Member postings for Jerry Cashman

Thanks very much guys - I'll double check the drive line alignment and the physical state of the drive belt - the type of vibration I'm getting is shaking the engine on it's mount, so the belt is an obvious culprit now that it's been pointed out

Thanks again!

Hi guys,

I've gota small, cheap (probably the problem) bench top drill press (Ryobi handyman brand) - it vibrates a lot which hasn't been a real problem when I was using it for woodwork - but is a bit of a pain when I'm trying to drill accurately in metal.

From the investigation I've done the problem appears to be something in the drive train is unbalanced or uneven - the pulley attached to the drill stem is solid, but the drive motor and belt dance around a lot and the vibration carries through to the whole machine.

Is this typical of cheap drill-presses or have I got a dud?

Thanks very much Clive, and thanks for taking the time to document your build - I've already read it through several times and it's provided a great deal of confidence! Much appreciated

cheers. Jerry

Yep, that's it, 5/32 flat (rectangular) bar...

but it sounds like I'm creating more work for myself - a bit of 3/4" BMS rod won't break the bank...

thanks guys

Thanks Jason - yep, if I had square bar that's what I'd do... but I've got rectangular bar, the thckness of the crank disk and width enough to get 11/16th out of it...

Should I just put that back in the spares bin and go buy some rod?

Hi guys,

I'm trying to plan the machining operations for an Elmers 25 wobbler.

The crank disk is a bit of mild steel, a bit less than an inch across. To make this, I have a length of steel bar the right thickness - I plan to mark it up, cut off a square length the right size - drill the crank-shaft hold in the middle, then mount it on an arbour and turn it down.

The bit I'm not sure of is if this will work :^)

What I will end up with is a square shape that I've got to knock the corners off to turn it round - but the mounting will be an bolt on an arbour held in a collet. I'm pretty sure this will spin in the arbour rather than cut as the tool hits the corners of the work piece...

Never having used (or made) an arbour before I've no idea how securely it will grip the work piece...

Is there a better way of making this piece that doesn't involve buying more material (round BMS rod of the right thickness)? (or am I making a problem for myself that $10 will solve

cheers. Jerry

Rolls-Royce aero engine ball joints -

Way cool

Thats the one! thanks Mike!

cheers. Jerry

Thansk very much everyone, really appreciate the advice and support!

cheers. Jerry

Jerry Cashman
Canberra - Australia

Thanks guys, the tool I'm looking for looks a bit like the following...

I'm sure I've seen plans for one somewhere, but can't find it now that I want it

Hi Bob, it's a very simple part - I'm going to be building an Elmers #25 Wobbler and the cylinder is bored into a rectangular block, with the cylinder bore off-set a little from centre of the rectangular end - so I plan to mark up and pop the centre of the hole, then mount the block in the 4 jaw (a bit offset) and drill/bore.

cheers. Jerry

HI guys, I've got to use a 4 jaw chuck for the first time soon so have been reading up on how to easily centre work... I found a reference to a simple looking tool called a Centre Finder Wobbler which has a mount you place in the tool holder, than a longish indicator bar which has a short end and long end with a ball mount in the middle - you carefully put the short end in the centre pop of the workpiece then as you rotate the chuck the long end wobbles about to indicate which way you need to tighten the 4 jaw - sounds much simpler than fiddling around with DTI's for irregular components....

Can anyone ether tell me with I can buy something like this or share 'how to' plans so I can have a go at making one myself please?

cheers. Jerry
Canberra - Australia

Hi Hopper,

I found a couple of these firebricks at my local Bunnings! Mind you, I got lucky - the guy I spoke to said they used to stock them regularly, but had dropped the line several weeks ago and he had two left that someone had returned. He sold them to me for $4 each.

The girl at the cash register had a nightmare as they weren't even in their product database anymore - so don't just try asking at the front desk - they'll say they don't have em. I found them by wandering around out the back near all the pavers and just lucked out by asking the right guy who knew where these returned blocks were. If you try Bunnings, recommend you try the same tactic

Hi guys,

Just though a quick post in order - after lots of learning my Hero Engine fired up last night!

It's waay too ugly to photograph, it's dinged, scratched covered in soot and wonky - but it spun under it's own power (albeit slowly).

I'm over the moon and am now scouring for my next project - which will be a simple oscilator of some form...

Thanks for the help and support !

cheers. Jerry

Canberra - Oz.

