Here is a list of all the postings Anthony Knights has made in our forums. Click on a thread name to jump to the thread.
|Thread: Case Hardening|
I had intended making the end caps (or plugs) on the end of the container a fairly tight push fit in order to prevent unwanted explosions, but the suggestion about sealing with clay seems a better idea. There is loads of it in my garden.
Cyanide, being a compound of Nitrogen and and Carbon would supply the neccesary carbon for hardening, but personally, it's not something I would like to try, even assuming one could obtain supplies of it without being raided by the anti-terrorist squad.
My original query was prompted by reading the book which used to belong to my Dad (part of which I quoted ) and also by the fact that I have ready made furnace (AKA central heating boiler) and that the coalman usually manages to deliver at least half a bag of anthracite dust with every load of smokeless fuel. I have to admit I am trying to save money.
Before retiring , I managed to buy a small lathe and mill/drill machine and set up a basic workshop. I also took government advice and "Saved for My Old Age". What they didn't tell me was that as soon as I started to draw on this money along comes HMRC wanting their 20%. I am now hard pressed to afford basic materials, let alone luxuries like "Kasenit" or brazing rods.
Quote from my dad's book "THE HANDYMAN AND HOME MECHANIC" (reprinted 1948)
".....it is necessary to heat the metal in contact with the carbon to a very high temperature. This can easily be done by enclosing the material to be treated in a piece of gas barrel charged with bone dust, scraps of leather etc"
Question:- I have a solid fuel Central Heating boiler which can get to a bright red heat. If I made a suitable container from steel tubing, with end caps and packed the object to be hardened inside with either charcoal or anthracite dust, would this work?
|Thread: Brass turnings|
I have recently been machining brass and have ended up with a quantity of brass swarf. Not quite powder but very fine. There is not enough to weigh-in (recycle is the current approved term), but I would like to know if this material would be suitable to use in brazing.
|Thread: How to drill a square hole?|
unfortunately. having only recently become involved in mechanical engineering (having spent most of my working life in electronics) I do not have access to a copy of M.E.No.4285.
As a mere beginner at this game I wasn't aware one could obtain hexagon bar which could be hardened enoungh to use as a cutting tool. The idea of using hexagon bar to make the cutter is amazing and just goes to show the ingenuity of the people involved in engineering. Is there any information available regarding the size of cutter in relation to the hole required, or is it all down to the drilling guide (jig or whatever is the correct terminology).
Sorry. I have a dyslexix keyboard. I meant to type ciRcular.
Just a thought. If the item has a constant diameter, why would you need to turn a cicular end on it?
The cutter in Mr Abbott's picture appears to have a constant diameter cross section, made from 3 x 120 degree arcs centered on the opposite vertex. I seem to remember pencils with a similar cross section. Machining one in a 4 jaw chuck shouldn't be too difficult, assuming one takes care with the setting up.
Hi there Wallace. The triangular holes thing is another manifestation of the constant diameter phenomena mentioned above. I find the best way to drill holes in thin metal ( without making a special drilling jig) is to clamp it between two pieces of wood. I have recently replaced the flooring in the lounge and now have enough MDF laminate to use for this purpose until I am called to the great workshop in the sky.
Warrington coupling was mentioned in one of the posts, but putting this in Google did not supply any useful information. An Oldham coupling was also seen on my trawl for more information. Could this be a Lancastrian thing ? A Manchester screw driver (AKA Big Hammer) springs to mind.
Tried "Floating tool holder" and was directed to the U.S. patents site, where the are s**t loads of entries for this. Drawings are available for download. One of these has been added to my future projects list, as has the recently published "Wobble Broach" tool.
|Thread: unable to add new postings|
for some reason I am unable to scroll to the end of the "How to drill a square hole" thread to reach the add new posting box. Any suggestions?
|Thread: repeated postings|
just checked my E mail and found the new postings which for some reason had been shunted into the junk folder. Probably need to adjust the junk mail settings.
Regarding my original post and the responses I got, I have repaired and tested the original speed control PCB and it is now available as a replacement for my lathe, should the need arise.
Thank you to everyone who helped.
On the 6th of April this year I posted a request for information on the CL300 lathe. I received the information I required and am very grateful to all who responded. The original posting has now misteriously re-appeared dated 11/8/2010. This has also happened with other threads. WHY?
|Thread: Alignment of lead screw on CL300|
the 8 thou difference was over the whole length of the bearing block (4cm and a bit). The actual base is only 2cm wide. I only took a very fine skim to level the base. It turns out I should really have taken a bit more off to allow for adjustment by shims. After all the messing about I couldn't be bothered to set the block up for machining again. It was close enough for me and seems to work fine now.
Sid, I did mention in my original posting that since I first got the lathe, engaging the lead screw seemed to load the motor but thought it was normal so it possibly never has functioned correctly. It was only when I came to refit the leadscrew that I found the cause of the problem.
