Drawings and Instructions 

Drawings and instructions for the Quarter-Scale Merlin were created to accompany the castings - they are not available separately.  (Why?)

1/2-scale views of the engine can be downloaded in PDF format.

Side View  (77kb)
Front and Back Views  (73kb)

Sample drawings and instructions also can be downloaded in PDF format:

Crankcase Group Machining Instructions  (22kb)
Scale Propshaft Drawing  (62kb)
Timing Chain Cover  (105kb)

The Quarter-Scale Merlin was designed on a CAD system.  Drawings for machining the castings and other parts needed to build a running engine have been derived from the CAD design.  A considerable amount of time has also been spent in producing detailed instructions for many of the machining operations.  These instructions are offered as suggestions only, first because it is impossible to guarantee that every single detail is correct, and second because it is recognized that experienced machinists will undoubtedly come up with other and better ways to do things.  Some descriptions of engine parts have also been produced.

Currently, there are almost 100 sheets of drawings, and almost 30 pages of descriptions and instructions. This represents at least 90% of the information required to build a complete Quarter-Scale Merlin, and will keep an engine builder occupied for quite a while. Running versions have been built by experienced model engine builders when less information was available, and obviously, the level of detail required depends on the person. The goal is to provide all the information required to build a running engine, but exactly how much information that is has yet to be determined. People with the level of knowledge and experience needed to build this engine typically are very creative, and do not need to have every detail defined. It is expected that customer feedback will help determine what information should be concentrated on. Although the Quarter-Scale Merlin is much simpler than the real Merlin, it is still a very complicated engine. Many hundreds of drawings are required to define every part of the real Merlin, and hundreds of pages of pictures and information to show its assembly. This does not count the vast amount of knowledge and experience needed by the companies that built it. Certainly hundreds of drawings and a great deal of information would be required to cover every step of building a Quarter-Scale Merlin, and even then a certain level of knowledge would still be necessary.

Following is a list of released descriptions, instructions, and drawings. Customers should consult this list to see if there are new or changed items.

A Size Drawings:

QSM1110C  Main Bearing Cap
QSM1111-  Main Bearing Stud
QSM1120-  Crankcase Crossbolt
QSM1130A  Crankcase Line Boring Fixtures
QSM1140-  Gearbox Cover Spreading Tool
QSM1151-  Crankshaft Oil Caps
QSM1200C  Propshaft
QSM1210-  Propshaft Gear
QSM1220-  Propshaft Retainer
QSM1250B  Drive Shaft
QSM1251A  Drive Gear
QSM1253A  Drive Shaft Key
QSM1254-  Drive Gear Retainer
QSM1255-  Drive Shaft Support Housing
QSM1260A  Drive Shaft Assembly
QSM1310B  Fork Rod
QSM1311-  Fork Rod Stud
QSM1320B  Blade Rod
QSM1321-  Blade Rod Stud
QSM1410A  Split Bearing Stock
QSM1420A  Rod Bearing
QSM1430D  Main Bearing
QSM1510-  Piston
QSM1520-  Piston Ring
QSM1530A  Wristpin
QSM1540-  Wristpin Retainer
QSM2110-  Cylinder Block Stud Seal
QSM2150B  Cylinder Liner
QSM2151-  Cylinder Liner Ring
QSM2152A  Cylinder Liner Collar
QSM2161A  Cylinder Cross Section 1
QSM2162A  Cylinder Cross Section 2
QSM2202-  Rocker Arm Mounting
QSM2209A  Camshaft Bracket Stud
QSM2210B  Camshaft Bracket, Front
QSM2211B  Camshaft Bracket, Intermediate
QSM2212B  Camshaft Bracket, Rear
QSM2213-  Rocker Shaft
QSM2225A  Camshaft Drive Sprocket
QSM2226A  Camshaft Drive Hub
QSM2227A  Camshaft Drive Retainer
QSM2230-  Rocker Arm
QSM2231-  Camshaft Roller
QSM2232-  Camshaft Roller Shaft
QSM2233-  Valve Roller
QSM2234-  Valve Roller Eccentric
QSM2250-  Cylinder Stud
QSM2251-  Cylinder Head Stud Tube
QSM2252-  Cylinder Head Stud Washer
QSM2253-  Cylinder Head Stud Nut
QSM2260-  Valve
QSM2261A  Valve Seat
QSM2262A  Valve Guide
QSM2263-  Valve Spring Retainer
QSM2264-  Valve Spring Retainer Clip QSM4100-  Exhaust Pipe
QSM5020-  Wheelcase Countershafts
QSM5040-  Rear Drive
QSM5050-  Timing Chain Arrangement
QSM5105-  Wheelcase Boss Drill Jig
QSM5110-  Wheelcase Bearing Plate
QSM5120A  Mag Drive Bearing Adapter
QSM5125A  Oil Pump Idler Bracket
QSM5130-  Starter Countershaft Support
QSM5140A  Coolant Pump Adapter
QSM5150-  Rear Drive Shaft
QSM5151B  Timing Chain Drive Sprocket
QSM5152A  Pump Drive Gear
QSM5153A  Mag Drive Gear
QSM5154A  Rear Drive Spacer
QSM5155A  Main Gear Adapter
QSM5156A  Wheelcase Main Gear
QSM5160-  Countershaft
QSM5165-  Supercharger Drive Gear
QSM5166-  Supercharger Slip Clutch
QSM5170B  Timing Chain Idler Sprocket
QSM5300B  Oil Pump
QSM5400-  Coolant Pump
QSM5500-  Magneto Housing

B Size Drawings:

QSM1100F  Crankcase Group
QSM1102B  Lower Crankcase
QSM1150E  Crankshaft
QSM1155-  Crankshaft Blank
QSM2100B  Cylinder Block
QSM2101-  Billet Cylinder Block
QSM2200B  Cylinder Head
QSM2220C  Camshaft
QSM5010-  Wheelcase Gears
QSM5030A  Rear Drive Adapter
QSM5060-  Timing Chain Cover
QSM5100B  Wheelcase
QSM6100-  Supercharger


Additional Parts
Available Gears
Cylinder Block Assembly
Ports, Valves, Camshaft
Scale Fasteners
Supercharger Section
Lubrication System

Machining Instructions:

Crankcase Group
Cylinder Block
Cylinder Head
Intake Manifold

Why aren't the drawings and instructions available separately?  A great deal of the information in the drawings and instructions deals specifically with machining the castings.  Without the castings, that information would be of very little use to anyone.  So, here we have the problem of something that is of great value (in fact, indispensible) with the castings, and of relatively little value without them.  Rather than trying to arrive at a price for the drawings that would seem reasonable to both purchaser and Dynamotive, the solution at present is to not offer them for sale.