Frequently asked questions


What does T12x3 mean?

This applies to our leadscrews, the TR12 indicates that the scre is 12mm diameter, the '3' indicates that the lead screw has a pith of 3mm whis means that for each revolution of the screw the lead nut will move 3mm linearly

Are M8 bolts really that much stronger than M5 bolts?

Yes! but don't take our word for it, find an M8 bolt and compare that to an M5 bolt, you will see and feel the difference!

Why do you have different M8 bolts?

The M8 bolts are very similar but some are specific to gantries: From the picture above either the top or 2nd bolt can be used in 'side' gantries or gantries that will not have other items bolted to them. Depending on what we have in stock at the time either of these bolts would be included in the package but they would ALL be the same type. The 3rd bolt from top may also be used for the purpose described above but could also be used in the X /Z gantry however, the lower bolt shown above is the prefered option because it is the lowest head height at only 1.5mm so the spacing between gantries would be at most 3mm. However, this is also the most expensive bolt, very expensive in fact compared to the other bolts.


WorkBee Linear Upgrade

What type of rail is used?

The proper guides to use are HGR15, these are 15mm square, and the carriages are the narrow type. We use a very, very reliable supplier from China. We never use the ultra low cost stuff from Amazon or eBay.

Can MGN rails be used?

MGN Application: Fit for semiconductor manufacturing equipment; printed circuit board IC assembly equipment; medical equipment; machine arm; precision measuring instruments; office automational equipment; other small linear sliding devices. So, the answer is not really. We certainly don't recommend MGN type rail for CNC applications.

Why are up to 10 linear rails required?

The rails are used as shown below: X=2 rails, Y=4 rails, Z= 2 rails, Anti-Twist = 1 or 2 rails. So up to 10 rails. 10 rails means extreme rigidity and very smooth operation.

To upgrade to linear and KEEP your existing leadscrews and nuts you need:

  1. Linear Rail set
  2. Linear Plate Set
  3. Extra X axis C-Beam

Linear Rail Set

X axis, 2 rails your X axis C-Beam length, 4 of carriages

Y axes, 4 rails, your Y Axes C-Beam length, 2 sets of 4 carriages, 8 in total

Z gantry, 2 rails, 240mm length, 4 carriages

Anti-Twist Set: This is what makes our kit the best available option!

X axis Anti-Twist Set, 2 rails same length as your X axis, 2 of carriages.

We also supply high quality rails, and HIWIN rails, if you require a quote send us your machine dimensions, X and Y, plus your address and email. The quote will include shipping which is why we need your address.

Linear Plate set

Custom linear plates, fit 15mm linear rails and 15mm narrow linear carriages with 26x26mm hole dimensions. Laser or CNC cut for absolute accuracy. Link here this set also includes the necessary bolts, spacers and nuts needed to attach the linear plates to the blocks / carriages.

Extra C-Beam

Same length as your current X axis

FAQ’s here

To upgrade to linear and CHANGE your existing leadscrews and nuts you need these as well:

SureGrip T8x8 / Tr8 Leadnut | Website (

You can choose to upgrade some or all. Also for each axis you can choose to have single carriage or dual carriage, the linear plates have been designed to accept either. So for instance on the X gantry you can have 2 carriages or 4 carriages.

Can the rails be butted together?

Yes this is possible, so for instance on a 1500mm length it is possible to butt 2 750mm rails together. The only issue with this is that alignment is made a little more difficult than using one rail.

What is the Anti-Twist set?

This is what makes our kit not only the lowest cost WorkBee Linear upgrade available but also the best available. That is not a light claim. At the time of writing no other kit includes an Anti-Twist feature on the X axis, but this is absolutely necessary for any WorkBee kit to alleviate the X/Z twist that occurs, especialy on 1000mm and larger X axis kits. The Anti-Twist set comprises of an extra C-Beam ( 6mm shorter length than your X axis C-Beam) which sits at the back of the X axis. The plates used for this join onto the Y gantries. The plates hold the C-Beam in place and are joined to the X back plate, this helps to alleviate the twist of the front C-Beam which is common in 1M or longer C-Beam X axis lengths. You can choose to use both anti-twist plates or a single plate.

What is part 6 in the parts drawing / list?

These are provided if you purchase our Sure Grip lead nuts, the plates shown are included in those sets and are used to provide the correct positioning of the lead nut in relation to the lead screw.

Can I use my original 8mm leadscrews?

Yes you can, but note the following: 1. The Y axes need no adjustment, the original lead nuts fit onto the Y linear plates. 2. Extra spacers are needed for the X gantry, it is not possible to use a linear carriage and not have to use extra spacers. The extra spacers required are 6mm for each lead nut bolt. We highly recommend buying our Sure Grip lead nuts to complement your linear upgrade, these lead nuts are far better and far more secure than the oroinal lead nuts, installtion is easy and they are supplied with everything you need to install them.

