Here is a list of all the postings ANDY CAWLEY has made in our forums. Click on a thread name to jump to the thread.
|Thread: Cast white metal bearing advice needed.|
The original item is cast white metal and has lasted very well for 89 years. It's just me who is a clumsy b*st*rd that broke it.
As I said in my OP, of course, it would make sense to machine from solid but that is not what I want to do, I want to stick to original specification.
On the moulding rubber question I had a long conversation with some one who uses the very hard grade professionally and he told me that because of the very high viscosity of the un cured resin a very high vacuum is need to properly degass the mix. He also said it is impossible to avoid air entrapment and get a good mix.
So casting white metal it is then!!!!
Oh, I forgot to say that I started this thread off 'cos I couldn't find any tool geometry, feeds and speeds data for machining white metal!
The broken off bit is left hand thread. Needless to say when I removed the brass collar that was screwed on I didn't know it was left hand hence the break.😞
It is about 35 mm long and the diameter of the parallel bit is 20 mm approx and it carries a shaft 15mm diameter.
I need to make a replacement and I want to make it in a similar manner to the original. I know for a one off it probably makes sense to machine from solid or to machine one from a lump of bronze but I really want to make a casting and machine it.
I tried to make a silicone mould but it wasn't succesful for a variety of reasons the principal one beind difficulty of de-aerating the resin before it went off.
My proposed method is to make a two part mould out of a couple of chunks of ally that I have in stock.
I propose to spigot the two pieces of ally bar with a shallow spigot then bore one piece to make the parallel bit including a slight angle to permit separation from the mold, this will be through bored to allow molten metal to be poured into the mold.
The other half I intend to machine a triangular pocket to produce the flange and bore a recess to produce the tapered bit. I will add a short bit onto the taper for a chucking allowance.
The mould cavity will be carbon blacked to ensure release ( or would Zebrite work).
The two halves of the mould will be clamped together, preheated and the metal poured.
Or is it? Any advice or suggestions will be great fully received.
Edited By ANDY CAWLEY on 26/10/2014 06:56:36
|Thread: Gear Cutting Advice|
Michael, thanks for that. I have an English version of the manual that Tony Griffiths has however that is for a plain bearing lathe and mine is a roller bearing version. I have now got a later manual for the roller bearing version however it is in German a language with which I am not familiar.
Google translate goes part of the way but the translation of technical German is rather quaint. I'm gradually unpicking it, I think!
Oh dearie me, bearing adjustment was the one thing I was hoping you would know about.
Never mind they are wonderful pieces of kit.
Hi there Versaboss, mine's a LZ4S as well (must remove boxing gloves when typing). The 90 tooth is on my list to make.
Is yours a solid bearing or the later roller bearing spindle?
Are you in the UK?
I believe it's mild steel, the spec number quoted by the Waterjet cutting bloke was a number un familiar to me. He said he thought it was mild steel. A bit vague I know but as the gears are not highly stressed I thought it would be ok.
I'm about to cut some change wheels for my lathe, a Leinen L4ZS as I don't have the appropriate full set to cut the threads I need for a particular job. This will be the first time I have ever cut gears.
The gears are 1.25 MOD and I have bought the gear cutter for the job.
I'm thinking of cutting the 15mm thick gears on my Centec 2A mill with the axis horizontal and the cutter in the vertical head.
The full depth of the teeth is a little less than 3 mm.
My question is should I be thinking of cutting the teeth in one pass with a fine feed rate or should I consider several passes.
I could also do the job with the cutter mounted on a horizontal spindle.
I'm also thinking that I need to complete my powered feed project first.
What advice can you offer?
|Thread: Metric thread|
Check that they are not left hand thread on one side and right hand thread on the other. The wheel nuts are definitely different on each side. I did some of those dust caps ages ago and I can't remember for definite.
Edited By ANDY CAWLEY on 19/09/2014 21:00:19
|Thread: Soba\Vertex HV4 Rotary Table|
Isn't India in Asia?
|Thread: Backyard Casting|
I tried making an RTV silicone mold and it was full of bubbles ( the rtv that is). Is it possible to produce a good mold with out vacuum degassing? If so how does one get rid of the inevitable entrapped air?
|Thread: Machine vice - Vertex/Arc Euro Trade/Gloster?|
I went through the same exercise and finally chose the Gloster vice however they had no stock so ended up with the Arc type 2. I have no regrets and find the Arc vice excellent.
|Thread: 5/16 x20 tpi thread size|
I suspect you are looking at a thread that complies with British Standard 86. My copy is the1956 version. It covers (among other things) a constant pitch series of threads of 20tpi of whitworth form, that is 55degrees.
I am aware of this because all GN and Frazer Nash motor cars manufactured up to the mid thirties had threaded components,as distinct from fasteners, at 20tpi.
http://www.tracytools.com/ stock taps and dies of this type.
Edited By ANDY CAWLEY on 03/08/2014 04:43:09
Edited By ANDY CAWLEY on 03/08/2014 04:46:28
Edited By ANDY CAWLEY on 03/08/2014 04:47:45
|Thread: Cutting 6" aluminium in a band saw.|
Yes, I didn't quite follow what you were trying to do.
Have you got a 6" diameter disc 30 mm thick that you want to make into two discs 15 mm thick( less the saw kerf)?
|Thread: Electrical installation|
When I had my shed built I decided to have twice as many sockets as I thought I would need. I planned to have them mounted on the roof beams which were at a height where I could easily reach. The logic was that the cables would not be trailing over work benches. My electrician pal found this very difficult to accept and persuaded me to have sockets fitted at the conventional height, just above the work surfaces. We reached an compromise and he fitted some sockets to the beam that went accross the middle of the shed.
How I wish I had stuck to my guns and had all the sockets mounted on high.
Despite having a seemingly extravagant number of sockets fitted I still one of those multi socket adapters in my battery charging area!
|Thread: What did you do today? (2014)|
How nice of you to say so. I've been telling people for years but nobody believed me!!!
When I got my first Chinese lathe, a Chester Model B, It had a variable speed control with an unmarked knob and no graduations so I bought a knob with numbers on it from eBay. I then marked a zero point on the machine and then produced a rev chart to hang by the machine.
I didn't have a rev counter so I improvised by putting a length of all thread in the chuck, marked a length on it with a felt tip and then ran a nut down the length under power. I measured the time for the nut to run the distance between the two marks making the rpm easy to calculate. The longer the length the less margin of error. I checked the actual rpm at each of the numbers on my new knob.
Hey presto! No need for a rev counter.
Edited to add:-
I have just re read this and would say for the less experienced beware a long length of threaded rod in the chuck at high revs it could whip most savagely. If I remember correctly I constrained mine within the tail stock having frightened my self at medium revs..
Edited By ANDY CAWLEY on 01/06/2014 08:32:08
|Thread: quickest way to bore a large hol using a lathe|
Oh yes, I find that by editing you can't change a post to have the email notification bit on, hence this post.
This is an experimental posting which I intended deleting.
I'm blessed if I can find out how to do what seems like a simple task.
I went to the Website FAQ and got lost in a thread about deleting threads which drifted into a long discussion about SHOUTING.
No surprise there then!
Despite a bit more trawling I could not find out how to delete one of my own postings. I did try deleting all of the text but when saved just left a blank postings.
Please can somebody advise?
Edited By ANDY CAWLEY on 17/05/2014 09:44:20
I thought that was a bloke looking through a pair of specs!
Thanks for that.
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