I’ve recently started doing a bit of welding. I’ve made a couple of dragon heads. Why would I do that….Continue reading
This was a fun one with a couple of neat features to make the most of the limited parts.Continue reading
There have been many and varied changes to the workshop in recent months, so it is time for a bit of a catchup.
To start with, the workshop is now the Glittery Girly Blue Room of Glittery Girlyness.
I’d love to be able to say that at the touch of a concealed button…
- The bed flips over to reveal a workbench & milling machine
- The headboard flolds to reveal the tool board
- A lathe rises magically out of the dressing table.
But I can’t – it’s all rather domestic now. Well, aside from the large quantity of small engineering tools which are hiding under the bed. Continue reading
I have a dovetail milling cutter.
So I shall use it to cut my first set of dovetails on some holders for my lathe quick change tool post.
I’ve long had a bit of a Tennis Elbow problem in my right elbow. It started after a weekend at the UK Pinball Party, and it seems that it isn’t going away any time soon. Usually it’s all fine, just if I do a bit of strenuous sawing it aches a bit and I have to be a bit careful of it.
So I was after a cheap method of cutting stock without any effort. I don’t have room for the traditional metal cutting bandsaw, and as my workshop is my back bedroom, a screaming bandsaw might not go down too well with next door. They have a small baby, it screams, but I’m informed that it is “not the same thing at all”.
I unpacked it, and managed to find the angle grinder that I’d bought for cutting up an oil drum to make a furnace (still got to do that…)
I’d seen various unboxing and assembly videos on YouTube, but was surprised to find that the base is cast iron. I’d assumed that it would be nasty plastic. The stand cost me the grand total of £18.25 and my expectations were not high.
Assembly is straightforward, it coped well with the angled handle attachments on the Bosch grinder. I used a square the set the rather primitive vise back jaw square and to set the blade vertical. It’s not blob on, but I’ll be tidying the ends up on the mill so no great worries there.
I’m going to make a few tool holders (using the knurled nuts) so I thought I’d give it a try on the 1 inch square aluminium stock I’ll be using for those. All was not straighforward 😉
It seems that the grinder can’t quite cut all the way through the stock. It left a tiny whisker attached. This is no big deal, but it would be interesting to look at the reasons why.
It seems that the guard on the grinder hits the stock before it cuts all the way through. This is a grinder issue – essentially the grinder is only capable of cutting through one inch – pretty much exactly. Ho hum. It’s no big issue to either flip the stock over and cut through the last bit, or just bend the cut portion off, but it does illustrate the limitations of using an angle grinder rather than one of those dandy Evolution chop saws.
This was the point where I realised that the wear of the cutting discs was significant. I put the disc that I’d used to make two cuts through the inch square aluminium stock on top of a new disc.
I reckon it took about 2mm off the disk on each cut. The discs are not expensive – about 60p each, but combined with the depth restriction it is a significant effect.
You can see each of the four cuts is slightly less deep than before. I was able to snap them apart by just bending them, but I did think about holding the last one in a vise (but then tried a bit harder instead).
So, well worth the few quid, takes up much less space than a gert big chopsaw, but does have restrictions. I’m satisfied with it.
A quick update on the knurling.
A little musing and I realised that the wheels on the knurling tool were 3/4″ diameter and had 48 knurl features around their circumference. This means that if they were an inch in diameter, they would leave 64 features. This is a nice round number in imperial-world.
So I needed to ensure my diameters were in 64ths of an inch for the pattern to repeat properly.
I also did a bit of reading up and discovered – much to my amazement – that you can/should feed the knurling tool across your work. Which seemed a bit counter intuitive to me.
So I gave it a go, turned my nice 14mm metric brass rod down to ‘arf hinch, set the centre of the knurling tool on the right height, clamped it reasonably tightly and started at a very slow speed.
Once the knurl had picked up, I was able to tighten the clamp nut a bit more and noted the roughened surface. I kicked in the feed and it very slowly traversed.
After it had done a bit, I gave it a squirt of cutting oil, just to see if there was a difference.
So, looking at the picture above, the knurl is pretty (there are a couple of flaws where I held the nuts in pliers to tap the holes), but I’m quite happy with that.
