Here is a list of all the postings andrew lyner has made in our forums. Click on a thread name to jump to the thread.
|Thread: Min lathe steady rest for up to 65mm diameter|
The lathe comes without one. But I have only a small milling slide and no circle facility either.
One of the 'excuses' I used for buying my Mini lathe was to allow me to make up 2" extension tubes and adaptors for my astro telescopes. Ideally, they have internal threads to suppress reflections from the sides of the tube (shallow and no particular pitch required). The lengths of tube involved would be up to say 150mm, which is a lot of overhang so I wanted to make a steady rest so I can work inside the tube safely.
There are dozens of designs on Google Images to give me a clue as to a design for a steady that I would have a chance of making but my main question is just how chunky it needs to be. It would be easier if I could make it mostly out of aluminium, and to use some tough 40mm steel angle to sit on the bed. There would be a good area of contact so the off-plane clamping arrangement would not be a problem I think.
I do have some 6mm steel plate of the right size but I hesitate to try to mill it on my mini lathe vertical mill slide. I could go easy, I suppose and I could weld it to be steel angle base. Mig welding is another thing I am getting into so it would be a suitable learning project for that skill. Unfortunately it could end up looking like a dog's dinner right next to the nice new painted lathe.
|Thread: Breaking drive belts on super mini|
@Ron. I found the belt you refer to in the" timing belts" but I only got there by a circuitous root. Knowing one's way around can be a big help. Those belts are more like mine. Not chunky like on the other pages.
Actually the Warco belt has 70 teeth and is 9.5 mm wide so they could be compatible.
But I couldn't find a direct equivalent on Bearing boys site; their stuff all seems to be more chunky. (Don't go making me feel bad about my running costs. I have enough trouble with my own conscience as it is. )
On the subject of dropping and finding things. The magnetic base of my dial gauge is fantastic. You can 'turn it off' and drop all the steel things right in their box. Because of that, it's better than my super magnet that I bought for the purpose.
I managed to order their last two belts from Warco. (It hurt a bit). The belt is more flimsy than any I can find elsewhere. My sprockets are steel but I wonder if that belt size was chosen to protect nylon sprockets on earlier models (to be the weak link, perhaps). Anyway, I should be in business by tomorrow and I will adjust the tension. It will be interesting to find if the earlier catastrophe had managed to jerk the motor mounting enough to slacken it further - to account for the much earlier failure of the second belt. I will go into the shed and find that out soon.
On the topic of cutting rates, I only recently found that there is a speed and depth when turning a diameter that seems to settle down very convincingly - and it's deeper and faster than I would ever have dreamed of (having heard but not properly listened to the comments on YouTube) . The swarf seems to lift off very nicely into coils and the whole thing gets noticeably warm. The motor power is definitely doing its job. It's only when I disengage the power feed that the 'chattery noises' start and I have to pull the cross slide quickly. I guess I can translate that experience (with a cut depth of say 0.5mm) to a suitable speed for parting off with a 2mm cutting tool width. Plus the fact that, when parting, the speed across the surface will always be less as the piece gets thinner.
So many questions and so many points. Where to start?
The tool post is fixed at one point on the cross slide - no T slots so no adjustment of position is possible.
I keep the tool sharp with some relief on the top. I try to have the edge square on and noticed that an angle can pull it to one side.
I didn't understand the calculations about feed rate and cutting speed in the context of parting off. 300rpm is too fast? It took me a while to understand that there is an optimum speed and that I had been going too slowly and I also only recently found that I can quite happily cut at least 0.5mm along an Aluminium rod.This has allowed me to speed up work a lot. But parting off seems to require less depth and speed.
This is all very frustrating because I haven't even had a chance to order a new belt yet. It's still only Sunday night.
@Neil "Don't move the blade sideways while cutting, that's a real recipe for a dig-in. If you want to do this retract the tool before moving it sideways."
I only move it to stop it from drifting to the side of the cut. But where is the drift coming from if the carriage is locked and the blade is square on? (I ask myself. - there's a lot to learn here, I think.)
Luckily, the sprockets are steel.
I know there's no shame in using a hacksaw but parting off is something I'd like to be capable of but not at £20 per failure.
The belt was tight enough to need to remove the top sprocket to fit it. But I will still address the tension problem.
I was searching for info on rear tool posts and came across this link. There are some valid sounding arguments against mounting tools in a way that lifts the cross slide off the bed. I shall investigate height and angle of the cutting face
Thanks for all the responses. Of the possible causes, I don't think it's my being heavy handed as I am on the timid side. I get the blade well lined up at right angles and re-adjust the compound on the go, to stop the blade touching the sides. It's a narrow blade, of course and it cuts very convincingly when it does cut. It really could just be failure to clear the swarf. This last time, there was a really solid ball, jammed / welded in the slot which I had difficulty clearing manually - going in alternate directions until it loosened. The speed was only about 350rpm. An upside down blade may help me out and I can easily try that at no extra cost(!).
I must update my profile (I live in West Essex aamof) but I haven't found anywhere local for these things. I mostly use eBay for bits and bobs but I don't know how to specify a belt and the ones I have seen seem to be only 8mm wide for mini lathes. Mine is 10mm wide.
