Author Topic: Quarry Bank Mill Engine  (Read 8468 times)

Offline Captain Jerry

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Re: Quarry Bank Mill Engine
« Reply #45 on: February 08, 2019, 12:18:25 PM »


Dave


I should have thought to get some pictures but at the time, I was too absorbed by the problem and too aware of the consequence of failure to pick up a camera.  The hole has not been reamed and was used help in holding.  One of the concerns was keeping the cap registry while the sides we milled to thickness.  The bolts are not enough and I don't trust superglue under the impact of milling so I clamped down on a slug of 3/8" rod.  The rod was also used as a pivot to get the top radius. The bore will have brass or bronze bushings which will be reamed in place.


Jerry


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Offline steamer

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Re: Quarry Bank Mill Engine
« Reply #46 on: February 08, 2019, 12:23:20 PM »


Dave


I should have thought to get some pictures but at the time, I was too absorbed by the problem and too aware of the consequence of failure to pick up a camera.  The hole has not been reamed and was used help in holding.  One of the concerns was keeping the cap registry while the sides we milled to thickness.  The bolts are not enough and I don't trust superglue under the impact of milling so I clamped down on a slug of 3/8" rod.  The rod was also used as a pivot to get the top radius. The bore will have brass or bronze bushings which will be reamed in place.


Jerry

Sounds good Jerry!    Yeah I get the "pucker moment can't take a picture right now ....glad I'm not the only one.     It's coming along great!

Dave
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Offline Captain Jerry

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Re: Quarry Bank Mill Engine
« Reply #47 on: February 23, 2019, 01:28:52 AM »
More to report.  I have been putting in some time to get this going and I have been following the mantra of my uncle Ralph who often said "measure if you have to, keep cutting till it fits, and don't be afraid to start over."  Uncle Ralph was a perfectionist of a different order.  He had a reputation as the best Rolls Royce mechanic  between NYC and Miami and had a customer following in the 1920's during the seasonal north/south migration of wealthy owners.


He chewed tobacco but also had his tongue in his cheek most of the time. I try to be a little more careful and have not had many do-overs but I have modified the design a few times to more closely match my work.  I haven't posted much, partly because my couch time is mostly taken up following the really great works in progress and partly because what I have been doing is pretty commonplace milling aluminum bar stock.  I did get into the brass recently but nothing out of the ordinary. 


Yesterday, I did get into something a little bit different so I thought I would post some pictures.  There is not very much different that you can do with eccentric followers but I will try.  These will be cut on the bias, a 30 deg slant, unlike the original that uses a typical 90 deg dividing line.  There are two practical reasons for this.


The first reason is because the location of the valves, that angle down to the crankshaft, the bottom stud or bolt is difficult to see or reach,  Using the bias cut design makes both of the studs point up at a 15 deg angle for easy service and assembly.


The second reason is that it is common to provide an oil hole in the follower and that can be done much more easily with no interference with the top joint and the oil hold is functional, whether the engine is mounted level or vertical. There is slightly less waste material as well.


I'm going to post this now and return with pictures in 30 min
NOTARY SOJAK

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Offline Captain Jerry

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Re: Quarry Bank Mill Engine
« Reply #48 on: February 23, 2019, 02:41:58 AM »
It didn't take 30 mins. but the dogs came over with an urgent plea to be let out and I hate to leave an unfinished post open,


The first step is to get a piece of 1/8" brass,  1" x 1.5" centered up.  I drilled a small hole which will be used as a positioning aid later:


EccFollowerl0001 by captain.jerry Ginn, on Flickr

Then three corners are nibbed out which could be done with an end mill but since I'm going to be using a slitting saw soon to split the blank, I decided to use it for this as well.  Also quieter and less swarf with the saw.

EccFollowerl0009 by captain.jerry Ginn, on Flickr

EccFollowerl0009 by captain.jerry Ginn, on Flickr

The fourth corner is cut at an angle, also using the saw.  This will provide a face for the arm.

