What are you machining?

[Hood]

Made some crash bar sliders from Acetal. Only ones I have been able to find are thin moulded plastics that doesn't do much so cut these from some 140mm dia Acetal I had and sliced a couple of 25mm thick bits from it.
Still waiting for the black stainless cap screws to arrive.

Also made a few Acetal plugs for a job, m10 x 0.75 thread.

 

[Kram]

Does acetal engrave ok with the laser?

Finished the alu test piece. This has taken over a year!

I was taking 0.5mm passes as somewhere said 0.2* diameter for slotting.

So on to the 316 stainless. Took me ages to get the cutter true. If my indicator is to be believed it was under 0.5μm of runout at the shank. 0.0005mm runout. Mitutoyo with 2μm divisions and the needle has just a slight wobble. I would have said that is impossible?! Was not bottomed out or sticking.

First cut I found forces much higher, it was jumpy. A longer handle was required. 0.25mm passes as 0.5mm was too much for it.

 

[Onoff]

Does acetal engrave ok with the laser?

Finished the alu test piece. This has taken over a year!

I was taking 0.5mm passes as somewhere said 0.2* diameter for slotting.
View attachment 440595

So on to the 316 stainless. Took me ages to get the cutter true. If my indicator is to be believed it was under 0.5μm of runout at the shank. 0.0005mm runout. Mitutoyo with 2μm divisions and the needle has just a slight wobble. I would have said that is impossible?! Was not bottomed out or sticking.

First cut I found forces much higher, it was jumpy. A longer handle was required. 0.25mm passes as 0.5mm was too much for it.
View attachment 440596
View attachment 440597

View attachment 440598
View attachment 440599

I said it'd be a doddle!

Sorry, meant to come back on WhatsApp last night but crashed out knackered.

Very, very grateful for this. Jake's impressed his design worked and that the printing stood up. He's going to be less impressed when I ask him to print me a rudimentary dividing head...

 

[Hood]

Does acetal engrave ok with the laser?
...

Yes, as long as you don't breathe in the fumes

Acetal stamp and the leather I tried it in.

 

[ukracer]

Yes, as long as you don't breathe in the fumes

Acetal stamp and the leather I tried it in.


View attachment 440603

So that's actually taking away most of the plastic leaving a small amount raised up in the shape you require?

 

[Hood]

So that's actually taking away most of the plastic leaving a small amount raised up in the shape you require?

Yes.

 

[Hood]

Got the black stainless cap screws today and also got the sliders lasered.

 

[Onoff]

Got the black stainless cap screws today and also got the sliders lasered.


View attachment 440778

How do they black stainless steel?

 

[ukracer]

Got the black stainless cap screws today and also got the sliders lasered.


View attachment 440778

What material are the sliders?

 

[Hood]

How do they black stainless steel?

No idea but would like to find out.

What material are the sliders?

Acetal

 

[Onoff]

No idea but would like to find out.

A long, long time ago I looked into it. I have a feeling oxalic acid might be involved. The architect was hell bent on it (big, posh named one). I didn't want to do it so said yes we could but couldn't guarantee it wouldn't affect the corrosion resistant properties of the 316. He decided against it.

 

[ukracer]

No idea but would like to find out.


Acetal

Ah Ah that's why it engraved

 

[Kram]

Had a go with new boring bar. Chip breaker works well. Tiny curlers.

It can do light cuts, I think this was 0.04mm and chips are curls rather than dust, if you look close.

Possibly fragile. Not sure how I did that.

Been thinking I should mount the bars better than just the screw clamp 250-101 holders. For the round 10mm bar a sleeve seems ideal.I will run a 2.5m endmill along one side to split it.

The 6 and 12mm bars both have flatted shanks so theres little point in a rounds sléve. Thinking I may use their shanks to broach good fitting slot

 

[Agroshield]

I will run a 2.5m endmill along one side to split it.

Once you get part way along (even before you reach full depth), consider putting in a spacer in (feeler gauges if nothing else) so the cut does not try to close up on you.

Is it possible this 8 foot diameter endmill may be contributing to the belt issues you are having in your rear end?

 

[Kram]

I will try to check my posts better for silly mistakes.

 

[Hood]

Fitted the sliders today, quite happy with them.

 

[RichardM]

@Hood are your crash bars "home made"? Could you take the pads round the corner at the top?

 

[Hood]

@Hood are your crash bars "home made"? Could you take the pads round the corner at the top?

No, they are AS3P bars or actually rebranded CrossPro bars. I just wish I had a means of bending tube to tight the radius required as I would have liked to have had bars similar in design to the Heed bars I had on my previous Africa Twin originally but instead of the steel the Heed are I would make them aluminium like the AS3P ones are.
The location I have them is where the bar would impact, the scratch on the right side is where it touched before I had the sliders on but there is also scratches under the slider. The reason the left side is scratched above is when I hauled the bike around on the road the other week, to make it easier to lift, the crap plastic slider just slipped down the bar so was basically useless, you can see where it ended up in the pic below.

 

[RichardM]

I was just thinking if you made them to go round the top and hide other "hero marks" then it may stop them sliding down under impact. Dependent on costs it may be an interesting option for other AT owners.

 

[Hood]

I was just thinking if you made them to go round the top and hide other "hero marks" then it may stop them sliding down under impact. Dependent on costs it may be an interesting option for other AT owners.

Too expensive to buy I would think. If I thought there was a market then making a mould and casting would be the better option but I don't think there would be enough of a market as it would only be suitable for these particular bars.