Author Topic: Arnold's take on the MEM Corliss  (Read 167297 times)

Offline b.lindsey

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Re: Arnold's take on the MEM Corliss
« Reply #210 on: May 14, 2013, 01:34:47 PM »
Great update as usual Arnold....sorry to hear about the flu though.  Take care of yourself and feel better soon!!

Bill

Offline arnoldb

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Re: Arnold's take on the MEM Corliss
« Reply #211 on: May 25, 2013, 10:19:30 PM »
Thanks Bill  :) - took me a while to get over the 'flu, so nothing happened in the shop for a long time...

After spending the last two weeks sneezing, I was not about to get started on woodwork for a return shop-session; more sneezing from the wood dust would just be the pits.
I figured I might as well start on the flywheel, so I had a bit of a think about how to proceed with making it...

I checked some spacings on the lathe, and thought I might get away with making the flywheel rim without too much fuss.  If I hacked off a suitable length from the parent stock shown in an earlier photo, I could actually mount it on the 4 jaw chuck and swing it in the lathe's head gap to turn - and end up with a flywheel that's just 2mm narrower than the plans show.

On to the "simple" shop session that became an entire saga, and a hidden "gotcha".  There's not really a lot to see in today's update, though the tribulations might be amusing to some  ;)

A quick check on the bandsaw, and there was no easy way to mount the stock on it to start hacking at it.  A 4"x6" bandsaw really isn't built to saw a slice off a 180mm (7") bit of round stock...
Next option - a slitting saw on the mill.  I know my 1mm slitting saw cuts cast iron like butter, so I mounted the stock on the rotary table and 4-jaw chuck.  No problem with headroom, even though the lot stands a bit tall:


I started the cut, and promptly ran into a problem...  I forgot to check that the cut wouldn't make the chuck unscrew from its mounting on the rotary table - which it promptly did :-[ .  A new lesson was learned as well; my slitting saw arbor has a safety feature in it that I never knew of.  If things suddenly gets too tight, the holding screw shears off  :lolb: .  It worked well to prevent damage to the slitting saw.  Here's what remained of the holding screw - I'd already managed to get the rest of the screw removed from the arbor, replaced it and re-mounted the saw:


In the process of unscrewing the chuck, the slitting saw dug a nice trail of tooth marks  :facepalm2: :

Something about the tooth marks looked wrong, but I didn't listen to my gut feel...

To prevent the chuck unscrewing again, I attacked things from the inside:


Soon after the last photo, the slitting saw arbor sacrificed another holding screw...  The alarm bells were ringing, but Arnold wasn't listening  :-[ .  Replaced the holding screw, started again, and not long before the screw popped again.  The slitting saw still felt nice and sharp, but I was not about to push things any further; the saw blade itself cost me three times what the stock cost, and I wasn't going to push things any further and risk breaking the blade and have bits of high speed steel flying around.  And I didn't hear the penny drop.

So, what next ?...  I could just go for the hacksaw, but my energy levels are still a bit low after the flu.  Tel mentioned a grinder...  Hmmm...  Got two of those; a 5" and a 12".  The 12" takes quite a bit of effort to wield, and I was not feeling up to man-handling it yet.  So, on to the 5" and the thinnest cutting disk I have.  Securing the workpiece was a bit of a problem, but I eventually managed to clamp it in the big vise on the workbench.  Things went OK until the blade started getting deeper into the slot, and then the blade started biting - a case of me not being steady enough.  Rather than risk breaking it, I stopped and did some more thinking  :headscratch: .  The penny didn't drop...

Back to the bandsaw...  I removed all the add-ons I'd made for it, checked things out, and eventually figured out I could clamp the workpiece to the extended bit of the vise:


Then I started abusing the poor bandsaw:

Saw a bit until the "head end" blade guide stops against the workpiece, stop, rotate the workpiece a bit, clamp up again and repeat.  The blade barely penetrated into the inner hole - it just left some short stringy burrs on the inside to show that it did go through.  Stringy burrs, and still, the penny didn't drop  ::)

There were still some thin sections that were holding the bit I wanted to the parent stock.  Seeing as this is cast iron, it's brittle, and a good whack with a hammer should just break it apart.  Took more than a single whack though:

I had to basically tear apart one last section that held the bits together - where the band saw lines met, they were a bit out of alignment. Took a lot of wiggling around to break off that bit, AND STILL THE BLOODY PENNY DIDN'T DROP!  :facepalm2:

On to the lathe, and mounted on (or rather over the body of) the 4-jaw chuck in the head gap.  I left just enough space for the chuck key, and the lot fits nicely in the head gap:


