Stewart Hart’s Vertical Mill Engine

[SarahJParticipant @sarahj]

Hi,

I would like to make a start on Stewart Hart's Vertical Mill Engine.

In the drawing of the cylinder, there are four M3 tapped holes in each end for the cylinder covers. The drawing doesn't show how deep to drill/tap into the cylinder, I was going to drill the holes 8mm deep and tap into that by 6mm. Does that sound okay?

One other point I was wondering about was the 3mm dia hole into each end of the cylinder for the two steam passages. This leaves a wall thickness of 1mm between the cylinder wall and the steam passage. I could reposition the hole slightly to give a slightly thicker wall thickness of 1.4mm. I was just concerned about when drilling the hole the drill bit wandering. Any thoughts on this?

Many thanks,

Sarah

[SarahJParticipant @sarahj]

[JasonBModerator @jasonb]

Welcome to the forum Sarah

I'm sure Stew himself will be along at some time but those depths sound fine to me.

Again the drilled passages could be moved if you wished, I think as shown the hole comes mid way between the cylinder bore and the flat surface the valve chest mounts to so just watch the outside. A good sharp drill should not wander too much it helps to retract the drill quite often to clear any swarf and also a little lubrication in the way of parafin or WD40 will help too.

J

Edited By JasonB on 18/01/2015 17:54:01

[Stewart HartParticipant @stewarthart90345]

Hi Sarah

Pleases to her that you've made a start on the vertical, the depths you've suggested will be fine, sorry I missed the depth off the drawing. The passage is a bit close if you want to give yourself a bit more space by all means move it over a bit and it wont arm if you drill it 2.5mm, and follow Jason's good advice.

I hope you enjoy the build.

Stew

[SarahJParticipant @sarahj]

Hi Jason and Stewart,

Thanks for your replies. Another question for you if that's okay.

When drilling/tapping the eight M2 holes in the cylinder for the Valve Chest, I calculate that there is 5.86mm depth of material for the tapped holes. What depth would be suitable for drilling and tapping.

Regards,

Sarah

[JasonBModerator @jasonb]

A good rule of thumb is that you want 1.5times the dia of thread in the part so for a M2 thread you want 3mm of thread. Now its almost impossible to thread right to the end of your hole so I would say drill 4.5mm deep and tap until you feel the tap won,t turn any more.

One thing I do with a lot of my small taps is grind off the pointed end as that usually allows you to get a bit deeper into a blind hole, not enough to cut into the teeth but just enough to remove the pointed end

[SarahJParticipant @sarahj]

Hi Jason,

Thanks for your help, I'll mark up the drawing with the depths I need.

Many thanks,

Sarah

[JmccrackParticipant @jmccrack]

Stewart. I am looking for the material list for this project. Has it been published yet?

[Stewart HartParticipant @stewarthart90345]

Hi its on the home page towards the bottom on the right or click below

Materials List

Stew

Edited By JasonB on 20/03/2015 15:20:50

[Mad muppetParticipant @madmuppet]

Good morning All.

Help please How can I obtain a set of drawings for the cross vertical engine.

Regards Mad Muppet

[JasonBModerator @jasonb]

If you ask Stew nicely he may sort you out.

[Eric CoxParticipant @ericcox50497]

Sarah, for material you will find 5" pipe for the flywheel here

.ebay.co.uk/itm/Mild-Steel-Pipe-127mm-5-x-3mm-450mm-long-Chimney-Round-Tube-/291164852350?pt=LH_DefaultDomain_3&hash=item43cac7107e

and aluminium plate here

ebay.co.uk/itm/Aluminium-Flat-Bar-Plate-width-from-120mm-to-250mm-many-thicknesses-and-lengths-/151080276666?pt=UK_BOI_Metalworking_Milling_Welding_Metalworking_Supplies_ET&var=450190730544&hash=item232d1612ba

usual disclaimer

[Mike BondarczukParticipant @mikebondarczuk27171]

Hi Sarah,

I am just putting the finishing touches to the Stewart Hart Horizontal engine and will be starting the vertical engine build once completed.

I hope that you will be posting a build log so that I can follow your progress as well as any hints, tips or get-me-out-of-jail situations you come across.

I have posted a short video of my engine on the Model Engine Maker forum and have entered it into the built from plans section, so you are welcome to have a look.

I may also post it on this site if I can find a way of attaching a YouTube video, and a full build log will follow shortly together with the cosmetic changes I made to the original design.

Mike

[JasonBModerator @jasonb]

Mike have a look part way down this page on how to post youtube video. Or ask me to do it

[DullnoteParticipant @dullnote]

Hi hope this works, first run for the engine today, not completed but enough to get it alaive

[DullnoteParticipant @dullnote]

https://youtu.be/4j-VnLrUyPc

[SteviegtrParticipant @steviegtr]

Posted by Dullnote on 13/02/2021 16:45:35:

https://youtu.be/4j-VnLrUyPc

JUST TRIED TO VIEW & IT SAYS THE VIDEO IS PRIVATE.

Steve.

[DullnoteParticipant @dullnote]

I will have a look though it was anyone who had link

[DullnoteParticipant @dullnote]

https://youtu.be/4j-VnLrUyPc

Changes to unlisted, try now

[SteviegtrParticipant @steviegtr]

Yes but that is not a link. It is just the address to put in the search bar. I always set my videos to anyone can view.

Steve.

Edited By Steviegtr on 13/02/2021 16:56:36

[SteviegtrParticipant @steviegtr]

No still not able to view.

Steve.

[duncan webster 1Participant @duncanwebster1]

I can't see it either

[David WallbankParticipant @davidwallbank94791]

Regarding Stewarts Hart's "True Vertical Mill Engine" is possible to get drawings ? I managed to find a link for the materials list but not constructions drawings. I have not found a way to ask Stewart directly.

Thanks, David.

[Jim NicParticipant @jimnic]

David

As a fan of Stewart's with 4 of his designs built I have always found him to be very generous and accomodating. Although he doesn't post on here much these days I'm sure he won't mind me telling you how to get in touch with him. If you send him a Personal Message and ask him to send you a set of drawings I am sure he will oblige.

To send a PM Click on "Inbox" at the top of the homepage, Click on "Compose new message", address it to Stewart Hart and ask away.

Jim

[Stewart HartParticipant @stewarthart90345]

Hi David

I'm sneakily watching as Jim said just send me a PM with your email address

Stew

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