Here is a list of all the postings Buffer has made in our forums. Click on a thread name to jump to the thread.
|Thread: What Did You Do Today 2021|
|Thread: 2mm endmill help|
Ok many thanks I will give it a go at about that and hope it survives.
I have just been looking through this as I need to cut a couple of bits out of 2.4mm mild steel sheet with a carbide 3mm 4 flute end mill. I have an 1800rpm top speed on my mill an SX3 which is why I am asking as most of you on here are using much faster spindles. I very rarely use such small cutters and I don't really want to start snapping them. It's a slot I would be cutting using the full width. Can anyone give me some idea what sort of depth in mm I should be cutting and at what sort of feed in mm/min? Does it matter if I go shallow depth and feed a bit quicker or deeper and slower feed etc.
|Thread: Looking to upgrade my lathe advice please|
I have owned an ML7 and I still have a Super7, so first thing is why upgrade to an ML7 when you could get an S7 for that money?
It is possible to pick up an S7 for less than or around the £1000 mark with tooling and on a myford cabinet. I can't comment on Chinese lathes as I don't own one but I do think that £1500 for an ML7 with limited tooling sounds like too much to be asking. I suppose if its in very good condition you might think it's worth it but I personally would be looking for a good S7 for that money.
As far as spending money on a sieg mill, I don't know if you already have a mill or not. I suppose any mill is better than no mill as you would soon get very fed up with milling on a Myford. I do have a sieg mill (sx3) and it seems to do a good job.
Edited By Buffer on 04/02/2021 11:46:11
|Thread: Hemingway Kits filing Machine|
Thanks Brian and to the other guys who have commented with encouragement and advice. I've got two more days teaching the kids again now and then I need to do a bit of studying for a 6 monthly check i have to do for work, so it might be a little while before I get it going.
I got the holes MIG welded up and then I milled the mess flat to the table. I think it looks worse in the photo than it actually is. So with the holes re drilled it all goes together nicely. It wont be long now before I can give it a go.
Edited By Buffer on 27/01/2021 22:10:09
I managed to do what I thought was going to be the hardest part of this build which for me was the aluminium bow shaped casting.
I set it up as flat and level as I could and then machined a reference surface along the long centre portion. I could then flip it over onto a parallel to get the important end done.
One job I wasn't looking forward to was drilling a hole through both ends because they need to line up. I followed the instructions that tell you to centre pop each end then drill it on the lathe like this.
I finally got the bow fitted to the machine and couldn't believe there was a mistake. My hole I had drilled was 1/8th of an inch off centre but I knew the problem wasn't with the bow.
The problem was I didn't drill the holes in the table mounting bracket in the correct place. I didn't read the drawing correctly the 7/16th is not from the edge of the part. D'oh! Lucky I've got a MIG welder.
|Thread: Creating your own scale drawings|
Thanks for all this great advice and ideas, lots for me to read through again tonight. I did try importing an image into solidworks and possibly Autocad but when it was set to the scale I needed the lines went really thick. So when tracing you had to try and guess where the centre of features were and then of course dimensions started to get out of hand again. I think I will set myself a minimum dimension to work to, I probably should have done that right at the start.
Once again many thanks for your time.
Does anyone have any good advice on creating your own scale drawings of complex projects from pictures of the original and full size drawings? I'm trying to do this for a piece of artillery and it's so hard. As an example everything ends up as decimal inches and not the fractions you normally see. Nothing just matches up with available sections. Do you just modify your bits to fit what you can get and no one notices? Should you just make bits that look and feel right rather than are absolutely to scale?
I have been tinkering with fusion and solidworks but to be honest when copying an original its pretty hard to model parts unless you have a drawing to work from which is a bit of a catch 22.
I'm sure a lot of you will have done this sort of work and I would really appreciate any advice you have to offer.
|Thread: Advice for surface finishing|
Stuart the rod lying around might be the problem lots of guys wont use stuff unless they know what it is. Also I seem to get my best finish with HSS. I can hone it with a diamond lap and then take a nice light cut with lots of cutting oil to bring it to size and finish. I normally use a tangential tool for this.
