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bluejets

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There was a request to see a few details of the crankshaft grinder and cam grinder machines I built a few years back so here we go.

Anyone feel free to add your bits here as well as I am just as interested in your setups also.

Firstly the both machines shown were born out of necessity and probably just as much a test to see just what I could achieve.

Building the little 25cc 4 stroke 4 cylinder was the original catalyst for both.
George Punter whom some of you may know,had given me a casting he made years before but never managed time to get any further with the build.
Plans were not around anymore so I had to work with what I had been given (the casting) and just experience from a past single cylinder 7.5cc 4 stroke, also from George's (at the time) little 2m x 3m tin shed out back.

Both the crank and cam grinders run automatically once set-up for a particular grind project. Use was made of the accurate ( I found) nature of the basic optical slot sensor found in many old printers and the like, as limit sensors. Machines are set to look at these in the setup as "end of grind" positions.

The cam grinder mechanics are wound back to a start position a small amount clear of the new job, and then when grind starts, a rotation pulse automatically feeds the grind "in" a little each time until complete, and then the machine shuts down and "ejects" the grind mechanics for access to measuring.

George built a similar machine but using mostly mechanical gearboxes as opposed to my "electronic" sensors and mechanics.

He has since built a new grinder based on a horizontal feed arrangement. This copes with the problem of grinding complex cam shapes that the "rocking" mechanics of the orignals just cannot reproduce. As such, he is often asked to build cams for old turn of the century motorcycles from all over Australia.
I'll see if I can get a photo of that machine later.

The crankshaft grinder is a little more complex and as well as using the above, it also uses a PC driven (free stuff off the internet)PLC.
Reason is because the grind sequence when started, feeds the grind "in" a small amount (adjustable) and then along the journal length, and then feeds "in" once again and traverses back along the journal. Routine continues until "end of grind" is tripped and the machine does one more traverse cycle without feed-in for finish and then retracts the grinding head. Grinding is done with the journals set as centres. Attachments allow the grinding of the crank webs after journals are completed. You will see the results of this in the parts of the 4 cylinder engine.

I had quite a large setback during and after the January 2013 floods we had here when all my house and workshop were pretty much destroyed. I had the house up and running again in 6 weeks but the workshop and all the gear (models included) had to be rebuilt/renovated and here we are in 2017 slowly getting everything back to square 1 again. Many thanks to all those who helped out and especially my mate George Punter who came and "stopped the rot" with most of my gear by dismantling, cleaning, drying out and generally swamping my workshop with CRC, emery tape, rags and steel wool.

A couple of short videos of the machines and a couple of the other engines are shown in youtube.

https://www.youtube.com/channel/UCYI-CCoY-M9bN-JY-r3_PXg?&ab_channel=JeffBluejets

BeforeRebuild_Cam.jpg


BeforeRebuild_Crank.jpg


RivierraEngine.jpg


RivierraC.jpg


George Punter Cam Grinder.jpg
 
Hello Jeff,
That's a quite impressive piece of machinery - your crank and camshaft grinder. Since I am not very well versed in electronic controls related to building a cam and crankshaft grinder, I build a grinder strictly based on mechanical motion and the master cam principal.

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IMG_0303.jpg

Here are some pictures of the grinder I build a while ago for the building of two ETW Westbury Sealion engines, which are finally now being close to completion. I am a slow builder.

Peter J.
 
Hi Peter,
Wow. That is impressive. Did you ever do a write up on your builds?
Wondering if the cam blank shown is the one used for the cam grind shown.
If so, why is there such a difference in profile or is it just the angle of the photo.

I am presently mid-stream on the design of a v8.
George has a design and castings of one with inline cylinders using offset or forked conrods.
I started on it but decided on some changes that made it easier to start again with a new casting.
Hence the new patterns below.

Other pic is the mill with the home built dro. Uses a monitor from an old ATM.

IMG_2950.jpg


OldV8_Castings.jpg


New_V8Patterns.jpg


New_V8_cores.jpg


Mill.jpg
 
Hello Jeff,
Thank you for your kind words. This cam and crankshaft grinder I designed and build is based on a concept originating from a German model engineer, Joachim Steinke. His work and grinder is documented in this thread:

http://www.homemodelenginemachinist.com/showthread.php?t=10361

I was bold enough to use his concept and designed and build my grinder to suit my requirements as shown in previous pictures. When you look at Joachim's thread, you will also find the explanation of how the shape of the master cam was derived from, explained by Joachim and further down in the thread by a post / sketch from me that shows the inlet cam master of which I showed the picture.

Unfortunately, I do not have any dedicated threads that show any of my builds. I have bits and pieces of my builds and of equipment that I designed and build for the making of the two Sealion engines strewn throughout various replies I posted in different threads. They range from pictures of the Sealion building progress through pictures of a tube bender I designed to the cam and crankshaft grinder. If interested you could search and find my threads and posts on the HMEM site.

Your latest project of the V - 8 you are starting looks very interesting and I can assure you that I will be following the progress very closely. Have a good day!

Peter J.
 
Little scale Neptune boat with a 7.5cc side valve water cooled engine.(my first engine)
Runs on methanol with glow and on-board glow driver I built.
There is provision to run a set of points off the cam at the rear for spark ignition.

It has done many hours work and still runs like a clock. Speed is close to scale and the engine will idle down to around 500rpm.(big flywheel)
Kids in the local neighbourhood would arrive whenever I took it to the local lake with my grandkids.
Of course , everyone wanted a turn so it would be a matter of a 2 or 3 minute run, spin it around and usher in the next kid.
Would run all day on a 100ml of fuel.

