Author Topic: The Dickson!  (Read 16001 times)

Offline maury

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Re: The Dickson!
« Reply #90 on: November 24, 2018, 10:49:19 PM »
Thomas, thanks for the compliment.

I'm back from the Thanksgiving trip, so I thought I'd post a bit more progress.

I've finished the upper mains, or bearing caps. The photos show some of the steps along the way.

Next step is to order a long 39/64 drill to bore the mains. I have a .626 reamer. Next post will show the setup and steps.

maury
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Offline crueby

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Re: The Dickson!
« Reply #91 on: November 24, 2018, 11:48:56 PM »
Very nice progress! Looking forward to seeing how you do the boring, going through that many bearings always makes me pause and think. A lot.
 :popcorn: :popcorn: :popcorn:

Offline maury

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Re: The Dickson!
« Reply #92 on: December 01, 2018, 08:59:25 PM »
Cruby, thanks for the compliment.

Boring the mains is not as much a challeng for me as it is for my equipment.
I have a Bridgeport, and still had to improvise. The 39/64 drill came in yesterday, I already had
the .626 reamer, so I got started.

1) The first pic shows the main setup jig I used. I have a square tower block that I used to hold the
engine base. I needed it to be above the table a bit, so I raised it a bit. The tower isn't exactly
square so I had to shim the base a bit to get everything square with the table. This took a bit of fiddeling,
but it wasn't bad.

2) After that I found the zero on the bearing, and set up ther DRO in case my  work was interrupted.

3) Center Drilling where the hole will be bored.

4) Since my Bridgeport can't accomodate a 12" drill on top of the base I have, I used my 39/64 Jobber drill
to start the hole. I was able to drill the top 2 bearings and start a nice centering hole for the long drill.

5) With the table all the way down, I removed the top 2 bearing caps and was able to get the long drill
into the chuck.I was able to complete drilling all the bearings.

6) Reaming, the reamer was shorter, and fit into the space if I used a collet to hold it. All the bearings
were reamed.

7) Finish on reamed bearings.

8) There was a generous amount of burring on the soft leaded bronze. I cleaned up the parts, and assembled
the crank to the base and added the caps. The moment of truth! Did I bore the holes straight, and did I
get the crank straight? It turns out the fir is silky smooth through the rotation, and just a little bit
snug to turn. I probably could have used a .627 reamer, but I didn't have one. I've found that when reaming
soft leaded bronze, the fit may be a little tight. It'll wear in nicely.

maury
"The trouble with socialism is that you eventually run out of other people's money."... Margaret Thatcher

Offline 10KPete

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Re: The Dickson!
« Reply #93 on: December 01, 2018, 11:12:29 PM »
That's just beautiful!!

Pete
Craftsman, Tinkerer, Curious Person.
Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline b.lindsey

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Re: The Dickson!
« Reply #94 on: December 02, 2018, 01:13:19 AM »
Awesome Maury!!  Had missed a few posts but caught back up again now.

Bill

Offline PJPickard

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Re: The Dickson!
« Reply #95 on: December 02, 2018, 03:14:20 AM »
OK now that I found this thread I will be following closely!
Nice work!

Offline Dennis

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Re: The Dickson!
« Reply #96 on: December 02, 2018, 03:44:13 PM »
Really good work Maury, thanks for posting your progress on the crank.  I have been looking forward to seeing that assembly.  You are getting way ahead of me!  I like the way you made the bearings and crank shaft, and the assembly looks perfect.  I am working the drawings and photos you sent me into the drawing package so all the options will be there. 

My crankshaft material is cut and squared with the machining centers in the ends.  I decided to make the machined crankshaft because I have never done that before.  I'll never learn any younger.

I will be looking forward to seeing your base with the columns and cylinders installed.  The low pressure cylinder pattern has been at the foundry for 7 weeks now so we should have parts soon.  I know they are very busy and our pattern is not the highest priority.

Paul, glad you found the Dickson thread.  Welcome, I hope you enjoy following it.  Maybe we will see a new thread on your compound engine one of these days?
Dennis


Offline J.L.

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Re: The Dickson!
« Reply #97 on: December 02, 2018, 03:54:38 PM »
Incredible work!
John

Offline maury

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Re: The Dickson!
« Reply #98 on: December 07, 2018, 11:10:58 PM »
Hay guys, Thanks so much for the compliments, I appreciate them a lot.
]So, I have some progress to report in the con rods. I have completed one, and will finish the con rod assembly on my next post.
here is the progress on the  cross slide and the  throw bearing parts.

1, 2, 3 ) The cross slide part was made on the CNC, but there was material left over to be trimmed off to match up with the cross slide bearings on the columns after they are machined. This will happen in a later post. The original drawings show the part to be more than 1 piece, but since there are no cross slide shoes on this engine, I made it in 1 piece to simplify the construction.