Why are your rails upper and lower on the C-Beam instead of on the edge?

Very simple answer, putting the rails on the edge of the C-Beam increases the distance of the spindle from the X gantry, this makes Twist on the X gantry worse because the distance to the spindle is elongated. Twist on the X gantry is already a problem with the standard set up, why make it worse by extending the distance to the spindle?

What do I use to clean the rails?

You can use a scraper to remove the excess grease and a rag cloth then remove the fine coat with isopropyl alcohol cleaner or solvent cleaner.

What grease should I use for the blocks / carriages?

For greasing something like this:

Castrol Lithium Grease 400 g LMX Cartridge RS Stock No.: 692-671

How do I assemble the X gantry?

First, you need to be aware that the U channel can be orientated two ways. One way suits the standard OB lead nuts, use this if you have not changed your lead nuts (you will need to add spacers to the lead nuts and longer bolts) Second, the U channel is orientated to suit the Sure Grip Lead Nuts Then, insert all the bolts into the linear rail, and add the T-Nuts. Step1, place the T-Nuts so they 'hang' on the bolt, and are in line with the slot Step2, drop the linear rail into the C-Beam slot, align in line with slot Step3, tighten the bolts hand tight only at this stage.

Why choose the Roboteer Linear Rail Upgrade?

Steel plates attach to your existing WorkBee plates, no need change your WorkBee plates as other (more costly) similar upgrades require Far more rigidity all round, ultimately this is the main reason for upgrading the WorkBee Lowest overall cost for this type of upgrade Lifetime linear rails. No more wheel changes Smoother, easier motion Keep existing OB lead nuts (standard option) Upgrade to Sure Grip lead nuts for better grip and harder machining ability (option) X/Z Anti-Twist included as standard, ( you need an extra C-Beam for this as that is not supplied, this C-Beam should be 6mm shorther than your current X axis C-Beam). NO OTHER UPGRADE OFFERS THIS! Fit larger heavier spindles, the X / Z axis support these weights with the upgrade Eliminates random judder when a wheel has worn Easier to align overall, no more eccentric spacers to rotate Ultimately, Machine harder, faster and deeper, reduce overall machining time!

How do I align the rails onto the C-Beam extrusion?

You would normally properly align AFTER assembly of all components. I cannot stress enough that slow and steady is the best way to get perfect alignment, tighten one bolt at a time, check, repeat. For a quick way to align with some accuracy before full assembly see below.

The edge of the rail should be 2.5mm distance from the edge of the c-beam.

Insert Linear rail with bolts into the C-Beam, make sure all T-Nuts are seated corectly and the rail is flushwith the face of the C-Beam.

First end, measure 2.5mm from the edge of the C-Beam to the edge of the linear rail, slightly tighten nearest bolt.

Other end, measure 2.5mm, slightly tighten nearest bolt..

Repeat until happy that alignment is as close as you cant get.

Then tighten the middle bolt, work out over from this bolt, constantly checking the 2.5mm distance is correct.

How does the Sure Grip lead nut fit onto the X gantry back plate?

Back Drill Plate Shown as orange. This is used to show the position to drill 5 holes into the back plate that are required to install the SureGrip Lead nut. If you do not have these lead nuts (shown below) you do not need to follow this guide, proceed to X/Z gantry part list Attach the Drill Plate to the WorkBee back plate as shown below, note the radius corner on the plate is on the top, the chamfer corner is on the bottom. Secure the plate to the back of the WorkBee X plate with 4 of M5 bolts and locknuts placed in each corner as shown. You can use any bolts as these are temporary. Drill 5 of 5.1mm holes. Remove the drill plate and use on the Front X plate to attach the Z Sure Grip if you retain the front X plate.


What happens if I want to return an item or order?

We offer a no quibble return, simply use the contact form and send us details of your order or send an email to We will then contact you to organise the return.


Where do you ship from?

We ship most items direct from our main address in the UK, however, heavy or long items that we supply such as linear rails or ball screws may be sent direct from our supplier(s) in China or USA.

Will I pay tax on my order?

This is dependent on your countries customs procedures. Most goods are sent from UK, but some items are shipped directly from our suppliers, these products are clearly marked as sent from China, USA etc.

Do you ship to (country)?

We can ship worldwide, if you are unsure about your country then please do contact us.


What payments does the store accept?

We accept, credit or debit cards and paypal (which we recommend using)

Can I pay with a cheque?

Unfortunately we cannot accept cheques, our bank does not have this facility.

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Roboteer Ltd

16 Fieldfare Gardens, Guisborough, TS14 8NB


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