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: Solidworks help please|
You've fixed it!! I saved it as a parasolid (whatever that means) and it worked. Thanks so much I have wasted hours on this.
Emgee and SOD thanks for your input as well but its all done now.
Thanks Jeff, its not the blue cube icon I think its something in the settings. Or maybe its a lack of computer power. It doesn't do it on any other models but they probably don't have as many parts as this. I don't have a separate graphics card in this pc and the reboot doesn't fix it either. It's probably not related but about the same time as the above problem the model practically disappears now when I use the other blue cube which is the view orientation. It used to stay as a large model on the screen but now it almost vanishes. I was wondering if I had a rogue point or something way out in space but I can't find anything.
Does anyone know how to switch off this strange feature I've got myself into where the model has some but not all hidden lines visible. You will see it in the photo below. I thought maybe the computer isn't upto the job but my other models are fine. I am now running out of ideas of what to search for to fix this.
|Thread: RML Cannon of 7"|
I have a book from 1860s on rifled artillery manufacture and they say the reason for the greater strain on a rifled gun is because of the following which are quotes from the book. "The greater weight and length of the projectile increases the friction and inertia". "The opposition is greatly augmented if the projectile is constrained to travel through the bore in a spiral". "Round shot yields promptly to the impulse of the powder gas (to which it presents half its surface) and bounds freely forward through the bore almost unimpeded by friction, while the strain of the gun is immensely relieved by the comparatively great windage. Also the inertia and friction of a projectile increase with weight in a cubic ratio, whilst the surface of the chamber and the base of the projectile increase as the square ratio, it follows that the larger the charge and the weightier the projectile the harder and stronger must be the barrel".
I've also got a photo of a gun in New Zealand which claims to be a mark 4 but it could I suppose be the similar looking 2. Anyway here's the progress so far.
I thought I would start a thread on the latest piece of artillery I am hoping to model. Progress will be a bit slow I'm afraid as I have quite a few distractions at the moment, however I'm hoping that putting this on here will encourage me to pull my finger out and get on.
For any enthusiasts it will actually be a Mark 4 barrel. The carriage will be a Garrison Casemate or Dwarf sat on top of a Dwarf A Pivot Slide. Its going to be about 1:12 scale so the barrel will be about 12" long as that is about as large as I can handle in my lathe.
At the moment I am slowly producing a CAD model of it so I can get a few bits cut such as the carriage side plates.
I hope at least one of you might find this interesting. Thanks.
Edited By Buffer on 01/03/2021 19:43:06
|Thread: Kingscale 5" models|
I asked Mike Pavie at a show if it came with drawings so I could take it apart and maintain it in the future. He said "No, its my hard work why would I give you a drawing"
|Thread: What Did You Do Today 2021|
I have sent you a message.
|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?
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.