CHAPTER

12 Turbine and Centrifugal PumpTurbine and centrifugal pump

designs are quite deep subjects andwill not be covered here. These aresimplified designs based on deadreckoning and a smattering of expe-rience, and will probably make expe-rienced turbine and centrifugal pumpengineers cringe. However, they dowork and they show the principles.

The COVER is 1116"clear plastic,although any 1/32" metal will do.You may use any convenient mate-rial you may have for this model.Start the HOUSING with an accu-

rate 1/4" x 1-5/8" x 1-5/8" block andlayout the outline, foot holes, coverscrew holes and the steam connec-tion. Drill the #60 nozzle before bor-ing the 1-1/4" x 7/32" chamber.Complete all the tapped holes. Sawand file to the outline at the 13/16"radius. This is a place where BobMaynard's filing machine would be a

most handy tool for this job.The ROTOR shown is the fourth

one tried in this design and workedthe best. Itis simple and not difficultto make. Try for uniformity andbalance, as this will spin up in thethousands of revolutions per minute.Start with a 1-1/4" diameter x 3/16"disk. Chuck in a 3-jaw, grippingabout 1116"of the width. Next, turnto 1-7/32"diameter and face true witha skin cut. Drill the center hole instages with the final pass a #34 drill.While in the lathe, scribe the 35/64"and 9/32" radius circles. Reverse inthe chuck, true up and face to about.164"thick and turn theO.D. to matchthe first cut. If you have an indexingfixture, proceed to drill the twenty- ufour 3/32" holes and four 3/16" holes.A dividing head is great for this typeof drilling. If not available, pace off24 spaces and drill in the drill press.

49

Dothe same for the four holes. Chucka piece of 114"diameter steel in the 3-jaw with about 112"projecting. Turnto .112" diameter for about 3/8" for aclose fit in the Rotor and thread #4-40for 114". You now have a stub arborfor dressing down the Rotor to 5/32"thick and 1-3/16" diameter. This op-eration must be done slowly and care-fully with a finely-honed tool bit.Remove it from the arbor and insertthe Turbine Shaft. Then lay an ac-curate 1/4"strip ofmetal on the Rotoragainst the 1/8" diameter Shaft andscribe lines tangent to each hole asshown. File each opening to this line.As with all models in this series,

the steam connections are for 3/16"plastic tubing. Your first test will bemost interesting as you begin run-ning it it on pressures all the wayfrom 10 to 60 psi. A pulley or collarshould be used in order to keep the

Rotor centered in the Housing.This PUMP is very simple. The

material can be anything you mayhave on hand. If you pump water, itis well to use material thatwill notrust.For the HOUSING, make the lay-

out on an accurate block 3/S" x 1-1/4"x 1-1/4" . Saw and file to the 1-114"di-ameter. Here, again, a filing ma-chine is handy. Mount in the 4-jawand bore the 29/32" x 7/32" openingand 114"center hole. Reverse it in thechuck and turn to 9/32" thick down to3/S" diameter. Drill and tap footholes and the discharge hole. Lateruse the head as a jig.Next, make the OUTER BEAR-

ING, BEARING and WASHERwith 5/16-40 threads as shown, al-though you can adapt to 32 threads.The 40 series ofthread is a big help inmaking tiny model parts. Set theBearing in the Housing with Loctite.The packing is 1/16" strands unrav-eled from braided graphited asbestospacking. The Spring has awide rangeand should be a cut-and-try opera-tion from your odds-and-ends box.The HEAD, SHAFT, PIPE CON-

NECTION and FOOT need no com-ment.

The IMPELLOR is a tiny part thatmay try your patience. The one shownin the assembly requires careful lay-out and filing. A filing machine isgreat here, too, although it is possibleto do the job by hand. Two alternatesare shown which can be straight mill-ing cuts.To make the curved bladed Impel-

lor shown, start with an accurate 7IS"diameter x liS" disk. Scribetheexactcenter and prickpunch. Set the divid-ers at 21164" and scribe a circle.Without changing the setting, paceoff six points on the circle and prick-punch. Scribe the 7/32" circle. Drawthree centerlines through the sixpoints. Drill the six l/S" holes. Usingthe intersection of the three center-lines and the 21/32" circle as centers,scribe tangents to each hole as shown.Chuck in the 3-jaw and bore 3/32"and turn the 7/32" and 7/16" diame-ters 1116" deep. Round the 7/32"hub for an easier flow of the liquid tothe vanes. Use a jewelers saw andfile to the curves as shown. Attach tothe Shaft with a press fit or Loctite.Assemble and give a test run at a

