Member postings for Captain Biggles

Thanks for the reply Robin.

Sadly you can't save the .pdf on the iPad, only on a laptop.

The magazines I get through the iPad's "Newsstand" app are presumably authorised (or whatever) by Apple, but I cannot see any way of copying them for illegal distribution (surely Apple, if anyone will have solved this problem!) and so I'm at a loss as to how Railway Modeller can manage but Model Engineer can't.

I just got back from a couple of days in Germany on business, and managed to liberate the iPad from my wife's grasp so I could enjoy the digital editions of Model Engineer on the flight over.

Seatbelt sign comes off, iPad comes out, flight mode on... no digital editions.

Why do I have to be online to read them? The other magazines I/we subscribe to digitally (Railway Modeller, wife's Vogue) are available offline. I notice that the other magazines are available in the "Newsstand" app on the iPad, whereas the Model Engineer ones are a separate app altogether.

This seems a real shame, why only do half a job MyHobbyStore?

Please sort it out. Although I subscribe to the paper copies (I pass them on to others when I'm done) it'd be nice to have the back-editions offline. I'd be particularly miffed if I'd paid for the digital-only subscription if I had to be online to read them.

Joel

I've just started my first - an S50. Only reason I chose it though was it was the cheapest horizontal engine they made (I had / have a preference for horizontal over vertical) so can't advise for / against the others though.

Have been impressed by the castings, kit and drawings so far. Tubal Cains has a write up in Model Engineering for the S50 if you're worried about the lack of books etc.

Good luck!

Joel

Cheers for the sarcastic reply Stub. How about the 239 replies for the JCL15-120E of which none appear to be suppliers (in the UK) or likewise the 506 for the CK3 parting tool?

Jason - thank you for the very useful answer, and you've rather confirmed my fears about the Chinese import tooling (why is it so hard to find anything other than cheap Chinese imported tooling at shows these days though?). Sadly none of those suppliers you suggested stocked (on their website at least) all 4 types of tool, are any of the above likely to be able to get all of them in (at a reasonable price)? Someone at work suggested Cromwells - anyone got any experience of using them?

Not only are there a bewildering array of different shapes & sizes (something I've just about got to the bottom of) but there are so many different materials too. Is there such a thing as a "good all rounder"? As I said above it's mainly cast iron, stell, brass and aluminium that I work in.

I bought Amadeal's kit of 9 12mm indexable carbide lathe tools back at the Bristol show and I'd now like to buy some replacement tips. After quite some digging around online I've worked out that the insert codes are as follows:

SCMT09T304

WCMT09T304

JCL15-120E (for threading)

CK3 (for parting)

Can anyone recommend a good, online (ideally) source of the above, preferably with a range of material options as I typically cut cast iron, steel, brass & aluminium (in that order).

Cheers,

Joel

Robin,

That was shimmed up using nothing more than a business card - the beauty of these magnetic encoders (compared to the optical ones which are often so finicky that they have to have integral bearings and come as a complete module costing big ££ that they have a really wide range of setup tolerances.

Rideheight (from the scale surface) can be anywhere between 0-1.5mm (compared to an optical which is, say, 0.8mm +/- 100um). Pitch, roll and yaw all have wide tolerances too, so all my holes on the mounting brackets were ovalised to give me maximum play, and the dead-easy-to-use set up LED simply turns green (from red) when everything is aligned.

More info on the readhead itself can be found here: **LINK**, the original manufacturer's page where datasheets and installation guides can be downloaded.

Under normal circumstances I would consider this sort of system to be beyond the budget of the standard home hobbyist, but with a readily available second-hand and v cheap source on eBay it all becomes worthy of serious consideration.

Joel

I took a photo of the completed axis last night, for comparison to the last photo I put up. Note that the LED is now green, rather than red, showing signal strength & alignment etc are all correct and the encoder is working properly. You can also see how the top cover screws to the backing bar and seals the scale in place, protecting it from swarf & coolant etc.

P.S. Other photos are available in my profile album thingy - called Encoder.

If anyone has any questions I'm more than happy to help - DM me.

The first thing I'll say is bear in mind that these bits of kit are designed for a wide range of environments, and in some of them the fact that the scale is stuck to the substrate is actually a good thing from a metrology (accuracy) point of view. I could go into more detail, but in our world the benefits gained from having a scale that stretches as the substrate changes shape due to thermal expansion are by far outweighed by the physical environment. So...>>

I simply mounted the scale in a 2-part support profile (link in previous post). These consist of a bottom part with mounting holes that you screw to your machine and then stick the scale onto, and a top cover, that screws to the bottom part and completely covers the scale protecting it from swarf and coolant and being bashed. The readhead is perfectly capable of reading through the ally top cover with no affect on accuracy (ok, there is a tiny one, but being in the region on nm we can ignore this error source too!). The photo below shows the bottom part mounted, ready for the scale to be stuck to it and the top cover screwed on.