I had to set the top slide parallel to the lathe ways and crank it in to maximum to get enough clearance to be able to turn the workpiece without the carriage hitting up against it.  This literally is pretty much my Myford's limits.  There's some room left in the head gap, but even so, the cross-slide was just barely hanging on by a few threads on it's feedscrew.
With slowest speed back-gear engaged, I started turning the workpiece.  It was only during this operation that THE PENNY FINALLY DROPPED:


I was looking forward to the smell, taste and black hands that come from the dust of turning cast iron.  And fully prepared to duck the stream of tiny chips it makes.  This material didn't do any of that; it came of in stringy swirls, didn't generate dust or give me any of those other (to me) feel-good cast iron experiences.  In fact, I'm now pretty much convinced this isn't cast iron, but rather steel, and the bad experiences with the slitting saw, the stringy burrs on the bandsaw and all the rest adds up.  That changes the ball-game a bit, and I have to re-think how I'm actually going to construct the flywheel.

I finished the shop session by rough-turning the outside of the workpiece to get rid of the crud:


So, now I have to sleep on what I'm going to do next.  With the original intent of the material being cast iron, I was going to bore out the rim section I did today by about 50% on the ID, then cut off another shorter section from the parent stock to turn down to a press fit inside the rim and drill it on the periphery to fit the flywheel spokes.  Right now, I'm not keen on the "extra" ring idea anymore; I might just bore out the rim to leave an internal "ring" in it, make a hub and spokes, make that fit inside the rim and solder the lot together.  Choices... Choices...

Kind regards, Arnold
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline b.lindsey

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Re: Arnold's take on the MEM Corliss
« Reply #212 on: May 25, 2013, 10:31:17 PM »
Quite a saga arnold!  Frustrating when everything seems to be working against you, but you prevailed. Have to agree, that sure dont look like cast iron.

Bill

Offline vcutajar

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Re: Arnold's take on the MEM Corliss
« Reply #213 on: May 25, 2013, 10:37:34 PM »
Glad to hear you are feeling better.

That flywheel is a project on it's own.

Vince

Offline Bearcar1

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Re: Arnold's take on the MEM Corliss
« Reply #214 on: May 25, 2013, 11:32:37 PM »
Geesh, what an undertaking unto itself. I didn't catch on to what was a problem until you got into cutting the piece on the band saw, Arnold.  Glad you are feeling better BTW. The stringy shavings was what set off the alarm bells for me. Though it is a fair amount to handle this size of material, couldn't you still continue on with your original thoughts of an inner rim with holes drilled in it to accommodate the spokes? Dunno. The flywheel has proven to be a real bear for the few folks that are making this engine. Me. I'm laying back in the weeds until I have seen what/how everyone else has done it, THEN, I'll make a decision as to if I want to proceed.  :Lol:  Take care of yourself my friend and do avoid saw dust for a while. Use a good respirator if you do though please. Exotic woods can be hazardous to the respiratory systems of some people.


cheers


BC1
Jim

Offline tel

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Re: Arnold's take on the MEM Corliss
« Reply #215 on: May 26, 2013, 05:05:34 AM »
Quote
I had to set the top slide parallel to the lathe ways and crank it in to maximum to get enough clearance to be able to turn the workpiece without the carriage hitting up against it.  This literally is pretty much my Myford's limits.  There's some room left in the head gap, but even so, the cross-slide was just barely hanging on by a few threads on it's feedscrew.

Yer gotta think outside the box matey, a stout boring bar, taking a HSS bit, mounted at the rear (operator's side) of the topslide will restore things to a more rigid condition. That's how I did this rim, tho, sadly, no pic of the actual set-up.

The older I get, the better I was.
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Offline sbwhart

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Re: Arnold's take on the MEM Corliss
« Reply #216 on: May 26, 2013, 07:35:59 AM »
Hi Arnold

Pleased you're feeling better, I thought you'd been a little quite.

As Tel said when faced with a problem like this you have to think outside the box. If you flip the tool over and hold it in the near side of the tool post and run in reverse you'll have a far more secure set up, the metal doesn't give a dam which way the lath is running or which was round the tool is. like this



I take it you'll have to turn down the OD some to make the inner rim, well if you turn it down whilst it's still on the parent material, this way you've thinned the section down so you could then part it off from the inside with a cranked tool or use the same tool upside down  working from the outside.

Hope this helps I'm sure you will come up with a solution.

