Author Topic: Custom handlebar clamps (Read 30058 times)

MadNick · « **on:** January 22, 2012, 01:33:57 PM »

Afternoon,

I wanted to lie in bed all day today but instead kicked myself up the backside and made the trek to my workshop, full of anticipation

The reason for making the ball cutter was to put a radius on the top of a pair of custom handlebar clamps - I am building a hardtail chopper. I finalised a rough design for the clamps, found a couple of nice pieces of stainless around the right size and got stuck in.

Having worked with stainless before and got quite rough results I had some trepidation but really neednt have worried (so far anyway).

The raw material -

I put the ball cutter into action and it cut a very clean radius on the top of clamp 1 -

Sure there were a couple of rough bits but some fine wet and dry and then autosol and wire wool cleaned things right up - will still need polishing properly though.

I then spun clamp 1 round in the chuck, piloted a hole for the retaining stud (which bolts up to the top handlebar yoke) and turned down a slight shoulder so it seats slightly above the yoke (no more pictures at this stages as my batteries went).

Anyway, I hope to get some more work done on this possibly for next week or maybe at the weekend. Will keep you posted.

Nick

sparky961 · « **Reply #1 on:** January 22, 2012, 02:18:11 PM »

How big is that chunk of metal? How long did it take to put the radius on the one end?

-Sparky

MadNick · « **Reply #2 on:** January 22, 2012, 02:26:51 PM »

Sparky,

Its about an inch and a half in diameter and it took about 10 minutes to cut the radius.

Nick

DaveH · « **Reply #3 on:** January 22, 2012, 05:49:24 PM »

Nick,

Good start, nicely done

What is the raw material?

DaveH

Brass_Machine · « **Reply #4 on:** January 22, 2012, 08:16:18 PM »

Nicely done Nick.

I am a bit of a bike guy... a little more about the hardtail?

Eric

MadNick · « **Reply #5 on:** January 23, 2012, 08:45:27 AM »

Afternoon,

I ran into a problem! The base of these needs to take a 1/2" UNC thread running at 1/2" deep - I have drilled it out ok with a new 27/64 drill, taking it very slowly and using lots of coolant but the tap is getting so tight that after a couple of turns I had to back off before something breaks.

Any ideas what could be wrong please? I suppose now would be a good time to ask what kind of taps I should be using ... ;)

@DaveH the raw material is stainless - I really wanted to use mild steel but have nothing of the right kind of diameter. Might have to buy some now!

@Brass machine. Its an Ironhead Sportster lump in a custom hardtail frame. Ill put some pics up once I get a bit further.

Nick

Fergus OMore · « **Reply #6 on:** January 23, 2012, 09:08:22 AM »

Nick,
Two issues! One is what tap were you using and the second is what drill did you use?

Of course, you might have work hardened the stainless steel.

A lot of possibilities but really you should have screwcut first and then followed up with the 'first' cut tap.

Mebbe, a dremel type of grinder might slightly open the hole and the dremel might sharpen the tap.

I'd use lard oil for tapping- but I'm funny that way.
I'm also funny peculiar because Lidl has these Dremel type beasties for sale------TODAY

Kung Hay Fat Chow

Norman

sparky961 · « **Reply #7 on:** January 23, 2012, 09:43:43 AM »

I've never had the opportunity to hand-tap anything much larger than 1/4-20 in stainless. I have, however, tapped many a through hole that size under power on a bridgeport clone. The way it was done was to use plenty of "Tap Magic" on a small brush, keeping the tap dripping with it as it went in. Lots of torque and very slow. Smoke is good - if it stops smoking, you're screwed.

As was mentioned, with stainless you have to be concerned with work hardening. Basically you need to get in there and do your cuts with conviction and get out.

The 1/2" deep part also made me wonder - are you trying to start the hole with a bottoming tap? A taper tap probably wouldn't start, and a plug tap might be a bit tight. Just thinking out loud on this one...