EccFollowerl0010 by captain.jerry Ginn, on Flickr

EccFollowerl0011 by captain.jerry Ginn, on Flickr

Look carefully at his picture,  It is a 7/32" hole, drilled in the edge of a 1/8" plate.  The drill bit that I used is a bit of an odd-ball design by Dewalt.  It has a small pilot tip followed by the body of the bit at full diameter with cutting edges at 90 deg to the axis, almost like a Forstner Bit but with a pilot drill tip instead of a tapered wood screw tip and without the grain shearing knives at the perimeter.  It works very well in aluminum and brass but I will stick with the standard tip for steel.  In this case, I have used it without drilling a pilot hole first and the breakouts on the sides are very clean and there was no evidence of wandering.  The hole is only .25" deep.

EccFollowerl0012 by captain.jerry Ginn, on Flickr

Holes drilled and tapped #2-56 for clamp bolts/studs.

EccFollowerl0012 by captain.jerry Ginn, on Flickr

EccFollowerl0014 by captain.jerry Ginn, on Flickr

And then split down the middle with a slitting saw.

EccFollowerl0015 by captain.jerry Ginn, on Flickr

Now it is just a matter of screwing the halves together, drilling the center to .625", and profiling the outer edge to .700"

EccFollowerl0016 by captain.jerry Ginn, on Flickr

And here it is at 5/8" after first going 1/4", and 1/2" to prevent grabbing of the cutting edge by the thin material.

EccFollowerl0018 by captain.jerry Ginn, on Flickr

This is a poor quality picture but you can now see the purpose of the big hole in the small plate edge.  It makes a good looking joint as well as a very strong joint.  It is fairly easy to turn a force fit tenon on a 1/4" bar.

EccFollowerl0019 by captain.jerry Ginn, on Flickr

The rod is then profiled and the clevis hoe drilled.

ecc follower arml0001 by captain.jerry Ginn, on Flickr

ecc follower arml0002 by captain.jerry Ginn, on Flickr

I made two of these of course but only photographed one.  Then I turned the eccentrics to fit the followers.  I will hold off on drilling the eccentric offset for now.  Only a few more parts now and the parts crew will be finished.  It may be time to put the assembly crew on alert.

Jerry
« Last Edit: February 23, 2019, 08:28:03 AM by Jo »
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Offline Captain Jerry

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Re: Quarry Bank Mill Engine
« Reply #49 on: February 23, 2019, 02:55:18 AM »
I am really disturbed. I spent a good amount of time writing a detailed description of the above photographs that should have appeared between  each pictures and none of the interspersed text got posted.  Rats!!!


Oh well, you guys are smart, you will figure it out.  Ask questions if it is not clear what is going on.  I don't have the energy to go back and try to edit it tonight.  Maybe tomorrow after my meds kick in.


Jerry
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Online crueby

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Re: Quarry Bank Mill Engine
« Reply #50 on: February 23, 2019, 03:13:19 AM »
I really like the design of that. Will the arm from the follower be silver soldered in place?

Offline Jo

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Re: Quarry Bank Mill Engine
« Reply #51 on: February 23, 2019, 08:28:32 AM »
I am really disturbed. I spent a good amount of time writing a detailed description of the above photographs that should have appeared between  each pictures and none of the interspersed text got posted.  Rats!!!


All fixed  ;)

Jo
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Offline Captain Jerry

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Re: Quarry Bank Mill Engine
« Reply #52 on: February 23, 2019, 02:18:58 PM »
Jo, thanks for the fix.  Where did I go wrong? Did I exceed some limit?
 
Chris, thanks for the comment.  The slanted part is not an original design concept.  I first saw it on this forum in photographs of a beam engine in a museum but I can't recall anything more specific.  It is also useful where the crankshaft is close to the base. 


