Marking drill holes on a BBS02 frame battery holder

Raboa

Esteemed Pedelecer
Aug 12, 2014
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Hi, I have started to install my BBS02 frame battery holder.

To try and get the bolt holes more accurate I done the following
1. Covered the down tube in duct tape
2. Put one of the bolts in the battery holder and tightened, i first made sure the holder was level using a spirit level on the side of the holder..
3. Put a 5.5mm Brad point drill bit in the holder bolt holes
4. Softly hit the drill bit to make the centre point of the bolt holes on the masking tape. The Brad point drill bit is only being used to mark the centre hole, a metal drill will be used to drill the metal out.

I now need to buy a right angle bit holder for my drill.

Improvements on the holder.
The centre hole is not extended like the other two, if all the holes were extended this would allow maximum adjustability. The extension of the other two holes could be shortened to keep the holder rigidity.
 

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Raboa

Esteemed Pedelecer
Aug 12, 2014
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Hi, I am just using this bit to mark the centre hole, a metal bit will be used to drill the metal out.
 

peter.c

Esteemed Pedelecer
Apr 24, 2018
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thurrock essex
A centre punch replacement, i like your style, the 90 degree chuck still does not always fit, start with a smaller hole and work up to the dia required.
Drilling at an angle is great fun the needle file set and Dremel often get used deep joy the fun of fitting rivnuts
 
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Swizz

Pedelecer
Oct 1, 2017
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Sk14
Hi, I have started to install my BBS02 frame battery holder.

To try and get the bolt holes more accurate I done the following
1. Covered the down tube in duct tape
2. Put one of the bolts in the battery holder and tightened, i first maked sure the holder was level using a spirit level on the side of the holder..
3. Put a 5.5mm Brad point drill bit in the holder bolt holes
4. Softly hit the drill bit to make the centre point of the bolt holes on the masking tape. The Brad point drill bit is only being used to mark the centre hole, a metal drill will be used to drill the metal out.

I now need to buy a right angle bit holder for my drill.

Improvements on the holder.
The centre hole is not extended like the other two, if all the holes were extended this would allow maximum adjustability. The extension of the other two holes could be shortened to keep the holder rigidity.
Much prefer your level of accuracy to mine.

I put two lines of masking tape along the tube, sucked in through pursed lips & took a good guess at the centre line.

Think I got away with it just but wouldn't recommend it as a foolproof method!
 

Raboa

Esteemed Pedelecer
Aug 12, 2014
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Hi, what size drill piece are people using to drill the frame with, I measured the diameter of the river nut and it is roughly about 6.8mm.

I found out that you can buy short drill bits which might help, 7mm seems to be the best size to go with.


Thanks
 

Swizz

Pedelecer
Oct 1, 2017
188
132
44
Sk14
Hi, what size drill piece are people using to drill the frame with, I measured the diameter of the river nut and it is roughly about 6.8mm.

I found out that you can buy short drill bits which might help, 7mm seems to be the best size to go with.


Thanks
Yep, 7mm for an M5 rivnut