fairly fast speed. ACentrifugal Pumprequires flooding or priming to startpumping. If your Pump is above the

supply level, a foot valve will beneeded to retain a prime.Apulley or collar should be used to

keep the Impellor centered in theHousing.The Centrifugal Pump is mounted

on a Base driven by the Turbine.A common rubber band of about

1116"square (cross section) runs inthe V-pulleys. Try several to get onethat will drive the Pump freely with-out too much pressure on the Bear-ings. The Turbine doesn't have muchpower until it is running at a fairlyhigh speed.The parts shown require little com-

men t. You may have Erector pulleysor such that can beadapted. TheBASE and PULLEYS are aluminum,though any odds and ends can beused. It is well to consider rustingwhen selecting material ifwater is tobe used. This model was tested onwater and then drained to preventrust on the Shaft. It should havebeen made of stainless steel. Pump-ing light oil will lube the Inner Bear-ing. It showed a nice stream at highspeed with the turbine running onabout 60 psi air.This is a cute little unit and it is fun

to run and show off.

50

~lr

TURBINE

TURBINE ANDCENTRIFUGAL PUMP

BUSHING"Oilite" or Bronze2 Required

COVERV32" Bross

for lI256

FOOTAny Metal

PULLEYAluminum

51

Note:drillM37depth 5/16top #5-40drlllll60depth !!16beforeturningI V4 dio.

drill 3/32. 24 holes

'

equally spacedf lie to outlineshown

- 1 112" """"'--1=9: '

ROTORAluminum

l~L-;"-,,,- ....j 2-56BEARINGAluminum

=t;II\i\llllf:;ft 0>0=4111----~4-.-40-7w ~

~. ~3/8 ==rSHAFT JStainless Stee

C1JdEllll:::::~~ ~drill Vl6I W~5'40

7/16

STEAM CON.Brass

CENTRIFUGAL

PULLEYAluminum

4=1 Ii j3/8

I"

BASEAny Metal

r m _ __ __ ,....-+_I_'13

VJ

2ri"n;7;i

,,,,,

PUMP

*2-565 holes

~/8 j'1"~*2.56

}!=I ~ -- U~IL. I.)_~ HOUSINGI 7/8 j Aluminum

FOOTAny Metal

BEARINGBrass

SPRING WASHERSf. Steel Brass

~16 3/16MTPf19~rl6l I '12 l rs!EUI=3~ ~ ~-18'32 ~"%4 drill 7/64J

PIPE CONNECTIONSBrass

52

\

IMPELLERBrass

ti:;:;

~,. 11SHAFTSt. Steel

HEADAluminum

., '\':

Here are some details to help you

Create Your Own DesignsThroughout the development of

these engine designs, there have beencertain details that were reused. Theyworked, they were easy to build andthey were handy. They also simpli-fied the preparation of the text foreach article.Although you see them through this

book, we have grouped them here forthose who might want to design their

own engines, using these referencesand details.There are the Symbols which indi-

cate a condition that should be met ata certain point. There are two differ-ent Cylinders, a Steam Chest, SteamChest Cover, Valve Plate, a Valveand Valve Nut. There is an InboardHead and an Outboard Head, anEccentric, two Pack Nuts, and a Fly-

wheel which was used several times.Check them over before you begin

work on a new project and apply anyof these parts to any engine you de-cide to build.Once you are familiar with these,

their relationship to the engine youenvision will be clear and you canproceed in your project with utmostconfidence.

SYMBOLS

@ CLOSEFIT Close clearance between two parts.A close but free-running fit with no shake.Make one surface and machine the other to fit.

(0 SMOOTH A fine polished surface for minimum wear.

0 FLAT Ground flat with very fine emery paper on asurface plate or plate glass for a tight metal-to-metal sliding seal.

CD BRAZEOR SOLDER Silver solder in some cases; up to you and yourequipment. Most soldering in these designs hasbeen with 4300 type solder.

0 PRESSFITOR LOCTITE Your choice. Loctite has been quite sucessful.Follow Loctite's instructions.

CD LOCTITE Loctite recommended.MTP MODEL TAPERPIPE Tapered pipe thread for model makers.

- PACKING Packing ismentioned in the text on some enginesand stuffing boxes are shown. In all cases, use yourfavorite packing which can range from common cottontwine to graphited asbestos. Some models depend ononly a close fit and a bit of lube to seal at low pressures.

The small symbols inside the circles shown at various sur- should meet. They reduce the amount of data onfaces and dimensions indicate a condition that that area the drawing and you will soon learn their meaning.

253