Author Topic: Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine  (Read 8062 times)

Offline mikehinz

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I've made a start on my 3rd engine.  This one is going to be the famous Pottyengineering Horizontal Mill Engine as originally created and drawn by Mr. Stewart Hart.  Since I'm located in the US and Imperial fasteners and tooling is the most readily available, I decided to build the engine in Imperial measure and use the closest and most appropriate sized fasteners and stock.  Additionally, in my seemingly unending quest to learn 3D CAD, I created a model using Fusion 360 and will generate drawings from that model as I go along. 

I've linked a YouTube video that I just did of the animated model just showing that it all works and that there are no apparent collisions or other issues.  I've also posted a couple of renderings of how I've been thinking about the appearance of the engine.  My decisions to this point are to purchase a 4" cast flywheel from Martin Model & Pattern, some oil cups from PM Research and scale model fasteners from American Model Engineering Supply.  I've also tried to use some brass parts for accent and plan to use a brushed type of finish. 

I'm ordering the materials that I don't have on hand right now and will be starting a bit slowly as I'm in the process of making a few mods to my shop equipment including installing a DRO on my lathe.  But I'm now at least making process on engine number 3!



Enjoy and follow along!

Mike
MIke
Wichita, KS, USA

Offline b.lindsey

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Re: Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine
« Reply #1 on: October 09, 2018, 10:16:04 PM »
This will be a nice addition Mike. I will be following along.

Bill

Offline Johnmcc69

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Re: Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine
« Reply #2 on: October 10, 2018, 12:35:41 AM »
Looking good Mike.
 I'm on board.

 John

Offline mikehinz

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Re: Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine
« Reply #3 on: October 13, 2018, 02:00:37 AM »
An exciting day, I got started on the engine! 

I decided to start with the aluminum base as there are a number of parts that have to fit on the base properly all have to align pretty closely.  As per my previous post, I'd modeled this up in Fusion 360 and have started generating working drawings from the model.  The engine worked in F360 so I'm reasonably confident things will fit, as long as I don't screw up the machining!   I thought I had some 1/4" AL for the base but it turned out I didn't when I actually looked for it, so yesterday I made a trip to The Yard here in Wichita and picked up a piece of 1/4" scrap 6061 plate they had. Prices there for drops are extremely cheap, currently $1.70/pound and they have almost any size and shape of AL that you could dream of.

Anyway, on to the machining!  First pix is after sawed a piece more or less to shape and then squared it up and brought it to the spec'd dimensions, 9" x 2.25".  This is drilling the clearance thru holes for the #10 mounting bolts


Next pix shows what you (or at least what I did) when you don't have a proper counterbore tool on hand for 4-40 shcs.  I just put a 2 flute 3/16 end mill in the drill chuck and plunged in with the quill at each required location to .115".  It worked perfectly as far as i could tell.


Tapping 4-40 in 4 locations.  I kicked the mill out of gear and simply rotated the chuck by hand while putting light pressure on the quill.  I'd drilled for 75% threads and this process went smoothly.  No broken taps and a test 4-40 shcs went in each hole with a good fit.


Here's the finished AL base plate on top of the drawing.


I also started on the crankshaft supports.  The drawing spec'd 5/16" plate and I only had some 3/8" on hand.  I cut a piece to rough shape then squared it up in the mill and brought it width.  I then used a flycutter to take the plate down to 5/16".  After getting to the required thickness, I cut that piece in half and the pix shows bringing them both to the required height fo 1.60".  I did them both at the same time to get them as equal in height as I could.  This pix just shows the final measurement.  I used a 3/4" HSS 4 flute end mill.  Worked well.


The last pix of machining today shows the crankshaft support pieces on top of the drawing.  The next time I work on this I'll try to complete these pieces, being careful to get the bearing holes as exactly to the same height as closely as I can and will turn the bronze bushings and get them pressed into place. 


And the final pix of the day is of some parts that arrived.  I ended up getting a 4 1/2" cast flywheel from Martin Model and a small selection of scale model fasteners from American Model Engineering Supply.  Both vendors had excellent service with extremely fast shipment and the quality of everything is extremely good. 


All for today.  I need to place another order for some raw material.  I need a bit of drill rod and some 1/4" square stock for the crosshead slides as well as a few other small items.  I'll try to get an order in tomorrow.  I also need to work on a few more working drawings for the next parts I want to attempt.  That always takes me a bit longer than I anticipate and I end up redoing them a couple of times generally.

Enjoy!

