Hall sensor mount

[Gordon]

Has anyone made a mount bracket for a Hall sensor? I found one on Thingaverse but it is too big for many of the small engine applications. I am not even too sure what a good design would be so I am looking for ideas. I am not familiar enough with 3D design to actually design one.

 

[BaronJ]

Hi Gordon, Guys,

Basically use anything you like to make a mount as long as it is not magnetic, and you must get it the right way up. In general you could just glue it in place, the wires to the device can often be a problem. They need to be thin enough to solder and thick enough to handle.

A technique that I've used is to solder thin flexible wires to the device leads and then use heat shrink to insulate them. Use a larger diameter heat shrink over all three (sometimes four) wires to form a single lead. Terminate the other end as necessary/needed.

 

[doc1955]

I have a video playlist for the Kerzel that I made a hall mount.

 

[stevehuckss396]

I super glue the devise right down to the aluminum surface of the distributor.

 

[Gordon]

I was thinking about something like this but probably without the tab so that it can be mounted in a hole in a bracket or block with a hole in it.

 

[BaronJ]

Hi Gordon,

Attached is a drawing of a typical hall device, there are many that are just a fraction of this size. Some that I have are four lead switches and are 2.4 mm by 1.2 by 0.75 mm intended for surface mounting onto a PCB.

Dimensions are in mm with max and min values. Just to give you some idea of size. The one in this drawing is 3 mm thick.

 

[doc1955]

I super glue the devise right down to the aluminum surface of the distributor.

I did that originally on the Little Demon but after haveing some trouble getting them to not fry I ended up cutting a little window and making a tiny bracket to mount them in so I could change them easily and guess what haven't had to change one since I made the bracket lol. Go figure I did that so I didn't have to mess with the timing or anything if I had to change them. No watch next time I run one I'll need to change it lol.

 

[rsholl]

Gordon, it is best to use the plastic holder to insulate the hall from the engine. If your ground to the engine gets corrupted for any reason, the high voltage will try going through the ground wire in the hall sensor. Max voltage on a hall is less than 30 volts. The hall sensor with Futaba connector on our site is shipped in a D-tube which works very well. I think about a 1/4" hole is good to mount it. If you order either length of the mounts in your photo I always send a short and long. In any case, keeping the hall sensor insulated from the engine is your best option.

 

[BaronJ]

Hi Guys,

Since the hall device itself is in a plastic package that is also an insulator. The only way that you can fry one is by allowing the high voltage or current flow from the ignition coil through the actual wires of the device.

If you are frying them then you have a wiring problem, the most likely is not having a common return path. Any part of the engine that carries the return voltage or current from the ignition needs to be firmly bonded to the common ground, ie a single point return.

The easiest way to do this is to connect the electrical return to a bolt or screw on the engine itself.

 

[Gordon]

I understand the use and function of the sensor. My problem has always been finding a way to mount the sensor so that it is held next to the magnet. The sensor is small and it is hard to find a robust way to mount it. I have used the D Tube shown by Rsholl which works but you still have to find a way to mount the D Tube. I am not very good at 3D design so I was hoping someone had mad a 3D print which they have used successfully. I have found one on Thingaverse that is close but I would like a change in it so I guess I will have to get back to playing around with the software.

 

[doc1955]

I understand the use and function of the sensor. My problem has always been finding a way to mount the sensor so that it is held next to the magnet. The sensor is small and it is hard to find a robust way to mount it. I have used the D Tube shown by Rsholl which works but you still have to find a way to mount the D Tube. I am not very good at 3D design so I was hoping someone had mad a 3D print which they have used successfully. I have found one on Thingaverse that is close but I would like a change in it so I guess I will have to get back to playing around with the software.

If you sketch something you would like I can put into cad and export an STL file for you. I tinker around in the mornings some times before I start my day lol
Some day I need to invest in a 3d printer.

 

[BaronJ]

Hi Gordon, Guys,

That might be instructive ! Post a picture of the engine and where the magnet is or will be located. That way others can see exactly the issues involved in getting a suitable mounting.

 

[Charles Lamont]

This is an arrangement I have used. The sensor is epoxied to a little brass mounting plate that has a sensor sized rebate cut across it.
The terminal block is home made in delrin and brass with a phenolic cover plate. All the screws are 10-BA. The OD of the aluminium cover is 1-1/16" diameter.

 

[Gordon]

I don't have a specific engine at this point. This is what I found on Thingaverse which I used on a previous engine. It worked but it was really too big and I ended up cutting the mount lugs off and tapping into the body. I had not really thought about epoxying the sensor to a brass or aluminum plate. That would actually work well since the actual mount changes with each application. One of these days I am going to have to get serious about learning 3D cad. I have used 2D cad for years and they say that makes it harder to learn 3D. I have played around with Fusion 360 and Freecad but by the time I need them I have forgotten too much and end up spending hours trying to relearn stuff.

 

[iosensor]

View attachment 117579

This is an arrangement I have used. The sensor is epoxied to a little brass mounting plate that has a sensor sized rebate cut across it.
The terminal block is home made in delrin and brass with a phenolic cover plate. All the screws are 10-BA. The OD of the aluminium cover is 1-1/16" diameter.

That looks quite nice: lots of work for a little sensor, but it pays!

 

[gbritnell]

Hi Gordon,
I have always used a metal bracket to hold my Hall sensors. On any engine that I had trouble with it wasn't because of the holder but rather a poorly fashioned wire joint. Attached are pictures of the distributor from my flathead engine. There's quite a few of them so I'll have to send them in a couple of postings.
gbritnell

 

[gbritnell]

The remainder of the pictures. The magnet is pressed into the small angle bracket which mounts to the floor of the distributor. The window is cut into the side of the distributor for the bracket to fit into. The bracket is held to the distributor with 0-80 socket head screws. The timing wheel has to be steel. The wall thickness of the timing wheel is .020. The cap is made from black Delrin. The rotor from white only for the reason that it was easier to see. The strap on the rotor is .010 phosphor bronze with the brass end screwed to the rotor. I use a set screw in the rotor for timing. The timing disc also has a set screw so that it can be adjusted for timing.
gbritnell

 

[Peter Twissell]

It should be noted that it is not a good idea to have ferrous metal parts close to the hall sensor. Even a small screw will have an effect on the magnetic field which the sensor uses to dtect the rotor position and can generate errors. I woud suggest aluminium brackets and stainless screws.

 

[BaronJ]

Hi Peter,

I agree !

But be careful because some stainless steel screws are just as capable of being magnetised as ordinary steel ones.

Actually I warned about anything magnetic in post No:2.

 

[Peter Twissell]

1) I should read through the whole thread before posting.
2) I should have specified austenitic stainless, e.g. 304 or 316.