Model Engine Maker

Engines => From Plans => Topic started by: tangler on April 27, 2019, 05:34:35 PM

Title: Tangler's Air Cooled Farm Boy
Post by: tangler on April 27, 2019, 05:34:35 PM
Moving home is an unsettling business.  One exists in a sort of limbo, waiting for the stars to align so that there is a buyer for one's house and suitable property available to buy.  So, whilst this was going on I decided to distract myself with a new project - a Farm Boy from Jerry Howell's plans ( No 585). I had some suitable lumps of ally in stock that were (nearly!) the right size.  I won't bore you with the detail but here are some pics of the roughing out process:

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FB1.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FB2.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FB3.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FB4.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FB5.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FB6.jpg)

Then the move..and the new house... and the new BIG workshop happened  :)

Moving on 9 months and here we are:

The 2 halves of the frame have a halved lap joint which I crept up on to get a matching fit.  Note that the stock for the front half of the frame was not quite tall enough  >:( but as an oiler is fitted here I am not to worried about that (there's always JB Weld ;) )

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FB7.jpg)

Prepared for drilling through the joint

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FB8.jpg)

Having obtained a suitably sized ball ended mill the cavity was tidied up

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FB9.jpg)

And this is the current status:  screwed together with 6BA screws, not yet glued and awaiting a considerable amount of hand tidying

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBA.jpg)

At some point, and with at least 584 other Farm Boys under construction ( 8) ) I conceived the need for some personalisation and decided to try and make an air cooled version with a finned cast iron cylinder.  Here are a couple of mock ups in Fusion 360

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBB.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBC_.jpg)

The fins are 1/16" wide at the top and a bit thicker at the base. So, what do you think guys?  Is it a goer?

Cheers,
Rod


Title: Re: Tangler's Air Cooled Farm Boy
Post by: Ye-Ole Steam Dude on April 27, 2019, 05:57:21 PM
Hello Rod,

Beautiful machine work, keep the photos coming.

Have a great day,
Thomas
Title: Re: Tangler's Air Cooled Farm Boy
Post by: b.lindsey on April 27, 2019, 07:14:07 PM
Great to see a new project starting Rod. Congrats on the move and new shop also!!

Bill
Title: Re: Tangler's Air Cooled Farm Boy
Post by: Jasonb on April 27, 2019, 07:46:29 PM
As I said before it's a goer. Have you considered a small cooling fan like the air cooled associated engines have, rather than a hefty bracket as has been seen on here recently a boss could be bonded between a couple of fins ( I assume you are turning them) to take the fan's pivot. Then all you need is a of small vee pulliey and a fan cut and twisted from thin sheet.

(http://www.oldengine.org/members/smigle/Associated%20pics/bb/amanco6_jpg.jpg)
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on April 28, 2019, 12:04:30 AM
I like the fan idea.

Thanks,
Rod
Title: Re: Tangler's Air Cooled Farm Boy
Post by: Don1966 on April 28, 2019, 12:16:09 AM
Cool “Rod I am here for the ride..... :popcorn:




 :drinking-41:
Don







Title: Re: Tangler's Air Cooled Farm Boy
Post by: b.lindsey on April 28, 2019, 02:27:49 AM
Jerry's "Vickie" Stirling engine has a similar arrangement though I did not incorporate it and the engine runs fine and for a long while without it. Farm Boy will no doubt generate more heat. Could be a good addition!

Bill
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on May 02, 2019, 11:01:36 AM
Thanks for the comments.

This is the plan of action together with the lump of cast iron that (I'm hoping) contains this shape.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBD.jpg)

The first job was to clean up the outside

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBE.jpg)

I then moved the job to a four jaw for a more secure hold and drilled through with a 3/4 bit, the only drill bit I have with a morse taper shank.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBF.jpg)

I think using a between centres boring bar is the best way to ensure a parallel bore, even if they are a bit of a pain to set up

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBG.jpg)

Adjusting the tool bit is pretty tricky but I managed to get to 0.998" and there is some light chatter to lap away

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBH.jpg)

Off to Exbury gardens now to look at some pretty azaleas and mayby ride on a steam train.