The scale is magnetic and I guess, could get damaged by introducing foreign magnetic fields. However in practice you'd have to be trying pretty hard, i.e. by mounting a mag-base for a DTI right onto it, and even then you'd probably be ok. To give you some idea, I managed to put some scale in the same plastic carrier bag as a replacement motor for my lathe, and had no probs. The actual fields themselves are fairly small and don't radiate much above the surface of the scale so you'd basically have to place a strong magnet right up on the scale itself to damage it - and remember we've now got a cover on it so we've got an extra layer of protection.

You're right, these are serious pieces of kit, and new they cost several hundreds of pounds. But they can be sourced much more cheaply on eBay and I'd much rather have a product designed precisely for this kind of application than one based on dismantled calipers or otherwise. That said, £300 was for me affordable, and for others it may not justify the cost.>>

For those interested in fitting magnetic encoders to their lathes / mills (etc), I have just done exactly that to my 3-in-1 machine using the following parts from the following vendors (no links / connections to businesses implied, just a happy customer with the experience of it all working together.)

1um Renishaw / RLS readheads were bought from eBay from America, chap has plenty to offload and is open to offers. Service and knowledge is excellent. **LINK**

Scale and rails can be bought from Allendale, here: **LINK**. I used the 2-part scale support, but the only disadvantage is that the screws to mount it to your table / bed etc are under the middle of the scale, so once the scale is in place it can't be adjusted.

DRO was also bought from Allendale, here: **LINK**. I bought the 3-axis one even though I only intended (thought it possible) to mount X & Y, but now I've worked out a way of doing it I'm going back for more!

Total cost was probably in the region of £300.

Joel

Thought I'd take the opportunity of this thread to ask why the Digital Issues are downloaded as an "app" on my iPhone / iPad so appears individually, whereas other magazines I subscribe to (Railway Modeller, for instance) appear as magazines on my Newsstand app?

Joel

I've just added a 3-axis Universal DRO (from Allendale) to my Chester Centurion 3-in-1, and am using Renishaw / RLS 1um magnetic encoders.

I've used the Allendale 2-part tape support as well, a fantastic modification and one that means both the readhead and tape are totally sealed and can be doused in grease and swarf and coolant. I don't have to worry about bashing anything either.

The readout has transformed my performance. I'd hesitate to say it's changed the machine's performance as the back-lash and sloppy handwheels are all still there, but my ability to overcome these and produce accurate parts has been transformed!

As was mentioned above, even though the backlash is there, provided you've attached the scale and readhead to the correct parts of the machine, the DRO will always be reporting actual position. Things it can't compensate for are when the tool slips in the toolpost / collet or the workpiece slips in the vice etc. But if everything is held tightly, then if the table / toolpost move then the DRO will show this - then just wind the handle to compensate. Key to this is just to think about what's moving, and what the encoder is measuring. Get your head around this and you'll be fine.

DROs can't compensate for anything, so you still have to approach the same problems in the same old way, there's no substitute to age-old techniques etc. But the DRO will give you a much better idea as to what is actually happening, without having to back off & measure etc.

Finally, I'll add that of course a 1um encoder will not enable me to produce parts to 1um tolerances. I should imagine my machine has all sorts of slop and lack of stiffness that means I'd be lucky to get to 10um tolerances. But that's got to be an improvement on using Chinese handwheel scales!

I used to work for an encoder manufacturer, so I know a little about the subject and it meant I was able to get the encoders for free - the whole exercise has cost c. £250. But I'd recommend it to anyone.

I've recently bought a second-hand Chester Centurion 3-in-1 (at such a cheap price that usual objections over an all-in-one vs two separate machines were null & void) and would like some advice about commissioning it in my workshop.

Firstly, it's on a stand but is not bolted down to the floor. Is this likely to cause problems?

Secondly, having attempted to turn a 1" dia steel rod (for practice) I'm concerned about the stiffness of my cross and longitudinal travels. The finish on the piece was ripply and could be seen and felt by hand. The crosslide I can even wobble by hand. Does anyone have any experience of adjusting the jib-strips on this model?

Finally, the milling table is miles from the milling head, in order to get anywhere near it the spindle has to be fully down, i.e. in its least stiff position. Anyone got any tips about how I could overcome this shortcoming? Bolting a mounting block would presumably help, but might this introduce more errors (e.g. squareness) than it solves?

Have managed to get hold of some Renishaw magnetic scale and readheads. Anyone got any experience of mounting such devices to this or any other machine? Was planning on using the 2-part extrusion mounting from Machine-dro.

First project is a set of Stuart S50 castings. After that, who knows???

Cheers all,

Joel