Boring Loco Cylinders

[chameleonrob]

steammadman said:

We seem to have an awful lot of model engineers these days with an awful lot of
money to waste on fancy tools etc,in the old days we had to make as many tools
as we could, wages were only 1 AND 9d an hour , in propper money.

some of us are still have to have the same philosophy, i'm building my loco and living off income support as i've been ill for about 5 years now, hence the home made between centres boring bar and boring head, first one's quick and cheap to make and the boring head is used for drilling holes that I don't have either a drill or reamer for.

[Shawki Shlemon]

Hi
I am amazed on so much discussion on the subject , I made my tools from available stock in the workshop 25 years ago and used them for more than 20 engines . I explained the set up with photos in my thread on page 6 of this forum. Most of my equipment other than the machines are made by myself , most of the time the ideas are from ME.AME , live steam or myself . We don't have to spend a lot of money to achieve our goals .

[ron]

Hi Everybody
Thanks for the replies, it looks like a between centres boring bar is the way to go even if it's just for the final cut, what I'll do is set the casting up on the cross slide and bore it to slightly undersize with the boring head, this allows me to check for parallel, then finish it off with a boring bar if the boring head isn't cutting parallel. The final cut with the boring bar also has the advantage of making both cylinders exactly the same bore.
I hope the CI the cylinders are made from is the same as Blackgates use for the wheels as it machines beautifully.
I didn't really want to get involved in a debate about buying or making tools, that is really up to the individuals preference but nice as the Arrand stuff looks it's a bit hard for me to justify the price for the small number of cylinders I'm likely to bore.
Ron

[Laurie_B]

stevew said:

I then found Myford did a little compound gear (a different one for ML & S7) that sits at the beginning of the set. I've found this to be one of my best buys from Myford and gives a good finish.

I can't remember how much it was, somewhere between 10 and 15 quid a while back.

Just for info:about 5 years ago I purchased a second hand (sorry-pre owned!) S7 lathe from Myfords.I looked into the possibility of retro-fitting their 'Quick Change Gearbox' (or Norton box if you prefer).

However the price of a new gear box was over £900 at the time,and a good second hand one seemed to be about the £400 mark.
However,like SteveW,I found that Myfords produced a 'Fine Feed Gear Cluster' (part no.A1974A/1,suitable for the ML7-R and S7) for about £22 inc VAT.
The finest feed rate from the Norton type gear box I found,was 0.002"/rev of the workpiece.The fine feed cluster actually gives 0.0018"/rev,giving a very slightly finer feed rate,and at a lot less cost!So I bought the gear cluster,and found it produces a very good finish.

As for buying expensive tooling,as Ron says,it is very much a matter of personal preference and circumstance.I doubt there are that many model engineers around who actually have such unlimited funds to spend on this hobby,most of us have to restrict our spending,on what has never exactly been a cheap hobby.
Quality items will always last.

[Shawki Shlemon]

Hi
One thing one have to make sure when boring cylinders is that the bore must be 100% at 90 degrees to the rear face and that is why I machine the rear face and bore the cylinder at one set up . No room for error . See my thread. I have bored cylinders for 21 engines like this successfully . Please yourself and good luck .

[ron]

Hi Shawki
Thanks for the info, if I set the casting on the cross slide and face it with the boring head then bore it as I described previously I should get 90 degrees as long as I don't disturb it. I don't really want to either buy or make a lot of kit for cylinder boring as I don't expect to be boring a lot of cylinders.
Ron

[Laurie_B]

Just for interest,having just been perusing the ads section Model Engineer (over my morning vat of tea!),I noticed this 'Cylinder Clamp' available from Warco Ltd.
I think that many years ago these were sold as a 'Keats Clamp',or a 'Keats Block'.Might have the wrong name of course!
The idea being that the block can be bolted to the faceplate (presumably with suitable balance weights also) so that awkward shaped items like cylinders could be held and machined,as an alternative to boring between centres.
www.warco.co.uk/shop.asp?catid=61&ProdId=897

[Peter W.]

Chronos do a "Keats angle plate" for £35 which includes VAT, & P&P

RDG do one at £32.50 inc. VAT, not sure about P&P

[John Lee]

laurieb said:

Just for interest,having just been perusing the ads section Model Engineer (over my morning vat of tea!),I noticed this 'Cylinder Clamp' available from Warco Ltd.
I think that many years ago these were sold as a 'Keats Clamp',or a 'Keats Block'.Might have the wrong name of course!
The idea being that the block can be bolted to the faceplate (presumably with suitable balance weights also) so that awkward shaped items like cylinders could be held and machined,as an alternative to boring between centres.
www.warco.co.uk/shop.asp?catid=61&ProdId=897

And then we are back to tool flex Laurie, the boring tool that you will put in your toolpost for one, plus whatever crosslide lash you have unless you have a locking device ( a worthwhile mod), add in a bit of bed wear and inaccuracy... etc etc.

A between centres boring bar is something you can make yourself, no bought in Keats Plates, Arrand Tools or whatever, and you get a guaranteed parallel bore. This is dependant on your lathe, which is one reason why Myfords are popular. You have T slots on the crosslide. Boxfords do too if you get the optional crosslide, and are much more rigid to boot. And they are cheaper . A Southbend copy for our US friends.

Regards,

John

[Deleted]

Hi
My observations of the various methods are:

If mounting the cylinder on the spindle, (chuck, faceplate etc) the bore may or may not come out parrallel depending on the machine.
If the bed is worn then there will be an error, and apparantly this is worse for boring than it is on external work.(I can't remember why but I think I read it somewhere)
If the bed is worn you can lock the saddle and use the topslide, with careful setting up this can work well, but only if the topslide has enough travel.
To get a good bore you need as stiff a boring tool, or boring bar as you can fit in the hole, and it needs to be sharp!
If using a between centres boring bar, i've seen it recommended to have two. One to adjust for each cut until nearly to size, then the other for the final cut, then remove the second bar, and keep it for the final cut on the other cylinder, then they both come out the same size! Ron's method of boring head followed by the bar for the last cut achieves the same thing.
For the last cut put the tool through more than once.

Hope this helps