Cheers,

Rod

Title: Re: Tangler's Air Cooled Farm Boy
Post by: Roger B on May 02, 2019, 02:02:42 PM
You're off to a good start  :ThumbsUp:  :ThumbsUp: I will be following along  :wine1:
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on May 07, 2019, 03:40:12 PM
(http://lister-engine.com/coppermine/albums/userpics/10027/normal_exbury.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_exbury_loco.jpg)

That was a pleasant afternoon.


Since the the cylinder was packed up on the cross slide the the outside is no longer accurately aligned with the bore so I remounted it in the 4 jaw centered on the outside and then  banged the other and around with a hammer till it was centered according to the bore and took a cut along the exterior as far as the chuck.  Then turned it end for end and repeated the process.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBI.jpg)

Once that was done I turned the register that fits into the end of the frame and started on the fins with a newly sharpened 1/8" parting tool

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBJ.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBK.jpg)

I turned it end for end again to finish the parallel cutting of the fins because corner of the topslide was interfering with the cylinder.  I've drawn a 2 degree taper on the fins.  Moving the topslide around to 2 degrees means that the topslide handle interferes with the cross slide handle so I replaced it with this little knurled knob which does the job

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBM.jpg)

I changed to a narrower parting tool, cut the tapers down one side and then shifted the topslide to 2 degrees the other way and tapered the other sides.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBL.jpg)

The top of the fins are 3/16" diameter so I drilled a 3/16" hole in a bit of oil hardening steel (Ground Flat Stock in the UK) then filed away half the diameter of the hole and hardened and tempered.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBN.jpg)

The bottom of the fins are 1/8" diameter and I already had a HSS tool which I modified on the grindstone to suite

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBO.jpg)

A family shot to finish

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_FBQ.jpg)

Cast iron swarf everywhere so lots of cleaning up to do- including me: Mrs Tangler and I are off to a local restaurant this evening to celebrate our Silver Wedding anniversary.

Cheers,

Rod










Title: Re: Tangler's Air Cooled Farm Boy
Post by: Jim Nic on May 07, 2019, 04:44:37 PM
Lots of effort to get the "cast" look Rod but it turned out beautifully.
Jim
Title: Re: Tangler's Air Cooled Farm Boy
Post by: Dave Otto on May 08, 2019, 12:59:25 AM
Great progress Rod, the cylinder looks very nice!

Dave
Title: Re: Tangler's Air Cooled Farm Boy
Post by: b.lindsey on May 08, 2019, 02:11:26 PM
Looking great Rod, and congrats on the anniversary too!!

Bill
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on May 21, 2019, 02:15:56 PM
Hi guys,

Sorry for the delay.  I decided to have a go at the connecting rod next.  This seemed like an ideal subject for my little Denford/Sherline CNC mill

I started with a blank of HE15 (2014) aluminium alloy, milled to thickness on the manual mill and with 2off 6mm holes at the correct centre spacing for the big and little end bearings.  This was then mounted onto the CNC milling table and squared to the X axis with a dti.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr7.jpg)

The Denford software has a simple CAM system that coped with the external profile pretty well

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr8.jpg)

The rest was less successful:  I had to fiddle around with the DXF drawing files to provide pathways that the mill could understand, then it started translating circles into polygons and, to cap it all it decided that it needed to drill a hole in the middle of the web.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9a.jpg)

The polygon issue has been addressed in a recent update to the software (which, obviously, I have downloaded after the event) and the spurious hole was probably operator error in entering the Z height.  Fusion 360 has a Denford post processor so I have spent the last week or so delving into Fusion CAM.  There's a long way to go so I have decided to carry on with the bit I've made.  The hole could remain as a "feature" - it is at least on the centre line or I could put an ally plug in it.  Anyway, I have tidied up the little end with some filing buttons

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9b.jpg)

I used a boring head in the manual mill to bring the 2 bearing holes to size

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9c.jpg)

The 1/16" oil hole was drilled after spotting with a 2mm end mill

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9d.jpg)

There is quite a bit of cosmetic work to do to make it look more like a forging but I am going to get on with the bearings next.