-Sparky

DaveH · « **Reply #8 on:** January 23, 2012, 09:44:52 AM »

Nick,

You need to start the taping with a "tapper tap" use some cutting fluid, again take it slow and steady.

I am assuming you are familiar with the accepted way of hand taping.

DaveH

MadNick · « **Reply #9 on:** January 23, 2012, 09:54:16 AM »

Thanks fellas,

Quick responses too - are we all working from home today?!

I dont think my taps are adequate this time and I used my lard in the pastry I made the other day ;)

Time to reconsider my approach...

Nick

Fergus OMore · « **Reply #10 on:** January 23, 2012, 10:15:04 AM »

Nick,
"Wo**' that's Four Letter word!

Do you recall me quipping about a turning attachment but mine held a diamond- well, this is for shaping the grinding wheels to do the gullets on taps. If you have a dead steady hand you might re-sharpen the leads on your tap with an angle grinder. It only requires a touch on the cutting edge at the beginning.

Lard oil, well, that's what they use to make these fancy tapping compounds. Whoever thought that that it can be used for baking?

N

MadNick · « **Reply #11 on:** January 23, 2012, 11:01:00 AM »

@Fergus,

"There is nothing new under the sun".

Where do you get your lard oil from or is it possible to make some up at home?

Nick

Fergus OMore · « **Reply #12 on:** January 23, 2012, 11:30:17 AM »

Lard oil is actually what the great engineers of the past used for cutting oils mixed with washing soda and water.

I bought mine from one of the one of the oil suppliers who got me a 5 litre container- not a gallon- What next?

However, there is no reason why you shouldn't use ordinary lard or even the remains of the bacon and eggs left over in the pan.

I fiddled and faffed with all sorts of fancy lotions with wonderful names and addresses and went back to lard.

In all seriousness, it is great stuff for the home lathe guy. I have mine in a dirty jam jar, a cheap paint brush and a collection of swarf, dead bees and wasps that have commited suicide over the course of the last 10 years. It congeals and softens with the heat and all sorts of exotic smells and it leaves a lovely finish both on my hands and the work.

Quietly think, this was the stuff that was probably used on your old lathe- and mine too.

Mix it with a bit of perfume, water and witch hazel and flog it as Pond's Vanishing Face Cream.

MadNick · « **Reply #13 on:** January 23, 2012, 12:20:51 PM »

Fergus,

Ill give it a spin, let you know what I think

Nick

Scuba1 · « **Reply #14 on:** January 23, 2012, 04:17:15 PM »

I don't do ferrous metals by default and my lathe has not seen anything other then stainless, brass and ally. For cutting threads in SS i use a few drops of slideway oil and a " want to do attitude" ..That is constant prerssure without backing off. I do cut a lot of threads on in Stainless at home and at work and this method works fine for me ....... a lot of my taps and dyes are over a year old and have cut hundreds of threads without so much as a touch up with a honing tone.

ATB

Michael

MadNick · « **Reply #15 on:** January 24, 2012, 02:15:09 PM »

Thanks,

Ive ordered a new 1/2" UNC tap set and saved some bacon fat for another go at it.

The Hacienda must be built!

Nick

MadNick · « **Reply #16 on:** January 27, 2012, 04:45:34 AM »

Morning!

The 1/2" UNC tap set have arrived from Namrick and are up to their usual good quality. I also bought some Ruko cutting paste from screfix for a fiver.

Big difference and a nice clean thread has now been cut

More progress and pictures over the weekend...

Nick

DaveH · « **Reply #17 on:** January 27, 2012, 08:04:58 AM »

Nick,

There you go - well done

DaveH

MadNick · « **Reply #18 on:** January 28, 2012, 04:42:13 AM »

Morning,

Here are the blanks for the clamps loosely assembled on the bike.

