[DiyGail]

Hi, newbie router user here. I have managed to get my Bosch plunge router fixed into the Kreg bench top table, and put a scissor lift underneath, which I was hoping would raise and lower the cutting bit easily, but all it is doing is lifting the whole table up off the bench! Do I have to disable the clamping lever somehow? There is a you tube video in which the guy seems to do something to the lever but it’s speeded up and I can’t catch what he is doing. There is no narrative with the video so I’m hoping someone here can help. I have to turn the table upside down and push really hard on the plunge (after releasing the clamping lever), to get the bit far enough up, I was hoping not to have to do that each time I make a change
Thanks
Gail

 

[old55]

Welcome to the forum.

 

[jw2170]

Welcome to the forum @DiyGail It sound like you have the router locked in one position.

What is the model of the router? Did you buy it second hand or new?

 

[mgmine]

When you say a scissor lift do you mean a scissor jack made into a lift? If so give up on the idea. That will work great for lifting a car but when it comes to a router it doesn't have the precision that you would need.

 

[Biagio]

Hi Gail,
for ease of discussion, please refer to the user manual (can be found at www.bosch-diy.com).
Firstly, I assume that the depth stop ( item 11 in the drawings) is free to move, ie the wing boltt (11) holding it in place is loose . You can remove the stop when in the table, it will tend to fall ou anway.
Secondly, that model self-locks the cutting height when the spring-loaded clamping lever (16) is released. The clamping lever is situated at the rear left-hand side of the body, accessible to your left thumb when using the router in hand-held mode. Normally, one pulls the lever towards the handle, plunges the router to the desired depth, then releases the handle to lock the depth until the cut is completed.
For what you are trying to do, you either have to reach under the table to yank on the clamping lever, or disable the clamping mechanism, or somehow bind the lever in the unlocked position. It sounds like you have figured out how to keep the power switch on when the router is table-mounted, perhaps a similar approach will allow you to defeat the auto-depth lock. The lock is actually in some ways desirable, but since you will be using a scissor-lift, it is not necessary in table-mounted use.
You will still have some resistance to lifting from the springs inside the rubber dust boots. Your scissor lift should be able to overcome the resistance easily, but if necessary, the springs can be removed (painful to re-install if you subsequently want to use the machine hand-held). Just make sure the whole mounting plate - cum - router cannot be physically lifted out of the table.
Some points about the scissor lift:
1. As mgmine says, a car jack has too coarse a mechanism.
2. There are some lifts designed for this purpose. In general, it is better to creep up on the bit height, so the whole system is under compression. If you overshoot, drop back don to below the correct height and creep up again. The machine may not drop fully, if you try to just wind down the lift.
3. That machine has air intake holes at the top of the body (in handheld mode). Make sure that you do not cover them with the plate of the scissor lift. You may need some sort of spacer to ensure air flow.

Good luck with your endevours.

 

[sreilly]

Welcome to the forum. As to your question, all of the above is sound advice and worth reading carefully. Any additional questions just ask but as a side note, pictures help tell the story visually seeing exactly what you're referring to so please post if possible.

 

[TenGees]

In my table, I reach under and unlock the depth lock and then lock it again before cutting. I have removed the plunge springs. I wonder if you can reach under and hold the lock open as you adjust the height.

 

[Souza1969]

When you say a scissor lift do you mean a scissor jack made into a lift? If so give up on the idea. That will work great for lifting a car but when it comes to a router it doesn't have the precision that you would need.

They make a scissor lift specifically for use as a lift, not necessarily for a router. But folks adapt them all the time. And yes they look much like the cheap little car jack supplied with newer cars

 

[mgmine]

They make a scissor lift specifically for use as a lift, not necessarily for a router. But folks adapt them all the time. And yes they look much like the cheap little car jack supplied with newer cars

A router lift needs to be able to lift something accurately with precision. This is something that a scissor jack can't do. At least I have never seen a jack of any kind lift something accurately to a height of the thickness of a piece of paper or less.

 

[Souza1969]

A router lift needs to be able to lift something accurately with precision. This is something that a scissor jack can't do. At least I have never seen a jack of any kind lift something accurately to a height of the thickness of a piece of paper or less.

I've designed machinery for 30 years, your statement is untrue. All the lift does is give linear mobility, up and down in this case. So long as it's properly guided a scissor mechanism is a perfect way to raise or lower a router motor.....if it's guided!

 

[mgmine]

I've designed machinery for 30 years, your statement is untrue. All the lift does is give linear mobility, up and down in this case. So long as it's properly guided a scissor mechanism is a perfect way to raise or lower a router motor.....if it's guided!