I did try on e enquiry but he said he couldn't help me.
The idea of an electrical cut-out is attractive. I was wondering how to detect a speed drop that would operate faster than the simple rev counter that's on the machine already. There is probably a good mod that can be done on the brushless motor control directly.
I would like to know how to avoid jams better in the first place, though. I am, much better at parting off these days. I make sure the carriage is locked down, the gibbs strips are not sloppy and I regularly sharpen the blade. It may be I am too chicken to run at a fast enough speed, perhaps.
I have a Warco Super Mini lathe and I have just bust my second drive belt. The first one lasted longer than the recent one. I though I had learned how to treat it right but obviously not! It os starting to get expensive.
When I replaced the belt I looked for a motor adjustment for belt tension but couldn't find anyone the vicinity of the motor. Has anyone had this problem and is there anything I can do about it? Could it be too slack?
The belt is actually quite flimsy and replacing it takes an annoying length of time. Buying one from Warco is expensive and a cheaper source would also be handy to know about. But basically I'd appreciate tips for ways of avoiding having to put in a replacement.
|Thread: Mini lathe speed and tailstock question|
I think that's very credible. There aren't many 'substances' I can think of that will act as a screen to a magnetic field when applied as just a small piece at the front. If you wanted to screen the sensor coil from a passing magnet you would need a big clunky piece of mu metal.
|Thread: More collet and milling tools confusion.|
Just to give closure on my situation, I got an ER 25 collet chuck on a 100mm flange which fits right on the lathe flange. It was only £40 and I now have just one 6mm collet and 6mm end mill. I shall buy things as and when I 'need' them. One day I may even put work in a collet and there is a useful range on each collet.
PS those ER style collets are pretty damn clever with the interleaved cuts. They give you even pressure all along the contact with the tool. Worth buying even if just to sit and watch the way it works!!!
|Thread: Sourcing materials|
Good idea, thanks. Anything is worth a try and I'll make a few visits once I have a shopping list.
Thanks for yet another useful set of advice and opinions.
i really would like to use a 'local machine shop' or small manufacturer as a source of offcuts. However, I have not been able to find anything of the sort in my area, which is West Essex. All the hots I get from a search seem to take me to 'fabricators', who make things with sheet metal or steel fences and gates (wrought iron work). I am amazed that East London isn't littered with the sort of places described in the above posts.
Scrap dealers just don't want to know. I have visited or rung all the ones advertising locally on the internet. The big ones quote Health and Safety as a reason for not dealing with the public and the small ones seem to have discarded versions of the sheet metal work that the local shops produce. I must be pressing the wrong buttons somewhere. I would have thought that the East end of London and beyond should provide rich pickings.
I'll have a look at LINK and Tracy have a site which is hard for me to use because the pages seem to be messed up with the non-printing images.
People will probably say that I have not gone about this in the right way but I have been buying my bits of aluminium and steel from eBay sources.
Some of the steel I have used leaves a very 'gritty' finish and doesn't seem to produce nice spiral swarf whatever I do about grinding tools or the angles I use.
The way they behave seems to be pretty varied. I realise that there are other factors due to my inexperience but is it safe just to order 'steel' rod or profile from eBay. If not, what would be a good source? How should I specify what I want?
. . . . and I realise this is a 'how long is a piece of string? question,
|Thread: More collet and milling tools confusion.|
Thanks for yet another useful list of comments. The lack of reach for a basic 3MT collet is something I hadn't considered (well you don't do you?) so something a but longer would be good.
A flange fitting system could also give me problems, I think because I would also need a backing plate
I have already found my new four jaw chuck very good. Getting it well centred is not quick but has given me an encouragingly small runout and, with a bit of ingenuity with the four jaws in odd positions, I managed to put a dovetail (male) on a 10mm, 30mm square piece of aluminium with it. The carriage lock I made, plus other measures that you guys suggested seem to have stopped the chattering and singing on that exercise. My point here is that it could be worth trying to use a cutter in that chuck, at least to try things out. I am waiting for one of the milling slides that Warco have on back order. The spec of that seems better than others that are available and it looks the same basically as one that's on offer from India.
Some great pictures above - I'm a great believer in 'unofficial techniques' and I certainly need some more odd studding and bolts for me to get inventive with. I basically got into all this in the hopes of producing some affordable hardware for my Astronomy / Astrophotography. The simplest stuff is not cheap and I have not been over impressed with the basic Engineering of many parts. It seems to be way behind the optics, which can be stunning.
I need to be able to mill the occasional slot and rebate in (as far as I can predict) aluminium. The sort of jobs will be appropriate for a Super Mini Lathe.
I am looking all over - including my Metal Workes's Data Book and this Forum and the longer I look, the more information I am getting - on a divergent path at the moment. I can't decide which way to go.
If I only need a small range of end mills then is there any reason not to buy an MT3 direct collet of a particular size and then use only end mills that will fit in that? Is the advantage of an ER system just that it is easy to swap tools? eBay and other places are just bombarding me with options.
|Thread: Chuck compatibility with mini lathe|
Just to let you guys know that the four jaw chuck I bought fits fine (tightly) onto the flange of the lathe. Looks like I didn;t need to worry after all.
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