Stew
A little bit of clearance never got in the way

Offline tel

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Re: Arnold's take on the MEM Corliss
« Reply #217 on: May 26, 2013, 09:02:12 AM »
yep, there's how it's done, right there!
The older I get, the better I was.
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Offline zeeprogrammer

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Re: Arnold's take on the MEM Corliss
« Reply #218 on: May 26, 2013, 11:25:38 AM »
Glad you're feeling better Arnold.
That was a fun post to read although I could feel the frustration build as you went along.
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Offline ozzie46

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Re: Arnold's take on the MEM Corliss
« Reply #219 on: May 26, 2013, 02:18:12 PM »


   Glad you're feeling better Arnold. Your flywheel saga is going to give some valuable lessons for us mere mortals.  Will be watching and learning.

   Ron

Offline arnoldb

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Re: Arnold's take on the MEM Corliss
« Reply #220 on: May 26, 2013, 07:47:52 PM »
Thanks all  :praise2:

Bill, yes, it's definitely steel.  The biggest problem was that I was trying to machine it like cast iron, and I was just plain miffed at myself for not catching on sooner that it was steel; all the signs were there  :-[
Vince, you know it   :cheers: - fortunately I won't have as much milling to do on this one as you did  ;)

Jim, thanks my friend.  Just make sure those weeds aren't wet, else you might also end up with the 'flu  >:D .  You'll be happy to know that I'll be hacking off another piece from the parent stock to make the inner rim, just like originally intended.  I don't think everyone will have as many problems with the flywheel.  There is the option of buying a casting for most.  The biggest problem for me is that it's a rather big job for my lathe.  I'll have to start saving up  ;D

Tel & Stew - yes, the boring bar was my next option.  Unfortunately, it's one of those "make-a-tool-first" options  :ROFL:
Stew, good tip about running the lathe in reverse.  I can't do that though; the Myford uses screw-on chucks, so machining in reverse could prove interesting...

Thanks Carl - had to try and make the post a bit of fun, otherwise it would be terribly boring  ;D

Thanks Ron - but I'm as much a mortal as everyone else.  This build (not just the flywheel, but the entire engine) is a steep learning curve for myself, as it's a much bigger engine than I've built to date, so there's a lot of new techniques that I have to use.  It's a lot of fun though!

There's not much to show for today's shop session, though I made lots of chips.  Now that I know this is steel, and that I'm going to make the flywheel with a separate inner rim, I finished off the rim to a better standard, and started boring out a lot of excess.  This was slow-going; to get any kind of sensible surface finish, I had to go right down to lowest back-gear speed.  That also meant fine feeding.  On the ML7, the apron feed is a bit coarse, so I just locked it to the leadscrew and fed with the leadscrew handwheel.  That gives a finer and more controllable feed.  I did something I've never done, and that was pull up a stool next to the lathe, and sit down while working   :-[ .  Eventually got to this state:


Once that was done, I reversed the jaws in the 4-jaw chuck, and clocked up the rim in it again to start work on the other side.  It clears the lathe bed by 1mm on the front part of the bed, and by just 0.7mm on the back part...  That should be enough; it's a bit close, but I'm not going to be heavy handed during the rest of the operations; slow & steady will get the job done just fine:


After setting up, I faced off the front to true it up; no photos of that.  And then I had to call it a day; four hours gone and not much to show for it  ::) - this might be a bit slow  :lolb:

Kind regards, Arnold
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline Tennessee Whiskey

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Re: Arnold's take on the MEM Corliss
« Reply #221 on: May 26, 2013, 08:13:20 PM »
Good problem solving. Now, keep your eyes on the indicators and quit worrying bout the clock. 8) I'm sure none of here are going anywhere, on our own accord at least. :cheers:

Yo Redneck,
Eric

Offline Jo

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Re: Arnold's take on the MEM Corliss
« Reply #222 on: May 26, 2013, 08:18:58 PM »
Arnold you can always sneak up on it from behind:



Or in the case of a Myford make yourself an extension that bolts on using that spare tee slot in front of the standard tool post. Nothing sexy just a piece of thick steel bar with a holes to enable you to clamp in that tee slot, (or clamp it down at a jaunty angle if you are going  :o really wide) ... If you have the original Myford tool post kicking around all you have to do it put a 7/16" BSP stud in the other end and you can transfer over the ball handled clamp as well.

Jo
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Offline vcutajar

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Re: Arnold's take on the MEM Corliss
« Reply #223 on: May 26, 2013, 09:01:47 PM »
Way to go Arnold.  Slowly but surely.  That's my motto.  That flywheel surely goes beyond the limits of our lathes (at least mine).

Vince

Offline Don1966

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Re: Arnold's take on the MEM Corliss
« Reply #224 on: May 26, 2013, 09:08:14 PM »
As the others have said, yes nice save. One of the good things that I like about this hobby, is that it's makes you think and that programs us to overcome adversities. You have shown that here, great job Arnold and a good lesson for us beginners. Thanks!

Don
« Last Edit: May 27, 2013, 03:24:58 AM by Don1966 »

 

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