So, I now have four knurled nuts, two nice, two satisfactory (grumble) and can move on to making a batch of four tool holders.
Some time ago, I bought a cheap “Clamp type” Knurling tool from eBay there are many sellers.
I stuck it in a tool holder and bashed it onto a couple of bits of aluminium rod. One bit knurled really nicely, the other didn’t. I’ve not really played with it since.
I’ve recently been making tool holders for my quick change tool post. I’ll blog about that when I get round to making half a dozen of them and can document the process. You can see the tool holder above, the ones I’m making are tighter and better…
So let’s make some.
Somewhat naive, I just turned a rod to the approximate diameter required and clamped the knurling tool onto it. This merely produced a roughened indistinct surface. Clearly a bit more subtlety is required.
So I measured the knurling wheels in the tool – 19mm diameter. then I counted the number of knurling features on the wheel. There were 48 features.
So, each element of the knurling pattern occupies pi*19/48 of the circumference of the knurled part.
Using this, I turned my brass rod down to 13.06mm diameter, this is 33 knurling patterns. The results were OK, but not massively impressive. Alignment of the knurling tool is important, the pressure is important, the exact diameter is also important. I’m guessing a bit more experimentation is called for.
Anyhow, I tidied up the edges, added a bit of shape to make them similar to the original one, drilled and tapped them to M5 and while I’m not overly happy with the result, they are satisfactory for the purpose.
I think a bit more experimentation is called for to get a really crisp pattern, possibly allowing an offset of half the depth of the knurl when calculating the circumference is called for.
Still, I made a thing 🙂
I’ve recently been attempting to turn some mild steel. I wasn’t getting good results.
I started out trying to use a HSS bit which was included in a set supplied with the lathe. I can’t say it was particularly sharp. I’d used it on a bunch of brass and aluminium and it had performed well.
The results with steel were, frankly, awful. Scored and lumpy (and this was supposed to be a bearing surface).
So I was inspired to try grinding my own.
I followed the Little Machine Shop guide to grinding tools that I’d found through google, http://littlemachineshop.com/instructions/grindingtoolbits.pdf
It is quite a simple guide to follow.
I don’t have a particularly good grinder. It is a cheapie B&Q special, upgraded with a wider pink wheel for sharpening my woodworking lathe tools and a newly fitted tool rest that I picked up cheaply at Cardiff Axminster’s opening day. Other grinders are far superior.
Anyhow, I set the rest to an eyeballed 10 degrees or so, angled the tool blank at an eyeballed 10 degrees-ish and ground the front face compound angle.
Then I put the bit parallel to the front surface of the wheel, overhanging the left hand side and ground the side relief to the 10 degree angle set on the table. This took some time and I dipped in a glass of water to keep it cool enough to hold comfortably.
The top relief was achieved by flipping the bit over to the right hand side of the wheel and angling it to an eyeballed 10 degrees-ish again. This grind took a while.
Then I touched the point surface on the wheel – you have to elevate it from the table as all the compound angles mean it’s quite high on the wheel.
So, all very approximate. I wasn’t expecting great things at all. I was expecting something that would cut, but probably no better than the blunt tool I’d used previously.
However, a quick check on some silver steel gave great results. So I pulled out my rough and horrible mild steel and gave that a spin. It cut like a dream producing lovely tightly curled long strings of springy swarf. The surface finish was vastly improved.
Either I have been really lucky and hit some magic angles, or maybe it’s just that any sharp tool gives a decent result. I’m sure I’ll find out sooner rather than later.
So that’s a happy bit of grinding 🙂
It’s been a while since I posted on this blog. You often get the two or three posts blogs where someone has lost interest, and I always find that rather sad.
So I reckon it is time to make a commitment to post regularly. I’ve been fiddling with a lot of stuff. TheLab has undergone a few revisions and is now more techno sparkly than ever.
I did get round to buying a lathe – erm, three actually, and a milling machine.
I shall be posting reviews of the new machines and following progress (when I make some) on creating my first bit of model engineering – an Elmer’s Wobbler tiny engine.
So, hang on til tomorrow when my first Monday update will be posted!
A while back i bought a lathe. Well, kinda….
I made the mistake of buying a Draper Micro Lathe Mill Drill. (Don’t believe the price, they are less than half that price on eBay). It’s not very good at all.
