Gear ratio for steam engine

[sandy_ACS]

 

Hi All,

Bogstandard......happy to make some suggestions that may help you.....

4:1 sounds ok and setting the output shaft on top will be just fine...I actually do a version with just such a layout for the same purchaser.

I agree that frictional losses can become significant, however, if you choose reasonably fine tooth gear forms (I use 64DP) and don't overmesh them (allow about 5 thou (0.005") on the shaft pitch spacing for meshing slack) then the loss is more than acceptable.
Larger tooth forms will give a lot more frictional loss.

Also, since you are proposing to use loose gears (modified) then glue them to the shafts with high strength 'Loctite' and then pin through both gear (boss) and shaft......otherwise THEY WILL come adrift.

Eddy....sorry to post pictures of    :rant   STEAM LOCO's.....
Please yer HONOR..  :respect2 I only did it to provide some idea of the gearing methods possible.....honest GUV.......the final drive to the front and rear shafts on this loco are via 2:1 90 degree bevel gears...thus 8:1 total reduction....the boggies (trucks) are fully articulated (steerable) and use specialy manufactured 'Carden' shafts with sliding universals at both ends....why sliding?....think about it.

BTW Eddy......how much space is available in the 'Glen Sannox' for the boiler?.....Grovel Grovel......one what will drive a 3 cylinder diagonal?    :yeah

All the best.

Sandy.

[Eddy Matthews]

BTW Eddy......how much space is available in the 'Glen Sannox' for the boiler?.....Grovel Grovel......one what will drive a 3 cylinder diagonal?    :yeah

All the best.

Sandy.

No problem with the loco photos Sandy, they are "on topic" considering the rest of the thread

The Glen Sannox will take a 3.5" diameter boiler - The diameter is limited by the height of the hull rather than the beam. Length isn't really a problem..... Why though? You've got me curious now!!  :?

[sandy_ACS]

:twisted:  :twisted:  :  :  :wink:  :wink:

Hi Eddy,


Just a little something I am playing with...don't want to say to much just yet......lets just say....BE PREPARED TO BUILD 2 of them....he he.

[kiwimodeller]

John, I have been playing with a large double acting slide valve single cylinder engine (built to the design of A H Rayman from the 50's) which is similar to a Stuart 10 in a large (80") sidewheeler. I began with an overall reduction of 5:1 using a V belt but the engine struggled to get the wheels started and there ws heaps of belt slip. Once it did get under way the bow wave was near over the superstructure! I also tried a toothed belt drive but the tension needed on the belt was too much drag for the engine. I am using a 1:1 reversing box with tumbler gears but the shafts only run in bronze bushes and the tension of the belt loaded them up too much. I have come to the conclusion that I need a ratio of around 8:1 and am currently trying to track down suitable sprockets to achieve that. I have some 5mm chain and also some 25ASA (1/4" pitch) but have not yet found an engineers supply place that has sprockets. If I get desperate I can get them made but at over $100 each I am balking a bit and hoping to find bits out of old machinery such as photocopiers. Will keep you posted. Cheers, Ian.

[derekwarner_decoy]

Hi PD's - Ian, don't forget the "Stock Drive Products People" [on our WEB site links], but be prepared to trade in the PORCHE , [my 412 mm length of 3.76 mm pitch S/S roller chain + a 9 tooth pinion + a 48 tooth pinion cost AUD$350.00]  :sob  ....but there is worse to come  :ohno ...the 9 tooth pinion has been (NC) produced incorrectly - I am now awaiting a resolution from the importers with the manufacturer ..... -  :rant    :rant - Derek

[bogstandard]

Just to show what the finished engines are like here is a picture of one next to an old Cheddar Puffin engine.
Mine is only about 1/2" taller but it has double the stroke. It is mounted on aluminium rails to raise the bedplate to allow the cranks to penetrate underneath, but as you can see the output shaft is still only the same height.
I was going to convert one to a horizontal paddle engine but have decided against it as my next project I am looking to design a small piston valve twin that I might do as a paddle engine, it all depends if I last that long.

[derekwarner_decoy]

Hi PD's - well John.... considering this effort :clap2.... we all hope you last a bit longer to produce your next engine... [the only thing I can suggest is GARLIC & a few   each day]    :music

Your oscilitator reminds me of the ANTON [French] product being modular and squarish in design, however held together with hex head screws & SHCS - my guess is all stainless steel :?:

The increased diameter of the central fly wheel suggests calculation based upon the longer engine stroke & hence a stable low RPM

The square profile design of your lubricator also has the fins in the body...is this for additional suface cooling area :?: [again as both ANTON & JMC provide] :?:.....regards Derek

[bogstandard]

Hi Derek,
If you look at the earlier posts I made it gives the url of the French site where I downloaded the basic plans.
I made a lot of design changes to make them easier to produce or more robust, and to add extras that were not on the original and also correct a few mistakes on the original design.
The engine is assembled totally with stainless fasteners, all shafting and bearings are also stainless, all threads being metric.
The slots on the side of the lubricator give approx 60% more surface cooling area.