Cheers,
Rod
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on July 31, 2019, 09:52:51 PM
Hello again.  OK, I really wasn't happy with the con rod so decided to have a go using Fusion 360.  The CAM package has a Denford post processor.  This turned into a really steep learning curve for me but I managed some sort of result after a lot of trial and error testing with the tool path simulation.  Sadly, it turned out that the Denford software/ Computer/Winows Vista combination I'm using couldn't cope and repeatedly crashed halfway through the program  :Mad:

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9e.jpg)

The next fallback was Manual Numerical Control using the DRO on the manual Mill

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9f.jpg)

The circles represent a 4mm 2 flute cutter centered on the big end bearing.  The red figures are for a 3mm ball end mill.  The plan was to hold a fixture in the vice on a rotating base and shift it 2 degrees either side of the centre line to provide the tapers where necessary.

So, this time around the first job was to drill a pair of holes for the bolts that would fasten the end cap on the big end

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9g.jpg)

The end cap was the slit off

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9h.jpg)

and the holes tapped 4mm in the con rod body while the cap was drilled for 4mm clearance

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9j.jpg)

Centres for the big and little ends were drilled through with a 6 mm spotting drill which leaves a very nice 6mm hole indistinguishable from a reamed hole

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9k.jpg)

The con rod blank was then milled on both side to the overall maximum thickness

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9l.jpg)

I mounted a scrap of aluminium in the vice and mounted a pair of 6mm studs at the con rod bearing centres

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9m.jpg)

The con rod was then mounted on these pins and milling and profiling the shape was undertaken using the coordinates in my drawing

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9n.jpg)

The blank was then flipped to do the other face

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9p.jpg)

The little end was tidied up using the rotary table

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9q.jpg)

I centered the con rod using a length of 6mm drill rod held in a collet

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9r.jpg)

The big end was bored out for the bearing using my boring head: I made a plug gauge to get the size correct

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9s.jpg)

I used the ball ended cutter to break up the corner and make it look a little less like a bar stock engine (is that OK Jason?)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9t.jpg)



(http://)



Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on July 31, 2019, 10:42:49 PM
Of course, It didn't go quite that smoothly.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9u.jpg)

On the third attempt I forgot to allow for the cutter width on my drawing and made the big end too narrow  >:(  C'est la vie

The big end needs a 1/16" hole to allow oil to get to the bearing.  This little gizmo is very useful on my mill since have only a rising knee and no quill

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cr9v.jpg)

The big end bearing was cut from an over size lump of bronze and each side faced

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_BEB21.jpg)

The 2 halves were then joined together with solder paste

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_beb22.jpg)

The lump was the rotated in the 3 jaw chuck until the centre was on the split line

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_beb23.jpg)

The bearing was drilled and reamed before mounting on a mandrel.  I turned the smaller diameter with a 1/16" HSS parting tool.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_beb24.jpg)

The bearing needs a pair of semi circular grooves 180 degrees apart to allow clearance (and anti-rotation location) for the studs holding the bearing cap.  There also needs to be a 1/16" hole in the bearing to allow penetration of oil at 90 degrees.  I mounted the bearing, still on its mandrel on the dividing head on the mill and then carefully located the split in the bearing on the spindle centre.  I seem to have forgotten to take any pictures of the actual machining - sorry.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_beb25.jpg)

It wasn't, of course, my first attempt so here is a picture of one I made earlier but in the wrong orientation

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_beb7.jpg)

Cheers for now,
Rod








Title: Re: Tangler's Air Cooled Farm Boy
Post by: Craig DeShong on July 31, 2019, 11:41:03 PM
Hi Rod.  Just picked up on this build.  I have to say that CNC machining must present it’s own set of problems.  Being a programmer for an occupation you’d think I would have gravitated to this type of machining but I guess i’m just old school.  :old:

I also like that you’re showing your attempts.  We’re not infalable ( at least not me) and I appreciate you honesty in showing your previous attempts.  I think it helps the newer guys in seeing that none of us are perfect. 

