New I/C diesel project - ETA15d-x2

Piece of 1/2 MS for the shaft, head from MS and a piece of thick - 10swg - copper

The head is silver soldered to the shaft, drilled and tapped on the centreline of where the copper will fit and one half removed.

Not long now then

Edited By Ramon Wilson on 07/06/2011 22:45:15

Finally, how ever did you turn a flat piece of 10 swg copper into such a beautiful cylinder?

The copper can be held in place on the mandrel head by a screw in the adjusting screw hole but make sure this screw is well carboned up as if this gets silversoldered in then its start again time. Once the soldering op is complete the cut off half is inserted into the lap and the adjusting screw set in so that it is just exerting pressure on the copper. Set in the lathe this is then turned using a very sharp tool. Please note however if the silver soldered edge is not the 'leading' one then you will very quickly unwind the copper

The size to aim for is such that it will just enter freely the bore. If the bore is slightly tapered then it should just do so at the narrow end.

The lap is not charged by rolling in abrasive powder on a hard surface - rather the powder, mixed with light oil, is applied to lap and liner and the liner pushed over the lap. It should be a tight but not overly so fit. Start up the lathe -around 400 rpm - grasping the liner which should allow the lap to revolve with a reasonable drag - if it is difficult to hold against rotation or gets hot then stop, back off the adjusting screw and repeat. Parafin and light oil at about 10:1 makes an ideal lubricant. It gets messy so cover the lathe and wear gloves if you don't want black hands - really black on cast iron

The lap is fully adjustable by increasing pressure on the inserted floating half of the head via the grub screw and whilst the expansion is not fully radial it does remain round and will true a slightly out of round bore. If the liner is tapered to begin with the taper can be taken out by dwelling in the tight area more but we are talking tapers of tenths here not thous. Conversely putting in a desired taper is done the same but 'opposite' way. Providing the adjusting screw location is on the centreline of the length of the copper the lap expands parallel.

This is the lap after the initial lapping of all three cylinders using 260 grit. It is important to thoroughly clean lap and part before going to the next grit. If the surface finish from the tool is good then you should be able to begin with 400-600 grit. I began as such but had left too much on so reverted to the 260 to remove the initial amount quickly.

Something I did overlook to mention before was that these laps are not 'specific' in that within the amount of copper left they can

Edited By Ramon Wilson on 08/06/2011 23:01:33

Something I did overlook to mention before was that these laps are not 'specific' in that within the amount of copper left they can be further turned to suit smaller bores.

Well XXXX ('name withheld to protect the innocent' ) I hope that helps to answer your questions and of course anyone else I may have confused. I would just like to emphasise this is very definitely not the way to go about it, merely the way I have tackled it --- and they've got to run yet!

 

As always hope that's useful

 

Regards - Ramon

 

 

Edited By Ramon Wilson on 08/06/2011 22:34:42

As the 'protected innocent' mentioned by Ramon, I feel suitably chastised for not coming straight out and asking my question openly. So – publicly – thanks for a superbly detailed and helpful answer. It has been 'cut and pasted' into my 'Tips from the ME forum' file, which is growing steadily.

Ramon Hi. Thats a great idea for an internal hone/lap, I sometimes start to lap with valve grinding paste, just to get the lathe tool marks out, (over exuberance and no patience) I have got 12 tubes of diamond paste, they cost about A$9, so they are much cheaper now than years ago, then finish with Brasso. The internal hone that I tried with SS rod and a fine stone, I should have said that the length of the actual stone is about 35mm long, that way there is less chance of distortion, as it wears more evenly, I have got two slate oil stones which are at least a 100 years old, so I aint cutting those up, so I might get a slate tile and see how that goes. over in the UK just wait for a wind storm you should have plenty???? I think in a previous post. that I do what Dave Owens does and use a thread die holder, to hold a slotted and grooved piece of round Aluminium, that makes it adjustable. Anyway a Gindall or a Delapina is a better option, especialy the one by Tom Blough..

I have a small roll of cling wrap that I got from the butcher/greencrocer, its wider and a bit thicker than domestic stuff, CHEAP if you ask the butcher nicely ie FREE. Providing you dont have to traverse the saddle very far, it some times sticks to the lathe bed, and also wrap it clock around the chuck, it keeps most of the rubbish out of the moving parts, the grit also sticks to it. PLEASE be careful with things spinning on a revolving part. then just screw it up when you have finished, and give the lathe a wipe with an oily rag. works for me!!!!

Now, the Allen Booths article on the external hone that was mentioned by Dave Fenner, in his article on the Sugden Special. At the present this time I cannot get to my MEW mags, but I think its somewhere in the 90s (I am also having trouble getting the on line index to work as well) maybe someone out there has a better memory than me, can help.

I apologise for my spelling and grammer, as I can only type with two fingers and have to look at the keyboard to do that!!!!, just hope it makes sense????

John Holloway

Hi Mike, No I don't mind at all, in fact it would be pleasing to hear a few more

Fortunately (?) there is little control line flown in this area now which I have to admit would be a big distraction if it were. It would not take much to respond to an ever present itch

Edited By Ramon Wilson on 26/06/2011 23:52:36

I've had a really good session in the workshop today anodising all the requisite parts and the engines are now finally complete. There remains but one thing and that is to run them. I was about to do this this afternoon as the last part was done but my neighbour decided to have a Bar-B so I felt it was not exacly an opportune moment - ''Maybe tomorrow Jack''

You know, it's strange but now they've been anodised I think I preferred them in 'all ali'.

Edited By Ramon Wilson on 27/06/2011 23:38:33

Well that's it then folks, journeys end

Mk2

S&J Version

 

Just remains to say thanks for your kind words, Bill and Ady, and thank those who have responded over these last few months either by post or PM. It's been difficult to assess whether it's what is wanted by the majority but as you obviously keep looking I could only assume it was. Hope I haven't gone on too much

 

 

Now, I'm respectfully(?) reminded by my tolerant and ever patient better half that perhaps it's time to catch up on those domestic issues that have been somewhat neglected over recent weeks so it's time for a break for a short while before tackling the next one.

 

Regards to you all - Ramon

Edited By Ramon Wilson on 28/06/2011 14:17:05