Not working correctly

Good morning all, i’m French (sorry for my english), i have a CNC Goliath since 5 mounths now and i can’t do a correct piece with.
I try to do a side for a arcade machine, soihave a big straight line and the machine can’t do it properly. The wood is a white laminate 18mm thickness.
I allready contact Springa team, they send me some new tower, but no changes.
Yesterday i see the width is not correct as well (on slingshot is around 42cm wide on the wood is 40,5cm only)
Since 2 days goliath tech team don’t answer me.

regards for your help

Hi benc!

Can you share your machine settings with us?
Also, wich bit and router speed are you using?


Hi Christian,
so i use the defaults settings for MDF
1mm depth
1.000mm/min (and i try with 500mm/min)
the tool is the original one 1 flute.

May be i have to try the settings for Solid wood
if you need more informations ask me.

which number do you use on the router speed dial?

can you send some more pictures of the working space / router bit?

for the speed on the router is n°6
and you have a picture of the working space


here are some thoughts what could cause the issue:

  • router speed 6 is way to fast - try reducing it to 3 - 4
  • from what I can see, the router bit is standing out far - try inserting it further into the collet
  • try other sheets (maybe Goliath doesn’t grip as good as on normal wood - I’ve never tried laminated sheets)
  • try changing the contact springs of the router (you should have received two subsitutes) - afaik several people had similiar issues and fixed it by replacing the springs
  • actually it should work with 3 mm depth per pass :thinking:

concerning accuracy: Goliath has problems with accuracy, thats also what I noticed during my projects, but 1.5 cm seems like a lot

just my 2 cents

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Hello christian,
thanks for the ideas, i try it today or tomorrow.
for the contact springs of the router, is it the brush ?


Hello,it’s to hot the last 3 days to try. I hope it’s possible this week


Hi benc!

I worked with laminated wood lately and more or less know that issue.
I was working with 18mm birch plywood with 0,8mm HighPressureLaminate on both sides.
The HPL is a very robust material and the problem is the very smooth surface of the laminate.
From my experience this two things lead to the problem with wobbly edges.

The first and I think mayor problem is the smooth surface which let Goliath’s wheels slip. I’m not sure, but telling from your photo the wheels are very dusty.
So you have to clean them as good as possible and remove all dust from the wheels before you start. You also have to remove all dust from the surface. All the dust that Goliath can’t remove by it’s own and which is no problem on a wooden surface, is a killer on laminate!
Try also to vacuum clean the dust out of the already cut lines and even from the wheels while Goliath is working. So you actually should babysit Goliath throughout the whole cut and clean everything around him all the time while he is cutting… just take care you are not touching the tower sensor cables! :wink:

The second problem is that I wasn’t able to get a good result with the 6mm router as it needs too much force to cut I assume. Try to change it to a 3 or 4mm one. I can’t remember well, but I think a 4mm router worked for me. I also can’t remember the other settings, so try Christian’s advices as well.

All the best,

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Hi John, thanks for your return.
The wheels of goliath are dusty on the picture, but they are clean when i start the job, first layer and i have some troubles.
I have to try the tools 3-4mm


I try today the machine
wood: Laminate 18mm
speed of the router 4
800 feed rate
3mm depth
speed: default one

wheels clean just before the work, piece of wood clean.
1st layer all normal
2nd layer all normal
3rd layer 1 error for “obstacle”
4th layer 5 stops for error “obstacle”

Your feed rate is too high… try 300 mm/min or even 240 mm/min.

The standard Goliath bit is a single flute bit, which vibrates more… buy yourself a 2 flute bit (if possible diameter 4,76 mm or smaller, but check the cutting length).

If you want a clean first cut, install a “downwards milling bit” but change it for the other cuts to a “upwards milling bit”.
Or, place your laminated plate upside down. This way you can use an upward bit for all the cuts.

If you smell burnt wood, reduce the router (spindle) speed to 2 or 3.

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Hello all
I tried today
Speed of the router 3
It’s look like good cut, just a little bit burn after 30 minutes running.

Tomorrow i try at 300mm/m at speed 3.
I put some pictures of the cut tomorrow.


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So i tried yesterday
Speed of the routeur 2
Feed rate 300mm/m
Plunge rate 300 ( not sure it’s necessary?)

It’s look like a good pièce, just 2 parts are strange.
It’s a strait lane of 1.40m
On the bottom of the lane 5mm are missing, at 30cm only 3mm are missing and at 50cm thé machine adjust the path.
See the videos, if you have some ideas !
sorry i can’t add videos they are too big :frowning:

Check the real thickness of your plate material… maybe it’s a bit thicker due to the tolerances. (You can always tell Slingshot that your plate is a bit thicker then actual, say about 0,2 mm).

I presume that the missing pieces of 5 and 3 mm have nothing to do with the tabs?

If Goliath is adjusting the path of the track, this means that your feed rate of 300 mm/min is to high… better reduce it back to 240 mm/min.
(And set the spindle speed at 2+ or lower if you smell burnt wood).

(Other reason for track deviation might be the lack of flatness of your plate/table/floor… but I guess that’s OK in your situation).

Do you think it’s possible to put 300mm/m but 2mm depth only?
When Goliath start the 1st layer the depth is 1mm a round, and At the end of the path the depth is 3-4mm.
On slingshot depth for 1 passe is 3mm and flunge rate is 300.


Yes that’s also possible.

In the case of a closed track (path) Goliath goes down in a spiral motion. So Goliath always starts at z = 0 and by the end of the first round z= pass depth.

Plunge rate is not used in the case of closed tracks…
Edit: It’s not even used for open tracks.

And try to buy a mill of about 3 mm diameter with minimal two cutting edges (2 flutes). That makes a huge difference!

In your case - with the hard top layer (laminate) - a tapered end might also be useful.

Thanks for all,
I can’t find 3mm tools, i find 4mm with an adaptator.
I think they arrived in 1-2 week-end.


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Hello benc, technical team is working to understand the reason of issues you are experiencing. We will get back to you as soon as possible.

hello to all, new problem with Goliath it does not cut straight in depth. For 1 week the machine has shifted by 0.5 -1mm with each pass; therefore, after 7-8mm of depth, the machine can no longer cut correctly. My cutting parameters have not changed and neither has the wood. The files have already been used several times.
it looks like the machine is not well positioned (in the photos with the white wood the cutting line should be at the edge of the board).

Technical support has been notified for 1 week but I remain unanswered.

Attached are some photos of the cuts.
The cutter is new.

Thanks for your help