Watching this build with interest.  :popcorn: :popcorn: :popcorn:
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on August 01, 2019, 08:06:00 PM
Craig,

Thanks for the comments.  It's nice to know that someone is looking in  :)

I wasn't entirely idle during the period that I have been wrestling with Fusion 360, although we did have a nice holiday on The Isle of Mull

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_Otter.jpg)

I've made the crankshaft by fabricating from ground silver steel (drill rod) and Bright Mild steel for the webs.  I drilled and reamed the webs on the mill to get good location using the DRO

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cs1.jpg)

I put an accurate centre into each arm of the shaft for use later

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cs2.jpg)

The crankshaft was then assembled using Loctite retainer. A couple of Jo Blocks were used to keep the spacing correct.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cs3.jpg)

After a couple of days to let the Loctite cure I drilled and reamed for taper pins

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cs4.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cs5.jpg)

I then released the piece of crankshaft between the webs

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cs6.jpg)

Again, I've tried to get rid of the "made from barstock" look by rounding the ends of the crankwebs.  I used half of a cylinder as a filing guide for the crankshaft pin

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cs7.jpg)

The other end of the webs was much easier using my toolpost mill and the GHT HDA

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cs8.jpg)

There are still some keyways but the bulk is done

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cs9.jpg)

It only needed one attempt - things are looking up  ;D

Thanks for looking,

Rod




Title: Re: Tangler's Air Cooled Farm Boy
Post by: Admiral_dk on August 01, 2019, 10:02:37 PM
There are more looking in / following your build - though admittedly not saying much so far.

I can fully relate to certain CNC errors as it took me two hours today, to get a simple rectangular "slot" in a piece of plywood right - it was a "jig" to hold the boxes I needed to "drill" for some prototypes at work  :facepalm:
Title: Re: Tangler's Air Cooled Farm Boy
Post by: Roger B on August 02, 2019, 08:00:01 AM
Glad to see you back on this one  :ThumbsUp:  :ThumbsUp: I hope you can sort out your CNC problems  :killcomputer:
Title: Re: Tangler's Air Cooled Farm Boy
Post by: Johnmcc69 on August 02, 2019, 03:19:08 PM
There are more looking in / following your build - though admittedly not saying much so far.
:popcorn: :ThumbsUp:
 john
Title: Re: Tangler's Air Cooled Farm Boy
Post by: rudydubya on August 02, 2019, 10:11:04 PM
There are more looking in / following your build - though admittedly not saying much so far.

Indeed there are, Rod.  Following along quietly.

Regards,
Rudy
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on August 03, 2019, 06:35:30 PM
Thanks for the love guys  :)

The next job is to bore the holes in the body for the main bearings.  To do that I need to make the bearing caps so it was time to glue the 2 halves of the body together with JB Weld.  I did that yesterday so today I took a skim across the bottom

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cap1.jpg)

I was quite leased with that - I could feel it sticking to the surface plate.  The caps are just some bits of ally which I squared up in the mill and used the DRO to get the hole spacing which I've drilled for 5mm tapping

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cap2.jpg)

The caps were then clamped to the body and drilled through

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cap3.jpg)

I've come to really like these spiral flute taps, almost as much as the tea fairy who appeared at an opportune moment

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cap4.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cap5.jpg)

The caps were fastened in place with some temporary cap head screws.  The bearing caps are taller than they need to be at the moment and I'm thinking that I will give them some fancier shape rather than leaving them square.  The crankshaft needs to be nicely aligned with the cylinder so I clamped the body to an angle plate and then squared it up in both the Y and Z directions

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cap6.jpg)

The distance from the centre line of the crankshaft to the front face of the body is also reasonably critical so I Used an edge finder against the front face and used the DRO to find the correct distance to spot on the split line of the caps and then drilled through the upper cap 1/4"

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cap7.jpg)

I then used a long centre drill to spot the lower cap

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cap8.jpg)

A succession of holes where then drilled using a stub drill for the upper hole and a jobber for the lower where I had the right drills

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cap9.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cap9a.jpg)

The last drill was 12mm of which I only had a jobber length.  I had now run out of headroom using the ER chuck but was able to use a one of the Myford patent collets which are 2mt with a securing nose piece which screws on to the nose of my mill.  I've done a bit of buying and selling part sets of these collets on ebay to acquire some useful sizes in both metric and imperial

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cap9b.jpg)

The final operation was to ream using a 1/2" machine reamer which, oddly, has a 10mm shank

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cap9c.jpg)

Cheers,

Rod


Title: Re: Tangler's Air Cooled Farm Boy
Post by: Jasonb on August 04, 2019, 01:19:29 PM
It's progressing well Rod. The bearing caps will look nicer with a bit of shape to them rather than the boxy drawing shape.