Gordon, I treated the leadscrew as if it was made of glass and certainly didn't drop it. A "pool cue " test didn't show any distortion visible to the naked eye. I always start the lathe from zero rpm using the speed control knob. I suspect the interlock relays in the control circuit would prevent you starting at full speed anyway.
Now the good news. Left hand bearing was found to have the bore and base not parallel.
Clamped it onto the milling machine table and using a 13mm drill shank as a test bar
clocked both ends. Checked again with the drill shank inserted from the other side.
Turn the bearing through 180 degrees and repeat. All tests gave a discrepancy of 8 thou.
Shimmed up the low edge until the bore was level and then skimmed the mounting lugs. Used these to mount the block upside down and machined the base. Check again and bore now parallel to base. Fitted bearing and then clocked the leadscrew from the saddle (apron removed ). Found to be higher and further away from the saddle at the
headstock. Removed the paint under the left hand bearing mounting position and opened up the screw holes in the bearing block. This improved the horizontal and vertical alignment, which although not perfect, I considered close enough.
Fitted the apron and set every thing up using Sids method (thanks Sid)
I suppose if I had used the lathe as it was it would have been a bit like running in a car and everything would have eventually freed up through wear.
it's me again (Anthony). We appear to be working at cross purposes here. I appreciate you explaining how to align the lead screw with the half nuts, but my problem is somewhat different. There is some inaccuracy with either the bearing blocks themselves, or the places they are mounted. This means that when they are bolted down the normally straight lead screw is being bent into a banana shape. No amount of adjusting is going to correct this without shimming the blocks so that their axies are in line.
This weekend I intend stripping the whole lot down again and checking the bearing blocks for accuracy. I will also make a shoe for the DTI lever so it surfs the top of the leadscrew threads and clock the whole length of it from the saddle. I will report back later.
as you have to open the half nuts in order to install the lead screw, the answer to your question is NO. The correct method (if you believe what I have read) is to fit the lead screw, slacken the screws holding the apron,THEN engage the half nuts (which is supposed to pull everything into alignment), then tighten the apron screws.
I recently removed the lead screw on my CL300 lathe to drill the tailstock end to fit an extension shaft (a la Dave Fenner) When refitting, I found that as I tightened the screws on the bearing at the headstock end, the leadscrew became progressivly stiffer, until, withe block fully fitted, I could not turn the leadscrew with my fingers. Could this be the reason for the change in motor noise when the leadscrew was engaged ? This had been something I had noticed since I first got the machine, but just assumed that it was normal.
Decided that the problem was due to some sort of mis-alingment of the leadscrew bearings. Having contemplated the problem with a can of lager,
I then cut some shims from said can (probably the best shims in the world) and tried fitting them.Two shims seemed to do the trick.
I do have Mr. Fenners excellent book on the Mini Lathe and have explored numerous websites dedicated to these machines. I have not found the above problem mentioned any where and would appreciate any constructive comments from anyone, as to the problem or my solution.
|Thread: Harrogate show|
Hi Keith (and anyone else who might have an interest)
The shop I found is located at number 384 York Road. This is on your left as you travel towards the city centre, just before you get to the White Horse pub, before the Lupton Avenue flyover. It used to be called "Intro Industrial Supplies" although I believe it has changed hands. I have had a selection of different metric screws, bolts, nuts etc. from there, as well as various drill bits and a 3 to 2 MT sleeve. Dont know if he has any old stuff (imperial or BA) but he might have some old stock, you never know your luck.
|Thread: speed control pcb for Clarke CL300 lathe|
have already found D1 to be short circuit. Somewhat ironic that when functioning it is there to protect the mosfets. I now need to search my "bits box" to find a suitable replacement. I still have a new pair of mosfets, so I live in hope
Thanks for the tip about using a dummy load.
got my kit back from Macine Mart after (expensive ) repair and my CL300 is now running . I said "repair" but all they have done is replace the control PCB. I insisted they return the original faulty PCB, which they have done.(It is my property after all)
Thanks to you providing a circuit diagram, I am now in with a chance of repairing it so I have a spare available in case of another failure.
Anthony (better known as TONY) Knights
|Thread: Harrogate show|
Yesterday I made my first visit to the Harrogate show. Apart from the hike from the main road I was suitably impressed, especially with some of the superb engineering on the club stands. I have been retired for just over a year and have only just started the model engineering game, although I was trained in all the basics at A.E.I. in Rugby, on leaving school.
I was somewhat astounded, if not dismayed at the prices on some of the trade stand for miniscule packs of nuts and bolts. I realise these are oddball sizes and "they don't make them in the quantities they used to", but even so I find the prices horrendous. I have sets of metric taps & dies from12mm down to 1mm and these are all I am likely to need , although I do have a few B.A. UNC, and imperial size taps from long ago.
I recently got ripped off by a national DIY chain, where I paid £3.80 for 10 (yes ten) M5X12mm csk machine screws + nuts which I needed urgently. Enough! I have since found a small independant supplier in Leeds who sold me the same items for £1. Need I say who gets my future business.
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