Member postings for Stephen Follows

Problem solved. Having read all the replies, (thanks everyone), I have made a new tool from an HSS blank.

The cut was excellent and the sides parallel. All that I have to do now is lap the piston in. It seems to me that the tool I was using must have been flexing as it cut despite being a professionly made, (I assume), item.

I used the carriage to move the tool, not the top slide. The boring bar is about 3/8" thick with a 1/2" square section to clamp it in the lathe. The cutting edge seemed sharp enough, it was taking long shavings off. I assume that it was being pushed off deeper into the cylinder.

My first intention was to drill through with a 31/32" drill and ream to finish. The drill had the same problems of fit, i.e. morse taper 3 and price. A drill and reamer would have been in excess of £60, even if they did fit!

I have attempted to machine a cylinder of 25,mm bore on my Myford ML7 lathe. Using a boring bar with a separate bit secured by an allen screw the result is a bore of 1.5mm less at one end than the other.

I suppose the obvious answer is a reamer. Unfortunately they are morse taper 3, the lathe is morse taper 2. Also, upwards of £40 for is lot to spend for one job!

Any ideas how to solve the problem. (The length of the cylinder is 50mm).

Martin,

What lathe did you fit it to? The question for me is Myford bearings, whether they will stand up to 2000rpm. Seems not according to most replies. Upgrading to Bronze costs around £330. Silly Money! I can buy a mini lathe for approx. £500, less than bearings and inverter system.

My reference to 2000rpm was not from a post on here.

I have thought of fitting ball bearings to the Myford, (two each end), at least the shaft wouldn't get hot. Not sure if they would fit in the existing clamps.

What size boiler would I need to feed a stationary steam engine with a cylinder of 1" bore and 2" length?

Would I be better off making one from copper. I would like to build one to use coal.

I have some old fire extinguishers, I though I might be able to fit an electric element to one and use it as a temporary boiler, is this feasible? (I am qualified to fit the element!)

REALLY CONFUSED!

I'm more uncertain now than when I began this thread. Looking at answers here and reading other websites it seems that:

a). Never run an ML7 faster than 1000rpm at the chuck on pain of destroying the machine unless bearings are upgraded.

b). Run it at up to 2000rpm for hours on end with white metal bearings and don't listen to the doomsayers.

c). Pick an option somewhere in between.

Not sure what to do now. I've been trying to work a space in my workshop for a minilathe but not having much success without seriously inconvenient access to some other item. If it was an easy option I would have one on order by now.

Would love to run the ML7 faster as the easy option but still cannot find bronze half bearings and shaft at a sensible price.

I'm thinking of getting a mini lathe in addition to my ML7. Upgrading the ML7 would till be my preferred option but not Paying over £300 for a pair of bearings and shaft.

I assume that the Chester super conquest must have a motor with brushes because the next one up makes a bold statement about being brushless. An extra £213 though.

Edited By Stephen Follows on 07/11/2017 22:43:16

Having abandoned the idea of upgrading my ML7 motor system due to the ridiculously high cost of bronze bearings and hardened shaft I am now looking at mini lathes as an extra.

The one I have so far wittled down to is the Chester Conquest Super lathe advertised in Model Engineering Workshop.

Is this a good buy, another example of Chinese tat or somewhere in between? It would be interesting to know if anyone has one and what they think.

Another lathe is a good idea, just a matter of space.

Looks like I have started an interesting topic here. Thanks again for the continued contributions.

I think I will have to abandon the idea of speeding up my lathe. The cost of new bronze bearings and hardened shaft added to fitting an invertor and three phase motor takes the price to over £700.00. £339.50 for shaft and bearings seems a bit excessive to me, (a lot excessive if I'm honest), but I cannot find any cheaper anywhere.

It's a shame but unless I can find affordable bearings etc. it will have to stay as it is!

Bearings continued. Having said it would be easy to change the bearings I have found that a matched hardened shaft and bearing kit costs £339.50. Ouch!

Thanks for all of the replies to my post. Excellent advice in abundance!

My ML7 has white metal bearings. Don't know if it has a hardened shaft, don't know how to tell if it is or not.

My main reason for fitting a new motor is speed. At present the maximum I can get is 680rpm. there are a few occasions that I would like 1000rpm, changing the bearings would not be a problem, not sure about the shaft.

I am thinking about fitting a Newton Tesla motor system to my Myford ML7 lathe.

Do I go for 0.5 HP or 1.0 HP motor?

What speeds will I get with this system?

Hi everyone,

I'm a subscriber to the magazine. I am currently building a small steam mill engine.