The top yoke isnt flat so when the clamps are tightened up they do not sit square. I need to cut a chamfer on the bottom for them to sit square in the recess on the yoke.

Before that though I need to do another tricky bit, drill two blind holes from the bottom almost the full length of the clamp - these will house two allen head bolts that will be used to tighten the clamps up with. And then onto boring out a 1" or 7/8" hole crossways for the handlebars themselves - I havent settled on a pair of bars yet.

I am also contemplating some yokes from billet alloy or really push the boat out and buy some springer forks.

Loads to do...

Nick

MadNick · « **Reply #19 on:** February 11, 2012, 11:59:59 AM »

Afternoon,

Well I have had a busy day so far. Thanks for all the suggestions, in the end I did it like this -

As far as I know so far - haha, it worked a treat. I finished up with these -

I drilled and tapped the outside holes with a 5/16 UNC thread - these will house the allens bolts that tighten up the clamps. I thought it would be easier to do them now before slicing the things in two.

Next is a tricky bit cross-drilling the 1" diameter holes for the handlebars to slide into. This will be a real test of my numbers as the allen bolts run very close.

Could any of you offer tips on getting the cross drilling right as the hole needs to be perpendicular to the two outside bolts. Theres a lot of metal to remove but I have a 1" diameter end mill and a boring head, so there are plenty of options.

Also I need to put some ridges inside the hole for the handlebars to grip against, again any suggestions please?

Thanks for reading,

Nick

BillTodd · « **Reply #20 on:** February 11, 2012, 03:33:56 PM »

Quote

Could any of you offer tips on getting the cross drilling right as the hole needs to be perpendicular to the two outside bolts. Theres a lot of metal to remove but I have a 1" diameter end mill and a boring head, so there are plenty of options.

Bolt them to a right anlge plate or similar fixture

I thought handle bars were 7/8" ?

Quote

Also I need to put some ridges inside the hole for the handlebars to grip against, again any suggestions please?

If making them a few thou" small doesn't get you enough grip, you could either pin them (as most of the jap bikes I owned did) or...

If you need to knurl them: mount a straight knurl wheel to the end of a rod, mount the rod in your boring head and knurl the inside hole in the same fixture you used to bore the holes.

Bill

MadNick · « **Reply #21 on:** February 11, 2012, 04:19:10 PM »

Thanks Bill,

These are 1" diameter bars. Japanese (and most british) bikes generally have the 7/8" diameter size.

Nick

MadNick · « **Reply #22 on:** February 13, 2012, 02:23:36 PM »

Evening,

Well its been a busy evening -

As you know the next step was to cross-drill the hole for the handlebars. I pre-drilled a couple of holes and then went in with a 1" slot drill which pretty much maxed the mill out - I used loads of fluid, half the cutting speed of steel and went for it. I ended up with these -

Luckily I seem to have got my numbers right and there was no intrusion on the passageways for the clamp bolts.

Pretty good. Now I need to mill some flat sides to make a feature of the handlebard hole. I ended up with these -

I just ran outside to check my measurements again. Both holes are the same distance from the bottom face of the clamps.

Heres what they look like roughly fitted -

I am pleased with these. The next step is to use a slitting saw to slice them apart so they actually clamp up when the handlebars are shoved between them.

A good evenings work despite a couple of heart stoppers. Also I realised that I managed to do what I wanted with what I had even though I ordered more tooling this morning.

Nick

DaveH · « **Reply #23 on:** February 14, 2012, 11:12:17 AM »

Good job Nick,

In the home workshop the cutting speed for steel is what works for you. Half speed, quarter speed if it works nicely then that is the correct cutting speed.

Nearly always slower is better.

DaveH

MadNick · « **Reply #24 on:** February 14, 2012, 02:02:51 PM »

Thanks for your support Dave.

Always learning despite setbacks and heartache, I love my hooby!

Nick

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Author Topic: Custom handlebar clamps (Read 30058 times)