4) The castings are fettled, drilled and tapped, then cut with a 1/16 saw in the Bridgeport.
5) Then, they are mounted in the lathe, center drilled, and drilled for boring.
6) Boring to about .01 under size.
7) Reaming to final size: .626

maury


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Online steamer

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Re: The Dickson!
« Reply #99 on: December 16, 2018, 04:15:58 PM »
Maury.....this is great    watching along!
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline maury

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Re: The Dickson!
« Reply #100 on: January 13, 2019, 09:18:01 PM »
It's been a while folks, so I thought I'd give an update on the Dickson. Still haven't gotten the LP cylinder casting, so I'm trying to make progress on the valve gear. This is an intricate contraption, and I'm not sure I fully understand how it works. I have made all the parts for the HP cylinder, and have fitted them to the engine base ans columns. After working through a few minor interference issues, it does seem to work. The true test will happen when I actually try to get it to run. The CNC has been busy, and will be even busier this week when I will be duplicating those valve gear parts for the other 2 cylinders.

I have a few shots of the lower engine assembled with what I have completed so far. Enjoy.

maury
"The trouble with socialism is that you eventually run out of other people's money."... Margaret Thatcher

Offline Dennis

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Re: The Dickson!
« Reply #101 on: January 29, 2019, 03:48:58 PM »
Hi Maury, Thanks for posting the assembly photos for the Dickson, I have been wondering how it would look as the columns went on and it looks really nice.  I talked with the foundry this morning and they are having problems with the LP cylinder cores.  We are going to get together next week (after the cold breaks) to figure out another way to make the valve cores.  With two piston valves in the cylinder casting, the internal passages are quite complicated.  It seems that every time the foundry teaches me something new, we push the design detail a little farther and get in trouble again.  Looking forward to next weeks meeting and learning more.
Dennis

Offline maury

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Re: The Dickson!
« Reply #102 on: October 15, 2019, 10:48:20 PM »
OK Folks, I'm back on the Dickson. I was waiting for a casting, the LP Cylinder which has very complex cores internally. The foundry just couldn't make the cores, so they had to be redone. I now have the LP Cyl casting, but there are some interesting caviats. I'll be posting progress on this thread again soon, so now is a good time for those interested to re-familiarize with it.

In the mean time, I worked on the Forest 1889 6 cyl engine design, and built a Bob Bromps Tank Mogul engine kit I had. I might post that when I finish it and get it running.

maury
"The trouble with socialism is that you eventually run out of other people's money."... Margaret Thatcher

Offline maury

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Re: The Dickson!
« Reply #103 on: October 16, 2019, 05:09:22 PM »
Dennis dropped off the patterns and core boxes at the foundry just at the beginning of the year.
So we have been waiting about 9 months for this casting. Overall, the casting seems to look ok,
but closer analysis has shown a number of issues.

1) Looking at the bottom view one can see where the foundry has unfortunately cut off the mounting
foot at the rear side of the cylinder. I have designed a foot part that will replace the cut off
part. I will show it on a later post.

2) The cylinder bore core apparently floated up a bit and put the cored out metal off center. This
would not normally be a problem, and is actually expected. Unfortunately the  core should have
been a smaller dia. This can be taken care of with a pressed in liner. I want to press it in because
the bolt circle for the head may intersect it, and probably near the OD.

3) I'm still looking at this issue, so there may be some changes later. It appears the cores for
the valve cutouts have been placed too high in the cylinder. I believe there is enough metal as
to not compromize the internal geometry and the valve operation, but the problem is at the top
of the cylinder. There is not enough metal there to keep the part geometry in dimension. If the
cyl height is held to dim, one of the ports will be cut into. The first solution I have thought
of is to add height to the cyl casting by attaching a plate above the casting. This compromizes
the scale , but may be necessary to make the engine work.

Some of you may think this is a disaster, but I look at as a challenge. We don't want to go through
the expense and long wait for a better casting. so we will do what we have to do to make the best
of it. This is a bit of an extreem example of a problem with a casting, but it will be a good
experience doing the fixes to make it work.

1- Top of cylinder casting showing the bore and cast in valve ports.
2- Bottom of cylinder showing the cut off foot area.
3- Bottom of cylinder showing the cast in valve ports.
"The trouble with socialism is that you eventually run out of other people's money."... Margaret Thatcher

Offline Art K

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Re: The Dickson!
« Reply #104 on: October 16, 2019, 05:43:16 PM »
Dennis & Maury,
I have seen this post but haven't read it till now due to the length. But as you say it's a good time to re familiarize myself with it. Vacation can work wonders for the amount of time one has to read & get caught up with interesting threads. I have to say that the work that has gone into this build so far is just amazing. Seeing some of the setups used to machine complex shaped parts is a learning experience. Thanks for the detail you are putting into your posts.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King