The big hole in the edge may be an original concept.  I don't remember ever seeing it anywhere but who knows?  All of our ideas are the result of accumulated exposure to other ideas.  I had first thought of milling a slot on the end of the arm but my 1/8" end mill produced a slightly oversize slot and the fit was not adjustable.  I can't adjust the size of the hole that the drill bit makes but turning a tight fitting tenon is easy.  The curve at each side of the slot provides a very stable connection.  The fit is so tight that adjusting the angle of the rod to get the pivot hole in line with the eccentric bore required the use of a fair amount of force.  Silver solder not in my skill set.  Soft solder may be used mostly for the cosmetic of blending the exposed end of the rod.  If I use threaded rod for the stud (I will) the end of the stud adjacent to the arm can be used as a set screw to clamp the end of the rod.




EccFollowerl0019 by captain.jerry Ginn, on Flickr


Jerry
« Last Edit: February 23, 2019, 02:33:39 PM by Captain Jerry »
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Offline Jo

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Re: Quarry Bank Mill Engine
« Reply #53 on: February 23, 2019, 04:52:12 PM »
Jo, thanks for the fix.  Where did I go wrong? Did I exceed some limit?

For some reason your post had some odd HTML code in it  :headscratch: I can only think it was picked up when you put your links in to the photos and where the HTML code had not been 'closed' our site assumed it had to be sent to the photo hosting site as part of the image insertion request... All very odd   :zap:

Jo
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Offline Captain Jerry

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Re: Quarry Bank Mill Engine
« Reply #54 on: February 28, 2019, 01:45:48 PM »
Having completed the eccentrics, I could begin to assemble the crankshaft.  I have never used a crankshaft this long.  It is 4" between the outer bearings with a third bearing in the middle so it must be STRAIGHT!  The piece of TGP steel shaft that has been lying in my storage for over two years, that I intended for this job is not.  It looks pretty good until th e bearing caps are fitted.


Is it possible to straighten this shaft that measures about .010" out in the center of 5" length?
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Offline Captain Jerry

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Re: Quarry Bank Mill Engine
« Reply #55 on: March 04, 2019, 03:14:03 AM »
Well it is apparently not possible to straighten a shaft like this one or at least not easy.  All of my efforts just made it worse so I will take another approach.  I could order another shaft but part of the purpose of this project is to use stuff that I have on hand so I will make one.  I have a bunch of 3/8" mild steel rod with a head on one end and a point on the other ( 60d nail ) that I have used for other parts so why not for the shaft?


I don't know how straight it is but won't the process of turning it in the lathe take care of that?  Well not on the first attempt.  I know that I should set up between centers instead of driving it with the three jaw but if i'm going to do this from one setup whats the difference?  I'm going to cut off the short piece at the chuck end anyway so the part will be spinning on the spindle axis anyway.  I did center drill the tailstock end and set it up on the ball bearing center.


Well, here is the problem.  I used a freshly sharpened tool bit but the material is relatively soft, and even using a conservative feed, the force on the cut was hard to keep even.  It would go along smoothly, turning up a nice, even curly chip and then it would dig in a bit, causing the stock to deflect upwards before the cutting edge would break out and continue cutting evenly.  Of course the rising stock is more of a problem in the middle of the rod than it is at either end and even if the bit wasn't digging in and jumping, just the cutting pressure of the normal cut was causing the rod to deflect upwards and change the effective radius of the part.  Scrap one part.


My analysis was that the 3-jaw was the problem.  Not because it is not perfectly centered but because it gripped to hard. When the bit digs in, the torque to keep turning the rod goes way up and it is that torque that causes the rod to deflect upwards.  What if the rod just stalled when the torque got too high?  My solution was to take another short length of nail, Put it in the chuck, and turn a point on it to match the angle of the center drill hole.   The rod is set up between two centers.  A hard one on the tail end and a soft one in the 3-jaw.  The only torque turning the rod is provided by the friction  of the soft point in a center drilled hole.  If the torque load gets too high, the part will just stop turning.  Un-believably, it worked.  No upward deflection.  Occasional stalls but one I got the feed rate and depth of cut worked out, it went smoothly and I got a six inch long shaft with only about .002" difference over the whole length.   By the way,  the optimum DOC was about .004" and the feed very damned slow.  But it is done. It only took about 25 passes and was boring as hell and you would not enjoy a picture of me asleep at the lathe.  But I caan now proceed with the crankshaft.