Keep up with the Fusion I'm slowly getting the hang of it and like you my spiral flute taps are the ones I reach for first especially now that Uncle Ketan has topped up the sizes I already had together with a set of spiral point ones.
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on August 04, 2019, 04:59:27 PM
Thanks Jason, I'll give it some more thought.

I had an hour to make the main bearings this morning, They are simple turning jobs from bronze

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_mb1.jpg)

The overall shape was parted off and the reversed into a 1/2" collet before drilling and reaming

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_mb2.jpg)

My 3/8 reamer is of unknown tolerance but I know from experience that it is too tight for a running fit in bronze so I have made a simple D bit from 3/8" silver steel that works very nicely to enlarge the hole. That hardened end has swollen with the heat treatment and measures 0.376" - the untreated bit is a true 0.375

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_mb3.jpg)

This is how the bits go together

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_mb4.jpg)

Thanks for stopping by,

Rod

Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on August 06, 2019, 09:45:54 PM
I've made a start on the flywheels today.  I  bought these a few years ago from College Engineering Supply.  They were being sold off at £25 for the pair and were actually the genesis of the idea of making the Farm Boy.  They are not particularly good quality, I think they were essentially seconds.  They're good enough - nothing that JB Weld can't fix  8)

I mounted them on a faceplate with some sacrificial pads behind the rim and then centered them as best I could on the inner rim which will not be machined

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_f1.jpg)

I turned the rim and sides and faced the central boss.  Then drilled and reamed the central hole for the crankshaft.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_f2.jpg)

I then turned it around on the faceplate, centered it according to the rim and faced the other side

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_f3.jpg)

A little bit of novel excitement now.  I took advantage of a couple of recent discount offers from ARC and Machine Mart to buy a 2 and 3mm set of push broaches and a small arbor press.  The drawing calls for 1/8" key way but I think that 3mm will be fine.  I did need to make a new guide to suit the 3/8" hole in the flywheel.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_f4.jpg)

And so I got to play with the press as well.  It all went very smoothly.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_f5.jpg)

Rod



Title: Re: Tangler's Air Cooled Farm Boy
Post by: Johnmcc69 on August 06, 2019, 10:16:36 PM
Nice work Rod!
 Is the broach secured in the arbor press? I have a small press & have often thought about adding some sort of block or chuck to hold tools.

 John
Title: Re: Tangler's Air Cooled Farm Boy
Post by: b.lindsey on August 07, 2019, 02:33:59 PM
Its beginning to look like an engine now Rod. Nice work on all the recent parts!!

Bill
Title: Re: Tangler's Air Cooled Farm Boy
Post by: Don1966 on August 07, 2019, 03:01:45 PM
Just finish catching up on your build Rod always great work and setups. What I am surprised about is you haven’t build the micrometer dial for the Mayford tailstock yet. ...... :praise2:


 :cheers:
Don
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on August 07, 2019, 03:54:15 PM
Hi Chaps,

John,  The arbor press just has plain end.  I've only used it for the broaching and pressing in the bearing on the little end of the connecting rod.  I'm sure it could be modified if required.

Don,  I have been tempted. Gray, as usual, has designed a very elegant solution but I have been satisfied with my own fix for a few years now and it's dual reading   8) :

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_tailstock.jpg)

I've been doing some sums today.  Jerry's drawing calls for 48DP 72T and 36T gears to provide a half speed drive for the cam.  I have set of 0.5MOD gear cutters.  PCD of the 72 T gear is 1.5" which is 38.10mm.  PCD of 0.5MOD 76T gear is 38.0mm.  Good enough.  Jerry also calls for the larger gear to be made of brass or bronze with the smaller gear being steel.  Good engineering practice but surely not usual in full size engines.  Anyway, I haven't got a suitable bit of brass or bronze so both will be made from FC steel  :o

Cheers for now.
Title: Re: Tangler's Air Cooled Farm Boy
Post by: Jasonb on August 07, 2019, 04:07:56 PM
All the hit and miss engines I have made have had both gears in steel so can't see that as a problem.

Those are quite fine teeth you could probably come upto 24DP or 1MOD quite easily if you have the cutters.
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on August 08, 2019, 11:50:02 AM
I've got a set of 0.8MOD cutters.  48T has a PCD of 38.4mm and 24T half that at 19.2.  Seems like a better option,  I'll be adjusting the position of the crankshaft gear to fit anyway.