Neptune_Scale.jpg


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Neptune_engine.jpg
 
Fabulous work !
One of the best-ever examples of mechanical art (non cnc) self built - anywhere.

It partly resembles many of the early fabricated/bolted lathes I saw in the Paris mechanical arts museum, last spring 2016.
Musee Arts Metiers.

How did You get the gib plate straight/flat/true ?
Or does it not matter ?

For my stuff, testing with a ground machine builders straightedge shows errors from 0.01 mm to 0.04 mm, fairly well, with a backlight.
The high/low spots are very obvious.

Then I marked with sharpie, and sanded with a very wide belt sander. More time/pressure where more material needs to be taken off.
When the sharpie is gone, about 0.02 mm has gone from the material.

Edges get rounded doing this - so this would not, imho, work for a lathe using full-contact gib surfaces like Yours- theoretically.

In practice, the gibs would ride on the high spots, flat, at center.
I think.
I only used the center areas, and mounted linear guides.



Hello Jeff,
Thank you for your kind words. This cam and crankshaft grinder I designed and build is based on a concept originating from a German model engineer, Joachim Steinke. His work and grinder is documented in this thread:

http://www.homemodelenginemachinist.com/showthread.php?t=10361

I was bold enough to use his concept and designed and build my grinder to suit my requirements as shown in previous pictures. When you look at Joachim's thread, you will also find the explanation of how the shape of the master cam was derived from, explained by Joachim and further down in the thread by a post / sketch from me that shows the inlet cam master of which I showed the picture.

Unfortunately, I do not have any dedicated threads that show any of my builds. I have bits and pieces of my builds and of equipment that I designed and build for the making of the two Sealion engines strewn throughout various replies I posted in different threads. They range from pictures of the Sealion building progress through pictures of a tube bender I designed to the cam and crankshaft grinder. If interested you could search and find my threads and posts on the HMEM site.

Your latest project of the V - 8 you are starting looks very interesting and I can assure you that I will be following the progress very closely. Have a good day!

Peter J.
 
Hello hanermo3,
I assume your question relates to my cam grinders slider bar on which the tailstock end rides. You refer to it as gib plate.

The gib plate you refer to is made of tool steel, ground but unhardened and perfectly parallel, straight and square within a quarter of a thousands of an inch. (It was one of the more expensive pieces I purchased) Its dimension is 3/4 inch thick by 2 inch wide by 15 inch finished length.

I purchased the gib from Speedy Metals and had it checked and locally skimmed over on a table grinder, mechanically held to the table to prevent any distortion during grinding when using a magnet to hold it to the grinding table.

I hope it answers your question.

Peter J.
 
Hello Bluejets / Jeff,
That's a very nice Myford lathe restoration you did. Excellent job!

I have a Myford Super 7 big bore lathe with a 1 inch spindle bore and did upgrade that lathe by installing a Newall two axis read out / Newton Tesla VFD drive and a tailstock read out as well.
My lathe has almost all the accessories available at the time of purchase including the long taper attachment plus a number of additional chucks (4 jaws with reversible jaws / 3 Jaws with reversible jaws / 3 inch chucks of the 3 and 4 jaw variety)
I am very pleased with the lathe performance, in particular the accuracy that can be obtained. Of course it isn't a heavy duty piece of equipment but when treated well, it does the job well.

Here are a few pictures of the lathe I have.

IMG_0604 (800x600).jpg

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IMG_0602 (800x600).jpg

IMG_0601 (800x600).jpg

IMG_0600 (800x600).jpg

IMG_0599 (800x600).jpg

IMG_0598 (800x600).jpg

Unfortunately, getting on a bit I plan to put up my lathe and all the accessories up for sale by the end of this year / beginning of next year in addition to my manual mill and the bench top CNC mill (Similar in size to a Tormach) I own. That's life I guess.

Peter J.
 
Hi Peter,
Veeerrrry nice....... love good gear.
Friend of mine has a similar setup. Guess it pays to be an ex-doctor. :)

The restored ML7 I showed is from around 1950 odd according to the serial number.
My other machine that was used to build all my engines is an ML10 I bought back in the latter part of 1980.
Done a lot of work but still like new.

Modified a little with the tailstock dro like yours and have fitted a variable feed to the leadscrew for fine turning like cylinder liners etc.
Lathe in the background of boat construction photo.

Cheers ...Jorgo

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IMG_2158.jpg
 
Couple of photos of the latest engine to come out of the George Punter shed.
3 cylinder water cooled 4 stroke for a scale diesel loco.

Engine is 150cc, will have cdi ignition,(presently on my drawing board) manual advance retard via distributor, fuel pump, oil pump, electric start, and hydraulic unloader on the valves for starting.
Some parts are 3d printed to be actual working parts whereas the carby for example is just to get an idea of size and location in the model as well as access to the same.

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image2.JPG
 
Sorry to go off topic a little, Jorgo I like the DRO setup for the tail stock. Is it all aluminium??
 
The brackets, yes.

Not my idea by any means, found it on some model engineering site originally and adapted it to suit my Myford.

Just fits in( vernier slide) with the tailstock retracted right back on the stops.

The slide of the vernier is stainless and takes a bit of patience ( slow speed) drilling with a new bit but it does eventually get through.

I ground the original fork ends off the vernier with a dremel and a 1" cut off wheel.
 

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