How can I make this?

[paul]

I'm just starting to make the combined eccentric rod/strap for my engine but can't think of an accurate way to hold it together for soldering. Originally I thought of making the rod the same thickness as the rings at each end so clamping would be easy(ish) then filing away the rod to the required thickness but that would mean removing over 50% of the material and includes a taper (when viewed side-on).

It would be easier to make the rod the right size then solder it to the rings but it would be tricky to align properly for soldering.

Another thought would be to cut a slot in the strap and insert the rod for soldering but the strap is only about 1.5mm thick and I wouldn't want the rod to foul the inside edge as that's been accurately bored.

The rod is 2mm thick as indicated below.

Anyone got a suggestion please?

[baggo]

Hi Paul,

just make a simple jig from a piece of flat steel. Drill and tap a couple of holes at the centres of the strap and the small end boss and clamp them in place with a bolt and washer. Cut your rod to shape making it a good fit between the strap and the boss. Clamp it in place using a bit of thin steel or similar at each end between it and the jig to bring it up to the correct height then braze/silver solder. Paint the jig beforehand with Tippex or similar to prevent any solder sticking to that if you're a bit over generous with the solder! Be aware though that the soldering operation may distort your already machined bore on the strap. LBSC suggested a similar method for making built up connecting and coupling rods.

John

[havoc]

Well, you first take 2 slices of metal for both ends. Drill through them. Solder the rod in place. Then finish the holes to be sure the holes are where the need to be and not distorted.

Of make a gig to hold the lot while soldering.

[paul]

John, why didn't I think of that?!

Here's the jig I just made with the eccentric strap sitting on it's 'button'. I just need to make a button for the other end now. (Ignore the big 'ole in the middle that was already in the piece of scrap I used!).

Since the boss at the small end and the strap are different thicknesses I'll need to put some support under the small end as well as the rod. Ah yes - I can make the button for the little end 'stepped' to support and locate it!

Thanks once more for the assistance and thanks Havoc for chipping in!

[SteveW]

Paul,

I did something like that years ago. My solution was to start with two holes in what became the connecting rod and brazed the bits into the holes. Then whittled the unwanted material away with a file.

[paul]

Cheers Steve - that's another way I suppose but would involve lots of filing (dia of strap = 22mm width of rod = 6mm, thicknesses 5mm vs. 2mm) at least it'd be guaranteed to be straight though.

I'm pressing on with the jig method, here I've added the bit to locate and support the little boss and prepared the fledgling rod.

[Tel]

Well I. for one, would be inclined to whittle a rod like that from the solid.

Steve, you really need to beg, borrow, steal, make or (shudder) buy an angle plate and a couple of clamps along with a couple of end mills - you'll save yourself a lot of work.

There's lots of info out there on milling in the lathe - Len Mason or Ian Bradley are both good starting points

[Shawki Shlemon]

I make the rod out of solid mild steel or fabricate it from stainless steel , the small end will not be drilled at this stage ( the size of the rod should be as accurate as can be) .the strap or what you call ring or large ring is made of gunmetal casting or bronze, if the strap is thick one can machine a slot or if thin then position on side of the the strap ( In this case make appropriate correction on the rod) ,pin loosely with two 1/16 rivets to locate and silver solder. In most cases you need more than one and should be the same length therefore make a jig similar to the idea above and drill / ream the hole /s in small end .clean and the job is done .

[paul]

Tel it's me Paul with the lack of gear not Steve - lol your brain's goin' mate!

I'd have a couple of problems making it from solid - I can't drill/ream a 19mm hole and can't bore one easily (lack of gear to set up an asymmetrical shape in the 4-jaw accurately, not sure if it'd fit on my mini-lathe anyway).

It's all a question of gear/space/money - in the meantime it's graft!

BTW does anyone have any thoughts on this Clarke milling machine?...

www.chronos.ltd.uk/acatalog/Clarke_CMD10_Micro_Milling_Machine___Accessories.html

[ace]

Hi Paul

I have the Clarke milling machine and other than its limited height from the table to chuck its OK for small stuff and light cuts if milling and as a drill its fine, I have made a few mods to mine just to make life easier. However please note you will be getting what you pay for, poor finishing on the castings and machined surfaces, sloppy fitting threads on the axis screws and the dials are about as useful as a blunt knife. But thats just the one I bought.
PS. plastic gears in the gearbox and on the motor shaft and the variable switch was faulty on mine although it does have a fault light to tell you its broke. ;D

Hope I haven't put you off though.