BTW, hate garlic, and the medicos say no alcoholic pop.

John

[derekwarner_decoy]

Hi PD's & ok John....I think I can see a little clearer   :ohno  now - when I re read your posting on

Moteur Oscillant Double Effet 10 X 20

I see Item 105 are diameter 5 X 13 diameter sealed flanged ball races which are a pretty healthy sizing for the loadings  

Would I be correct in thinking that you have used FOUR of Item 105 :?:

Just   - how about Soy Sauce :?: - I purchased a bottle last week only to find that it is 2.2% alcohol..... :music  - Derek

[bogstandard]

Hi Derek,
For the main crankshaft I used 2 off 6x13 and for the power takeoff 2 off 5x13.
I beefed up the big end area as well, I thought on the drawing it was a bit lame, but I had to do a lot of remodelling of the big end around the sealing gland to get clearance, especially as I had used two nuts, one for locking on the gland, I have 1/2mm clearance in that area now, which is plenty.
Your really pushing on this alcohol bit aren't you, ok I'll come clean, I did have two cans of Carlsberg at new year.
By the way I would challenge you to drink enough soy sauce to get you falling over, I think your stomach would do a Barry McGuire well before.

John

[derekwarner_decoy]

Hi PD's.... & just a short note to John... in the UK..... do they have GARLIC capsules  in your land:?:

Just digressing, when we look at the WEB interest in our PD site you will see that the 'Steam Folders' rate 9/10 which is great... so on behalf of our PD group I welcome you on board

I know all PD's with an interest in steam will ask .....'where will the 10X20 oscilitator be installed :?: ' - please keep us posted & even more .jpg's would be great

Do you have a CNC multi work station   :respect2  :?:

Oh BTW, one or two drops of soy sauce is all that is required on the rice   - Derek

[bogstandard]

Hi Derek,
The CNC multi workstation consists of my brain, one good arm, a ball and chain that keeps me supplied with coffee in the workshop and a cat that gets a kick when I get something wrong.
Really I have an old Atlas (1938) lathe that I have brought up to date and is now super accurate, a Herbert manual surface grinder from the 1950's, with this I can get everything to within 0.0002". so I have no problems with things like port faces, they bed in within a few minutes of running, and a mill/drill from 1987 that has seen better days with a cobbled together 3 axis digital readout. With these three machines I am able to produce anything that takes my liking.
The engines were made for no specific purpose other than a couple of chaps from the model boat club said that they wanted a steam engine for their boats, so I made six, while you've got the machines set up you may as well make more, may be able to sell a few to get the costs back.
Unlike these I have just made, I usually design my own on the back of a fag packet and modify as I go along, never made any drawings (should have really) but I get engines that work and work well. I designed and made a 1/4" bore x 3/8" stroke v-twin a few years ago, ideal for mini vap, it ran great, made enough bits to make about 20, they didn't get finished because the pipework was so small and intricate that I just couldn't be bothered to assemble them all. Only two ever got finished, the prototype one I have and one was given to a friend and as far as I know is still running well. That is life.
As I said before, I am looking to make a slide valve twin that can be made either horizontal or vertical, just need to know if their is any market for them afterwards. I am not trying to compete with the big boys, just produce half a dozen and thats it. The only problem is I am smoking myself to death to get all the fag packets to design on.

John

[derekwarner_decoy]

Hi PD's - ok ok John -  all I can suggest is that we take up a collection & post over a ream of elCheapo A4 white paper & a 250 ml bottle of Soy Sauce  :  .....enjoy that & keep up the good work on your talented CNC multi station machines

  ....wasn't it that Captain Sir F. Drake that had a bucket of water thrown over him as they thought he was on fire  :?: ...but was only smoking the weed   :rant he bought back from the Americas  :?:  :?:  :?: ------- Derek

[derekwarner_decoy]

'specialy manufactured 'Carden' shaft universal couplings'

Hi PD's .....& just by any chance Sandy  do you  a version for  3/16" [0.1875"] shaft's that is :?: as PS Decoy could use two....[that is two couplings or four halves... OK   2+2=4 disc bits w hubs + bolts & NUTZ] - no shaft lengths required thank you  :nah

So if so   - just wondering :?:  :?:
1) the major OD of the couplings & hubs & are they brass LG2 or BS?
2) total length of coupling [both halves as joined together]
3) what size bolts & NUTZ & are they brass LG2 or BS? or Grade 12.9 structural steel
4) cost for two complete couplings or [four halves... as above ie., 2+2=4 disc bits w hubs + bolts & NUTZ] + HPGS for the hubs including transportation to the convict shores of OZ  

I understand the ACS order books are closed so a late delivery    would be OK  :hmph .......... Derek