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: Hemingway Kits filing Machine|
Well Wifey went to work today and the kids seemed happy scrapping with each other so I sneaked out to get another bit knocked off.
Now the instructions do say that you should give the table a skim over to get it flat. The piece is punched out so it has clearly taken on a bit of a curve. It's not obvious by looking at it so I wouldn't worry if your 4 jaw can't cope but mine can so I gave it a long going over. You can clearly see here that the middle is a bit lower than the edge. It's not a lot though probably less than 1/2 a mm.
This is the other side and its pretty obvious but the middle is now being cut before the edge. I only cut enough to get a flat surface for the casting to bolt to it.
A while back while I was making the smoke box for a loco I did what some might see as vandalism. I drilled into my best four jaw chuck so I could mount posts on it. I know I could have used soft jaws and I do have a bearing mounted on a tool post but I did it anyway and it has been very useful.
I used an old bearing outer as a parallel whilst drilling the mounting holes. I could of used normal parallels just as easily but there is an agricultural engineering business behind where I live and they always chuck big bearing in the skip so why not.
I got a bit more done last night. It wasn't the easiest to set up as the centre of the arc is off the casting by 3/16th of an inch. With hindsight it would have been a lot easier to just slip a piece of 3\16th steel between the casting and the angle plate but I only thought of that this morning. Anyway I got a good piece that fits very nicely to the main casting.
The main casting needs a curved slot with its centre 1/2 an inch off the casting in the fresh air. So I took a little bit off the top of the casting to get it to the exact length and then pushed it up to a 1 inch cylinder that was in the middle of a rotary table. I centred the table using the Osbourne manoeuvre. This works really well and I only had to do it 3 times and it was bang on as far as I could tell.
I then flipped it over and fixed it to an angle plate squared it all up and drilled the holes to hold the guide bars. I was really pleased when this came out spot on as I didn't mark out any of the locations just used the dro.
So that's it for now, back to work tomorrow but hopefully I will get a little bit more progress in the week.
Edited By Buffer on 13/12/2020 18:55:26
The 5 tooth shell mill actually gives a very nice finish when you want it too but I knew I was going to scrape this bit so I didn't hang about with it.
This is the casting after about an hour with the home made scraper
So I got some work done on the machine this weekend.
The piece below is the bit that goes up and down sliding on the main casting. It is supported and guided by the bits above. I rubbed it on the surface plate and as you can see there is very little contact.
After about half an hour with a carbide paint scraper blade that has been soldered to a length of steel rod it looked like this, which is looking much better.
This is the main casting that was cut with a 5 tooth carbide shell mill from Arc
I thought I would post a few pics and some info on the Filing Machine from Hemingway Kits.
This is what you get plus some build notes and good drawings.
Edited By Buffer on 11/12/2020 19:49:32
Edited By Buffer on 11/12/2020 19:50:01
|Thread: Boat hull formula|
With regards to the container ship loading. Anyone who has been in a rowing boat ( or kayak) will have first hand knowledge of just how high the c of g can be with what seems like very little under water and still be perfectly stable. But as we all know stand up in either and it's a different matter.
Are you sure about that?
Sod and Bob
working out the displacement to the planned waterline is fairly easy if Bob has a drawing of the frames or stations along the length of the hull. But I thought Bob would have a very hard time working out if the boat would float at the waterline in trim ans stable before he builds it.
From memory of about 30 years ago, Bob if you dont have CAD you need to measure the area of each station or frame for the boat that is below the planned waterline. The more stations along the length of the boat the more accuracy you will get. If you have a lines plan of the hull then you could draw your own stations as many as you like although I believe you need an odd number for simpsons rule Once you have the areas of the stations beneath the waterline use simpsons rule and you get your volume or displacement.
If you have a lirnes plan you can work out all sorts of things like the centre of bouyancy but unless you know where you centre of gravity is going to be you wont be able to work out how stable it will be.
I started out training as a naval architect and I can tell you that you will need an awful lot of work to try and work that out. Far more than I could tell you on this by typing. Simpson rule is one way of doing it having measured the areas of all the frames. Personally I would not even try to do it but ballast it afterwards to get it to float level where you want it.
|Thread: Reverse Sewing Machine Motor?|
If you put it underneath you need this one
Michael It does say in the book about using sewing machine motors.
Ega here you go
Thanks guys. I have just phoned up the supplier Beds sewing and knitting and they have a reverse direction motor same type for an extra tenner, I'm picking it up on the school run.
I have just finished a George Thomas Pillar Tool and like a complete idiot I never gave a moments notice to the direction of the motor until I found my drill going backwards that is! After much swearing I have looked online to try and find out how to reverse it. I have seen that it can be done and it seems to be the case that just moving one connection will do it. My question is does anyone know if its done in the foot switch or in the motor? I did try swapping the blue and brown under the motor cover and no surprise it didn't do it.
So if there's anyone or a few of you who find this stuff easy I would really appreciate the advice.
These are the two wires that go to the motor however it is connected to the foot switch by a 3 pin plug.
Edited By Buffer on 04/12/2020 10:25:00
|Thread: What Did You Do Today 2020|
Just looked at this to get the 100,000th view.
I have glasses but I also always wear an optivisor in the workshop. Just flip it up and down when needed. Its pricey but brilliant.
|Thread: Thread cutting problem|
I just did what Hopper and a few suggested and tried cutting a thread on the bench by hand on a 3/16th steel rod and I got the same problem. So I have filed the die in the round filing cabinet in the corner of the room. Just to be sure I turned the same bar down a bit and cut a perfect 4mm thread on the same material. So that's that as some said duff die.
I never thought to do that but there it is in the manual a chart with1-6 what a numpty!
thanks again to everyone who has taken the time to reply with advice.
I did what Andrew suggested and cut a thread perfectly on a piece of 3/16th brass. So there is nothing too wrong with the die it would seem.
I managed to cut a thread in steel but only by taking the bar down to about 0.18 but it didn't look very nice. It seems that despite me pushing the die towards the chuck it just wouldn't start pulling itself forward along the bar and it appears to just grind the steel away until it can get going and then it pulls itself along. So I did what I didn't really want to do and set the lathe up to screw cut. In the end I managed to get a very nice test piece cut on the other end of the brass rod so later I will try it on the steel.
I tried to find out at what point I could engage the leadscrew by looking at the workshop practice series book but soon realised it was going to take ages to work it out. So I reversed the lathe after each cut and engaged on the same number each time.
To speed this up does anyone know any easy way to work out when you can engage the leadscrew for a 40tpi thread with a 4tpi leadscrew?
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