Hey, turns out that you can heat Brass parts too much... found a nice spring clamp to hold the parts I was soldering next, got everything clean and fluxed up, poured the heat on and soldered nicely - when everything was cool I pulled the spring clamp off to find that it had sunk into the brass by about 2mm!

Live and learn - what fun

Succes! !

Thanks very much guys, really appreciate the advice and suggestions!

Here's what I changed (almost everything

1: I got some proper heat blocks for the hearth (I had sourced some 'heat bricks' from a BBQ company previously - they are sold to line the insides of Pizza ovens)... I think they were the wrong stuff and were absorbing heat, not reflecting it. I found some bulky white brittle heat blocks which glow bright orange very quickly when you apply the heat... they are light and easily sawn to shape with a hand saw - very cheap too!

2: Tenacity 4A flux - it now does exactly what all the books and kind advice suggests - goes powdery white as it dries then glossy clear as it melts.

3: 45% silver rods - expensive but they work

4: Patience!

Thanks again everyone, really appreciate the advice and help (and ps: I'm in Canberra, Australia - there is a model engineering club here which I am in the middle of joining, but it's great having this 24/7 resource as well

Link to pic of Hearth.

Link to pic of Joint.

PS: thanks guys who had concerns about this not being a good joint for making boilers - this is on it's way to being a Hero Engine (project 1 from the Stan Bray book) and as such isn't sealed - it always has an opening to atmosphere so will never build up much preasure! - I'll do proper flanged end plates for the next project

Edited By Jerry Cashman on 23/04/2013 00:50:36

Edited By Jerry Cashman on 23/04/2013 00:53:46

Edited By Jerry Cashman on 23/04/2013 00:57:02

Thanks guys, I know it's very subjective, but in general, how long would you expect to have to heat a couple of bits of 1.6mm copper before they were hot enough?

1 minute? 5? 10?

(just looking for broad generalisations here you understand)

re: flux - I used stuff which was specifically sold as 'brass and copper flux' it was a pink powder which i mixed with a little water - I also tried (the probably useless) plumbers paste flux (white paste).

I've just found a tub of Tenacity 4A flux powder and a couple of sticks of 45A silver solder alloy which claims to be 45% silver (it should be it cost enough!) which I will try tonight

Well isn't this fun, lots more to learn

I've watched several UTube videos on silver soldering and from these I expected that the job would all be done in a minute or so... not the case for me.

The pieces I was trying to solder were a short (50mm) length of 32mm 20g copper tube but-joined to a piece of 1.6mm copper sheet to 'cap' the tube off (first of two such joints to make a Hero Engine).

All joining surfaces were cleaned very bright with emery and not touched there after to ensure they were clean.

Flux paste was applied (sourced from the plumbing section of local hardware shop). The solder was also got from the same place, it's labeled 5% silver solder, 2.5mm diameter rod - unfluxed.

I assembled a small hearth from fire bricks and placed the end cap sheet flat on the brick with the tube standing vertically, then played the propane torch all over the joints for several minutes before removing the flame and touching the stick... nothing! Not even the slightest hint that it was even tacky...

I continued heating for maybe 5 minutes, the firebrick close to the piece started glowing bright orange, but still the solder wouldn't melt on the workpieces... so shut it all down and went to read some more

The torch I'm using is sold specifically for this kind of job **LINK** and it was putting out an awful lot of heat...

Did I simply not wait long enough? I would have thought 5 minutes would have been ample?

cheers. Jerry

Hi guys,

I'm about to start work on my very first project, a Hero Engine, basically a small capped cylinder that you put water in, heat and it spins around (if you get it right).

The main component is a simple sealed tube... a short length of copper tube that is has flat ends silver soldered on... I'm thinking through the operations required and it appears to be sensible to solder one end on, chuck it and clean the join up in the lathe, before doing the 2nd end, then finally the other fittings.

This approach means that I'd be heating the compoents several times and the whole thing is small enough that I'm sure the existing silver soldered joints would be heated up a lot each time.

I think I remember reading that this is Ok as Silver solder, through some arcane process, actually needs a higher tempretaure to melt the 2nd and subsequent times... unlike soft solder which pretty much always melts at the same temp.

Am I correct here and would this approach work? Or should I try to get all the various bits arranged and heat it once for all joints?

cheers. Jerry

Thanks very much for the suggestions guys, will let you know how I get on!

cheers. Jerry