Mike
MIke
Wichita, KS, USA

Offline sbwhart

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Re: Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine
« Reply #4 on: October 13, 2018, 07:04:56 AM »
Good Start Mike, I'll be watching with interest  :ThumbsUp:

Stew
A little bit of clearance never got in the way

Offline mikehinz

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Re: Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine
« Reply #5 on: October 13, 2018, 02:06:21 PM »
Stew, the credit on this one fully goes to you!  Your drawings are excellent and more than sufficient to build the engine.  Its a very nice design and I hope when it's finished it does credit to you!

Thanks!

Mike
MIke
Wichita, KS, USA

Offline JC54

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Re: Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine
« Reply #6 on: October 13, 2018, 07:27:16 PM »
Looking good Mike. As a beginner I like how you say what tool you used for each operation, really helps me. Thanks. JC

Offline mikehinz

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Re: Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine
« Reply #7 on: October 13, 2018, 08:01:04 PM »
If that's helpful info, I'll try to remember to put whatever tool info along with the speed and feed I used.  I'm afraid I won't always remember exactly what I did though!

Mike
MIke
Wichita, KS, USA

Offline mikehinz

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Re: Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine
« Reply #8 on: October 14, 2018, 03:29:19 PM »
I managed a bit of work yesterday but didn't get to post it until now.  My wife and I ended up taking one of the grandsons out for pizza yesterday evening. 

Anyway on to yesterdays shop work!

I wasn't really ready to work on it, but I couldn't resist a bit of examination and cleanup work on the flywheel.  To my inexpert eye, the flywheels looks very good straight from the package.  There was a very modest amount of flash and there didn't seem to be any hard spots that I encountered while filing.  First pix is showing the flywheel in my vise between the soft AL jaws and using a fairly large round file to clean up the inside of the rim a bit.


This photo shows just a couple of the files I used.   There was actually a 3rd round file, a very small round file, that I used at the spoke junctions at the rim and at the hub.


I'll make this a separate post as I do have a question regarding fettling on cast parts:  How far to do you go on the cleanup?  I want the flywheel to look like it's a cast piece so I don't want it too smooth.  IMO the flashing needs to be removed but what about unevenness at the parting lines?  In some areas of the flywheel the parting lines are very even and at other areas they are a bit offset.  Do most people leave them as uneven or do you level those areas out?  I know that growing up on a farm and from being around lots of old equipment, that machinery typically had quite rough castings with very little apparent cleanup done at the factory other than the machined surfaces so that's the look I'm used to.  But I really do want to know what people think.

Thanks!

Mike
MIke
Wichita, KS, USA

Offline pgp001

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Re: Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine
« Reply #9 on: October 14, 2018, 03:32:16 PM »
You haven't been using those files without handles fitted have you  :ThumbsDown:
Or are they just out of shot in the photo's.
Phil

Offline Jo

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Re: Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine
« Reply #10 on: October 14, 2018, 03:45:36 PM »
Fettling wise they look good.

But I am with Phil: using files without fitted handles is dangerous  :paranoia: Handles are cheap enough and make sure that they go on nice and tight so they can't come off again :ThumbsUp:.

Jo
Usus est optimum magister

Offline mikehinz

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Re: Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine
« Reply #11 on: October 14, 2018, 03:55:37 PM »
The continuation of yesterday's work. 

I started on the crankshaft stands.  Since the bearings has to be quite well aligned, I decided to do the ops on the bearing locating hole on both pieces at the same time.  I started by lighty clamping the 2 pieces stacked together in the vise.  I'd milled them to the required height at the same time, so they are quite close in height, but just to be sure that both pieces are well secured, I inserted a piece of card stock between the pieces and the movable jaw on the vise.   This pix shows that prior to trimming off the card stock


Next I took a Kant-Twist clamp and applied it to the sides of the part to assure that they are aligned in the X direction.  Before removing the clamp, I fully tightened the milling vise.  My theory is that this process will assure alignment in X and Y as best as possible.


This pix shows a tip that's helpful to me as a check.  After I use the edge finder to establish 0,0 I put a center drill in the chuck and bring the mill back to 0,0 and make sure that the drill point (or whatever I have installed) is exactly on 0,0.  The reason I do this is there have been more than one occasion where I forgot to offset 1/2 the edge finder diameter to X or Y and managed to start some ops in the wrong place.  So I do this now on a religious basis.  The 30 seconds this check takes is well worth not scrapping a part that you have a lot of time in.


