Author Topic: Barstock Heinrici Anyone?  (Read 3293 times)

Offline Laurentic

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Re: Barstock Heinrici Anyone?
« Reply #30 on: January 15, 2021, 05:21:31 PM »
Lovely work Jason, beaut!

Going back to post No.19 Jason - what did you use to pickle the black bar please?

Chris

Offline Jasonb

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Re: Barstock Heinrici Anyone?
« Reply #31 on: January 15, 2021, 05:26:38 PM »
I use brick cleaner https://www.everbuild.co.uk/product/brickclean/ Screwfix etc do it.

Just use and store outside as the fumes will rust your tools.

Offline Laurentic

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Re: Barstock Heinrici Anyone?
« Reply #32 on: January 15, 2021, 05:34:22 PM »
Thanks   :ThumbsUp:

Offline Vixen

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Re: Barstock Heinrici Anyone?
« Reply #33 on: January 16, 2021, 08:10:37 PM »
 :ThumbsUp:

Mike
It is the journey that matters, not the destination

Offline Jasonb

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Re: Barstock Heinrici Anyone?
« Reply #34 on: January 17, 2021, 04:20:35 PM »
After turning the second black I decided drill six 1" holes to remove some of the initial waste material as it's a bit more fun than watching the CNC do it with the added bonus that the swarf can drop down rather than need clearing out of deep pockets. While set up like this I also held a scriber point in the chuck and marked the edge of the disc so I could get in the correct position on the other mill.



As I had two flywheels to do and they would need setting up twice so that each side could be done I put a piece of the crankshaft material in a flange mount ER32 collet and clocked that in to 0,0 so the parts would always be centred. 1,2,3 and 20, 40, 80 blocks packed the work up to just clear the top of the collet nut.



It was then just a case of placing a flywheel on the pin, rotating until the mark lined up with a pointer in the chuck and clamping down tight. The basic shape was roughed out with an adaptive path using a 6nn 3-flute cutter at 4500rpm, 300mm/min feed, 5mm vertical DOC with 1mm stepover to leave it looking like this



I've actually just started the finishing "scallop" cut in the above photo using a 6mm 4-flute ball ended cutter at 4500rpm, 500mm/min feed and a stepover of 0.25mm which slowly worked its way around the rim and then down around each spoke to leave a finished half looking like this.



It was then just a case of flipping the part over and running similar cuts for the other side though the boss is round on the inside where as the outside had the boss for the crank pin.



The few od ridges and steps look a lot worse than they feel and were quickly removed with needle files and a bit of Emery.

I also got round to setting up an air lower for the second side and wish I had done it sooner as I was able to leave the machine to it's own devices rather than having to keep clearing swarf like I did on the first side during the roughing cuts, not so bad on the finish cuts as very little is being removed. Will show some photos of  this in the Dark Side thread at some time.
« Last Edit: January 17, 2021, 04:38:23 PM by Jasonb »

Offline Admiral_dk

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Re: Barstock Heinrici Anyone?
« Reply #35 on: January 17, 2021, 09:34:38 PM »
Simple, elegant solution and a very nice outcome  :ThumbsUp:

Offline Dave Otto

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Re: Barstock Heinrici Anyone?
« Reply #36 on: January 17, 2021, 11:51:29 PM »
Nice looking casting Jason! :ThumbsUp:

Dave

Offline Jasonb

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Re: Barstock Heinrici Anyone?
« Reply #37 on: January 19, 2021, 01:23:47 PM »
Thanks, second one is now done except for a quick final fettle. I have put a video in the dark side thread here

Offline Jasonb

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Re: Barstock Heinrici Anyone?
« Reply #38 on: January 24, 2021, 07:59:51 PM »
A bit more progress over the last few days. First a pic of the flange that will be soldered to the hot cap being counterbored using the 45mm stainless tube to gauge final fit, not easy when the tube is not perfectly round or 45mm dia.



The power cylinder was cut from some 65mm dia cast iron bar. This hole is 110mm long, 42mm finish dia and was cut with a 16mm insert boring bar. Started with blacksmith drills upto 1" then to 41mm with a CCMT insert 0.75mm DOC, 600rpm. Then for the last few cuts swapped to a CCGT with two cuts of 0.2mm and one of 0.1mm DOC all at 250rpm and ended up with less than 0.025mm ( 1 thou ) taper which was soon taken care of by selective use of a 3 stone hone.



And finally the near complete flange which just wants squaring off a bit, completed cylinder and in the middle the 42mm dia x 42mm long CI piston which as a 1.25mm wall and a M18 x 1 thread in the 6mm thick bottom to more closely resemble an original rather than the CSK screws shown on the drawings I'm using as a basis for the engine.




Offline Jasonb

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Re: Barstock Heinrici Anyone?
« Reply #39 on: January 27, 2021, 04:52:58 PM »
The next part on the list was the yoke that fits inside the piston, a spigot was turned on the end and then threaded M18 x 1 running in reverse so the tool moves away from the face.



