might need job doing

[mick70Participant @mick70]

might need help machining a bike crank square.

am building a special tapole style trike for my 7 yr old boy, and need to make a drilling jig for shortening crank arms.

not sure if i will be able to hold tapered square end safely in lathe to square of other end.

if i can't will anyone be able to help in exchange for beer tokens or services repayed?

am in wf 15 but pce is no bigger than 2" long by about 3/4" rd so could send it.

am still new to machining all my stuff as been welding / mechanical.

many thanks

[mick70Participant @mick70]

[Brian WoodParticipant @brianwood45127]

Hello N.B

I'm sure I could help you, I live in Thirsk. My only concern is that the part is hardened, can you establish whether or not that is the case?

Regards

Brian

[Tony Pratt 1Participant @tonypratt1]

Hi NB,

What's your location, I am in Bedfordshire.

Tony

[mick70Participant @mick70]

It is hardened as forms one side of bearing race.

I am nr Leeds west yorkshire

[Brian WoodParticipant @brianwood45127]

Hello N B,

That could be a problem for me, I don't have suitable grinding gear, but if I read your question correctly the work you want doing is on the other end, which might be unhardened. Is that correct?

Brian

Edited By Brian Wood on 18/02/2015 18:56:09

[mick70Participant @mick70]

It is centre section I need doing.

Will cut it with grinder on Fri and see if hardened all way.

[mick70Participant @mick70]

if it is hardened how difficult would it be to soften it?

its only to use for alignment when drilling the cranks.

[JasonBModerator @jasonb]

Should be able to do it by getting it to red heat and holding in there for a couple of mins then let it cool slowly. If you have an open fire or wood burner then chuck it in there for the night and let it cool in the ash until morning.

Can you not set the crank up on the full length BB spindle and measure the rise, then pack up the crank by the same amount while you work on it to get the thread true to the spindle axis and seating at right angles?

Don't forget you will also need a L/H tap for one of the new pedals

[mick70Participant @mick70]

**LINK**

hopefully this link will work.

it is article on jig i want to make.

sorry its taking while to reply on nights these two days and can't always get on comp at work during night.

got shock on price for set of 3 good quality taps but would rather buy quality and have them for life.

to many bad times with using cheap taps that work have bought.

[JasonBModerator @jasonb]

As its a through hole you should be able to get away wuth just the taper tap.

Would also be possibel to clamp it up with packer as I said above. Do you have a mill or just a bench drill?

J

[mick70Participant @mick70]

just bench drill.

hoping to get mill when we move later in year.

[Author]

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