SDMP
GEARBOXES AND DRIVE COMPONENTS 
These components are strong and accurately-etched gearboxes in 0.7mm (0.028") nickel-silver which use ballraces instead of the brass bushings commonly found. They typically include fixings for Canon 1833, Mashima 18xx, 16xx or 14xx motors.  
  
More information including Application Notes, Planning Sheets and Instructions are available towards the bottom of this page. Prices are available on the Chassis Bits page.

Branchlines/Ultrascale Based Gearboxes
13:1, available in motor-mounted ('Power'), non-motor-mounted ('Remote') variants which were originally developed for diesel locomotive bogies. In either version the gears require a 2mm worm shaft and fit 3/16" diameter axles:  
Blines Power 
Full gearbox (unassembled) including fret, gears, bearings, instructions.  
Assembled gearbox 

Blines Remote 
Full gearbox (unassembled) including fret, gears, bearings, 2mm diamter worm shaft, instructions.  
Assembled gearbox  
 
Romford Based Gearboxes 
Most useful for older or smaller prototypes, these gearboxes are available in 30:1, 40:1 and 54:1 ratios. The fret comes with two motor mounting plates which cover 10mm (Mashima 14xx and 16xx series), 12mm (Mashima 18xx series) and 15mm (Canon 1833) motor fixing screw centres. All gear sets take a 2mm motor shaft and a 3/16" axle. Please order by gear ratio (
Rford 30:1, 40:1 or 50:1)
Full gearbox (unassembled) including fret, gears, bearings, instructions.  
Assembled gearbox
 
Markits Based Gearboxes 
These are a variation on the classic Markits ‘7H’ gearboxes, available in 13:1, 20:1, 26:1 and 40:1. The latter is also available in a 2-stage variant; the 40L. They are each produced with motor fixing screws centres of either 12mm (Mashima 18xx series) or 15mm (Canon 1833). The single-stage gearboxes are additionally available with 10mm motor fixings for Mashima 14xx and 16xx series. Please order by gear ratio and motor/fixing screw centres (Mkits 13:1, 20:1, 26:1, 40:1 / 10mm, 12mm, 15mm). 
 
Single-stage gearbox (unassembled) including fret, gears, bearings, instructions.   
Assembled gearbox  
 
Two-stage gearbox (unassembled) including fret, gears, bearings, instructions. 
Assembled gearbox  

Sundry SDMP Components
Hornguides.
Known as ‘47961’, these are designed for use with Slater’s 7961 ‘Insulated Square Bearings’ and provide an easy to adjust, insulated, sprung hornblock system which is particularly useful for split axle or ‘American’ pick up approaches. These are a simple assembly in 28thou” (0.7mm) etched brass. To complete you will need a set of springs (such as Slater’s 7164) and the 7961 bearings. Axle cut out required is 7.5mm above axle centre line and 11mm wide.  
47961 six guides for three axles (inc fret, screws) 

Ballraces.  Good quality steel bearings, as used in the gearboxes*** 
FR156zz; 3/16"id, 5/16"od, flanged, shielded 
MF62zz; 2mm id, 6mm od, flanged, shielded  
New MF52zz; 2mm id, 5mm od, flanged, shielded 
 
Constant velocity joints.  A low-cost solution using a ball bearing and a short length of silicone tubing. 
For 2mm shafts: 1 ball bearing, 2cm tube 
Extra ball bearing
Extra cm tubing 
 
Notes 
* Please supply 3/16" diameter axle and motor (with 2mm diameter shaft) of your choice 
** Please supply 3/16" diameter axle of your choice 
***Other ballraces are available to order, please email us with your requirements, including quantity, and we will be happy to quote
DOWNLOADS FOR SDMP
Branchlines/Ultrascale-based 13:1 gearboxes
Markits-based 13:1, 20:1, 26:1, 40:1 gearboxes (coming soon) 
Romford-based 30:1, 40:1 and 54:1 gearboxes 
Etched hornguides for use with Slater's 7961 'Insulated Square Bearings'