Author Topic: Junkers CLM  (Read 15430 times)

Offline vtsteam

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Re: Junkers CLM
« Reply #30 on: February 12, 2023, 08:34:35 PM »
 :popcorn: :popcorn: :cheers:
Steve

Offline steamer

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Re: Junkers CLM
« Reply #31 on: February 12, 2023, 09:30:04 PM »
That's cool!!!    I'll be watching Roger!    that's a neat engine!

Dave
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Damned ijjit!

Offline Michael S.

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Re: Junkers CLM
« Reply #32 on: February 13, 2023, 10:24:04 AM »
Hello Roger, I have now discovered your construction report for the Junkers engine. An interesting project.
In my stable there is a 1 HK 65 with a 7.5 Kw generator. And I've been waiting for a power outage for a long time 😁.
It could be that I still have a spare parts list for the operating instructions.
If it helps you.

Greetings Michael
« Last Edit: February 13, 2023, 10:29:12 AM by Michael S. »

Offline Roger B

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Re: Junkers CLM
« Reply #33 on: February 13, 2023, 05:19:35 PM »
Thank you all  :ThumbsUp:

Michael  :)  I have a rather poor PDF of the spare parts list for a 1 HK 65 (NDZ 9/12) and some French operating instructions for what CLM called a CR1. More information is always welcome  :cheers:

Per, the French information I have suggests that the helix part was used by the governor in the conventional way to control the speed and the other rocker roller on the cam was used for stopping.

I have attached the current state of the design, some way to go  ::)
Best regards

Roger

Offline Roger B

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Re: Junkers CLM
« Reply #34 on: May 14, 2023, 05:08:09 PM »
Finally cutting some metal. The crankshaft is made from 60 x 15mm key steel which I have used before but the design of this shaft is on the limit for my Hobbymat (I can cheat if I have to, but model engines should be made on my machines). Marking out is also stretching my equipment but so far all is ok.
Hacksawing the waste away is somewhat of a change from fuel injection systems  :)
Best regards

Roger

Offline cnr6400

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Re: Junkers CLM
« Reply #35 on: May 14, 2023, 08:03:20 PM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
"I've cut that stock three times, and it's still too short!"

Offline Michael S.

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Re: Junkers CLM
« Reply #36 on: May 14, 2023, 08:59:02 PM »
Hello Roger,
I watch with interest.
Especially if someone is still sawing by hand.

Greetings Michael   :cheers:

Offline RReid

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Re: Junkers CLM
« Reply #37 on: May 15, 2023, 12:02:29 AM »
Off to a good start. Hope you're enjoying the part size "paradigm shift"! I'll be following along for sure. :popcorn:
Regards,
Ron

Online Kim

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Re: Junkers CLM
« Reply #38 on: May 15, 2023, 06:19:31 AM »
It's fun to mix it up a little bit, isn't it!  :D  :popcorn:

Kim

Offline Roger B

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Re: Junkers CLM
« Reply #39 on: May 15, 2023, 07:10:14 PM »
Thank you all  :) It is fun to play with some (relatively) big stuff for a while  :ThumbsUp:

A bit of 'dodgy set ups are us' machining of the exhaust crankpin. OK at 500 rpm for the webs and 250 rpm for the crankpin.
Best regards

Roger

Offline Roger B

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Re: Junkers CLM
« Reply #40 on: May 23, 2023, 05:41:22 PM »
On with hacking out the crankshaft. For the outer two crankpins I need to support the centre webs. This is done with a bolted on bridge piece as before. Some more was hacksawed away and the first outer crankpin was rough machined using a variety of tools to deal with the narrow (10mm) gap.
Best regards

Roger

Offline cnr6400

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Re: Junkers CLM
« Reply #41 on: May 23, 2023, 10:01:28 PM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
"I've cut that stock three times, and it's still too short!"

Offline AlexS

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Re: Junkers CLM
« Reply #42 on: May 23, 2023, 11:20:04 PM »
Great start. Sometimes designs or hobby work need some time to "cook" before to get started. Now you have more knowledge about making model diesel engines! Some crazy opposite engine is something on the list to design.

Offline Roger B

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Re: Junkers CLM
« Reply #43 on: May 28, 2023, 01:18:55 PM »
On with the crankshaft, it looks to be possible with my lathe.

There are a few more challenges to come  ::)

The cylinder liner will be 105mm long, bored 20mm. I may need to look at making a between centres boring bar. The maximum diameter will probably be 15mm so making a fine adjuster for the cutter will be difficult.

The scavenge pump is mounted on top of the upper piston. The original piston and cylinder were rectangular. I could possibly fabricate the cylinder from 4 pieces of flat steel silver soldered together  :headscratch: The piston will need to be aluminium on weight grounds. Leakage will not be too much of a problem on the compression stroke as it will be leaking into the crankcase that it is filling.

The valves for the scavenge pump are also difficult to fit into the space. I am looking at fitting reed valves to the underside of the piston as delivery valves, the suction valves can then be mounted on top of the cylinder. The original appears to use disc valves. I have some carbon fibre reeds that I bought when working on the two stroke diesel that I may be able to adapt.
Best regards

Roger

Offline RReid

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Re: Junkers CLM
« Reply #44 on: May 28, 2023, 03:00:35 PM »
Quote
I may need to look at making a between centres boring bar. The maximum diameter will probably be 15mm so making a fine adjuster for the cutter will be difficult.
A fine adjuster would be nice but not really necessary, since the piston can be sized to fit? I've had success in the past with such a boring bar. Takes a bit of patience, but we all know you have that covered! Looking forward to learning from your solutions to the various challenges to come. :cheers:
Regards,
Ron

 

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