I spotted the bearing hole location and then drilled thru with a 1/4" bit.  This shows the 31/64 bit about to enlarge the hole to 1/64" under a 1/2".  I then reamed it to .500" but didn't get a pix of that.  I tend to use good quality drills as they simply drill much closer to size and cut far better than cheap one.  There's a local supplier that sells good stuff at the same price as the much-inferior stuff from the big box stores.  Most of the drills I have are the Viking Black and Gold series.   This guy supplies most of the aircraft industry here in Wichita so the quantity he sells helps out the price to individuals.  I didn't manage to get a pix of the reaming operation.  I ran the mill at about 500 rpm for the 1/4" drill, the 1/2" drill and the reaming op. If this had been steel I'd have slowed the 1/2" drill and reaming ops down quite a lot. 


And here are the 2 partially finished bearing / crankshaft supports on top of  the print.


Today I want to finish these parts, the matching bearings and try them out on the AL base plate.

Enjoy!

Mike
MIke
Wichita, KS, USA

Offline mikehinz

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Re: Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine
« Reply #12 on: October 14, 2018, 04:10:48 PM »
Fettling wise they look good.

But I am with Phil: using files without fitted handles is dangerous  :paranoia: Handles are cheap enough and make sure that they go on nice and tight so they can't come off again :ThumbsUp:.

Jo

You know, I had thought to myself 'someone is going to comment about file handles'.  Those 2 pix were actually 'beauty shots' taken with a couple of new, unused files.  Here's a pix of a couple of files that have seen a LOT of use plus an extra handle! That i keep on hand.  And as a bonus, you can just see my safety glasses at the top of the pix! 


I do have a question though.  I've traditionally used Nickolson wooden file handles (the ones with the ferrel as in the pix) but I really don't like them as they tend to work loose over time.  So the question is, what does everyone recommend for file handles that don't work themselves loose.

Thanks.

Mike
MIke
Wichita, KS, USA

Offline mikehinz

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Re: Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine
« Reply #13 on: October 15, 2018, 01:20:45 AM »
Today's work - finishing up the bearing / crankshaft stands, except for making and installing the bearings.  I didn't get as much time in the shop as I'd have liked but I did get these parts finished.

This pix shows my setup.  Since the parts are symmetrical and I needed to do 2 of them, I setup a workstop and held the part as shown.  I started with a 1/4" end mill, 4 flute HSS at about 1600 rpm.  I stayed about .005 inside the required dimensions so as to be able to take a finishing pass. 


This shows the same setup but I installed a 1/8" end mill, 2 flute since that's what I had.  I stepped over to the full dimension and made a finishing pass climb cutting.  Also, this way I ended up with a 1/16" radius in the corner which I liked the look of. I left the mill running at 1600 rpm but should have turned the speed up to whatever the old Bridgeport could do.  Just lazy mostly.


In this pix, I turned the part over and you can now see why I installed the work stop in this manner.  This is starting the same op as earlier with the 1/4" end mill.  The 2nd part was done just exactly as this first part, so i didn't duplicate the pix. 


There are a couple of clearance holes for the 4-40 screws.  After I used the edge finder to find 0,0 I reset the work stop as shown to be able drill the holes on the 2nd part without re-finding the part edge.  Just saves a little time.


Spotting the hole locations.


Second part installed.  Just prior to spot drilling and drilling thru for the clearance hole.


Finished parts (except for the bushing to be made and installed) laying on the print.  You'll note all my hen-scratching on the print.  I typically make working notes as I go.  Typical would be writing down the DRO min/max for each axis taking into account the tool size.  Or whatever other useful, but short term info may be required.  I also make hand-corrections, but try to use an actual red pen for those. 


Stands installed on the AL sub base.  You can see the look I'm trying for with the scale model fasteners and the scale brass washers.  Those are 4-40 bolts and matching washers for 4-40.


And the final pix showing a closeup of the stands and fasteners temporarily installed.


All for today.

Enjoy!

Mike



MIke
Wichita, KS, USA

Offline sbwhart

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Re: Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine
« Reply #14 on: October 15, 2018, 07:20:48 AM »
Nice going Mike

Regarding your ? about fixing handles to files, the traditional way is to burn them into wooden handles:- heat up the tang of the file until its red hot then push it onto the handle as far as it goes the handle will smoke and bust into flames but don't let that worry you, pull the handle out let it cool a little then press it in again as far as it will go that it it won't come out.

Stew
A little bit of clearance never got in the way