An Acme screw has too few threads per inch coupled with all the crude connection points of a scissors jack spells disaster. This is the description of the Kreg lift.
"The Precision Router Lift is designed so that every full revolution of the adjusting crank moves the carriage—and your bit—exactly 1⁄16", though adjustments down to thousandths of an inch are possible".

If anyone can do this with a car scissors jack or any scissors jack then by all means get one or have someone make it for you. A piece of 1/4" all threaded rod will give you what you need with a router lift but it all boils down to TPI and diameter. A router lift is not meant to simply raise or lower a router or "give linear mobility, up and down" or as stated . It is meant to do it accurately. Anyone that had ever made rail and stiles know that the thickness of a piece of paper means either a proper job or an amateur job.

 

[TenGees]

Is a scissor mechanism linear? Is the number of turns required to lift X amount the same at various points in its travel? My old brain can't figure that out but it seems that it would be different at the low end as compared to the high end.

 

[Souza1969]

An Acme screw has too few threads per inch coupled with all the crude connection points of a scissors jack spells disaster. This is the description of the Kreg lift.
"The Precision Router Lift is designed so that every full revolution of the adjusting crank moves the carriage—and your bit—exactly 1⁄16", though adjustments down to thousandths of an inch are possible".

If anyone can do this with a car scissors jack or any scissors jack then by all means get one or have someone make it for you. A piece of 1/4" all threaded rod will give you what you need with a router lift but it all boils down to TPI and diameter. A router lift is not meant to simply raise or lower a router or "give linear mobility, up and down" or as stated . It is meant to do it accurately. Anyone that had ever made rail and stiles know that the thickness of a piece of paper means either a proper job or an amateur job.

You're assuming his scissor mechanism isn't driven by a 1/16th inch pitch. If you guided the router base plate with (2) 20mm case hardened shifts in a pair of 20mm X 40mm long linear recirculating bearings you'd have 2x the effective running diameter, which almost provide for zero play under load. Which all these items are commercially available for very short money. The scissor mechanism is only providing a mean to move the mentioned assembly, it doesn't need to be accurate or robust. It isn't seeking any load and the pair of shafts/bearing provides for only .0005" of lateral movements. Hair on your head is 3 thousandths in diameter. All the scissor jack does is eliminate and replace your lead screw

 

[Souza1969]

An Acme screw has too few threads per inch coupled with all the crude connection points of a scissors jack spells disaster. This is the description of the Kreg lift.
"The Precision Router Lift is designed so that every full revolution of the adjusting crank moves the carriage—and your bit—exactly 1⁄16", though adjustments down to thousandths of an inch are possible".

If anyone can do this with a car scissors jack or any scissors jack then by all means get one or have someone make it for you. A piece of 1/4" all threaded rod will give you what you need with a router lift but it all boils down to TPI and diameter. A router lift is not meant to simply raise or lower a router or "give linear mobility, up and down" or as stated . It is meant to do it accurately. Anyone that had ever made rail and stiles know that the thickness of a piece of paper means either a proper job or an amateur job.

And an acme thread profile has nothing to do with the threads per inch....you can have a 16TPI on any thread profile. Your acme and buttress thread allows more load, but they're also expensive to cut. You can chase a square thead which has more load carrying capacity for half the cost of the other two. Neither or all 3 should not be used when an accurate pitch is required.

 

[CharleyL]

Maybe a dumb question, but are you using a plunge type router base and have you released the plunge lock while lifting it? As I remember, that plunge lock is locked unless you are manually releasing it.

Charley

 

[Biagio]

@CharleyL
I addressed this in my reply above.
As it happens, I have just acquired the Bosch Professional version of the OP's DIY tool at an opening special. The mechanisms are almost identical. The plunge action is particularly stiff for this size of router, even with the plunge lock lever fully pulled into the unlock position. The lever is spring-loaded, and auto-locks on release. I know it is a personal thing, but I prefer the type which is ulocked by default, and has to be locked by intent. Far easier for in-the-table height adjustment.

 

[Biagio]

@Souza1969 ,

Neither or all 3 should not be used when an accurate pitch is required.

Forgive a non-mechanical ignoramus - I do not understand what you mean in this sentence?
Also, what is the real advantage, if any, of Acme thread? I spent quite a lot on an Acme threaded rod, and even more on the nuts, to make a Roubo-style leg vise and a Moxxon vice, based on recommendations, but am not sure if it was worth it. Is there any reduction in backlash?