Member postings for Andy_G

I have something very similar, and don't find it very useful - I do use it on a quick change toolpost for small diameter brass / ali or for cutting grooves.

I found this type much less touchy and more useful:

https://www.rdgtools.co.uk/acatalog/SMALL-PRO-PARTING-SYSTEM--9MM-SHANK--1729.html

As another fairly inexperienced mini lathe owner, I'd say don't rush into changing things (especially spindle bearings) - there may well be bigger improvements to be made through set-up and technique.

In addition to all the advice above, I'd say to run the spindle as slowly as you sensibly can (maybe 150RPM or less), at least to start with. My lathe has a brushless motor (no high/low gear) which might make this easier.

Check your compound slide for play (grab the toolpost and rock it across the direction of slide travel and look closely at the joint between the two halves of the slide for signs of movement.

[The main issue with my compound slide was that the gib strip was rocking as load came on the toolpost, allowing the slide to lift. The problem (in my case, and I suspect many others) was that the gib adjustment screws were acting too far back from the sliding face of the gib for it to be stable (the gib is too thick for its height). This was compounded by the shape of the adjusting screw tips and recesses in the gib.]

Bolt the lathe down to something (with care to avoid distorting it) - this helped a lot with mine - see here

Edited By Andy Gray 3 on 22/10/2020 20:12:33

Edited By Andy Gray 3 on 22/10/2020 20:13:31

I can't remember if it's twin cylinder or not, but the Stuart Victoria always puts me in mind of the mill engine at the Manchester Science & Industry Museum. Some nice pictures of details on the museum site, but no general view of the engine:

https://collection.sciencemuseumgroup.org.uk/objects/co8404994/firgrove-mill-steam-engine-steam-engine

Could one of the jaws be 'miss timed' in the scroll when you first fitted them? To be then fitted correctly after dismantling for cleaning?

It would certainly give an 'almighty wobble' and would fit with the sequence of events...

The problem I find with Hylomar blue on models is that unless you apply it incredibly sparingly, it has a tendency to ooze out and block / obstruct things it shouldn't. (I have used on full sized stuff without any problems.)

Rightly or wrongly, I used Loctite 542 thread sealant on the fuel and exhaust connections of my hit and miss engine. It was very easy to use and clean up, and it seems to resist petrol and oil. The fun may come if/when I need to take it apart!

Thank you!

Thank you all very much!

I'm not sure what would be involved in writing it up - I have (rudimentary) drawings for ~90% of it, but didn't take many photos during the build.

(I hesitate to confess that I haven't looked at the Model Engineering magazine since my father dabbled in model engineering in the early 1980s - there were plans for a shuttle valve engine from a small traction engine that my father and I started building at night school.)

Thank you also!

The tank body is chromed brass bathroom waste pipe. (I had an off-cut).

I wanted a brass bodied tank, but the price of brass tube seemed horrific - more expensive than solid bar of the same size. I tried all sorts to strip the chrome off the bit of pipe I had and failed, so ended up just using it as it was - it turned out OK!

The ends of the tank were cut out of ~2.5mm brass sheet and both faces of each end were turned. prior to assembly, using superglue to hold them to a piece of faced-off aluminium bar in the manner of the Clickspring Youtube channel:

• Centre punch brass sheet, scribe circle, saw roughly to size, then glue to the 'face plate' using a centre in the tail stock to locate the punch mark on centre,
• Turn the OD and face off to leave a small pip in the centre. Machine a small shoulder to fit inside the tube.
• Remove from faceplate and glue the opposite face using the pip to centre in a suitable hole in the 'faceplate'
• Face off and round corners.
• Remove from face plate. The pips stay on the inside faces (but nobody can see them )

These were a nice, tight fit in the tube, and I just soft soldered them on (one at a time) by laying a ring of 0.5mm multi-core solder inside the tank and gently heating until it flowed into the joint, The second end had to be done 'blind', but it worked OK. (The bosses for the filler and fuel off-take fit through holes drilled in the tube and were soldered on from the inside with plumbers solder before fitting the ends.

I hope that makes some sense!

Another edit for a photo:

Edited By Andy Gray 3 on 26/09/2020 23:41:26

Edited By Andy Gray 3 on 26/09/2020 23:45:01

Edited By Andy Gray 3 on 26/09/2020 23:48:48

Thank you!