Like most “transform-a-tool” do everything things, they are rather poor when it comes to doing any one specific job.
It has spent most of it’s time stripped back to the motor running various grinding, lapping and polishing wheels for shining up bits of pewter casting that I’ve been doing. It does that well enough, but I’d strongly recommend that you don’t buy one. It’s rubbish (I can’t even lock the compound slide on mine. It is that badly manufactured). Plus it doesn’t have any kind of automatic feed, so screw cutting isn’t going to happen without costly thread chasing tools.
So… That lesson learned, I’ve been looking at “proper” lathes with a view to buying something more worthwhile.
Comparing my requirements with my desires is interesting.
In terms of projects I want to do right away, there are a number of things on my mind.
Firstly, I need to make some handles for things. I’d like a nicely matched set of exotic hardwood handles – 8 in all. All shaped and sized to my hand. Obviously this is a wood turning job.
Secondly, I’d like to try making some pewter rimmed bowls. I’ve been reading about combining wood and pewter in turned objects for a while and I’m really excited by the potential. So.. another job for a wood turning lathe.
Thirdly, I’ve been intending to make a long stool (bench seat) and I’ve always been really taken by some of the early arts and crafts pieces after seeing them in the Whitworth art gallery in Manchester many years ago. Lovely airy structures made up from impossibly thin seeming turned forms. So… another job for a wood turning lathe.
Now I’ve always fancied making an engine. I had a Sabre .5cc model aircraft diesel engine as a child and the simplicity fascinated me. OK, I now realise that the simplicity is a result of really good design, the incredibly low part count is only possible because of the way that the design integrates – each part performing several functions. Even knowing this (ie it’ll be almost impossibly hard) I still fancy making one. So… a small model engineering lathe.
I also fancy making a Tesla steam powered turbine and connecting it to a dynamo so I can make electricity from fire. There is no reason for this, but it should be fun… Again, that’s a model engineering lathe.
You can turn wood on a metal lathe (you just need to hack together a tool rest and use the correct speed) but getting a metal lathe of sufficient size to turn pieces of furniture isn’t a good idea for an upstairs back bedroom workshop. I’ve been enjoying looking at antique Myford lathes on eBay far too much, but short of a house move that’s not going to happen.
So, on the wood lathe front, I mostly need something fairly small for turning handles, knobs, bowls and maybe the odd wheel or two. And once in a while I’ll need something long enough to turn a table leg.
This seems to be a common thing. There are a number of (seemingly identical) wood turning lathes which have an extension bed. So they start out with about 18 inches between centres and when required you can bolt on an extra part to take them up to about three feet between centres. There are many, one is the Axminster 1218 which with the extended bed will turn 1138mm (almost four feet). So that’s ideal, but rather pricey new. There seem to be many on eBay though – and often with a number of chucks and chisels so that’s the best option wood wise. I’m patient and want to spend significantly less than £200 to turn my first pewter rimmed wood bowl, so that is my best option.
However, all that said, the thing that I’ve really connected with in my tool-lust is mini metal lathes. I saw a lovely Warco Mini Lathe on eBay that really fired my interest. There seem to be many available from different vendors, but I guess they are all made to the same Chinese pattern. These also seem to come up on eBay fairly regularly and there is a fabulous website comparing them, MiniLathes.com.
Some vendors are,
Again, I’m in no rush, so I’ll keep an eye on eBay and see what pops up. The Sieg is likely to be the better name, but it’s so expensive. The Warco is painted green, which shouldn’t matter but somehow really does. It’s interesting to compare the price of accessories between the various vendors. There really shouldn’t be a difference, but when you see the same quick change tool post at such massively variable prices you have to wonder…
So, to summarise. My most pressing requirement is for a wood turning lathe with an extension bed. I’d like an electrically variable speed one (so when I’m turning bowls it’ll handle out of balance loads better) but I’d go for one with just pulleys if it was cheap enough. I’d sooner buy second hand – there isn’t much to go wrong with a wood lathe other than the head bearings or twisting the bed. I’m more likely to get surplus chisels, chucks and centres with a second hand one.
However, the Tool lust wants a nice green metal turning lathe with all the bells and whistles!