Cheers,

Rod
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on August 09, 2019, 04:40:52 PM
The first job with the gears was to slice off a piece of Free Cutting mild steel

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_g1.jpg)

I faced this and then drilled and reamed as before 3/8"

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_g2.jpg)

The blank was then fastened on to a mandrel and turned to the required OD for the gear.  When I can I like to make my mandrels from Precision Ground Mild Steel so I can keep them and then re-mount in a collet for accuracy.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_g3.jpg)

Getting the centre of the gear cutter is tricky since, in my experience, the cutting teeth are not necessarily in the centre of the tool.  Eyeballing seems to be the best method but care has to be taken to avoid parallax error as seen in the photo where the camera was not truly in line with the cutter.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_g4.jpg)

On my dividing head, 48 divisions is 1 and 1/4 turns - 1 turn and 15 holes on the 60 hole plate

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_g5.jpg)

Each tooth was cut to the full depth in one pass.  Always a relief when the final tooth is at the correct spacing

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_g6.jpg)

Rinse and repeat for the 24 T gear, 2 1/2 turns for each tooth.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_g7.jpg)

The gears were finished to thickness in soft jaws trimmed to size

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_g8.jpg)

The smaller gear has a boss for a set screw.  I'm going to have to make some new heaxagons for the jaws soon.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_g8a.jpg)

I drilled the hole for a M3 grub screw using my tool post milling attachment which is set on centre height

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_g9.jpg)

Here's the pair of finished gears.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_g9a.jpg)

The plan is to make all the stuff that goes in-board of the flywheel on the governor side so that I can make sure that the spacing is correct before I cut the keyways in the crankshaft.

Cheers for now,

Rod

Title: Re: Tangler's Air Cooled Farm Boy
Post by: Admiral_dk on August 09, 2019, 08:08:35 PM
Those gears came out great  :ThumbsUp:    :cheers:
Title: Re: Tangler's Air Cooled Farm Boy
Post by: Roger B on August 10, 2019, 05:36:10 PM
Excellent gears  :praise2:  :praise2:  :wine1: Something I need to try one day (along with CNC and … and …)  ::)
Title: Re: Tangler's Air Cooled Farm Boy
Post by: bruedney on August 10, 2019, 09:02:39 PM
I've got a set of 0.8MOD cutters.  48T has a PCD of 38.4mm and 24T half that at 19.2.  Seems like a better option,  I'll be adjusting the position of the crankshaft gear to fit anyway.

Cheers,

Rod

Hi Rod
I am just setting out on a water cooled journey and am going to metricise the build and have been wondering about the same issues. You say above you are going to adjust the position of the crankshaft gear. Does that mean you are going to move the crankshaft & bearings? I would have thought the big gear would be the easier one to move.

Watching with interest

Bruce
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on August 10, 2019, 09:29:21 PM
Hi Bruce,

No, that was clumsy phrasing on my part.  I'll adjust the position of the cam shaft so that the  2 gears mesh correctly.  In your metric version I guess you could go to even coarser gears as Jason suggests.  I wonder why Jerry chose such fine gears although it does provide the ability to have finer adjustment of the timing.

Cheers,

Rod
Title: Re: Tangler's Air Cooled Farm Boy
Post by: bruedney on August 11, 2019, 01:53:07 AM
Thanks for the clarification

Bruce
Title: Re: Tangler's Air Cooled Farm Boy
Post by: Jasonb on August 11, 2019, 07:30:51 AM
I wonder why Jerry chose such fine gears

Probably had the cutters to hand.

Looking at your finished gears I would say that tooth size looks about right though 1MOD would not be a lot larger and easy to buy complete gears cheaply if you don't want to cut them.

I've also just done some 0.8MOD size ones. 21T & 42T

(https://img.photobucket.com/albums/v156/jasonballamy/Engineering/Midget/20190810_191412_zpsnaaedg67.jpg)
Title: Re: Tangler's Air Cooled Farm Boy
Post by: b.lindsey on August 11, 2019, 12:43:38 PM
Fine looking gears and a nice family shot too Rod. Still following along with your build.