It has a fixed choke carburettor (fuel mixer?)  with a simple spray bar and needle valve that draws liquid fuel (Coleman fuel) from the tank.

Edited By Andy Gray 3 on 26/09/2020 23:19:27

I asked a question about cylinder oilers on here a few days ago that JasonB was good enough to answer.

Here's the engine that I've been working on. It is my own design, and scratch built from bar stock using my 7 x 14 Chinese lathe.

Thank you.

Edited By Andy Gray 3 on 26/09/2020 22:08:01

You can get apps for smartphones that act as a variable frequency strobe light, so you can do away with the strobe discs and separate light source completely if you wish.

I've been using this one on an iphone that gives an RPM equivalent

https://apps.apple.com/us/app/strobe-light-tachometer/id978182913

A cocktail stick (or other tapered sliver of wood) pushed into the end of the rotating tube and some polishing paste? 

If you apply some pressure to the end of the cocktail stick, the fibres in the taper will naturally compress leaving a sort of radiused transition where it enters the tube.

Edited By Andy Gray 3 on 22/09/2020 17:01:32

If they're decent cranks, they may well be hollow.

Wow! That is very nice!

Brilliant - thanks very much.

I can drill the hole in the liner now and get on with putting it together!

Hi folks,

I'm in the process of putting together a small horizontal I/C engine (in the style of the Kerzel HHM1 / Farm Boy / Odds 'n' Ends designs).

Most of these have a drip feed oiler on the cylinder liner to lubricate the bore and (in some cases at least) the small end.

My question is whether the feed port from the oiler needs to be covered by the piston skirt at all times, or if it is acceptable for the skirt to uncover the port as the piston approaches TDC?

My concern is that a very long piston skirt would be needed to keep the oil hole covered, but if the port is uncovered, doesn't it make it likely that the oil will be drawn into the bore as the piston ascends, then flung out of the bottom again as it descends (without getting anywhere useful)?

(I'm taking it as read that the port will be positioned below any part of the bore traversed by the piston ring.)

I've looked at the Webster plans, and it seems that the oil port does get uncovered, but in a number of videos of people running them, there does seem to be a lot of oil spat out of the bore.

Any hints or tips appreciated...

(Engine is 20mm bore, 26mm stroke, cast iron piston in a steel liner. Phosphor bronze connecting rod bushes).

Thanks in advance,

Andy

Edit to add: There doesn't seem to be much IC engine activity here - would I be better off asking on another forum?

Edited By Andy Gray 3 on 11/09/2020 23:09:37

High alumina cement is better at high temperatures. Last time I needed any it was available at my local builders' merchant at about double the cost of Portland cement. Mixes well with Perlite...

As an alternative, glow plug washers would fit, wouldn't they?

Traditional model plans seem to rely on the dying art of 'Fitting', rather than manufacturing to numbers - it is expected that the modeller had an understanding of how the parts function and fit together and applies their judgement and skill to making sure that this is achieved - if something is required to match a proprietary part (such as a bearing race, etc.) then a tolerance might be called for, otherwise, it is only required that the parts in the model work with each other;

If one were to bore a cylinder slightly over-size, would one scrap the part (manufacturing)? Or would one just make the piston slightly bigger to suit (fitting)? I realise this is entirely down to personal choice, and the ultimate goal of the modeller - a working model, or the satisfaction in producing a 'blueprinted' example.

I've recently watched a lot of machining videos on Youtube, and the trend of doing everything by DRO bemuses me - e.g. 3 accurate set-ups to drill 4 holes to hold a steam chest and its cover onto a cylinder block. Aside from true scale modelling, the position of the holes doesn't really matter, as long as they don't go into thin air - mark and drill the holes on the cover so they look" right" and then spot the holes through to subsequent parts - everything lines up, no tolerances necessary, no mill necessary, no DRO necessary. (If people have the kit, and want to do it this way I'm not knocking it, but it isn't the only way, and probably wasn't the method that the originator of the plans had in mind when they were drawn.)

Are we building models or are we manufacturing parts that someone else has determined can be assembled into a model?

Anyway, that's my rant!

(Part of my job is producing manufacturing drawings, btw.)