Prob A dumb question but..

[Noods]

Apologies in advance if this is a dumb question but..

When I mark out a piece of steel etc, to say, prep to drill holes, which, I wish to Line up with something else for them to fit together with, not matter how hard I try to measure accurately and then dot punch the holes etc, nothing ever seems to line up as I'd wish, always a tiny bit out.. Which then means making oversize holes etc.. Is there a toolmakers or engineers way, or tool to use to make this opperation easier.. It's really frustrating.. Ok I have no access to Cnc or similar but I have most tools to hand. I searched online but really cannot find anything..

Appreciate your help..

 

[rtbcomp]

A good pillar drill and clamping the workpiece securely would be a good start.

 

[Tinbasherdan]

Apologies in advance if this is a dumb question but..

When I mark out a piece of steel etc, to say, prep to drill holes, which, I wish to Line up with something else for them to fit together with, not matter how hard I try to measure accurately and then dot punch the holes etc, nothing ever seems to line up as I'd wish, always a tiny bit out.. Which then means making oversize holes etc.. Is there a toolmakers or engineers way, or tool to use to make this opperation easier.. It's really frustrating.. Ok I have no access to Cnc or similar but I have most tools to hand. I searched online but really cannot find anything..

Appreciate your help..

Are you marking from a datum or are you marking one hole, then measuring from that to the next one and so on? That builds error

 

[711jrp]

When possible i try to drill one set of holes first and then transfer this pattern for the second set, there are many ways/tools to help in this method

 

[mechman]

Could try Specsavers.

 

[BrokenBiker]

first port of call is identify a datum point and take/mark all measurements from that rather from each other, you will build a cumulitive error if marking from each other...if that isnt a n option then you can use transfer punches after ligning the part up with its mating surface, clamping them together and then use the transfer punch through the existing hole on the mating face, or you can use the mating face as a guide for the drill but you risk wallering the first set of holes if using a hand held drill

 

[Noods]

A good pillar drill and clamping the workpiece securely would be a good start.

I've got both.. It's not an issue of movement... It's accurate marking out I looking for help with.. But thanks

 

[Noods]

Are you marking from a datum or are you marking one hole, then measuring from that to the next one and so on? That builds error

I would say the latter.. I measure with a tape measure and then would use calipers or dividers to mark the next one and so on..

 

[Noods]

Could try Specsavers.

I just knew there would be one...

 

[eSCHEn]

I'm very comfortable with software so complicated layouts I print at 1:1 and then hold on with a magnet or spray glue for the complicated ones. Punch the locations and away you go. Need another one? Hit print again.

 

[Tiggy_dorset]

If you scribe a deep enough line, your punch should be able to slide within the scribe line/groove. Slide it along until it meets the cross scribe, you should be dead centre of the scribes for punching. Also though as said above, you need a datum really to eliminate acumulative errors.

If you can make one plate with holes in the right position, you can use it as a drilling jig and overlay it on the next piece for drilling.

 

[Noods]

first port of call is identify a datum point and take/mark all measurements from that rather from each other, you will build a cumulitive error if marking from each other...if that isnt a n option then you can use transfer punches after ligning the part up with its mating surface, clamping them together and then use the transfer punch through the existing hole on the mating face, or you can use the mating face as a guide for the drill but you risk wallering the first set of holes if using a hand held drill

Like what your saying.. But, I have a superb 6 ft pillar drill with no lateral movement etc plus various clamps.. I know what your saying about drilling thro one into another... BUT... if you've got blind holes in one and you wish to replicate their positions in another piece, you ob cannot drill and hence mark the second piece.. So how can I replicate my initial hole positions to a second piece.. Say the two pieces are to be joined via dowels or metal pegs.. That's the kind of scenario I'm talking about.. Eg very accurate marking out.. And dot punching I guess.. A transfer punch I will have to read up on.. Not wise enough for that but always, keen to learn..
Many thanks appreciated ..

 

[Noods]

If you scribe a deep enough line, your punch should be able to slide within the scribe line/groove. Slide it along until it meets the cross scribe, you should be dead centre of the scribes for punching. Also though as said above, you need a datum really to eliminate acumulative errors.

If you can make one plate with holes in the right position, you can use it as a drilling jig and overlay it on the next piece for drilling.

Like but, blind holes ref my later post ... X appreciated..

 

[Noods]

Ive just looked at transfer punches .. Another dumb Q.. What is so special about them eg what makes them better than a simple dot punch ? ( I'm not being dumb on purpose, I genuinely don't know, but, I like to learn and create ever improving projects, therefore I'm not too afraid to ask) X

 

[rich r]

Make up the template on a separate piece of material that you can drill all the way through, and use that to drill your blind holes. Or maybe you could use a dye to transfer the locations of the holes - coat the drilled one with dye then lay the other part on top. Lift off and you should have the positions marked. Obviously ensure the edges are perfectly aligned with some sort of jig before they come into contact.

 

[Lemo]

If you can't clamp/tack them together to drill you could use a transfer punch, although never used one myself so I'm not sure if they're any good. As mentioned, always work off one datum line. Don't measure for a hole off a previous measurement as you will get a accumulation of errors. What do you class as a oversized hole? General fab usually allows a hole 2mm larger than the fixing.

 

[I'm getting on a bit]

Through holes just use a tight fitting drill rotating it in the hole by hand while tapping the end to get an impression.

Threaded holes we used special hardened screws with a point then lay the new piece on top and give it a clump

For blind holes think of a rod with a point on the end with a flange to stop it from disappearing down the hole then give a clump

 

[BrokenBiker]

if you have blind holes then you will have to establish a datum and measure/mark from that single point each time, the only way to get good at this sort of thing is with practice and some decent marking out tools.

i have in the past made a pin to fit a blind hole, file a point onto it and then use it as a transfer punch, tap the plate to be drilled with one good firm whack and it will leave an impression...soft steel can be used if its all you have but it will be a one time job and wont leave much of an impression...engineers blue is good for this sort of thing too to highlight the impressions

 

[711jrp]

Ive just looked at transfer punches .. Another dumb Q.. What is so special about them eg what makes them better than a simple dot punch ? ( I'm not being dumb on purpose, I genuinely don't know, but, I like to learn and create ever improving projects, therefore I'm not too afraid to ask) X

They have parallel sides and each one fits a specific hole size putting the pop mark in the center of the hole, there are also some short one on tags to use in blind holes a bit like "I'm getting on a bit" sharp bolts

 

[MattF]

I would say the latter.. I measure with a tape measure and then would use calipers or dividers to mark the next one and so on..

Ditching the tape unless you're measuring over a metre in would be my first step. Those things are fine for rough measurement, but terrible if you're wanting precision. Some decent metal rulers are what you want.