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Tooling & Machines / Re: Mini Lathe Electronic Spindle Divider
« Last post by Vixen on Today at 10:42:34 PM »
Chris

Unfortunately you will get a lot of backlash with any inexpensive planetary gearbox. They may not be the answer to this application

You get NO backlash from a stepper. Most steppers, these days give 200 steps per rev. With microstepping you can get 400, 800, 1600 steps per rev ect. It all depends on how you set the drive electronics switches. Just a word of caution, 400 microsteps will only have half the torque of the normal stepper, 800 microsteps will have a quarter, etc etc. You could easily run out of torque to turn the worm gear, especially if you have set it "tight" to minimise it's backlash.

A dividing head with 200 divisions per revolution will be very limiting, you would only be able to cut gears with 10, 20 , 25,40, 50, 100 or 200 teeth. You need many more steps per revolution than that. More the better; but watch out for the torque reduction.

The good news is there is no need for a spindle lock, the worm gear will lock the spindle from rotation from the cutter action:



Mike
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Chatterbox / Re: 'WIDE A WAKE' - an anecdote
« Last post by Ramon on Today at 10:39:56 PM »
Hi Guy’s,

I thought you might like to hear of a very well meaning act by the wife of one of our forum members…….  A small gift came my way, perhaps quite insignificant to some, totally unexpected on my part but extremely thoughtful and received with heartfelt thanks.

You may recall that at some stage I took the boat and gave a talk to members of the Norwich MES. The result of the evening was that I was asked to do the same at the Halesworth MES. Destined for last October this was, due to various reasons, postponed until early this month.
I was well received with a good turn out of members including a couple of wives and began as before by showing an image of and describing receiving that Model Boat Magazine in 1972 in which WaW was originally featured. I commented that when writing the article for ME that I had sent that original copy to Diane at ME to scan the drawings but that unfortunately this had coincided with Diane becoming unwell and that under the circumstances the magazine would probably not be returned. I gave no more thought to it and moved on

Yesterday I had a visit from forum member 'Andy B' and his wife Miranda whom I have only met once before at Forncett but who had been present at the talk. She handed me a plain brown envelope with a grin and accompanied it with a “You might like this'’ comment. Oh Really???

Inside ? Well imagine my total and extremely pleasant surprise when I pulled out a very good condition copy of that February 1972 issue of Model Boat magazine. She had noted what I had said, gone home, sat down at the computer, found one and ordered it completely unprompted.

Small gift? well yes you may think so, Old magazine? well yes too but in my book a truly thoughtful and well meant gesture that brought a huge smile to my face ;D.

Quite taken back by this unexpected kindness I thought it deserved to be shared with you too. My sincere thanks Miranda - so immensely appreciated.

Regards - Tug

Incidentally, on the same evening I received a gift from a Halesworth member of the complete set of drawings and info, plus the one casting required for the Hodgson 9 Cylinder radial but that as they say is another matter  ;)

You could say a good evening all round  :)
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Vehicles & Models / Re: 1/3 scale V10 RC car.
« Last post by JC54 on Today at 10:38:37 PM »
 Now that is what I call AWESOME  :popcorn: :NotWorthy: :DrinkPint:
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Tooling & Machines / Re: Mini Lathe Electronic Spindle Divider
« Last post by craynerd on Today at 09:49:08 PM »
I was about to order and I’m Just tying myself in knots...your opinion again would be appreciated.

Steppers with planetary gears are cheap £50 but have backlash of <= 1.2 degrees! Anything with precision is £230+ but have backlash less than 20 arcminutes (0.3 degrees). My worry is that 1.2 degrees is a lot and although most of my dividing will be in one direction, I do occasionally step back to check the depth of cut. I really don’t want to spend £230 on a stepper motor!

Which got me doing some calculations.

I can get a 1:6 belt drive. 200 steps per rev, on microstepping is 400 steps per rev. Multiply this by my reduction 400x6 = 2400 steps per revolution.  360deg / 2400 = 0.15 deg per step.

Maybe I’m being dim and missing something but would this not be acceptable for basic dividing of up to say 200 divisions in a rovolution. I’m doubting myself because this is some way off the 36,000 steps per revolution that a dividing head gives you!!

Help appreciated before I part with my brass!

Chris

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Specific Engine Help / Re: Valve Packing material source?
« Last post by toolznthings on Today at 07:27:23 PM »
Look for graphite packing string for faucets. Use to come in generic faucet repair kits. Big box stores may have it if still made.
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Specific Engine Help / Re: Valve Packing material source?
« Last post by b.lindsey on Today at 06:58:54 PM »
What I have found at the big box stores in the US is a round extruded type material usually imported and not that good IMHO. For braided, Teflon impregnated packing seal material down to 1/8" square check McMaster. If you need something smaller you can always unbraid it as well.

Bill
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My Workshop / Re: BF20L Mill Stand
« Last post by Johnmcc69 on Today at 05:14:03 PM »
Very nice & professional looking.

 :ThumbsUp:

John
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Specific Engine Help / Re: Valve Packing material source?
« Last post by GordonL on Today at 05:12:27 PM »
Most any place which sells plumbing supplies. Home Depot. Lowes, local hardware store etc
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From Kits/Castings / Re: Roy's Little Engine
« Last post by Dave Otto on Today at 04:53:58 PM »
Getting closer, and coming along nicely :ThumbsUp:

Dave
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From Kits/Castings / Re: ME Beam engine casting source
« Last post by Jasonb on Today at 04:50:27 PM »
Looks like scratch building then.  :)
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