Edited By Buffer on 19/01/2021 19:59:57
|Thread: Hemingway Kits filing Machine|
It was Wife's turn to teach the kids so I sloped off for a few hours. I got the flywheel made by fitting it onto the centre shaft then used that in the lathe to turn the flywheel to size. It needs a square ended slot through it for the drive pin. I drilled out most of the slot then just finished it off with a slot drill. It went nicely as it's a cast iron flywheel.
This is exactly the sort of reason why I want a filing machine. The slot is supposed to have square ends and I hate doing this sort of job.
I used a Stevenson's Block to cut a square on the end of the drive pin. it was dead easy with this great little tool.
I then milled six flats on the end of the drive rod again dead easy with a Stevenson's Block from Arc. However this turned out to be a less accurate item than I had hoped. The flats weren't all the same size which was annoying. It wasn't a lot but it was enough to be visible.
I then just had to slot the base to fit the Myford cross slide and I could fit it and give it a spin. It was easy to fit but you have to be really careful to make sure you don't give your lathe bed or saddle a good wack. The tool has to be carefully fitted so that the sliding part goes down between the ways. I then locked the saddle and cross slide. The lathe was put in its slowest normal speed with the clutch slowly eased in and away it went.
There's not much more to go now Its really just the fittings to hold files and the aluminium bow for the saw blades. I've got two days of school work now so I guess I wont be out again until Friday.
Its been a while since I posted on here. I wasn't able to get anything done until recently as I had the dreaded Covid over Christmas. I felt so unwell and I have only recently felt well enough to get back into the workshop.
So I got the connecting rod finished. It wasn't difficult I just drilled and reamed the holes to size and then pushed the bearings in using the vice. I roughly shaped the ends in the milling vice using a pin through the hole and then finished by filing.
Here it is fitted to the rest of the machine. It's very important that the six screws are countersunk below the level of the surface, there is virtually no clearance of this crank over them.
The flange on this pin has to be made accurately or even better slightly thicker. If you get this wrong you'll have to make it again or fit a washer. Funny thing is it's not given on the drawings you have to do the maths to get the size which to me seems a bit odd for such an important dimension.
|Thread: 3D printing for investment casting article MEW 300|
Noel I don't think I made myself clear with my question to you. Are you saying that if the molten brass touches any left over PLA in the mold then there could be an explosion similar to molten metal on water?
Noel. Would the result of pouring metal on pla be similar to water?
I thought this was a very interesting article and its something that I will definitely be trying. I had no idea that plaster of paris could be used for this.
Could you just explain a bit more about using a metal wire across the spout to hold back dross. Does it all just stick to the wire and the brass flows out under it?
|Thread: Holding drills in ER collets|
I have to do it because my chuck wont close down less than about 1/16 th and it's a real pain. Does anyone know where I can get a chuck with a taper for a startrite mercury? I think it's a j33 taper from memory and not easy to find.
Edited By Buffer on 06/01/2021 15:36:23
|Thread: Milton Keynes Metals?|
I use Mac Models and M-Machine-Metals for my modelling supplies. For large stuff when I made driveway edging and plant supports I used F H Brundle who delivered it in 6m lengths that week and were a fraction of the price of the good old metals4u.
I phoned up early in the year and asked about a piece of steel. He said yes we've got that. So I went down to get it. The guy then spent about 20 minutes climbing over rusty piles of off cuts spread all across the floor. It was all in the most chaotic unit I've seen. He was licking his thumb and trying to rub the rust off the end of bars. He finally found a rusty piece of what he said was the steel I was looking for. I asked how much expecting it to have been about £30 from looking online elsewhere, anyway he came back and said 150!! And there was no guarantee it was anything other than a bit of old rusty mild. So I made my excuses and left never to return.
|Thread: Hemingway Kits filing Machine|
Nigel I have just sent you a message.
Well it seems there might be a little error in the drawings.
The screw that clamps the swivel up tight impacts with the the casting. I might be trying to tilt the table more than it is designed to do but made to the drawing it does hit the casting. It's not a problem yet as I think most of my filing will be done at ninety degrees. But if you want to tip the table over a a fair bit then make the thumb screw longer or make the tommy bar loose like you would find on a vice.
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