I got the two throws assembled, pinned and trimmed but before pinning them on the shaft, I had to do one more trial assemble to check clearances.  Its pretty damned close in there. 


This is really a simple project.  I'm just making it complicated by thinking about it to much. Here are some pics of the last trial assembly.


clearaancesl0001 by captain.jerry Ginn, on Flickr


And this one too


clearaancesl0006 by captain.jerry Ginn, on Flickr




clearaancesl0004 by captain.jerry Ginn, on Flickr




Jerry
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Offline Gas_mantle

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Re: Quarry Bank Mill Engine
« Reply #56 on: March 04, 2019, 08:46:56 AM »
Its coming along nicely Jerry  :)

Offline Captain Jerry

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Re: Quarry Bank Mill Engine
« Reply #57 on: March 22, 2019, 03:36:52 AM »
It has been several weeks since I have posted any progress but progress has been made.  I believe that I have completed all of the mechanical parts.  There remains plenty of work on the ancillary parts such as the flywheels and of course the piping, and of course all of the fiddly stuff to make it run smoothly and then the cosmetic work to make it look nice.


I have spent the last several days assembling all of the parts into a single assembly with the goal of seeing if it will go 'round and 'round without obstruction and interference.  It took several attempts.  Most of the moving components fit together but the height of some of the fasteners had not been allowed for in my planning.  The only major screw up was that I had somehow misread a dimension and made the crank throws too long by .010" which caused only a small correction to the piston thickness but with an overcrank design it created all sorts of havoc in the relationship between the length of the connecting rods and the return thrust plates.  I was able to recover from this near disaster with some modification of the conrod  bearings.


Here it is, all put together:


Motion l0006 by captain.jerry Ginn, on Flickr


I would like to thank Stew Hart for bringing this offbeat engine to our attention with his postings here and on his other forum.  I would also like to thank him for failing to mention what a nightmare it is assembling this thing and not mentioning that if  the builder was a little careless or forgetful that he would find himself repeating the process more times than he wanted too. Thanks, Stew.  I see now that I will repeat the process many more times before this is over.


It does go 'round and 'round!  I am going to attempt to post a short video here but as I have not used Flicker for videos, its a gamble.  If it doesn't come through, I will work on it tomorrow.


MVI_2229 by captain.jerry Ginn, on Flickr


Thats all for now.


Jerry
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Offline sbwhart

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Re: Quarry Bank Mill Engine
« Reply #58 on: March 22, 2019, 07:23:18 AM »
The Video worked for me Jerry

Quote :- I would like to thank Stew Hart for bringing this offbeat engine to our attention with his postings here and on his other forum.  I would also like to thank him for failing to mention what a nightmare it is assembling this thing and not mentioning that if  the builder was a little careless or forgetful that he would find himself repeating the process more times than he wanted too. Thanks, Stew.  I see now that I will repeat the process many more times before this is over.

You have to keep some issues to your self otherwise you make things to easy and there's is no challenge  :mischief: :mischief: :mischief:

Great work Jerry you'll forget all the trials and tribulations when you have it up and running.

Stew
A little bit of clearance never got in the way

Offline Jo

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Re: Quarry Bank Mill Engine
« Reply #59 on: March 22, 2019, 08:23:49 AM »
I would also like to thank him for failing to mention what a nightmare it is assembling this thing and not mentioning that if  the builder was a little careless or forgetful that he would find himself repeating the process more times than he wanted too. Thanks, Stew.  I see now that I will repeat the process many more times before this is over.
Quote
You have to keep some issues to your self otherwise you make things to easy and there's is no challenge  :mischief: :mischief: :mischief:

I could mention a few other models that are like that to put together :facepalm2:

Jo
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