SunSpot 2: Light guides & optics, every question, answered
43 answers below, written from the manufacturer's manuals and our own bench experience. Prefer to tap through them? The same answers power the live chat in the corner. Ready to buy? See the SunSpot 2 or request a quote.
Which light guide is included as standard?
A 1 m x 5 mm liquid-filled light guide, Uvitron P/N UV0570, the standard guide shipped with every SunSpot 2. Other types and lengths are optional.
What light guide types are available?
Single-pole liquid-filled guides (1 m and 2 m), a long-life UVB-compatible fiber guide, bifurcated two-leg guides in liquid or fiber, and a 3-pole fiber guide, all with a 5 mm common end for the SunSpot 2 receptacle.
An 8 mm high-flux single-pole guide and multi-pole splitters are also in our catalog; browse the light guides page or ask us for a recommendation.
Is there a longer light guide?
Yes, a 2.0 m x 5 mm liquid-filled guide, Uvitron P/N UV0572, plus a 1.5 m x 5 mm version, and made-to-order lengths from 0.5 m to 3 m.
Keep in mind longer guides lose roughly 10-15% output per meter in the UVA band, so order the shortest run that reaches the work.
Do you have a bifurcated light guide?
Yes, UV2168 is a bifurcated liquid guide (1 m x 2 legs, 5 mm common end), and UV0573 is the 1 m bifurcated fiber version. A 2 m two-leg fiber guide is also listed in the manual's accessories.
Do you offer 3- and 4-way splitters?
Yes, the UV2005 3-pole fiber guide splits one lamp into three legs, and a 4-pole splitter lets a single SunSpot 2 cure up to four zones in one exposure.
Is there a wider guide for big bond lines?
Yes, our 1 m x 8 mm high-flux guide gathers more of the arc for wide bond lines and small flood cures, trading spot intensity for coverage.
How does core diameter affect intensity?
The same lamp energy through a smaller core makes a hotter spot, a 5 mm guide delivers roughly 2.5x the irradiance of an 8 mm at the same setting. Pick the smallest diameter that still covers the bond line.
How much output do longer guides lose?
Expect roughly 10-15% loss per meter in the UVA band. Order the shortest guide that comfortably reaches the work, and verify dose at the tip with a radiometer after any length change.
What's the minimum bend radius?
Hold a 100 mm (4 inch) minimum bend radius and never kink the sheath, tight bends permanently damage the guide, and even routine bending reduces UV output and life expectancy.
How long do liquid light guides last?
Typically one to two years under normal use before optical decay calls for replacement. Prolonged high-intensity UV exposure, heat, and bending all accelerate the aging.
How can I extend light guide life?
Keep the shutter closed whenever curing isn't in progress, minimize the guide's UV exposure time, and avoid bending it. The in-line heat filter also helps by blocking the sub-300 nm wavelengths that degrade liquid guides.
How do I inspect a light guide?
Unplug it and hold the input end up toward an overhead room light while viewing the light exiting the output tip. Check the end glass on each side for contamination and look for discoloration in the core, excessive discoloration means it's time to replace the guide.
How do I clean light guide end tips?
Wipe the quartz end glass carefully with a soft cloth dampened with isopropyl alcohol. Inspect for scratches or remaining deposits before returning the guide to service.
Can I scrape cured adhesive off the tip?
As a last resort, heavier adhesive deposits that won't wipe off can be lightly scraped clean with a razor. Work with extreme care, scratching the quartz end glass changes its optical properties and permanently damages the guide.
When should a light guide be replaced?
Replace it when the core shows excessive discoloration, when tip output drops about 20% from its as-new baseline with a known-good lamp, or when an end face is scratched. Handled gently, a guide typically outlasts two to three lamp changes.
Is it safe to look into the guide tip?
Never look at the end tip of a light guide while it's plugged into an operating UV source, with or without UV protective glasses. Doing so could cause permanent damage to your eyes and the skin around them.
Inspect guides only after unplugging them from the unit, using an ordinary overhead room light as the source.
Do SunSpot guides fit other systems?
SunSpot 2 guides couple to its arc-lamp port and interchange freely with each other, including the multi-pole splitters. LED systems like the SkyBeam use a separate wavelength-matched guide family, the two don't cross over.
Can I order custom guide lengths?
Yes, single-pole guides are available made-to-order from 0.5 m to 3 m in 3, 5, and 8 mm cores, typically shipping in 2-3 weeks. Send us a quote request with your length and diameter.
Why keep end caps on the guide?
The caps protect the polished end faces from dust, adhesive, and scratches whenever the guide is disconnected. A contaminated or damaged input face absorbs energy instead of transmitting it and can heat-crack the guide.
What does the in-line heat filter do?
The specially coated glass filter (UV2554, 300-450 nm) works with the lamp's dichroic reflector to strip nearly all of the unusable heat-producing energy from the beam while only slightly reducing UVA output. The result is fast curing that stays gentle on heat-sensitive substrates.
Does the heat filter protect the light guide?
Yes, it attenuates wavelengths below 300 nm, which shorten the life of the standard liquid-filled guide. Those lower wavelengths aren't needed to cure most adhesives, so blocking them costs nothing in curing performance.
