# A carriage stop for my SM 1334 lathe



## ninefinger (Aug 1, 2012)

I decided that I would either build a few aids, buy a DRO or go full on CNC to help me produce the cylinders for my radial engine build.  I started with option 1 so here it is - a carriage stop with 8 positions.  That should help me get some even fin spacing on the cylinders - 16 fins per cylinder so I just need to reset the stop once to complete a set of fins - that's the plan anyways!







Here is a closer shot showing the screw on the carriage - it may get replaced with a fancier set of spacers to help with the other parts that are length sensitive but have more than 8 "features"...we'll see





Here is a back end shot.  I recessed the holding screw so that I can take the whole thing and set it on a surface plate to set the different stops using a height gauge (need to buy one of those..).






Lastly a shot showing my basic indexing method of a spring and ball bearing.  It doesn't really need to index but it helps a bit.  I also wanted to use a belleville washer to keep it tight to the mounting block but I don't have any so a split lock washer between 2 plain washers does the job of applying spring tension.






I have yet to try it out in anger - I hope it does the job as well after all the effort I put into it...

Also - I'll probably number the different positions so I can keep track of where I am.

Mike


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## ProdEng (Aug 1, 2012)

I like using a carriage stop, knowing the carriage can't go any further.  With a readout there is still the possibilty of overshooting and watching numbers scrolling on the display is tiring.  Love your turret stop, well worth the effort of making.  Another job to be added to the machine mods list


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## dsquire (Aug 2, 2012)

ninefinger said:


> I decided that I would either build a few aids, buy a DRO or go full on CNC to help me produce the cylinders for my radial engine build.  I started with option 1 so here it is - a carriage stop with 8 positions.  That should help me get some even fin spacing on the cylinders - 16 fins per cylinder so I just need to reset the stop once to complete a set of fins - that's the plan anyways!
> 
> .
> .
> ...



Mike

Having an 8 position turret will give you 8 positions. Now if you were to replace the 1 stop bolt with another turret with 2, 3 or 4 stop bolts all adjusted to different positions then you could have 16, 24 or 32 different positions. 

It's just an idea that popped into my head as soon as I saw the 8 positions and 16 fins per cylinder. 

Cheers 

Don


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## ninefinger (Aug 2, 2012)

Don,

I had thought of replacing the single bolt on the carriage with a stud I could thread onto with other fixed length standoffs to make more combinations possible.  A 2nd small turret with 3 or 4 positions would be neat but is probably overkill.  I still do want to have a cnc lathe someday for repetetive small work but I'll probably do it to my 7x14 mini lathe (I have visions of it popping out little valves, valve guides, etc for my radial engine build... )


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## Hopefuldave (Aug 5, 2012)

Hi Mike, that's a nice piece of work!

Just a thought - use the stud idea for the carriage bolt replacement, but make it with (e.g.) a 20- or 40-tpi / 1mm pitch (according to taste) section projecting from the carriage, then a graduated threaded sleeve to suit and - micrometer carriage stop with turret! Then you'd be able to machine 8 fins, move 8 times fin spacing on the micrometer and cut the other 8...

Dave H. (the other one)

(Whose Holbrook has a gauge tray on the front way cover, and a 0-500 thou" micrometer stop at the carriage end of it, hence the thought - I really *must* get a set of gauge blocks!)


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