kevingambrell

Hi
I know im new to this site but the one thing i think thats missing is a section helping people who are looking for machine's such as lathe's and mill's. maybe also a section on the tools tat are required to work the machines.

It seems there are a few people taht build live steam so maybe these would be the people to do somthing about such a section.

My main concern is people buying lets say a lathe no matter what size and not knowing how to use the machine safely. It dont take a big mess up to remove a finger or an eye.

Any way thats my two pence worth.

Kevin

Bunkerbarge

Hi Kevin and thanks for the thoughts.

I understand what you are saying but I think we may be wandering a bit too much off track there. We are, after all, a scale model forum and whereas I can see that machine tools can play a part in the manufacture of scale models as a percentage of total forum use they are not very often referred to.

The trouble is that steam plants and engines are not usually used in scale models but tend to be a model in thier own right and more a display than an accurate reproduction of an actual engine.

There are, of course, forums specifically out there for steam plants and model boat forums that already have a specific steam section which I am sure you would find interesting.

If John thinks there is a need for a steam forum he may want to give it a shot and see if it is popular or not. I would be more than happy to share my own experiences both from a modelling point of view and a proffessional viewpoint and I completely support the idea of bringing safety issues to the front.

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“Dirty British coaster with a salt-caked smoke stack, Butting through the Channel in the mad March days"

kevingambrell

Hi richard,
I do see your point, this all stems from the posts by the chap that was thinking about buying a small lathe. I got the feeling it was a new field for him.
Coming from a background in machines and suds its second nature or most of it is but to some just wanting to turn out a decent tank gun barrel or a set of cannons a lathe is a usefull addition. That said many of the RC car guys could save a fortune if they could chuck up a lump of 2011.

On a semi seriouse not I think every model maker should make atleast one live steam. I bet many would never go back to plastic kits.
I know of no other thing in life (well maybe one) that gives as much pleasure as steaming your first engine after making every part including nuts and bolts.

kevingambrell

My father an avid steam model maker always said if you buy a made part for a model you didnt make the model. not sure I agreed at the time but I do now.
He made every nut and bolt and refused to buy BA's that some one else had made.

Bunkerbarge

I'm sure that your fathers models are a piece of art in themselves.

If you have any pictures please feel free to post them and I'll see if I have one or two steam engine pictures.

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“Dirty British coaster with a salt-caked smoke stack, Butting through the Channel in the mad March days"

Bunkerbarge

Just as an interest I'll post a picture of one of my collection then.

This was an Ebay purchase a year or so ago and it has been made from a set of plans and a series of articles published in a model engineering magazine of about 1964. I was actually able to get hold of back copies of the six magazines with all the articles in them which surprised me to say the least.

Anyway the model is a four cylinder engine, or, more accurately, two twin cylinder opposed piston engines. As you can see opposite pistons are connected together via the copper con rods which turn the crank via the two crossheads mounted on the flywheel. The pistons are only single acting but with four cylinders the engine is still self starting and could be made reversible and controllable if a reversing steam control valve was fitted.

I would love to mount this engine in a boat but it is a bit too big and the centre of gravity very high. It would be best done with a belt drive to a pulley on the prop shaft with the engine mounted transversely across the hull.

The other down side is that it uses quite a bit of air from my air brush compressor to get it going so it would need a fair size boiler to propel a boat. To see it all spin around though is quite hypnotic and I just get it going every now and then for the sheer pleasure of watching it.

Attached Images

30-11-06-09SteamEngine4Cyl1.jpg (54.2 KB, 16 views)

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“Dirty British coaster with a salt-caked smoke stack, Butting through the Channel in the mad March days"

alan2525

Was this aimed at my post?

I've used lathes for a few years in Education but do not own my own lathe.

I was questioning the quality of these small chinese lathes as I've used mainly boxford student lathes and Boxford CNC lathes in the past and some larger Harrison gap bed lathes. The build quality of these machines is obviously high as they are industrial machines with an industrial price tag. A new Myford Super 7 retails for approx £20,000.

I was debating the quality of these lathes as I've seen posts regarding changing the bearings in the headstock, grinding the cross slides and comments regarding setting up the tailstock as on one example the user mentioned that none of the surfaces were actually machined true.

As the accuracy and finish of the part is going to rely heavily on the build quality of the machine that was my primary concern.

I've had bad experiences using chinese import equipment such as small bench drills, one example had so much slop in the spindle when a 4mm drill bit was inserted you could move the chuck approx 4mm from side to side. I've also experienced the phenomena of shafts being machined to be triangular so they wobble up and down as they rotate but have a uniform diameter when you put a vernmier on them.

I've also tried to put a spanner on a part to make an adjustment where the fitting just softens and shears off as soon as you even try to snug it up with a spanner.

It's obviously a compromise between price and the performance you can expect to get from the machine.

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kevingambrell

Hello Alan,
It was in a way but it was also spured on by a concern over unskilled people starting with what are very dngerouse machines.

I agree with you on the chinese machines, the problem comes from the outwork that most chinese achine makers use. I have seen forst hand machine parts being made and finished in kitchens in China. never a good start for quality. This said things have impreoved over the last few years.

Im not sure how you get the 20k price tag for an ML7 I see loads under 1500 pounds. If I bought a Myford it would certainly not be a new one I would budget to spend no more than 700.

The accuracy of a part not only depends on the machine it depends on the tooling and the speed/feed that cuts are taken at. Rake angle on the tools is also a big concern. It annoys me when I see people selling indexable tools for lathes with inserts taht are next to useless for model work. Tips are very specific and should be bought to fit the metals being worked and the job being done. In my shop i have about 35 types of tips and almost as many holders.

these and safety are the points I thought should be addressed.

kevin

alan2525

The 20,000 price was from another forum for a New Myford. I was just illustrating the fact that the price of some of these chinese lathes is probably less than some 3 jaw chucks for a competitors lathe.

Saying that I have seen some excellent work produced on them.

Regarding the accuracy there are obviously many variables and tooling and user skill being probably one of the main factors. There is also the fact that you can't turn something accurately if the headstock bearings are shot or of very poor quality. Also accuracy and ease of adjustment setting the tailstock etc are key factors unless all parts require a taper on them.

Also price and availablity of accessories is a factor, 4 jaw chucks etc, faceplates. They chinese jobs are obviously aimed at a user who probably would use them less often for lighter work but still wants to own a lathe without spending all of their disposable income on one.

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dipstick

you say it is the machine that is dangerous, but is the operator because on fridays at college in the workshop we have school kids come in and all ways leave the chuck key in the chuck, and every once in a while they forget to take the key out and turn the machine on. another one was a kid that got kicked out thankfully, changed a chuck but he didn't do it propaly and as he turned it on it got up to speed and then went flying in to the air and landed the other side of the workshop.
the last one is swarf as my brother as he was using a lathe, he put his hand down on the cross slide and there was a bit of swarf that went from the piece of work and went under his thumb and it cought and wraped around the piece and put a cut 1/2" long down to the bone.