Brian's 1" Minnie Traction Engine

Hello Jason, thanks for the info..

Spent an hour in the shed tonight having ago, not up to the standard of many of you gents but I'm happy with my efforts.

Good evening all. After some more advice on my minnie..

working my way through the wheels, when is the best time to drill the hole for the drive pin in the hubs ?

would it be ok to drill whilst finishing all the machining on the hubs, or wait until the wheel is finished as per the book ?

thanks in advance.

Edited By Brian Abbott on 12/09/2014 22:51:18

I left mine until last, that way you can be sure everything lined up rather than trying to match holes in 3 different parts. Mind you at the time it was all done on the lathe and a drill press, I might get things a better match now with the mill & DRO.

J

PS Brian do you want me to alter the title of this thread as its about a bit more than just the hub castings now?

Hello Jason, not sure what to do for the best,

worried that if I leave until the assembly is finish will I be able to set it up correctly to place the hole true.

I have not got a DRO at home but can use the scales on my mill, wonder if I could drill all the holes slightly undersize then run a hand team through the assembly..

While I,m pestering you could I ask what you think would be the best material for the axel, do you think BDMS would be ok, or shall I get a peace of silver steel ( might me a little straighter )

And, if you can rename to minnie build of something would be good..

thanks again for you help...owe you a pint one day..

The problem with reaming after the assembly is that the reamer will only follow the positions of the holes already there so they may come out the right size but could be off line. What I did when I made my 2" Fowler was to clamp the completed wheel to the mill table, locate centre of hole in the hub and just wind the table to the correct distance before drilling and reaming the hole.

My axle is just mild steel bar, same with the Fowler though that did take me 3 attempts to buy a straight bit of 7/8 stock. If I were doing it again I would likely go for PGMS (precision ground mild steel) has a similar ground finish to silversteel but easy to work like mild steel

Hello Jason..

Does sound like the best way to go..

thanks for the info.

just spent a happy hour boring the 7/16 holes through my hubs, first one perfect, second one 0.002 over size...

don't sound much but it given me a wobble, don't want to scrap it, anyone any ideas.

Edited By Brian Abbott on 20/09/2014 18:02:55

Unlikely to really notice when its all done. If you are really not happy them maybe bore it out to say 1/2" and soft solder or even loctite in a sleeve. Probably easier than turning down an axle with an oversize end from 1/2" bar.

Hi Brian,

I remember doing just that on my Minnie - oversized a bore on rear wheel hub. So I opened up the bore and slipped in a bush with 601 retainer and tried again. Second time I got it right; bit of a faff, but all part of the learning process

Regards

Phil

Thanks both for your reply's

Not done and soldering yet, so loctite may be the way to go.. Is 601 the one to get ?

Hi Brian,

I only mentioned 601 because that's what I've had on the shelf for years, shelf life seems very good. Here is the link to Loctite's retaining compound page.

http://www.loctite.co.uk/loctite-4087.htm?primaryFacet=000000028Z#.

I'm sure I've seen 638 mentioned elsewhere as a general purpose retainer - looking at the spec. it cures a lot quicker too. I'm sure that other members will have different suggestions.

Are you soldering the covers on the hubs after assembly of the spokes? This might help you make your decision.

Regards

Phil

Finished the hubs today, decided to include the drive pin hole to help me setup.

Wondering now which bit to do, guess the wheel jig is next.

Hello all, need some help if possible.

Progressing with the wheel build on my minnie, have now complete one side using the the wheel jig,

so now need to turn the wheel over and complete the other side, ( obviously )should I continue using the wheel jig ?

If I have done the first stage correctly and the hub is central to the rim case can I just sit the hub on a packer to stop any flexing whilst drilling, ect.

Thanks for any advice.

Brian

I can't offer any comments jig or no jig, but just wanted to say your wheel looks excellent! Very well done. JD

Thats how I have done them on all the wheels I have built, adjust the height of the packer and build the second side in the jig. Looking good.

Thanks both for your reply's,

I dropped the wheel onto the spindle but unfortunately it does have a few mm run out, should have taken more care i guess so need to sort this before starting the other side.

Jason..did you manage to get them running perfectly true ? or should i settle for what i have ?

Thanks

I don't think I had more than 1/32" woibble on teh Minnie. Main thing is to make sure you get the bends right as any tension put on when its screwed together will pull the wheel out of true.

You may want to try 4 spokes on one side, then 4 on the other and when its true start filling in the gaps

As Jason says, any tension in a spoke will pull the wheel out of true.

I made the wheels to my Minnie some time ago and remember it being rather fiddly, but I did manage to achieve wheels with very little run-out. Len Mason's description, in the Minnie book, which I followed, goes something like - working in opposite pairs... set the bend at the rim end, position the spoke with a 10BA screw through the central hole and press the spoke gently onto the rim, the spoke should just graze the edge of the hub groove and there should be no rock. It's probably more obvious if the bend is just a little too much at first, and then tweaked back to fit.

Now the hard part - mark the spoke at the hub end and bend the spoke (all bends must be a right angles across the spoke and each hub end bend should be slightly short of the hub groove). Now refit the spoke to check - there should be no rocking and the hub end should lie flush with the face of the hub.

Perseverance - bend, fit, mark , bend, tweak, fit, tweak, fit ---- ahhhh is quite satisfying.

Thinking about it now, for the second bend, I would make a little test jig, which would simply be a block of an appropriate height (inside rim to bottom of groove), resting on a flat surface, you could then test each spoke with Mk1 eyeball, so that it rests flat at both the rim and hub ends.

It might be an idea to do 4 each side and check before completing the wheel.

Regards

CP

Edited By CotswoldsPhil on 18/11/2014 19:29:14