. However, select one end of each tube in turn and create a sketch on each end with the circle the inner diameter in red below and extrude cut that all through.

And you end up with the cruciform as shown below.

I have, perhaps, not chosen the best size combination to illustrate my point, but you get the idea. As Ady1 says, there's usually a workaround.

John