ACE

[baggo]

Paul,

I bought the Chester version a couple of years ago but wish I had gone up a size or two. Like a lot of small machines it suffers from lack of rigidity and it's impossible to take a decent cut without chatter. Mine does have the tilting column though which I am sure does not help. It does make quite a nice small drilling machine though! When I bought it my intention was to stick to O gauge stuff for which it probably would be adequate but (happily!) I soon moved on to the bigger live steam stuff.
As Ace says, you get what you pay for. I stripped mine, cleaned all the casting sand out of it, and re-assembled with a bit more care in the setting up department. If you do decide to go for this, check out the other suppliers. These mills are all made by the same company in slightly different versions and you may get one cheaper elsewhere.

John

[steammadman]

Why does every one want to spend their hard earned money
these days?
Make youself a small boring head and bingo its easy peasy
there have been a number in the model press with detailed instructions
MAKE YOURSELF A TOOL TO BE PROUD OF
it will last you for years

[chameleonrob]

I have the Arc euro version of the mill which I think costs the same but with a longer table. as a machine its more capable than you might think, using a MT2 collet to hold cutters and a low vise along with the slides adjusted correctly improves the rigidity alot, chatter is only bad if you are doing an interupted cut, arranging it some that there is always at least one tooth cutting all the time. if you can afford a bigger mill get one because although it is good for its size, its still very small.

rob

[AndrewP]

Paul
I have the Chester version of that mill (it seems to be best known as an X1 clone) and would agree with all that has been said before. A rebuild isn't too difficult even if you've never seen a vertical mill before like me and helps no end. By the time you've bought a collet system, decent vice, mills, parallels and clamps etc you'll spend double that anyway.
I intend to cnc mine (got nearly all the bits), in theory for the day job, and wish I could have afforded a bigger mill now, but then I'm trying to build 5" gauge locos!

[paul]

Thanks all for the comments and suggestions - too many to reply to individually but all welcome and helpful nonetheless!

Getting back to the original topic for a while (!) I've managed to make a reasonable job of the eccentric rod/strap using the jig method:

Here's the bits assembled ready for clamping/soldering...


...and here's the part after soldering...


It all looks reasonably square/true too. I just need to file the taper (hence the odd appearance at the boss end!) and give it a general tidy up.

Happy

[jgb7573]

Happy? I should think so too.

Nice one Paul.

[ace]

Hi Paul

Having probably now been put off buying the Clarke mini mill or its counter parts have a look at 'Homeandworkshop' on the internet they sell second hand equipment and they are often found at the big model shows too. I to was in the search for a small milling machine but saw and then bought the Clarke on impulse ' a mistake I see now' it may pay to shop around and wait a bit you never know what may turn up at some of these stores.

ACE

[spurley]

Hi Paul and anyone else who doesn't know about this

There is also a site; www.homeworkshop.org.uk/ which hosts private (mainly) adverts for workshop machinery, parts, models etc. Free to use too It was set up following the demise of Chris Heapy's excellent site about three years back. I have seen a few of 'our' members on there too but I think, like this forum, that it is a great resource for us.

Hope this helps anyone who wasn't aware?

Cheers

Brian

[marksmith]

Hi there
I went to that site, but it does not allow pics to download which is ashame.
I found a couple of other sites that did allow free pics to be downloaded at www.modelengineeringsupplies.net/ own forum which is useful.

I also found that Tony Griffiths site www.lathes.co.uk also allow ads, but it costs, altough he does get alot of hits and is very popular so would be good ifg selling someting a little expensive properly , although EBAY is the real market place nowdays.

I miss Chris Heapy's site, it was a fantastic site and had a good turnover of interesting ads and items. Homeworkshop lacks the lustre somehow i think.

Anyone know of any other good sites in the Uk?
Mark

[Lurkio]

Mark,
Here's a few sites I keep my eye on for second hand stuff.

www.stationroadsteam.co.uk/ (look in the Miscellaneous section)

www.tradesalesdirect.co.uk/

www.premiermachinetools.co.uk/

Also for interest take a look at:

www.goindustry.com/en/

Lurkio