Bill
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on August 14, 2019, 08:24:50 PM
The cam is a simple 2 radii job.  The OD was turned to the diameter of base circle plus lift, then I mounted the blank on a mandrel in the dividing head a milled across the base circle at 3degree intervals (that's half a turn on the DH)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cam1.jpg)

I like to say a little mantra to myself on these types of jobs:

Turn  (rotate the dividing head to the next hole)
Sector  (move the sector arms ready for the next turn)
Cut  (move the job under the cutter)
Mark (cross off the cut on the list)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cam2.jpg)

I used a dead smooth (#6 cut) file to get rid of the machining marks and parted off the finished cam

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_cam3.jpg)

The spool is the bit that slides along the crankshaft to actuate the miss mechanism, driven by the governor's balls.  This a simple turning job but it needs a pair of slots on either side for the governor arms.  Again, I mounted it on the 3/8" mandrel in the dividing head and used a little 1/8" FC3 cutter after carefully lining everything up and zeroing the centre of the cut on the DRO.  Then rotated through 180 degrees and repeated

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_spool1.jpg)

This all went very well.  Since I changed the drive belt on the mill to poly V it runs very smoothly and quietly at 2800rpm

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_spool2.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_spool3.jpg)

That's all for the moment.

Title: Re: Tangler's Air Cooled Farm Boy
Post by: Jasonb on August 14, 2019, 08:31:28 PM
Rod, on a job like that does it really need the sectors moving? I tend to do as you said and simply do half a turn or one turn of the handwheel etc, 10mins either way won't make a lot of difference. At the most plate with two opposite holes marked with a sharpie will be Ok.
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on August 20, 2019, 10:00:42 PM
This job is the governor weight fulcrums and hub.  The fulcrums were first roughed out (very!).  The important spacing is the distance between the fulcrum holes and their height from the base.  By using a pair of filing buttons of 1/4"OD in the holes that pretty well defines the shape, the arms just need to be mounted at the correct angle in the vice before milling across, using the buttons to get the thickness.  The pair were sandwiched together with 8BA screws.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_gwf1.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_gwf2.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_gwf3.jpg)

The hub is also brass.  Jerry calls for the OD to be 1.045" but I've only got 1" so that will have to do.  My problem here is that I will need to hold the hub in something in order to mill the slots for the arms.  I decided on an ER25 collet block so turned a stub to 15mm diameter to fit in a collet

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_gwf4.jpg)

With the collet in the lathe I turned the hub to final thickness and then put a tiny centre in so I can find it in the mill

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_gwf5.jpg)

I've never actually used this pointed "edge finder" before and am not sure how they are supposed to be used but a finger seemed to work to determine whether the parts were concentric

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_gwf6.jpg)

So, with the DRO zeroed on centre I could cut the 2 x 1/8" slots

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_gwf7.jpg)

The holes in the arms were opened out to 3/32" with a reamer

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_gwf8.jpg)

A couple of lengths of 3/32" rod kept the arms aligned and they were anointed with soft solder paste and then warmed up with a torch until the solder flowed.  I had to ease the slots slightly with a file to give the solder some working room.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_gwf9.jpg)

The problem now was that I need to bore a 0.602" hole and the spigot is only 0.591.  Fortunately, the jaws of my little 4" 4jaw (just) fit between the arms.  I hadn't thought that through, I was just lucky  :-[

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_gwf9a.jpg)

Here it is, pretty much finished but I'll probably do a little more filing to tidy things up.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_gwf9b.jpg)

This is my rather Heath Robinson set up for ball turning.  The dividing head has a choice of seats.  It was manufactured on the Myford so the bore in this configuration is automatically on centre height.  On the other face the centre height is greater and allows a 4" chuck to be used on the mill.  The tool holder was made from an orphaned Flexispeed top (compound) slide riveted to a N0.2 Morse Taper.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_gwf9c.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_gwf9d.jpg)

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_gwf9e.jpg)

A pair of Governer's Balls.

(http://lister-engine.com/coppermine/albums/userpics/10027/normal_gwf9f.jpg)

Cheers,
Rod
Title: Re: Tangler's Air Cooled Farm Boy
Post by: Brian Rupnow on August 21, 2019, 12:12:11 AM
Tangler--You are doing nice work. when I get into assemblies that are as small as you show, I generally make a "one time use" jig to hold everything in position for soldering, then the jig is cut away.---Brian
Title: Re: Tangler's Air Cooled Farm Boy
Post by: Jasonb on August 21, 2019, 08:13:40 AM
You are making good progress on this one now Rod, your ball turner leaves a nice slim attachment point.

