Member postings for DrDave

I experienced a few sonic booms whilst I was working in Switzerland (I think that the Swiss airforce might be a little more relaxed about speed excursions than the RAF is). First time, we were working in a Portacabin which shook like the devil. Even the floor shook! I looked around to comment about the apparent explosion, but none of my Swiss colleagues had batted an eyelid. It then dawned that it had been a sonic boom.

Roughly south to north, up the eastern edge of Bedford. It was at only 1,00 feet or so; you should have seen it from Cople. I only noticed it because it was noisy and I thought that it was just a jet out of Luton that was still quite low, otherwise I would have missed it too.

You don’t see many of them nowadays. A Jet Provost has just flown over Bedford. First time that I have seen one other than at an air show.

I don’t normally listen to music in the workshop: I find that it is too distracting when using machine tools. But this morning I broke out the filing buttons to round off some clevises that I am making. Time to break out the dulcet tones of Led Zeppelin to help pass the time!

After Andrew’s comment about watching Gransden’s gliders online, I had a look at their website & found the relevant page. Watching this morning’s activity, I saw one glider had flown westwards and was circling between Cople & Great Barford: we should be able to see that from the conservatory. Staring out in that direction, lo & behold, a glider!

Don’t you just love it when all this technology just works? Well, it tickled me.

A very generous offer and an interesting view into the world of gliding, thank you. I did most of my flying training (not to PPL, I didn’t progress beyond solo cross country) out of Little Gransden, but I have not been to Gransden Lodge. I will have to rectify this!

Walking through the farms south of Bedford, this afternoon, we watched a glider pass overhead. Quite low, it circled a bit as if trying to catch a thermal. It then headed for the old RAF Cardington & descended to land. But, as it disappeared behind the trees, a motor popped out, started & they regained height.

I assume that was a bit of pilot training. They gained high quickly, going round in tight circles, and the wind carried them off towards Great Gransden. But now, MrsDave wants to try glider flying again: it must be well over 10 years since she last had a go.

+1 for Tracy Tools. I ordered an M3 tap online recently. 10 minutes later, I realised that it was actually an M4 tap that I wanted. On the ‘phone to explain my predicament: not a problem. They changed the order details and the correct tap arrived in the post the next day. I have always had good service from them.

When reading Facebook on my iPad, I get lots of adverts from Red Bull. Being youth-oriented, they tend to include many emojis in their text. I find them really annoying because of the way we actually read: not word-by-word, but scanning several words at a time. Coming across an emoji embedded in a sentence forces me to stop, translate the emoji into English and put it into context in the sentence. A huge waste of my time! Perhaps they are just like learning a new language: once the brain understands them, do they just scan with the surrounding words?

And don't get me started on texting abbreviations such as "ur". I read the sentence "Where is ur bag?", for example, as "Where is you are bag?". End of rant...

Making arbors for slitting saws seems to be topic of the month, looking at other forum posts. I need one for making some clevices for my tender, so this is what I have made. The hole through the end of the shank serves no purpose: it was pre-existing on the bar in my scrap box. I also made a 1 mm thick washer to avoid the corner radius on the cap, allowing the cutter to seat correctly.

It runs true in my ER chuck, but this is not important. The manufacturer of my slitting saw did not bother to put the hole in the centre and it runs like a single-point cutter...

I was wondering how you were going to machine the reversing chamber around the whole internal circumference: I had forgotten that you only need a short length. A very elegant design! I hope that it runs well.

With a maximum Fe content of 3%, Inconel 740 is hardly a steel! It is designed for the superheater section of a coal-fired boiler in a power station, but does its cost not make it less attractive, even given the probable difficulties in trying to get a boiler certificate.

Thanks for providing those links, Michael. I looked through the pdfs, but no sign of my “new” drill. I’ll put a photo in my album tomorrow to see if that stirs any further memories from anyone.

Dave

Went to Oxford to collect a rotary table that I bought. When I got home, I found a high speed drill press that had snuck into the boot while I was not watching. Seriously, though, I have been after one to replace my el Cheapo drill for some time & the gent that I visited offered it to me at a price that I could not refuse.

The drill is by Multico, but there is no other info that I can see. I cannot find any info on lathes.co.uk about this machine: does anyone have any info about it? The three speeds would be a start!

That’s impressive photography! I’ve only seen this type of photograph from a supersonic wind tunnel before: to achieve these results in the Great Blue Yonder opens up all sorts of possibilities.

Dave

Martin, they are due over RAE Bedford tomorrow. We went to RAF Cosford to see them today. Two hours there, two hours back, for an 8 second flypast... At least their museum has some exceptional aeroplanes and missiles to view.

Rod,

Further to John’s reply, I used the SI-5 “Barrier Terminal Board Signal Isolator” with my KBIC240 controller. It provides the required isolation between the power & control circuits (or at least no smoke has escaped so far).

Regards

Dave

Emgee, thanks for that info. I checked the DIP switches on my stepper drivers: I set them to limit the current to 1.5 amps (the driver is capable of 4.5 A). I recall that I set them to the low value to protect things whilst I got used to the machine. Perhaps I will leave them there! I am not chasing maximum feeds on this machine.

Regards

Dave

Hi Bitzer,

Yes, I used the KBIC-240 (stock code BB-9428), the reciept does not say whether it is the D model... I have used the 0.05 ohm resistor, but don’t take my word that this is the correct one! I has worked so far, but the mill has not seen much use over winter since I finished the mod.

Steppers & drivers are a bit out of my comfort zone. I chose steppers that looked to be similar to Emco’s originals in terms of torque, though I never did find the specs for Emco’s steppers. I was concerned that an increase in stepper torque, without beefing up the screws & nuts, would invite serious damage at the first crash.

Regards

Dave

Rod, I paid £102.60 for the SI-5 board from Axis Controls in May last year.

Regards

Dave