Then over to the mill to machine most of it away but leaving a flange at the bottom



A couple of 4mm wide slots were cut for the ends of the tuning fork shaped conrod and cross drilled for pins, picture of it assembled inside the piston



And another without piston but showing the thin walled brass tube that forms the displacer's piston rod passing through it.



Bearing in mind the weight issue that Jo mentioned on her engine while I was set up for squaring the ends of the brass tube for the displacer I thought I would thin the 1.25mm wall down to 0.9mm to save a bit of weight. I knocked up a bung to go in the end of the tube so that the chuck would not distort the tube which also allowed it to be tightened up well so no risk of teh tube walking out of the chuck



After silver soldering the endplates and a spigot into place it was back in the lathe to drill and tap the spigot. I then added ctr support while the spigot was turned down to finish size so it was a firm fit in the thin wall brass tube.



Finally a shot of the finished displacer alongside the stainless steel hot cap with silver soldered end and mounting flange

« Last Edit: January 27, 2021, 04:56:34 PM by Jasonb »

Offline Dave Otto

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Re: Barstock Heinrici Anyone?
« Reply #40 on: January 27, 2021, 05:18:09 PM »
Nice work Jason!

I'm curious about the choice of SS for the hot cap? It seems to me that the idea is to allow the heat into the engine not keep it out; so I'm wondering if copper or brass might have been a better choice?
On several of my original hot air fans the hot end is made from thin brass. Then on the other hand it seems that the brass displacer would easily conduct a lot of heat up to the cold end and that maybe thin SS would be a better option here.

Just kind of thinking out loud here; on my Essex engine the displacer and piston extension are SS which makes since to me. But David Abbot called out for SS for the transfer tube which is essentially the hot cap on this engine. I don't agree with this and mine will be brass tube like on the original engines. Again the idea is to get the heat into the engine not keep it out. Maybe its all a moot point, I don't know.

Dave

Offline Jasonb

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Re: Barstock Heinrici Anyone?
« Reply #41 on: January 27, 2021, 06:52:05 PM »
Dave, I really just went along with the drawings which list Stainless for the hot cap and either brass or stainless for the displacer. I could not find suitable stainless tube for the displacer anyway so went with brass which worked out the perfect size of 41.2mm (1 5/8") as the 45 x 1.5mm wall tube for the cap actually came in at 42.2 bore.

I have seen one running with this combination and another with an aluminium displacer so fingers crossed.

Offline Dave Otto

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Re: Barstock Heinrici Anyone?
« Reply #42 on: January 27, 2021, 07:43:04 PM »
 :ThumbsUp:

Dave

Offline Jasonb

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Re: Barstock Heinrici Anyone?
« Reply #43 on: February 04, 2021, 12:27:10 PM »
Next job on the list was to make the displacer rod which is made up on several pieces so that it does not tighten up as the rocking lever follows an arc, The drawings show the 2mm steel rod silver soldered into the two brass parts but I decided to allow for some adjustment if needed so went with a rod threaded M2.5 each end and some lock nuts. I also cut the thin wall brass guide tube to length



The "tuning fork" conrod would have wasted a lot of metal if cut from one piece so I decided to do it in two. Firstly the actual fork was cut on the CNC holding it by two extra 6mm pieces left at the ends which made it easy to flip over and run the other side.





The big end halves were also done on the CNC before reaming in the manual mill. I then managed to get two M2 counterbored holes in the bottom of the bore so that I could screw it to the top of the fork with a bit of JB Weld for good measure.



The last thing to do was ream the small end before cutting off the holding material and rounding over the ends



As with all the other pivoting or rotating holes through the aluminium bushes were fitter, in the case of the small ends there were Loctited into place and a traditional split bearing used for the big end.




This got me to the stage of having enough completed parts to see if the Lady wanted to dance. I eyeballed up the timing so the displacer lead the power piston by 90degrees, applied a little light oil to her joints and then gently warmed her bottom with my torch set as low as it would run. After 60seconds or so she decided to perform.  :pinkelephant:

A couple of observations that may help others who's dancing partner is not so willing.

1. My displacer is over 200g ( scales in shed only read up to that) plus the rod suggest I'm at least 300g yet just like the full size I don't have any counterbalance weights.
2. The engine hardly warmed up while playing and could easily be touched so certainly does not need any cooling at least for shortish runs of 5mins or so.
3. I do have some decent weight in my flywheels, although castings may be more desirable to some if the material is wrong then they are only good for fondling. I feel the weight of the flywheel should carry the engine over any imbalance.

« Last Edit: February 04, 2021, 01:05:11 PM by Jasonb »

Offline Alyn Foundry

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Re: Barstock Heinrici Anyone?
« Reply #44 on: February 04, 2021, 02:46:21 PM »
A very nice runner Jason, well done!

I also noticed another project nearing completion.... ;)

Cheers Graham.