Your post about the cam got me thinking about the ones I need for the present engine so I put them into F360's CAM and hopefully later today will post in the Darkside thread that it cut each cam in just over 2mins.
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on August 21, 2019, 09:53:18 AM
My intention had been to use the Denford/Sherline mill to make the cam - it should be a simple profiling job.  Sadly the mill has not been playing ball.  I've been driving the mill from a laptop via a USB to serial converter which seems to lead to communication errors.  I'm currently in the process of  resurecting an old XP desktop which I had been hoarding because it has a parallel output which could be useful for  Mach 3.  It doesn't have a serial output so I'm waiting for Ebay to provide me with a PCI serial card.

Rod
Title: Re: Tangler's Air Cooled Farm Boy
Post by: tangler on September 12, 2019, 06:20:32 PM
Sorry for the delay, hassle with the CNC mill (still bust) and the acquisition of a sailing dinghy for playing in Christchurch harbour have distracted me.  Also, I've been hosting my pics on the Coppermine Lister forum.  Although this was a generous offer, you may have noticed that the resolution and image size is not great and the bulk upload feature seems to be arguing with Flash.  So, I'm now trying to use Flickr...

Fabrication of the governor mechanism continues.  This little assembly needs a pivot with 2 arms at right angles - one holds the ball and the other actuates the catch lever spool.  The pivot was drilled for 2 off 1/8"  holes

(https://live.staticflickr.com/65535/48721314683_1c2b16acba_b.jpg)

Jerry calls for the bits to be assembled with silver bearing soft solder.  I'm more comfortable with hard silver solder so here they are anointed with silver alloy brazing paste.  The steel supports were roughly turned down ( horrible sticky steel ) to a diameter to ensure that the arms were parallel to the base

(https://live.staticflickr.com/65535/48721649236_1a1a4886da_b.jpg)

They were then warmed up with a torch 'til the solder flowed

(https://live.staticflickr.com/65535/48721649286_9123b648d1_b.jpg)

The outboard end of the balls have little brass mounts for the spring.  The drawing shows a plain shank to be Loctited in place.  I prefer a thread which will be screwed 8BA and Loctited in the correct orientation

(https://live.staticflickr.com/65535/48721314708_05b2406566_b.jpg)

Once threaded this was held in a little fixture that is just a hole threaded 8BA.  I have a few of these of various sizes made from Precision Ground Mild Steel so that they can be re-used in a collet chuck.  First chamfered

(https://live.staticflickr.com/65535/48721826927_a4c8fbf389_b.jpg)

and the round end finished with a hand graver

(https://live.staticflickr.com/65535/48721826932_d9766c0348_b.jpg)

The flats were then milled and the hole drilled using the toolpost miller

(https://live.staticflickr.com/65535/48721649326_3e04a4ab0c_b.jpg)

The pivot pins are 3/32" and I decided to retain these using 3mm E clips so the pins were grooved using my modified hacksaw parting/grooving tool from a Len Mason Design

(https://live.staticflickr.com/65535/48721827002_7f9407f0b2_b.jpg)

These bits now need to be fitted to the flywheel and the next step will be to make the flywheel collets and machine the matching tapers in the flywheels themselves

(https://live.staticflickr.com/65535/48721649406_33bac6a0d1_b.jpg)

Cheers for now,
Rod





Title: Re: Tangler's Air Cooled Farm Boy
Post by: Don1966 on September 12, 2019, 09:02:14 PM
Real nice work Rod and love the use of your various tools. ...... :ThumbsUp:



Don :cheers:
Title: Re: Tangler's Air Cooled Farm Boy
Post by: DavidLloyd on September 13, 2019, 12:48:17 AM
Excellent Job Rod,

DavidLloyd
Title: Re: Tangler's Air Cooled Farm Boy
Post by: Craig DeShong on October 04, 2019, 01:35:43 PM
Very nice Rod.  I've been silently following along.  Past time to comment.  I just love your work!
Title: Re: Tangler's Air Cooled Farm Boy
Post by: Brian Rupnow on October 05, 2019, 01:09:13 AM
Tangler--You are doing marvelous work. I am following.---Brian