Can I remove the heat filter for UVB work?
Yes. Thin-layer coatings and inks that need UVB (280-315 nm) to reduce surface tack can be cured with the heat filter removed.
For long light guide life with long, filter-less exposures, switch to the optional fiber light guide, which isn't affected by the short wavelengths.
How do I remove or clean the heat filter?
After the power-down and 15-minute cool-down, remove the lamp access panel, back out the filter retaining screw and Teflon washer with a #2 Phillips, tilt the top of the unit toward you, and slide the filter out by its metal holder, never touch the glass. Clean it with isopropyl alcohol and a soft cloth, or replace it if damaged.
Why is the heat filter mounted at an angle?
The angled insertion, outer vertical edge shifted toward the rear against the slot's retaining flanges, keeps reflected light energy from aiming back into the lamp bulb, which would cause undesirable heating. Reinstall it with the direction arrows pointing up and into the extrusion, then re-tighten the retaining screw.
What is the optional shortwave filter?
UV1973 is an in-line light guide filter that passes wavelengths above 300 nm. It's the larger of the two filter sizes and mounts in the slot closer to the lamp, ahead of the standard heat filter.
What does the handle lock thumbscrew do?
The locking thumbscrew on the light guide receptacle fixes the guide's rotation, used when balancing multi-pole guides, and holds a partial insertion depth if you're using guide depth to trim output intensity.
How does the guide latch into the unit?
The front panel receptacle is spring latched: push the grooved handle in until the locking spring clicks into the positioning groove. That click confirms the guide is fully seated and the safety interlock is satisfied.
What spot size will I get?
It depends on the guide's core diameter and the tip-to-part distance, the spot grows as you pull back and shrinks as you move closer, within the typical 1/2 to 3 inch working range.
For tighter control, our focusing lens assembly threads onto 5 mm tips and focuses to an adjustable 2-12 mm spot.
Do you sell a focusing lens?
Yes, focusing lens assemblies are available, configured to your guide and joint; request a quote and we'll spec the optics. Otherwise, spot size on the SunSpot 2 is set by guide core diameter and tip-to-part distance.
Do splitters divide light evenly?
Uvitron's long-life fiber multi-pole guides randomize individual glass fibers from the input bundle, so light distributes appropriately between legs from the start. The more economical liquid multi-pole guides don't have that feature and may need the rotary balancing procedure to even out the legs.
What does '5 mm common end' mean?
Multi-pole guides list a 5 mm common end, that's the single 5 mm input that seats in the SunSpot 2's front receptacle. From there the bundle splits into the individual output legs.
Does a splitter slow down curing?
No, the SunSpot 2's very high power density lets split guides deliver light to multiple cure sites simultaneously without compromising curing speed.
Does the guide tip get hot?
Yes. High temperatures can be present at the output end whenever the shutter has been open, so let the tip cool to room temperature before touching it or setting it down, and never rest it on or near flammable or heat-sensitive surfaces.
Why did guide output suddenly drop?
The usual culprit is adhesive cured onto the quartz output window or other contamination on an end face. Inspect each end against a room light, wipe with isopropyl alcohol, and check the core for discoloration while you're at it.
Can a worn light guide be repaired?
No, once the core discolors or an end face is damaged, the guide is replaced rather than repaired. Send us a quote request with your guide's part number and we'll get a replacement moving.
Does a scratched input face matter?
Yes, a scratched or damaged input face absorbs energy instead of passing it, which heats the glass and can heat-crack the guide. Inspect the faces during cleaning and replace a guide with visible face damage.
Do light guides carry a warranty?
Yes, each guide ships with protective end caps and a 1-year accessory warranty.
Which guide is best for UVB curing?
The UV0765 fiber light guide (1 m x 5 mm, long life) is UVB compatible and isn't degraded by short wavelengths. Pair it with the UVB-enhanced lamp and run without the heat filter when your process needs the 280-315 nm band.
How do I verify output at the guide tip?
Use a spot cure radiometer, Uvitron's UV0567 reads 0-19.99 W/cm² over 320-390 nm and comes with a case. Baseline a new setup and re-check periodically to catch lamp or guide degradation early.
What wavelengths do the guides transmit?
With the standard heat filter installed, the liquid-filled guides deliver the 300-450 nm band, UVA plus the violet-blue visible peaks that cure most adhesives. For work below 300 nm, use the fiber guide, which passes the shorter UVB wavelengths.
Can LED light guides work on the SunSpot 2?
No, LED guides like the SkyBeam's UV4053 are matched to LED channel optics and wavelengths and don't fit the SunSpot 2's arc-lamp receptacle. Stick with the 5 mm common-end guide family made for the SunSpot 2.
How well matched are dual-pole splitter legs?
Our dual-pole splitter is matched to within ±5% between legs, so simultaneous two-point cures see essentially the same dose.
How should I store spare light guides?
Keep the end caps on, store them clean, and coil loosely, never tighter than the 100 mm (4 inch) minimum bend radius. Kinks and tight bends permanently damage the core.
