Member postings for Neil Wyatt

Sorry Roy,

I must have pressed ctrl-V twice as the URL was doubled up. I've fixed it now.

Also, Diane has put a big box with a picture of the engine announcing the parts list on the home page.

Neil

Edited By Neil Wyatt on 31/03/2014 16:14:14

Hi Mike,

The tables are HERE

Neil

Edited By Neil Wyatt on 31/03/2014 16:11:37

Being completely tight, I have a different take. Instead of an empty box, by a box of cheap drills and do a 'bubble sort'.

If you find a duff one, wear one out or break it - replace it with a decent one - probably from the stock of drills that you already have. Any that are any good or unused will stay in teh box.

In time, all your regularly used sizes will magically be replaced by decent drills.

That way the good drills will bubble up to the top you will always have a backup for rarely used sizes without spending a fortune.

Neil

Ah! C-spanner AKA 'hook wrench'. Draper quote these sizes, note how great the range is:

19-51mm

32-76mm

51-121mm

Neil

Unfortunately a number of errors crept in to the large and complex gear tables in the article. Brian has now checked each gear combination individually, and prepared a corrected PDF version, one table to a page, which can be downloaded from the article HERE. The individual pages can be printed off and laminated to give a handy workshop reference.

Details of the individual changes to the tables and some minor errors will be printed in MEW 215. Sincere thanks to Brian for putting in enormous effort to produce and check these very useful tables for anyone with a gearbox equipped ML7.

Neil

P.S. My apologies for the confusion I caused earlier, I had to create this thread before I could link the article to it. I have deleted the comments saying the link doesn't work as it should be OK now.

Edited By Neil Wyatt on 30/03/2014 18:34:21

Daniel,

Most Farnell components are available through CPC (part of the same group) but they have no minimum order and free postage on web orders.

Neil

Hi Bazyle,

The sizes are, I can't see myself trying to machine or press something 1/2" diameter using it so there will always be a bigger hole available. I should have reamed them all for extra prettiness . Just out of interest, the central hole was done with a 1/2" MT1 machine reamer that i found in a bootsale for 50p and de-rusted electrolytically..

Funny how something so simple can generate such comment!

Neil

I guessed the hole sizes from the picture on the Chronos website. Mine are 1/2", 1/4" and 1/8" in the vee and the others 1/8", 1/4", 5/16", 3/8", 7/16" and 1/2". The very astute will see my holes are arranged as a mirror image of the Chronos ones! I wonder if that will affect its operation?

It works quite well as a pen holder, but the smaller holes need to be at least 5/16" to maximise its capacity.

Neil

> Neil, I think your VFD configuration would make a good article for MEW.

The old editor was quite keen, but I have to convince the new one.

Neil

I apologise for the deal in sharing full details of my setup, but I want to move everything over to the new control box, which means a slightly different configuration. I don't want to share details until I know the new arrangement works. Problem is, now I have had a chance to get in the workshop, I'm playing round making a few simple things and I don't want to disable the lathe...

Neil

> Just needs ten thou of case hardening

I was thinking of pack hardening it overnight with charcoal in the fireplace - the getting the top and bottom surface ground

> Really need to get myself one!

Shall I be honest? I use a home made straight knurler.- 3/8" bar about 2 1/2" long with a slot cut in the end of it for a knurling wheel. I use the shank of a 3/16" drill as a spindle, held in place witha few twists of insulation tape... just a stop-gap until I find a bit of phosphor bronze to make a proper one.

Neil

I wouldn't fret

Andy, there are 101 ways to skin a cat in electronics as much as engineering. Lots of folks have said 'just use a 555' but you are the first here to bother actually designing such a controller!

My most recent motor controllers use an AVR microcontroller and logic-level FETs. I use heatsinks, but I suspect they are pointless.

The ebay option isn't always ideal. Below are two pictures of a BLDC speed controller for a model multi-step hydroplane. It appears to have been soldered by a drunk gorilla in a straight jacket. Believe it or not, it works!

Neil

Point taken Andy; although as the LM311 has a slew rate of only 8-16 V/uS so at 12V it will take about 1uS to go from low to high even with an open loop so I suspect it takes a lot longer than 3.7ps to switch the transistor!

> why you are using a 555 and a comparator

To allow an external control voltage to be used, I assume.

Neil

Bob,

I see the photos here. Quite an achievement, very impressive indeed.

Neil.

Ferric chloride is easy to obtain from any electronic supplies company as it's used for etching PCBs. usually as dry 'crystals' (shaped like small golf balls).

Neil

Bench Block take 2.

I spent 20 minutes putting a really decent end on an 11mm slot drill with the diamond wheel.. the difference in the cutting made me wonder why I even bothered trying with it blunt (excuse - it looked sharp enough!)

Gave a silky milled finish, but still some light marks, so a couple of minutes with emery over a hefty steel bar.

The other side of the V still has a few marks where the cutter had dug in deeper over the holes, but I really didn't want to make the v any deeper.

Neil

A nice circuit taht could be used in many situations.

May I suggest an LM311N comparator instead of the op-amp? It will switch faster (200ns as against about 1 uS for the op -amp at 12) and it can take input voltages up to 30V above the negative rail.

Don't forget you'd need a pull up resistor (say 1K5) on the output as it is open collector.

Neil

Can you lot stop making these tailstock mods before John writes it up for me!

Neil

> Are you reading this Neil? Maybe a column in MEW called "What Are You Up To" is worth a punt.

Great idea but Jason would want - oh I see he's already spotted it.

Actually i think this is one of the areas where the website can complement the magazine.

I would be keen to feature photos of people's home-made tools/interesting setups that aren't a proper article but are still of interest in Scribe a Line.

Neil

Brazing is preferred to silver solder for radiant (i.e. in the firebox) superheaters as they can get red hot when the steam isn't flowing.

Some time ago I tried brazing with brass rod and borax as a flux. It needed a fair bit more heat than silver solder, but I was able to make the joint OK.

Neil